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1 CORE PROCESS SYSTEM PARTITION ATOM PREEMPTION BEHAVIOR ANALYSIS AND PARAMETERS DESIGN BASED ON EDF HE FENG, XIONG HUA-GANG Beijing University of Aeronautics and Astronautics Xueyuan Road 37, Haidian District, Beijing 009, China Abstract:In order to ensure the system information security, the avionics integrated core system adopts the hierarchical partition management model. Focused on the dynamical priority strategy in the upper scheduler, the bloc effect algorithm for partition executing atom time is proposed from a more microcosmic perspective, which can be used to get the maximal preemption impact for the requested time length. By analyzing the special scheduling features for the upper and lower strategy combinations and investigating the bloc impact on the last partition execution window for the tas load, the safety and unsafety partition design solutions are obtained. Compared with the virtual processing design method, the safety partition design approach has a higher efficiency and a wider adaptability for partition design. Key words: system information security, hierarchical partition management model, safety partition design, bloc effect algorithm. Introduction Avionics system is a typical Mission-Critical and Safety-Critical system. The mission-critical means that avionics system should quicly respond to internal/external events and implement missions in a predicted time interval. The safety-critical refers to the ability that avionics system should provide the physical or logical isolation for sensitive information processing to ensure the information security of entire system. These two aspects of ability requirements are mainly reflected in the Integrated Core Processor (ICP) and Universal Avionics Networ (UAN). For the core processing system, it needs to achieve the real-time processing and security management for different security-level tass. The core processing system with the features of high degree integration and open standard interface is one of the ey factors to the system implementation for the new generation avionic architecture. In order to guarantee the mission-critical and safety-critical requirements, the concept of Partition Management comes into being, which constructs time and space isolated partitions for different group tass through a hierarchical scheduling management strategy. Therefore, the appropriate analysis for tas real-time characteristics and reasonable design for partition parameters become increasingly important under the partition management model. Partition management model can adopt multiple combinations of upper and lower scheduling strategies, and different strategy combinations will bring different analysis and design methods. In [~], we showed how to analyze and design partition parameters for Round-Robin and Fixed-Priority scheduling strategy respectively. Lorente [3] discussed the tas schedulability under dynamic priority strategy in the upper scheduler, but didn t 73

2 continue to discuss the partition design problem. Lee [4] presented a parameter design algorithm for Rate Monotonic strategy based on the virtual processing concept. Lipari [5] extended Lee s model and used the parameter pair ( Δ, α ) to describe partition s executing features. Lipari s model didn t aim at a special scheduling strategy, thus it can be used for a variety of scheduling strategy combinations. The more detailed illustration and application was presented in [6]. Almeida [7] also adopted the similar method to achieve the partition design solution. Though these partition design methods in [5~ 7] had a wide adaptability, they had a relatively lower design efficiency. The virtual resource method can be also be found in [8~]. In fact, we can tae the advantage of the special scheduling features for the combination of the upper and lower scheduling strategies and obtain more effective partition design algorithms, so as to obtain better scheduling results. In this paper, we mainly focus on the dynamic priority strategy for the upper scheduler which manages partitions scheduling and switching in the real-time Operating System (OS). We will discuss detailedly the analysis and design methods for different scheduling strategies in the lower scheduler which manages tass executing and preempting in the local partition. Finally, we verify these solutions through simulation method.. Core processing system model So far, avionics architecture has gone through four typical development stages: the separate-type avionics system, the federal-type avionics system, the integrated-type avionics system and the advanced integrated-type avionics system. With the development of avionics system architecture, the function and structure of the core processing system is also constantly changing and developing. In the separate-type avionics system, there is no concept of the core processing system. The control, processing, and display for avionics equipments/subsystems (such as radar, CNI, etc.) are handled independently within dedicated processors. In the federal-type avionics system, the original independent avionics equipments/subsystems are interconnected through 553B data bus, and the control and display are also integrated through the tas software to achieve information sharing, but the information processing is still on dedicated processors. For example, there are inds of dedicated processors in F-5, and each subsystem adopts its own operating systems. With the development of electronics and computer technology, the design technology for avionics system has been rapidly developed. The boundaries for traditional separate equipments/subsystems are broen under the concept of the integrated avionics architecture. According to the implementation functions, the entire avionics systems can be divided into a core processing area and several corresponding integrated areas. In some sense, the core processing area can be seen as the brain of the avionics system, which implements signal processing and data fusion for radar, electronic warfare, optical sensors and achieves tas processing function for flight control management, navigation calculation, fire control calculation, display control and management. Thus, the concept of Common Integrated Processor (CIP) comes into being. CIP is composed of a number of Line Replaceable 74

3 Modules (LRM), and synthesizes CNI calculation and management, cocpit displays and graphic processing, tas scheduling, system health monitoring and so on. These tass are dynamically allocated to LRMs, and assemble different LRMs to achieve specified functions during different stages. In the advanced integrated-type avionics system, the philosophy of universality, modularity and standardization for modular avionics systems has further developed to reduce costs and improve the modules availability. The main feature for this stage is that the Integrated Core Processor (ICP) with higher integrated degree is widely adopted to replace CIP. The total processing capacity of ICP is about ten times than CIP but with a quarter of the module amount. ICP adopts unified military real-time operating system, and each processor module is interconnected by optical fiber channel to enable information exchange. F-35 has started to use this ind of processing structure, which will significantly reduce the burden of the size, weight, power consumption and cost for processing modules. Meanwhile this structure of the core processing system brings simplification for mission integration. It is shown that the use of highly integrated and open architecture system/module is the ey to implement fully the new generation avionics system. At the same time, in order to improve the mission-critical and safety-critical guarantee capability, the concept of partition management emerges. Meanwhile, partition management is also promoted by the widely application of tas software in avionics electronic system. The implementation of partition management is based on the comprehensive, modular and integrated avionics system, and the concept and role of partition management are defined and developed in the recent decade. Partition management, as a design technology, is used to eep the isolation for avionics applications within the scope of configured time and space to avoid effect to each other according to a certain group strategy. Actually, partition reflects the philosophy of system coupling in another way: the smaller the coupling between components is, the more robust the system could be while meeting the unexpected riss. Partition management is a hierarchical scheduling model, which is detailedly defined in the ARINC 653 [3] standard. The upper scheduler is in the operating system, responsible for partition scheduling and activation; the lower scheduler is in the local partition, achieving the tas execution and preemption. Therefore, each group tass in the same partition with the same security level are executed within partition activated window to satisfy the time isolation, and assigned different memory access entry to mae sure the space isolation. Thus the management mechanism fully supports the mission-critical and safety-critical requirements. In this paper, the standard partition management model in ARINC 653 is properly expanded, which maes the upper scheduler use priority-based scheduling strategy to enhance the flexibility and adaptability of partition management model. Considering a single processor system, not losing discussion generality, it contains K partitions, thus this single processor system formed by partitions can be expressed as follows: 75

4 { K} = P () P refers to the th partition,which can be further described by: partition cycle α ( 0 < α ). Therefore, in each cycle of the partition η α η and partition capacity P, the total length of the partition activated window is. When the upper scheduler adopts the dynamic priority scheduling strategy, the partition activated window will be dynamically allocated during the executing process. Compared to the round-robin scheduling and fixed priority scheduling strategies, this model has greater design flexibility and complexity. For the tass in the local partition P, they can be described by the quaternion, T, C, D ) ( i i i i J : J i means tas release jitter, T i means tas period, Ci means tas maximal execution time, D i means tas deadline. Supposing partition P includes n tass, partition P formed by these tass can be expressed as follows: { i n } Γ = τ () i The partition design solution in [6] uses the parameter pair ( Δ, α ) to describe each partition. Here, Δ means the intervals between two proximate partition activated windows and α means partition capacity. Under the precondition that the local partition can be scheduled successfully within the OS, it can be seen that the maximal value of Δ is Δ = ( η ηα) while considering the utmost partition bloced impact. Regardless of round-robin strategy or fixed priority strategy in the upper scheduler, the maximum intervals between the former and later partition activated windows will not exceed ( η ηα). Therefore, on this assumption, this partition design solution has some universality, but it also ignores the scheduling features of specific scheduling strategy combination. Using the utmost value of Δ and considering the virtual processing meaning of partition capacity, the partition implementation can be seen as the execution in a virtual slower processor which has the α processing ability instead of the unitary unit one. Thus α, as a time scale, describes the execution ability of the virtual processor. According to the tas load scheduling requirements, we can draw the relationship between tas load and partition capacity, which is shown in Figure. 76

5 α = α min t τ τ τ 3 Fig. The relationship between tas load and partition capacity. The slash mared by α = means the time passage for the normal processor and α means the slowest min virtual time passage case. For partition capacity, the value cannot be less than virtual processor cannot get enough executing time. α min, otherwise the tass in the 3. Partition preemptive behavior In order to obtain an optimal partition design solution for core processing system based on the dynamic priority strategy, the preemptive behavior between partitions by the upper scheduler should be considered to refine the final partition execution for tas scheduling. When combining the upper and lower preemptive behavior, we can get a hierarchical design method for partition management model: according to the tas load in the local partition, the needed execution times of partition can be calculated; then the extent to which the tas load expands into the final partition cycle can be obtained; based on the partition preemptive effect algorithm, the maximal bloced time by other partitions to the rest of the tas load in the final partition execution cycle can be refined; finally, according to a certain cost function, the optimal partition parameters can be balanced. Therefore, for the dynamic priority, it is necessary to establish a proper method to calculate the maximal preemption effect by other partitions for any request time length instead of only calculating the Worst-Case Response Time (WCRT). In [4], Spuri has proposed an algorithm to calculate the tas WCRT for the dynamic priority. Based on Spuri s EDF thought, we can get a method to calculate the maximal preemption effect for any request time length Δ. According to the concept of tas busy period [4], it includes the most difficult scheduling situation for partitions. Thus for any request atom time (not more than partition activated window η α ), the instant for the maximal preemption effect must occur in the same busy period. We can observe the each release instant of partition within EDF the busy period to get the worst execution for the request time length Δ. At the same time, the release instant EDF for the maximal preemption effect against the request time length Δ may not be as the instant for WCRT. When we calculate the tas WCRT, it only means that the last atom time has passed the maximal blocing effect, 77

6 not representing that each previous atom time have also experienced the maximal preemption effect. However, EDF when the value of Δ is assigned to η, the instant to calculate the maximal preemption effect for α EDF Δ is the same as the instant to calculate the tas WCRT. Thus, the maximal preemption effect algorithm for any requested time length is also suitable to calculate tas WCRT. According to Spuri s method, we can use W ( t, d ) to calculate the tas load for any investigated time t during the processor busy period,while the absolute deadline of partition P is d. The calculation expression is given by formula (3), while J is partition release jitter and D is partition deadline (in our partition scheduling model, J = 0, D = η. In order to get a universal discussion meaning, there is no replacement and omission): W ( t, d ) t + J J min, + d D + η α = η η (3) 0 For partition P, the ey investigated instant set for the request time length Δ EDF is the same as the instant set for calculating the WCRT, at which the deadline of a partition s new job coincides with the deadlines of any other partition. The ey instant is: Ψ = {( p ) η J + D } busy L + J p =... η, (4) Here, busy L is the length of processor busy period,which can be iteratively calculated by L busy busy L = ηα. η Focused on partition processor busy period, the absolute deadline is: P,if the arrival time for the first execution is A, for the p the execution during the d ( p) = A J + ( p ) η + D A For the previous,,..., p execution, partition P has gone through a complete implementation. For (5) the p th execution, the requested execution time length is is: EDF Δ,then the maximum requested processing load 78

7 EDF w ( p, Δ ) = ( p ) η α + Δ A j j A EDF W ( w ( p), d A + ( p)) (6) Thus for the p th execution of partition P, the maximal bloc impact by other partitions for the request execution time length EDF Δ is: Q A EDF A EDF EDF ( p, Δ ) = w ( p, Δ ) A + J ( p ) η Δ (7) Not all instant in the ey investigated instant set should be observed for the p th execution of partition P, and only the instants within the partition period need to be checed: Ψ = { Ψ Ψ ( p )η J + D Ψ < pη J + D } (8) When all needed ey instant are examined during the processor busy period, then the maximum preemption effect for the specified request execution time length EDF Δ can be figured out: Q ( Δ EDF ) = max( Q busy L J p =... η A ( p, Δ EDF )), A( Ψ ) (9) For the partition WCRT R,it can also be easily calculated out by using R = η α ) + η α Q (,thus the algorithm in this section has a more wide application, which gives the bloc impact for dynamic scheduling strategy from a more microcosmic perspective. 4. Partition parameter design The reasonable partition parameters design for partition management model is an important step to fully implement partition management strategy. When the lower scheduler uses different scheduling strategies, the partition design approaches have different features. For the fixed priority scheduling strategy, we tae tas deadlines as the important design factor. For the dynamic priority scheduling strategy, we introduce a ey point I ey method. 4. Fixed priority in the lower scheduler For the model that the lower scheduler adopts the fixed priority scheduling strategy, it can be named as EDF-FP. Given the observed time w i,the calculation load L i (w) for tas τ i is: L ( w ) = C + i i i τ j hp( i) wi + J i + J Tj p C j (0) 79

8 Where hp (i ) is the set of tass that have priorities higher than that of tas τ i and J P is the release jitter of the tas relative to the partition execution end. The typical value of J is P = R r, and P J r is the best-case response time of partition P. The calculating method for r = η α + I I = j r J j η j, η j 0 min r + J j r η j D j D η j η j r is as follows [5] : η jα j 0 () Based on the calculation load in formula (0), the partition implementation times and the partition total execution interval T gap except the last partition executing can be obtained by: T gap Li ( w ) i = η ( α ) ηα () The request execution time length EDF Δ for tas τ i during the last partition execution is: L w L ( w ) EDF i i Δ = i ( i ) ηα ηα (3) According to the improved partition scheduling pre-emption algorithm, the maximal bloc impact caused by other partitions for the requested time length EDF Δ is Q ( EDF Δ ), thus the tas busy period length is: w i gap EDF = L ( w ) + T + Q ( Δ ) (4) i i Finally, through the iteration operation, the tas WCRT can be obtained by R J + J + w i =. In fact, i P i for the partition design problem, the tas deadline can be brought into the formula (4) to get the tas scheduling time slac, which can be used as the scheduling guarantee. Considering that the function of tas busy period is an incremental function, therefore, the difference between the calculating results by formula (4) and tas deadline represents the time redundancy for tas scheduling. Accordingly, the partition design method can be acquired, which is as follows: 80

9 8 Ψ = Δ = Δ Δ = Δ + = = = K n i i i busy EDF A EDF i EDF P i i P i i P i P i i P i i EDF T C A L p p Q Q D Q J D L J D L J J J D L J D L s t F Min ) (,... )), ( max( ) ( ) ( ) ( ) ( ) ( ) ( ) (.. α α η α η α η α η α η η α (5) In formula (5), F function is a cost function, which achieves the balance between partition parameters η and α to guide the optimal partition design. The setting of the cost function is based on the following facts: partition cycle should be large to reduce partition itself periodical circulation and partition capacity should be small to reduce the useless idle time. Thus the optimal direction for the cost function is to get the smallest value. Besides, the sum of all partitions capacities must be less than to ensure the partition itself schedulability. However, this method has inadequate tas schedulability guarantee ability. Owing to the dynamic priority scheduling strategy in the upper scheduler, the preemption behaviours between partitions occur at the executing stage, which cannot be predicted in the design stage. Thus, the later designed partition will bring uncertain impact on the tas schedulability within the previous designed partition. Therefore, this method can only suit the last partition design. In order to ensure the tas schedulability against the influence by the latter designed partitions, a special safety design method can be adopted. For formula (5), the uncertain bloc effect between partitions is the main reason for unsafety partition design. Considering that the maximal bloc effect will not exceed R α η, we bring R α η into the formula (5) to replace the bloc effect ) ( EDF Q Δ within the last partition executing window, avoiding the bloc effect for the latter designed partition. Thus this solution provides a safety design style that the selection of the following partitions parameters will not affect the tas schedulability for the under-designing partition. The following is the corresponding design method:

10 Min s. t. F = α + η J i L + J α K = i i= α P ( D n + L i C T η α J i i i ( D P i J P ) + ) η + ( α ) η ( α ) D i (6) 4. Dynamical priority in lower scheduler When the lower scheduler adopts the dynamic priority scheduling strategy, this model can be named EDF-EDF. Either the upper or the lower scheduler adopt the dynamic priority strategy, thus the scheduling behavior within EDF-EDF model has the greatest uncertainty degree. We can follow a similar approach as in EDF-FP model to solve the partition design problem; however, the calculating method for tas load should be modified to accommodate the EDF strategy in the lower scheduler. In fact, we can adopt the tas demanded bound function F i (I) to calculate the tas load [6] for the dynamic priority strategy. I Di + J i + J P F i( I) = max 0, + C (7) i Ti To determinate tas schedulability, it is necessary to verify that S I max boundary is established. For any n I ( 0, I S max], if F ( I ) I can always be satisfied, then the given tas set is schedulable. The feature of the i = 0 i tas schedulability guarantee for tas demanded bound function can be used to implement the partition design. To verify equal to S I max boundary, we use a ey point I ey to simulate it. However this doesn t mean that I ey must be S I max. In fact, during the process of partition design, there is no partition parameters, thus the value of S I max can t be deduced out. Here, the ey point I ey just determinate the calculating boundary, which can be adjusted during the whole design process. When I is in the interval [ D min J, I ) ey, we examine precisely the tas processing requirements for any needed instant. For the interval I I ey, we construct an expanded tas demanded bound function, which only need to chec the scheduling requirement at point I ey to guarantee the success scheduling for I I ey. A reasonable expanded tas demanded bound function is as follows: I Di + J i + J P F = i ( I) max 0, + C (8) i Ti 8

11 83 In order to eep the scheduling redundancy at the point ey I, the ceiling operating is replaced by adding one to obtain the tas busy period length. Thus the ey point ey I brings a certain flexibility in the process of partition parameters design, which actually is an self-adaptive design method: when the design results are not ideal, we can increase the value of ey I to observe more critical points but with bigger computation amount. When the design accuracy is not the primary consideration, we can reduce the value of ey I to achieve a rapid design process. Combining the tas demanded bound function ) (I F i and the ey point ey I, we can get the full expression for partition design: Ψ = Δ = Δ Δ + + = Δ = + = = + = = Γ Γ K ey i si i i ey P i busy EDF A EDF EDF EDF i si i P i ey i P ey P i I R C T T D I J J A L p p Q Q I Q I F I F I F I F C T D I J J I F I I n i i T J I q J qt I s t F Min i i 0 0 ) ( ) (,... )), ( max( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) (,,,...,.. α α η α η α η α η α η α η η α τ τ (9) Similar to EDF-FP model, the method in formula (8) is suitable for the last partition parameters design, and cannot guarantee the tas schedulability within the earlier designed partitions. We can assign the bloc effect for the last partition execution as R α η to ensure the separate design process. The safe design solution is as follows:

12 Min s. t. F = α + η I ey + J P I = qti J P, q =..., i, i n, I I ey Ti J i + J P + I D i F = ( I) + Ci τ Γ T i si 0 F ( I) F + ( I) η ( α ) + η ( α ) I η α J i + J P + I ey Di + Ti C i + η ( α ) I τ Γ T i si α K = α 0 ey (0) 5. Performance evaluation We designed special tools to evaluate the design efficiency for the EDF-FP and EDF-EDF models which are discussed deeply in section 4. To achieve the evaluating process, we use partition expected load as the independent variable, which represents the total tas expected load in the partition. After randomly generating tass parameters, the actual tas load maybe not always equal to the expected load but fluctuate around it. In this section, we assume that the partition expected load changes from 0. to 0.8; the tas count in each partition is 5; the tas period and execution time are generated randomly; the partition count varies from to 5. The evaluation results are shown in figure. F Partition Number = EDF -FP G EDF -FP Unsafety 0.8 EDF -FP Safety EDF -EDF G EDF -EDF Unsafety 0.6 EDF -EDF Safety F Partition Number = 3 EDF -FP G EDF -FP Unsafety EDF -FP Safety 0.8 EDF -EDF G EDF -EDF Unsafety EDF -EDF Safety U U (a) (b) F Partition Number = 5 EDF-FP G EDF-FP Unsafety EDF-FP Safety 0.8 EDF-EDF G EDF-EDF Unsafety EDF-EDF Safety U (c) Figure. Result of partition design. 84

13 Diagrams (a), (b) and (c) of figure represent the results of the comparison when the number of partitions is, 3 and 5 respectively, and G models represent the design results according to Lipari s method. It can be seen from figure that as the partition expectation load increases, the value of the cost function for the six models increases accordingly. When the partition expected load is heavy, some models cannot get efficient partition parameters results. From the overall perspective, the design results under FP strategy is worse than the corresponding results under EDF strategy. Thus EDF strategy can get better partition parameter. The results of safety partition design and the unsafe partition design is extremely similar. In general, the results according to the model discussed in [5] are worse than our models results at most case. Thus, the safety partition design algorithms proposed in the paper provide an efficient approach for partition parameter design. 6. Simulation tools design On the basis of the analysis of ICP function and partition management mechanism in avionics system, we developed the ICP design and simulation suits. These suits can assist the designer to accomplish networ topology design, ICP tas allocation, partition scheduling simulation, schedulability analysis and partition parameters design, which can support completely the demands of ICP function development, simulation and verification. Among these functions, ICP simulation engine is the ernel tool. In the simulation engine based on the partition scheduling, the scheduling of the tass is determined by a two-level manner: the upper scheduler dispatches partitions according to round-robin, fixed priority and dynamical priority strategies and the lower scheduler dispatches tass by the priority-driven way. The holistic simulation dispatch model is shown in Figure 3. Fig3. The holistic simulation dispatch model. 85

14 The upper scheduler dispatches partitions according to partition special parameters, and the events in the mission system (such as tas completion and tas release) don t affect the partition s activated behavior. In the lower scheduler, all grouped tass will be dispatched according to tass states and special strategy. The major simulation events in the lower scheduler include: tas release, tas dispatch, tas execution, tas bloc, tas completion, message generation, message transmission, message arrival and so on. 7. Conclusions In this paper, we extend the ARINC 653 standard partition management model to let the upper scheduler adopt the dynamical priority strategy and carry out further study on partition parameters design. Through the analysis on the partition atom execution time during the processor busy period, the maximal preemption effect for the requested time length is proposed. Compared to the worst-case response time algorithm, this method can calculate the bloc impact for the dynamic priority strategy from a more microcosmic perspective and the WCRT can be seen as a special time length requirement. Based on this, the partition design methods are discussed both for the fixed priority and dynamic priority strategy in the lower scheduler. Compared to the virtual processing partition design method, the safety partition design solutions proposed in the paper consider the special features of partition scheduling strategy combinations, and have better adaptability for partition scheduling. The wor in the paper extends the standard partition model and establishes the theoretical basis for the extended model implementation. The following wor will focus on the realization of partition management models based on COTS technology. 8. Acnowledgement This wor is supported by the National Natural Science Foundation of China ( ). References He Feng, Song Li-ru, Xiong Hua-gang, Two-level tas partition scheduling design in integrated modular avionics. Journal of Beijing University of Aeronautics and Astronautics, 008, (5): He Feng, Song Li-ru, Xiong Hua-gang, Spacecraft Tas Hierarchical Scheduling Analysis within Fixed Priorities, Chinese Journal of Space Science, 009, 9(4): Lorente, J.L, Palencia, J.C., An EDF Hierarchical Scheduling Model for Bandwidth Servers, In proceedings of the th Embedded and Real-Time Computing Systems and Applications, NY:IEEE, Lee, Y. H. D. Kim, M. Younis, et al, Resource scheduling in dependable integrated modular avionics, Dependable Systems and Networs, NY:IEEE, G. Lipari, E. Bini, A methodology for designing hierarchical scheduling systems, Journal of Embedded Computing, 004, (3): Bini Enrico, The Design Domain of Real-Time Systems. Scuola Superiore S.Anna Pisa, PhD. Thesis, L. Almeida, P. Pedreiras, Scheduling within temporal partitions: response-time analysis and server design, In the 4th ACM international conference on Embedded software. Italy:Pisa,

15 8 Shin, I., Lee, I., Compositional real-time scheduling framewor with periodic model, ACM Trans. Embed. Comput. Syst. 008, 7(3): Maro Bertogna, Nathan Fisher, and Sanjoy Baruah, Resource-Sharing Servers for Open Environments, Ieee Transactions on Industrial Informatics, 009, 5(3): Moris Behnam, Thomas Nolte, Miael Sjödin, et al, Overrun Methods and Resource Holding Times for Hierarchical Scheduling of Semi-Independent Real-Time Systems, Ieee Transactions on Industrial Informatics, 00, 6(): Nathan Fisher,Farhana Dewan, Approximate Bandwidth Allocation for Compositional Real-Time Systems, In Proceedings of the st Euromicro Conference on Real-Time Systems, Ny: Ieee, 009 Farhana Dewan, Nathan Fisher, Approximate Bandwidth Allocation for Fixed-Priority-Scheduled Periodic Resources, In Proceedings of the Ieee Real-Time and Embedded Technology and Applications Symposium, Ny: Ieee, 00 3 Arinc , Avionics Application Software Standard Interface, Arinc Specification M. Spuri., Holistic Analysis of Deadline Scheduled Real-Time Distributed Systems, RR-873, INRIA, France, Bing Xue-Lian, Research on the scheduling technology of tass in real-time systems. National University of Defence Technology, PhD. Thesis, Baruah S. K, Dynamic- and Static-priority Scheduling of Recurring Real-time Tass. Real-Time Systems, 003, 4():

16 LATTICE BASED QUASI-ORTHOGONAL STBC WITH TWO AND FOUR-GROUP DECODABILITY FOR EIGHT TRANSMIT ANTENNAS LEI JING, WEI JI-BO, TANG CHAO-JING, LIU WEI School of Electronic Science and Engineering, National University of Defense Technology, Changsha, 40074, China. Abstract:Recently, two-group (Gp) and four-group (4Gp) decodable quasi-orthogonal space-time bloc codes (QSTBC) have been introduced to obtain the full diversity through the process of constellation rotation (CR), or both CR and interleaving the real and imaginary parts of different symbols. The diversity product is maximized by seeing the optimal rotation angles, where the maximum seeable diversity product is relevant to the number of rotation angles for constellation rotation. The current 4Gp- and Gp-QSTBC consider and 4 rotation angles, respectively, which can be regarded as rotation in and 4 dimensions. These designs achieve full diversity but are unable to exploit the maximum attainable diversity product due to the limited number of rotation dimensions. In this paper, by utilizing multi-dimensional lattice constellations, we propose a new full diversity design strategy for 4Gp- and Gp-QSTBC to obtain larger diversity product over current CR method for eight transmit antennas. The diversity product of the proposed strategy can be measured by the minimum product distance (MPD) of the corresponding lattice constellations. It is shown by simulations that the proposed lattice-based four-group decodable QSTBC outperforms the current 4Gp-QSTBC by 0.3 db with the same number of symbols for joint decoding. In the two-group decodable case, the proposed lattice-based QSTBC also obtains about 0.3 db gain and eeps the same decoding complexity compared to the current Gp-QSTBC. Keywords: quasi-orthogonal space-time bloc code, diversity product, two-group decodable STBC, four-group decodable STBC, constellation rotation, multi-dimensional lattice constellation. Introduction [ ~ ] Orthogonal Space-Time Bloc Codes (OSTBC) provide a promising transmission scheme in multi-antenna systems due to their full diversity and single-symbol maximum lielihood (ML) decoding. However, their symbol rates are less than one when complex signal constellations and more than two transmit antennas are [3 ~ 4] used. To increase the rate, the quasi-orthogonal STBCs (QSTBC) were proposed by relaxing the orthogonality constraint. The full diversity can still be obtained by rotating the constellations for part of the transmitted symbols [5]. In the case of eight transmit antennas, a full rate (rate one) and full diversity Gp-QSTBC with constellation rotation was presented in [6]. The symbols are separated into two groups and joint decoding of four symbols is performed. To reduce the decoding complexity, a coordinate interleaved orthogonal design (CIOD) with double symbols joint decoding was introduced in [7~8]. Recently, a full rate and full diversity 4Gp-QSTBC, with a lower pea-to-average power ratio (PAPR) than that of the CIOD, has been proposed in [9], where double symbols are jointly decoded for eight transmit antennas after the transmitted symbols are decoupled into 4 groups. The codewords in [5,6] and [9] are derived from QSTBCs and achieve the full diversity through the process of constellation rotation (CR), or both CR and interleaving the real and imaginary parts of different symbols. The 88

17 diversity product is maximized by seeing the optimal rotation angles [5], where the maximum seeable diversity product is relevant to the number of rotation angles for constellation rotation [7]. The current 4Gp-QSTBC [9] and Gp-QSTBC [6] consider and 4 rotation angles, respectively, which can be regarded as rotation in and 4 dimensions. These designs achieve full diversity but are unable to exploit the maximum attainable diversity product due to the limited number of rotation dimensions [0]. In this paper, by utilizing multi-dimensional lattice constellations [~], we propose a new full diversity design strategy for QSTBC to obtain larger diversity product over current CR method for eight transmit antennas. We also show that the diversity product of the proposed design can be measured by the minimum product distance (MPD) [] of the corresponding lattice constellation. Notation: The superscripts () T and () H denote transpose and transpose conjugate, respectively, of a matrix (or vector). det( ) denotes determinant of a matrix. and diag () stand for norm and diagonalization, respectively, of a vector. (), () I and () Q denote conjugate, real part, and imaginary part, respectively, of a complex number. j = is imaginary unit.. System Model with Full Decoupling By utilizing the fact that the eigenvectors of the equivalent channel are fixed and independent from the channel realizations for QSTBCs, the transmitted symbols can be completely decoupled if they are pre-processed by a decoupling matrix before QSTBC encoding [3]. We will first give a brief introduction of the full decoupled model upon which the proposed lattice-based QSTBC is constructed. Let N T be the number of transmit antennas, N R the number of receive antennas, and T the number of time slots for one codeword. The number of transmitted symbols in each codeword is K. Here, we focus on QSTBC with T = NT = K = 8. Without loss of generality, we consider the following codeword: x x x3 x4 x5 x6 x7 x8 x x x4 x3 x6 x5 x8 x7 x3 x4 x x x7 x8 x5 x f ( ) x x x x x x x x x = x 5 x6 x7 x8 x x x3 x 4 x6 x5 x8 x7 x x x4 x 3 x7 x8 x5 x6 x3 x4 x x x 8 x7 x6 x5 x4 x3 x x () where x = [ x x... x8] T is a symbol vector with x = x I + jx Q, =,,...,8. According to the analysis in [3], the decoupling matrix of the above codeword is 89

18 j 0 j 0 j 0 j 0 V = 0 j 0 j 0 j 0 j j 0 j 0 j 0 j 0 0 j 0 j 0 j 0 j () Choosing V as a pre-processing matrix at the transmitter, the vector x can be obtained as x= Vs (3) where s = [ s s... s8] T is a information symbol vector which is composed of s = si + jsq, =,,...,8. With some mathematical manipulations, we can derive a decoupled model as H H y '' = D V H' y' = Ds+ w (4) where y '' = [ y,..., y8 ] T, H' and y' are defined as Eq. (5) in [3], w = [ ww... w8] T is a N T noise vector, whose entries are mutually i.i.d. complex Gaussian random variables with zero-mean and identical variance. The diagonal matrix D is defined as D = diag([ ddd d d3 d3 d4 d4]), where d = α+ α + α3 α4, d = α+ α α3 + α4, d3 = α α + α3 + α4, d4 = α α α3 α4 and the α α4 are given in Eq. (5) of [3]. After transforming to a real-valued presentation, the (4) can be rewritten as y = Ds + w (5) where = y I y I... y8 I y Q y Q... y8 Q y [ ] T, D= diag([ D D ]) is a real diagonal matrix, s = [ si si... s8i sq sq... s8q] T, and w = [ wi wi... w8i wq wq... w8q] T. If a square QAM constellation is used for every s, =,,...,8, we now from (5) that no coupling is generated among the entries in s for the encoding process C= f ( Vs ) (6) 3. Proposed Lattice-Based Full Diversity Design We note that the codeword in (6) has only diversity order. In this section, we will provide a full diversity design based on multi-dimensional lattice constellation for the above code. Assuming the difference in codeword as ΔC= C C 0, combining the expressions in (), () and (6), we can obtain H det( ΔC Δ C) = 4 (( Δ s +Δ s +Δ s +Δ s ) ( Δ s +Δ s +Δ s +Δ s ) 8 I Q I Q 3I 3Q 4I 4Q ( Δ s5i + Δ s5q + Δ s6i + Δ s6q ) ( Δ s7i + Δ s7q + Δ s8i + Δ s8q )) (7) where Δ s = s s' =Δ si + jδ sq, s ' = s' I+ js' Q, =,,...,8. 90

19 H det( ΔC Δ C ) > 0 is guaranteed by utilizing the property that the MDC is grater than zero for full diversity multi-dimensional lattice [~]. The corresponding four-group and two-group decodable QSTBCs are presented in terms of the real or complex lattices, respectively, in the following sections. 3.. Four-Group Decodable QSTBC Under Real-Lattice We divide the real symbols { si,..., s8i, sq,..., s 8Q} into four groups as s = [ s I s 3 I s 5 I s 7 I] T, s = [ sq s3q s5q s7q] T, s = [ s s s s ] T 3 I 4I 6I 8I, 4 = sq s4q s6q s8q s [ ] T, and define four-dimensional real-lattice constellation as s = Ua,,,3, 4 = (8) where = ai ai aq aq a = ai + jaq, =,,...,8 a [ ] T, a = [ a3i a4i a3q a4q] T, a 3 = [ a5i a6i a5q a6q] T, a 4 = [ a7i a8i a7q a8q] T, and, represent information symbols from a square QAM constellation. According to full diversity lattice theory, the generator matrix U is given below [4] U = (9) Let us denote s ' = [ s' I s' 3I s' 5I s' 7I] T, s ' = [ s' Q s' 3Q s' 5Q s' 7Q] T, s ' 3 = [ s' I s' 4I s' 6I s' 8I] T, s ' 4 = [ s' Q s' 4Q s' 6Q s' 8Q] T and Δ s = s s', =,,3, 4. Our aim is to obtain the minimum determinant expressed in (7). Without loss of generality, we can assume Δ s =Δ s3 =Δ s4 = 0 and Δs 0. Then (7) can be rewritten as where dp R,min si s3i s5i s7i constellation. H det( ΔC Δ C ) = 4 ( d ) (0) 8 R 4 p,min =Δ Δ Δ Δ is the MPD and it is greater than zero for any full diversity real-lattice Substituting (8) into the real decoupled model in (5) yields four independent sub-models as y = Ha + w,,,3, 4 = () where H = diag([ dd d3 d4]) U, y = [ y Iy 3 Iy 5 Iy 7 I] T, y = [ y Qy3 Qy5 Qy7 Q] T, y 3 = [ y Iy4 Iy6 Iy8 I] T, y 4 = [ y Qy4 Qy6 Qy8 Q] T, w = [ wwww I 3I 5I 7I] T, w = [ wqw3qw5qw7q] T, w 3 = [ wiw4iw6iw8i] T, w 4 = [ wqw4qw6qw8q] T. Information symbol vectors sub-model. a, =,...,4, can be obtained independently by ML or sphere decoding in each 3.. Two-Group Decodable QSTBC Under Complex-Lattice We partition the complex symbols { s,..., s 8} into two groups as s = [ s s 3 s 5 s 7 ] T, s = [ s s4 s6 s8] T and define four-dimensional complex-lattice constellation s as s = Ua, =, () 9

20 where = aaaa 3 4 a [ ] T, a = [ a5 a6 a7 a8] T. The generator matrix U is chosen as j j j j j j j U= G4,4 = j j j j j j j j (3) where G 4,4 is calculated by Eq. (6) in []. Similarly, we can also assume Δs 0 and Δ s = 0, where Δ s = s s ', =,, and s ' = [ s' s' 3 s' 5 s' 7] T, s ' = [ s ' s' 4 s' 6 s' 8] T. Then Eq. (7) can be reformed as where d C p,min s s3 s5 s7 =Δ Δ Δ Δ is the MPD and has non-zero value. H det( ΔC Δ C ) = 4 ( d ) (4) 8 C 4 p,min Combining () and the complex decoupled model in (4), two independent sub-models can be obtained as y = Ha + w, =, (5) where H = diag([ dd d3 d4]) U, y = [ y y3 y5 y7 ] T, y = [ y y4 y6 y8 ] T, w = [ wwww 3 5 7] T, w = [ w w4 w6 w8] T. Using the sub-models, a and a can be decoded independently by ML or SD algorithm. 4. Numerical Results We consider data transmission over a quasi-static Rayleigh flat fading channel. The channel gains are assumed to be nown at the receiver but not at the transmitter. The simulation results are presented in Fig. to compare the bit error rate (BER) of proposed codes with the current 4Gp-QSTBC [9], Gp-STBC [6] and CIOD [7] with bits per channel use (4QAM) for 8 Tx and Rx antennas. 0-4 CIOD 4Gp-QSTBC Proposed-4Gp Gp-QSTBC Proposed-Gp BER SNR db Fig.. Performance of proposed codes compared with current CIOD, 4Gp-QSTBC and Gp-QSTBC, bits per channel use (pcu). 9

21 It is shown that the proposed lattice-based four-group decodable QSTBC outperforms the CIOD and 4Gp-QSTBC by 0.3 db with the same number of symbols for joint decoding. In the two-group decodable case, the proposed lattice-based QSTBC also obtains about 0.3 db gain and the same decoding complexity compared to Gp-QSTBC. As a tradeoff, the two-group lattice-based QSTBC has better performance than four-group lattice-based QSTBC at the expense of higher decoding complexity. Table : Diversity product of some STBCs, Nt=T=8 Number of complex symbols for joint decoding MPD Diversity product Gp-QSTBC [6] Proposed Gp STBC Gp-QSTBC [9] 0.77 CIOD [7,5] Proposed 4Gp STBC Table shows some diversity products of the STBCs discussed previously with 4QAM signal constellation. It can be seen that the proposed schemes for two-group and four-group decodable STBC obtain higher diversity product than the existing ones. The employed complex-lattice can provide larger MPD than the real-lattice, but requires joint decoding with more symbols. It is noteworthy that the proposed lattice-based 4Gp-QSTBC has higher diversity product than that of the current Gp-QSTBC but with slightly lower performance, which can be explained by the fact that maximizing diversity product does not necessarily minimize the pairwise-error-probability (PEP)-bound for 8 8STBCs [5]. Considering the proposed design under PEP-bound minimization criterion is an open issue for future investigation. 5. Conclusions An improved design of four-group and two-group decodable QSTBCs, which is built upon multi-dimensional lattice constellations, has been proposed with better performance and the same decoding complexity in comparison to current 4Gp-QSTBC and Gp-QSTBC. As two different full diversity design schemes for 8 8 QSTBCs, the larger diversity product can be obtained by using the mature lattice theory than the current CR method. The major advantage of the proposed code over the DAST [6] and TAST [7], which are also constructed on lattice theory, is that the proposed code performs two-group or four-group maximum lielihood (ML) decoding with lower complexity. 93

22 References. V. Taroh, H. Jafarhani, and A. R. Calderban, Space-time bloc codes from orthogonal designs, IEEE Trans. Inform. Theory, (): ,. Yuen C, Guan Y L and Tjhung T T. Power-Balanced Orthogonal Space-Time Bloc Code [J]. IEEE Trans. Vehic. Tech., 008, 57(5): H. Jafarhani, A quasi-orthogonal space-time bloc code, IEEE Trans. Commun., 00, 49(): Wang H, Wang D and Xia X G. On Optimal Quasi-Orthogonal Space-time Bloc Codes with Minimum Decoding Complexity [J]. IEEE Trans. Inform. Theory, 009, 55(3): W. Su and X. G. Xia, Signal constellations for quasi-orthogonal space-time bloc codes with full diversity, IEEE Trans. Inform. Theory, (): N. Sharma and C. B. Papadias, Full rate full diversity linear quasi-orthogonal space-time codes for any transmit antennas, EURASIP Journal on Applied Signal Proc., August Z. A. Khan, M. H. Lee and B. S. Rajan, A rate one full-diversity quasi-orthogonal design for eight Tx antennas, Internal Report, TR-PME-00-5, available at rep0.html. 8. Dao D N and Tellambura C. Decoding, Performance Analysis, and Optimal Signal Designs for Coordinate Interleaved Orthogonal Designs [J]. IEEE Trans. on Wireless Commun., 008, 7(): D. N. Dao, C. Yuen, C. Tellambura, Y. L. Guan and T. T. Tjhung, Four-Group Decodable Space Time Bloc Codes, IEEE Trans. Signal Processing, (3): W. Liu, M. Sellathurai, P. Xiao, C. Tang, and J. Wei, Improved Design of Two and Four-group Decodable STBCs with Larger Diversity Product for Eight Transmit Antennas, IEEE Acoustics, Speech and Signal Processing (ICASSP 009), Taipei, April J. Boutros and E. Viterbo, Signal Space Diversity: A Power- and Bandwidth-Efficient Diversity Technique for the Rayleigh Fading Channel, IEEE Trans. Inform. Theory, (3): ,. G. Wang, H. Liao, H. Wang, and X-G. Xia, Systematic and Optimal Cyclotomic Lattices and Diagonal Space-Time Bloc Codes Designs, IEEE Trans. Inform. Theory, (3): A. Sezgin and T. J. Oechtering, Complete characterization of the equivalent MIMO Channel for quasi-orthogonal space-time codes, IEEE Trans. Inform. Theory, (3): E. Viterbo, Table of Best Known Full Diversity Algebraic Rotations, 5. R. Grover, W. Su and D.A. Pados, PEP-bound rotation angle optimization of 8-transmit-antenna quasi-orthogonal space-time bloc codes, IEEE Acoustics, Speech and Signal Processing (ICASSP 007), Honolulu, Hawai'i, U.S.A, M. O. Damen, K. A. Meraim, and J. C. Belfiore, Diagonal Algebraic Space-Time Bloc Codes, IEEE Trans. Inform. Theory, (): H. E. Gamal and M. O. Damen, Universal Space-Time Coding, IEEE Trans. Inform. Theory, (3): 097-9, 94

23 A MEASUREMENT STUDY ON AN END-TO-END INTERNET PATH FRANK C, MA GINGA, WANG LEI, HEI XIAO-JUN Department of Electronics and Information Engineering Huazhong University of Science and Technology Wuhan, , China Abstract : Many networ applications have been commonly deployed as overlays over the Internet. The quality-of-service (QoS) of these applications is largely determined by the networ performance of the underlay end-to-end Internet paths. End-to-end measurements between Internet hosts are important in understanding networ characteristics and enhancing the performance of applications. In this paper we conducted a measurement study on the end-to-end performance on the Internet between two end-hosts located topologically far away from each other. As a case study, we evaluated a set of active measurement tools and monitored the networ performance of an overlay lin between two hosts over long periods of time to study the overlay performance metrics, such as one-way delay, pacet loss, and available bandwidth. Our measurement results indicate that Internet overlay lins are liely to be asymmetric in performance and highly dynamic at the time-granularity of hours. Our quantitative measurements provide consolidated data support for optimizing overlay applications. Keywords: end-to-end Internet paths, monitored, performance metrics, optimizing. Introduction The Internet has been significantly reshaping our daily lives. Over the years the Internet industry and academy have invented and deployed a number of enabling technologies to provide a common platform on which new multimedia applications and services are easy to run as overlays. These overlays usually require quality-of-service; however, the best-effort delivery service offered by the current Internet does not guarantee quality-of-service. Hence, it is important that overlay applications are able to understand the performance of overlay lins and apply adaptation for performance enhancement. To provide insights into Internet operations and performance, end-to-end measurements are becoming more and more popular in the networing community. End-to-end networ measurement helps to understand the performance of overlay applications, identify interesting research problems of overlay systems, and provide the evidence of application enhancements with measurement results. Measurement results may inspire appropriate theoretical analysis of the overlay performance and provide a consolidated foundation for analytical models with validated assumptions from real networing problems. End-to-end networ measurement may also offer applicable guidelines for developing overlay prototype, examining the correctness of the implementation and conducting performance evaluation on prototype systems. In end-to-end measurement users are able to measure performance metrics of overlay lins across the networ without any administrative authority of the networ. This convenience and flexibility leads to the invention of a large number of end-to-end measurement tools. In this paper we conducted a measurement study on the end-to-end performance over the live Internet between two end hosts located topologically far from each other. We evaluated a set of active measurement tools and too a close loo at an overlay lin between two hosts over long periods of time to study the overlay performance metrics, such as one-way delay, pacet loss, and available bandwidth. Our quantitative measurements provide consolidated data support for optimizing overlay applications. 95

24 The paper is organized as follows. We provide a summary of the related wor in Section. Our measurement methodology and the end-to-end measurement architecture and algorithms are briefly discussed in Section 3. We describe our experiments and discuss the measurement results in Section 4. Finally, the paper is concluded in Section 5.. Related wor In end-to-end measurements, two approaches are widely used in practice: active probing and passive sniffing. In active probing [], measurement apparatuses probe the networ by sending out pacets from a source to a destination for the measurement purpose. End-to-end performance metrics [8,0] can be determined by observing the particular characteristics of the probe pacets at the departure (e.g. the pacet size, departure time and bit-rates, etc.) and by analyzing the disturbed probe stream characteristics (arrival time, inter-arrival time etc.) at the destination. Active probing can determine the end-to-end performance experienced by a measurement flow for a particular path and then measure the QoS experienced by applications. In many end-to-end measurement scenarios, active measurements can be conducted in a flexible manner. In passive sniffing, some nodes are deployed in the networ. These sniffers capture the incoming and outgoing traffic of these nodes. One of excellent traffic capture tools is tcpdump, which is constructed based on the libpcap library. The major advantage of passive sniffing is that these techniques do not add additional measurement traffic. In this paper, we focus our attentions on end-to-end measurements on delay, pacet loss and available bandwidth. Over the years, there have been developed a large number of active and passive measurement tools. We only discussed a few measurement tools, which are mostly related to our experiments. In [] the authors developed a passive QoS measurement tool, namely QoSMeT. Their measurement results depicted the detailed end-to-end delay characteristics in a live HSDPA (High Speed Downlin Pacet Access) [9] enabled 3G networ. King [3] is a lightweight and fast tool to estimate networ latency between arbitrary Internet end-hosts by utilizing the existing DNS infrastructure. It only requires a few pacets to produce delay measurement. Owampd/owping [4] is an implementation of one-way delay measurement using OWAMP defined by RFC4656. For end-to-end available bandwidth measurement [5], a simple tool, abget, runs on a single host. Abget is able to connect to any TCP-based (usually web) servers on the Internet, pretending that it is a normal client, and then estimate the variation range of the available bandwidth from the server to the client within dozens of seconds. Abget is constructed based on an iterative algorithm of self-loading periodic streams (SLoPS), which was originally proposed in Pathload. The SLoPS algorithm was further refined in [6]. Another available measurement tool Abing applied the pacet-pair dispersion technique to estimate the available bandwidth for Internet paths. 3. End-to-end Measurement Methodology As shown in Figure, we proposed a QoS measurement architecture. This architecture consists of four levels: measurement point (networ nodes), traffic measurements tools, QoS analysis tool and QoS real-time monitoring or database. A summary of traffic measurements tools was conducted in [7]. Each lower level provides a measurement service to the upper level. In this paper we focus on the first lower three levels and conduct an in-depth measurement study to measure one-way delay, pacet loss, and available bandwidth of end-to-end Internet paths. We used abget to measure available bandwidth. As a comparison, we also conducted available bandwidth experiments using abing. We also utilized owampd/owping to measure one-way metrics including delay, jitter and pacet loss. In the following sections, we will evaluate the above measurement tools and discuss the measurement results in details. The parameters of the tools use the recommended values for the tools if not explicitly specified. 96

25 4. End-to-end Measurement Experiments and Result Analysis In our experiments, the main goal is to conduct measurements to characterize networ performance between the end-hosts over the Internet. We investigated two scenarios: ) monitor QoS metrics of the overlay lins between two end-hosts located in different geographic locations on the Internet; ) investigate the dynamics of available bandwidth of the overlay lins with the normal daily Internet traffic it is shown in Fig. Fig An end-to-end QoS measurement architecture 4.. Experiment Setup In our experiments, we too a close loo at an end-to-end path over the Internet. Figure depicts the networ setup of our experiments. Fig Networ setup for the measurement experiments Two end-hosts are topologically far away from each other. One host is located in the Internet technology and engineering research and development center (ITEC) in Huazhong University of Science and Technology (HUST) in Wuhan. The other host is located in the broadband networ laboratory (BBN) in the Hong Kong University of Science and Technology (HKUST) in Hong Kong. With the traceroute utility, we find that the Internet path from ITEC to BBN consists of 6 hops while the Internet path from BBN to ITEC only has 4 hops. This asymmetric property of this overlay lin in dual directions impacts the networ performance significantly, which will be demonstrated by the following measurement results. To differentiate two directions, we label the overlay lin from BBN to ITEC as upstream and label the overlay lin from ITEC to BBN as downstream. 97

26 4.. Available Bandwidth Measurement Table below shows two sample end-to-end available bandwidth measurements between the two hosts at different times of the day time. We observe that under normal daily traffic abget measures the available bandwidth at 5 Mbps ~ 0 Mbps for the upstream and 30 Mbps ~ 40 Mbps for the downstream. Table Measurement results for available bandwidth using abget. Direction Experiments Running Time (seconds) Available bandwidth (Mbps) Upstream Downstream We also ran the abing tool for bandwidth measurement for 00 times. Between each measurement, we added the idle time 0 seconds to avoid the interference between two measurements. As a by-product, abing also measures the round-trip-time (RTT) of the BBN-ITEC overlay lin under investigation. Table show the average results over 00 measurements. The results show the overlay lin had the average end-to-end available bandwidth of 59.0 Mbps for upstream and 74.0 Mbps for downstream. The RTT measurements average at 60.7 ms with a very small standard deviation ms. Comparing Table and Table, we can observe that the available bandwidth measurement results using self-loading periodic streams leads to much smaller values than those results using the pacet-pair dispersion. Table Measurement results for available bandwidth and RTT using abing RTT (ms) Avail-BW Upstream (Mbps) Avail-BW Downstream (Mbps) Average Standard Deviation One-way Delay and Loss Measurement We conducted the experiments for QoS metrics using owampd/owping in two different measurement scenarios. First, we ran a live monitoring session for 0 minutes in which owampd/owping measurement clients sent 6000 pacets in both directions. The session was further divided in sub-sessions with each session for 00 probing pacets sent. In the second measurement scenario, we continuously monitored the overlay lin for hour to study the long-time dynamics. A snapshot of the minimum delay measurement results in 0 minutes is plotted for both the upstream and the downstream in Figure 3 and Figure 4. The minimum delay is measured for 00 pacets transmitted in a sub-session. For the upstream we observe that the delay is mainly around 45ms while for the downstream is around 35ms. Interestingly the pacet loss for the upstream is much higher than expected in this wired networ. We recorded the pacet loss for the upstream more than 50% sometimes up to 00%. Nevertheless, the cause for this abnormal networ behaviour was yet to be concluded. 98

27 From BBN to ITEC Delay Loss % Delay (ms) :55.7 0:7. 0:57.5 :5.6 :55.7 :6.3 :58.9 3:8.9 Loss % 3:59. 4:30. 5:0.8 5:33.5 6:07.0 6:38. 7:07.6 7:38.4 8:09.9 8:45.0 9:7.3 9:49.5 Time (minutes) Fig 3 Upstream: one-way minimum delay and pacet loss results From ITEC to BBN Delay Loss % Delay (ms) :55.7 0:30.8 :0.6 :33.0 :03. Loss % :33. :58. 3:6.8 3:54.6 4:.9 4:5.8 5:.9 5:5. 6:4.8 6:55.4 7:5.3 7:54.5 8:5.0 8:56. 9:7.6 Time (minutes) Fig 4 Downstream: one-way minimum delay and pacet loss results Another observation for note in the results is that we captured some delay spies (>000ms) in both directions. This long delay closely correlates with the pacet loss. In the results pacet reordering was discovered in some cases. We conjecture that ISP has deployed some dynamic routing algorithms for load balancing. Nevertheless, this route switching may impact the real-time overlay application significantly. In VoIP applications, a satisfied voice quality requires the one-way delay less than 50ms [], the one-way jitter less than 30ms and the pacet loss less than %. Based on our measurement results, the performance of the BBN-ITEC overlay lin cannot meet the above quality requirements. VoIP applications for these two end hosts may suffer from severe quality degradation under these circumstances. The measurement results for the long duration ( hour) shown in Figures 5 8 have demonstrated clearly the asymmetric quality performance in both directions. The upstream suffered severely in pacet loss sometimes up to 00% and one-way delay spie above 600 ms frequently. For the downstream, the minimum average delay was 40ms. One interesting phenomenon was that during the first 30 minutes the overlay lin performance showed high variations in delay and jitter while during the last 30 minutes the delay was quite stable at around 38ms, 0% pacet loss and jitter at around ms. Many networ performance metrics are dynamic in nature. Zhang et al., [] reported that the performance metrics of Internet paths, such as delay, loss and throughput, remain steady at the minute scale and above. Our 99

28 measurement results reveal that at the time-granularity of hours the networ performance is highly dynamic and asymmetric. These characteristics, however, should be carefully considered for optimizing overlay applications. Delay (ms) From BBN to ITEC Minimum delay Loss % 3:6.6 5:0.7 6:49.4 8: :30.7 3:0.4 34:.9 36:0.4 37:5.3 39:44.8 4:3.8 43:7.9 45:3.8 47:0.9 48: :4.4 5: :7.7 56:4.3 58:0.8 59:55.8 0: : :9.4 07: :56.8 0:49.3 :38.8 4:7.3 6:6.8 8:08.9 9:58.5 :5. Time (minutes) Fig 5 Upstream: one-way minimum delay and pacet loss ( hour) Pacet Loss % Delay (ms) From BBN to ITEC Maximum delay Loss % 3:6.6 5:0.7 6:49.4 8: :30.7 3:0.4 34:.9 36:0.4 37:5.3 39:44.8 4:3.8 43:7.9 45:3.8 47:0.9 48: :4.4 5: :7.7 56:4.3 58:0.8 59:55.8 0: : :9.4 07: :56.8 0:49.3 :38.8 4:7.3 6:6.8 8:08.9 9:58.5 :5. Time (minutes) Fig 6 Upstream: one-way maximum delay and pacet loss ( hour) Pacet Loss % Delay (ms) From ITEC to BBN Minimum delay Loss % 3:6.7 5:05. 6:55. 8:4.0 30:3.4 3:4.9 34:7.0 36: :5.4 39:40.9 4:5.3 43:3.0 45:.5 47:09. 48: :5.3 5:38. 54:4.3 56:.4 58:03. 59:5.6 0: :6.5 05:9.5 07:.9 08:58.9 0:5.5 :37.5 4:8.6 6:.0 8:09.5 0:0. :50.8 Time (minutes) Fig 7 Downstream: one-way minimum delay and pacet loss ( hour) Pacet Loss % Delay (ms) From ITEC to BBN Maximum delay Loss % 3:6.7 5:05. 6:55. 8:4.0 30:3.4 3:4.9 34:7.0 36: :5.4 39:40.9 4:5.3 43:3.0 45:.5 47:09. 48: :5.3 5:38. 54:4.3 56:.4 58:03. 59:5.6 0: :6.5 05:9.5 07:.9 08:58.9 0:5.5 :37.5 4:8.6 6:.0 8:09.5 0:0. :50.8 Time (minutes) Fig 8 Downstream: one-way maximum delay and pacet loss results ( hour) Pacet Loss % 00

29 5.Conclusion In this paper we investigated the networ performance characteristics between two end-hosts on the Internet. The end-to-end measurement can play an important role in ensuring QoS for overlay applications. The networ performance metrics, such as one-way delay, jitter and pacet loss, can be monitored and controlled at an accepted level. The best-effort traffic delivery can be better provisioned through more efficient routing and scheduling algorithms. With the further penetration of the modern Internet, networ measurement is becoming crucial and more important for provisioning of multimedia services and applications. Acnowledgement The authors than Ms. Yunqing Cheng and Mr. Yujiang Zeng for their strong support and help for this paper. Reference. Sridhar Machiraju, Darryl Veitch, François Baccelli, Jean C. Bolot, "Adding definition to active probing", ACM SIGCOMM, Kyoto, April 007, 37, (): 7-8. Jarmo Proola, Mio Hansi, Maro Jurvansuu, Milla Immonen, "Measuring WCDMA and HSDPA Delay Characteristics with QoSMeT", In Proceedings of IEEE ICC'07, Glasgow (UK), June Krishna P. Gummadi, Stefan Saroiu and Steven D. Gribble, "King: Estimating Latency between Arbitrary Internet End Hosts" In Proc. SIGCOMM IMW, Marseille, France, November Helder Veiga, Rui Valadas, Paulo Salvador, António Nogueira, Thomas Pfeiffenberger, Felix Strohmeier, OWAMP Performance and Interoperability Tests, In Proc. IPS-MoMe 006, Salzburg, Austria, February Manish Jain, Constantinos Dovrolis, "End-to-End Available Bandwidth: Measurement methodology, Dynamics, and Relation with TCP Throughput", in Proc. Acm Sigcomm, August Mazni Amil, Mohamad Yusoff Alias, and Khairil Anuar "PathF3 - Improving accuracy and networ load in available bandwidth estimation based on SLoPS Methodology" International Journal of Computer and Electrical Engineering, April 00, (): Richard Blum, Networ Performance Toolit Using Open Source Testing Tools, Wiley Publishing Inc., st edition, Irina Rish, Gerald Tesauro, "Estimating end-to-end performance by collaborative prediction with active sampling", IEEE International Symposium on Integrated Networ Management 007, Munich(GER), May M. Jurvansuu, J. Proola, M. Hansi, P. Perälä, "HSDPA Performance in Live Networs", In proceedings of IEEE International Conference on Communications (ICC 007), Glasgow, Scotland, United ingdom, June M. de Oliveira, A. Pacheco, C. Pascoal, R. Valadas, P. Salvador, "On the Dependencies between Internet Flow Characteristics", Springer Berlin Heidelberg New Yor, vol. 5464/009, September, 009. A. Nogueira, P. Salvador, R. Valadas e A. Pacheco, "Modeling IP Traffic Behavior through Marovian Models", September, Hershey, PA, USA, IGI Global 007. Y. Zhang and N. Duffield, On the constancy of Internet path properties, in Proc. ACM IMW, San Francisco, CA, USA, Nov. 00 0

30 THE HARDWARE SYSTEM DESIGN OF LASER CARVING MACHINE BASED ON DS CONTROLLING NING XIN, NING LI-PU, WANG CHAO, ZHANG SU-JUN, MIAO QING-LIN Henan Institute of Science and Technology Xinxiang Henan, , China Abstract: The traditional ways are almost inefficient contact machine wor in which the contact between tools and circuit board can cause pollution. This paper mainly deals with the point which uses DS controlling technique to finish the control of laser carving machine. This device mainly research the functions of controlling laser carving machine to mae electronic component jac and serial number on circuit board. Based on DS controlling, this paper mainly studies the hardware system design of laser carving machine, including the fundamental motion design, model selection, I/O address assignment, I/O electrical wiring and so on. The DS control system studied in this paper realizes the motion control of laser carving machine woring table, and can change the program to finish the point to point control processing,which has the features of simple structure, high anti-interference and convenient coding. The merits of using laser carving and cutting are simple procedure, high efficiency, low pollution, convenience application and widespread availability. Keywords: laser carving machine; DS controlling; convenient coding; high anti-interference. Introduction With the development of industrialization in our country, large manufacturing enterprises, especially the electronics in coastal areas all apply assembly-line operation. And the serial number which is indispensable in the production of many industries is the lable number mared on spare parts during the production process. There are lots of woring procedures in the processing of circuit board and many electronic parts and blocs in each procedure, which cause a lot of trouble for management []. Therefore, the numbers mared on these spare parts bring more convenience for management. Before the production of electron plate, serial number is created by in-jet printing, which not only waste printing in, but also will grow indistinct gradually. The serial number mared by laser on circuit board not only save printing in but also can not cause pollution, which conform to the requirement of green manufacturing in the world today. The controlling method that prints serial number on circuit board is expressed as follows: PLC (or motion control card)+ servo driver + servo motor + actuating device. Programming and debugging are inconvenient, the development period of equipment is long, and the expectation for electrical control and mechanism staff is high. Japanese [A] company produces the DS series [A] controller composed by several parts instead of only one part in order to devise and install more conveniently. The [A] controller combines traditional PLC and servo driver together; and [A] mechanical hand maes traditional motor and actuating device together. The brief programming language maes programming easy; and the wor bench and steady rest can mae equipment run, which also mae mechanism staff device mechanism shoring and transmission unit with more sill and ease. In this way, a lot of problems can be reduced in the equipment program, the equipment development period can be shortened, and the stability of equipment can be improved []. This device mainly research the functions of controlling laser carving machine to mae electronic component jac and serial number on circuit board. The traditional ways are almost inefficient contact machine wor in which 0

31 the contact between tools and circuit board can cause pollution. Whereas the way of carving and cutting with laser is as easy as typing on paper by computer and printer. It can devise by use of various graphs, and the scanning graphs, vector graphs and CAD files can all be typed into the carving machine easily. The control system essence of this paper is DS shaft controller which is similar to PLC. The hardware system design of laser carving machine. The demand for fundamental motion design The control system of laser carving machine mainly control the motion of point position such as drilling and tagging. And its basic motion functions include the following requirements: )Move X-Y axis table to the origin and be in standby mode. )Operators fix wor piece on X-Y axis table and turn on the switch. 3)X-Y axis table moves to woring laser position N.O., then outputs instructions to laser. 4)After finishing the laser motion, once the end signal is input, the laser move to laser position N.O. and N.O.3 in the same way. 5)After finishing the dot printing laser, X-Y axis table moves bac to the woring origin. DS shaft control system is composed of two parts: hardware design of control system, namely, confirming DS control machine and wire connection of hardware; and software design of control system, namely, composition of DS language program. This paper only design the fundamental functions of the control system of carving machine, and the design plans are as follows:. [A] series model selection Selecting the model of laser carving machine should be in accordance with the function of product, and choose high efficiency-costly DS shaft and control machine on the premise of meeting functional needs in order to have the best performance [3~4]. This method can be analyzed in the following aspects:.. According to the physical structure of DS shaft According to the different physical structures and functions of DS shaft slide rail, there are mainly several standards: high speed type(sa-s5h SA-S4H), medium speed type (SA-S5M SA-S4M)and low speed high thrust type(sa-s5l SA-S4L). For laser carving machine mainly processes the light circuit board, the bearing load and inertia of shaft are not strong, and there are always lots of holes on circuit board. In order to improve efficiency, the small-sized common high speed type should be the best choice [4]. Tae type SA-S5H for example, its shaft is a ind of small type which doesn t have the strong bearing capacity, but its function is as good as large-sized shaft and cheap as well. This type of shaft also has several products of different stroes, in order to develop the process scope, the stroe of 400mm type is selected as an example in this paper. (The specifications are shown as following Table ) 03

32 Table Characteristics of model SA-S5H DS shaft Specifications Structure and positon Standards of service limits Model SA-S5H Stroe mm 400 Rating output W 0 Rating speed mm/sec 800 Rating thrust N(gf) 6.7(.7) 重复决定位置 mm ±0.05 Weight g. Motor AC servomotor AC motor size A.B.Z phase voltage output signal waveform Coding device Input voltage +5V (Origin pulse:pulse[semi-cycle] / revolution) Wire 蕊复合线 5m(standard length) Maximum thrust N(gf) 33.3(3.4) Slide load Kgw Horizon usage: 4g Vertical usage:g Load moment N.m 5000m waling life (gf.m) Ma:4.9(0.5) Mb:6.8(0.7) Mc:7.8(0.8) Strain load length 长度 L Mm Ma direction 50below Mb,Mc direction 50below.. Type selection of DS control machine For the motion requirement can not be so complicated, and the present design function can mainly wor in the way of positioning control, combination of two shafts by the single shaft control machine can meet the requirement. Therefore the best choice is the single shaft control machine DS control machine. This ind of control machine has many input and output ports which can meet the requirements of switching quantity control system and have the surplus to use for function reformation [5]. (The specifications are shown as following Table ) Table Characteristics of DS shaft control machine Pin No. Division Port No. Functions Wire colors A P4 Outside voltage +4Vinput -brown B input PRG No. input -red A PRG No. input -orange B PRG No.4 input -yellow 3A PRG No.8 input -green 3B PRG No.0 input -blue 4A PRG No.0 input -purple 04

33 Pin No. Division Port No. Functions Wire colors 4B Ready -grey 5A Input CPU RESET -white 5B 000 Universal input -blac 6A 00 Universal input -brown 6B 00 Universal input -red 7A 003 Universal input -orange 7B 004 Universal input -yellow 8A 005 Universal input -green 8B 006 Universal input -blue B 04 Universal input 3-yellow 3A 05 Universal input 3-green 3B 300 Output alarm 3-blue 4A 30 Output READY 3-purple 4B 30 Universal input 3-grey 5A 303 Universal input 3-white 5B 304 Universal input 3-blac 6A output 305 Universal input 4-brown 6B 306 Universal input 4-red 7A 307 Universal input 4-orange 7B N Outside voltage 4-yellow..3 Estimating the storage capacity of DS control machine Estimating method of storage capacity of DS control machine: for the control system which only has switching quantity input and output signals, the required input and output point multiplies 8, which can have a the required storage capacity of DS control machine (the unit is bit), namely, (5+8) 8 64bit The storage capacity of DS control machine can achieve 000 steps, and the storage points can achieve 500 [6]...4 According to the type of switching quantity input module The input voltages of switching quantity input module are generally DC4V and AC00V. The delay time of direct-current circuit is short, which can mae direct-current circuit connect to electronic input equipment, such as proximity switch, photoelectric switch and so on. The contact of AC input way is reliable, and it s adequate for the severe environment of oil mist and dust. For this design is based on the dust free room condition, and DC4V is much safer than AC00V for operators, DS shaft control input module should choose the type of direct-current and DC4V input voltage [7]. To sum up the above arguments and integrate with the reality of laser carving machine control system, in order to mae laser carving machine wor well, confirming the DS series SA-S5H shaft and controller produced by Japanese [A] company. The small size, powerful function and low price of this series can meet the above requirements [8~9]. And its programming interface is widely used RS3C which can be connected to programming device or computer directly and conveniently. 05

34 -SEL.3 I/O address assignment The I/O address assignment is formed by the model of DS control machine (shown as following Table.3 and Table 4) Table 3 I/O address assignment table of x-axis control machine X-SEL Division Output NO. Signal name Specification Start up Button 00 Input Start Button 006 X-axis begins to move DC4V Output 306 X-axis in position DC4V Table 4 I/O address assignment table of y-axis control machine Division Output NO. Signal name Specification Input DC4VY006 Y-axis begins to move DC4V 306 Y-axis in position Output 307 Control laser machine DC4V.4 I/O electrical wiring design of DS control machine Figure is the I/O wiring diagram of DS control machine. In this diagram, there is one COM common port for A 6B 8B 3B 4A 6B 7A 7B, one point of input switch should be connected to DC +4V electrical source, and another point should be connected to corresponding input terminals of DS control machine. During the time of wiring, the input/output common port polarity common port of DS control machine should be care about. Because the electrical source of DS control machine is DC4V, the electrical sources of contactor coil, machine tools illuminating lamp and signal lamp are all DC4V. Fig I/O Wiring diagram of DS control system 06

35 3. Conclusion The DS control system studied in this paper realizes the motion control of laser carving machine woring table, and can change the program to finish the point to point control processing. DS control system is a new type machine control system which is widely used in automatic equipment, which has the features of simple structure, high anti-interference and convenient coding. This paper mainly deals with the point which uses DS controlling technique to finish the control of laser carving machine. In this paper, the DS control system still has some deficiencies to be further improved, such as be lac of corresponding protecting program design and illumination control. References. CAO Feng-qiong. Numerical control machine tool improvement for laser carving[j]. Journal of Zhengzhou University of Light Industry(Natural Science),008, 8(4): Japan [A] company. Description on DS-axis. Japan: [A] company in Japan, WANG ZONGJIANG. Design and Debug of New Digital Control System for the Laser Maring. Microcomputer Information,008, (7): REN Xin-bo; WANG Ke; XU Chang; CHEN Ai-hua; Li Qin; Zhang Jian. Design of Profiling Laser-engraving Machine for Bamboo[J]. Journal of Zhejiang Forestry Science and Technology,008, (6): Li Cheng and so on. Modern mechanical and electrical control systems[m]. Xi'an: Northwest Industry University Press, Li Li-min; Zhu Cheng-de; Xia Li-li; Zhu Ning-feng. Creation design and optimization of the critical part of laser engraving machines,machinery Design & Manufacture,008, 8(8): Seitz,S.M.and Dyer,C.R. Photorealistic scene reconstruction by voxel coloring[j].int. J. Computer Vision, 999, 35(): P. Riviale, Eugène Boban ou les aventures d un antiquaire au pays des Americanistes. J. Soc. Am. 00, 87(): Bíza,J.,Niedermeierová,H.,Pavingerová,D., homas, C.M., Klimyu, V.I., Jones, J.D.G.: Transposition patterns of unlined transposed DS elements from two T-DNA loci on tomato chromosomes 7 and 8.-Plant J., in press,

36 A NOVEL CMOS CCDVCCⅡ REALIZATION AND ITS APPLICATIONS TO PROGRAMMABLE INSTRUMENTATION AMPLIFIER AND MULTIFUCTION FILTER ZHAO YI, WANG WEI-DONG Information & communication school, GuiLin University of electronic technology Guilin Guangxi, 54004, China Abstract: The paper presents a new CMOS current controlled differential voltage current conveyor.a new gain programmable current mode instrumentation amplifier is presented.the new instrumentation amplifier consists of one CCDVCCⅡ,one simple amplifier and one resistor. The proposed instrumentation amplifier is a current mode circuit which has a wide bandwidth and fast slew rate than other voltage mode instrumentation amplifier. The gain of the instrumentation amplifier can be tuned by the controlled current I B.This maes it appropriate for IC implementation due to occupying less chip area, consuming low high power and with electronic controllability. The topology has higher CMRR and more stability than other current mode instrumentation amplifier without component matching.a multifunction filter is also presented in this paper.the filter performs completely functions: low pass, high pass, band pass, band reject, all pass.the quality and pole frequency can be tuned independently by input bias current.the filter includes only one CCDVCCⅡ, one DVCCⅡ and one resistor and two capacitors and without component matching. Furthermore, the filter types can be programmed by the controlled CMOS switch pattern. Using SMIC 0.8μm CMOS process parameters and Spectre, the simulation results agree well with the theoretical anticipation. Key words: current controlled differential voltage current conveyor (CCDVCCⅡ) differential voltage current conveyor (DVCCII) voltage mode multifunction filter gain programmable instrumentation amplifier. Introduction In analog signal processing applications it may be desirable to employ active component, such as communication, measurement and instrumentation and control systems. The multifunction filter and instrumentation amplifier is indispensable bloc in analog signal processing. Since the first introduction by A. Sedra and K. Smith in 970, the second-generation current conveyor (CCII) has proved to be a versatile analog building bloc that can be used to implement numerous high frequency analog in these applications. However, when it comes to applications demanding differential or floating inputs, the differential voltage current conveyor (DVCCⅡ) become useful in the applications. These blocs have been proposed in late 90s []. The literature surveys show that the current mode instrumentation amplifiers have been reported. Unfortunately, these reported circuits suffer from one or more of following weanesses() the gain of the amplifier lac of electronic adjustability [] () Excessive use of the active and/or passive elements [~4] (4)variety CMRR and unstable [3]. And the weanesses were also found in multifunction filter: The pole frequency and quality factor can not be tuned independently [5]. The novel CCDVCCⅡ and DVCCⅡ are introduced in this paper to constitute an instrumentation amplifier and a multifunction filter. The two topologies operate under a supply voltage of.8v. Cadence IC Spectre is used to simulate the circuits. 08

37 .The description of the DVCCⅡ and CCDVCCⅡ The DVCCⅡ and CCDVCCⅡ are the extension of the CCⅡ. In this section we briefly describe the circuits. The DVCCⅡ symbol is shown in fig..the matrix shows its properties: VX 0 0 IX I Y V + Y+ = I Y V Y IZ Vz () And the symbol and the equivalent circuit of CCDVCCⅡ are shown in fig..the relationship between the current and voltage can be described by following matrix: VX RX 0 IX I Y V + Y+ = I Y V Y IZ Vz () Fig.(a) the symbol of the DVCCⅡ (b)the equivalent circuit of DVCCⅡ Fig. (a) the symbol of the CCDVCCⅡ (b)the equivalent circuit of CCDVCCⅡ 09

38 Firstly, a novel DVCCⅡ is designed. Secondly, a trans-conductance linearity loop is designed. The proposed DVCCⅡ has exact voltage following performance, low voltage supply, low power dissipation and high PSRR. The proposed DVCCⅡ adopts the rail-to-rail input structure to improve the signal swing. Rail-to-Rail voltage range operation is implemented by using N-type and P-type differential difference input stages under.8v power supplies. All transistors operate in saturation region. And their buls are connected to the appropriate positive or negative supply rail. The current mirror formed by the transistors PM7 PM8 NM7 NM8 and NM7 NM8 PM7 PM8 forces the sum of drain currents of NM and NM4 to be equal to the sum of the drain currents of NM and NM3, and the sum of drain current of PM and PM4 to be equal to the sum of the drain currents of PM and PM3. Therefore, ( V + V ) V = ( V + V ) ( V + V ) Y bg bg Y+ bg X bg V = V V X Y+ Y (3) (4) V bg is the operate voltage applying by band-gap voltage reference. The gain of the proposed DVCCⅡ was given by V ( GmN, + GmP, )/( gdp3 + gdn 3) C = V V + ( G + G )/( g + g ) Y+ Y m, N m, P dp3 dn3 (5) The terminal C in Fig.3 is connected to the trans-conductance linearity loop in order to form a CCDVCCⅡ. Fig.3 the proposed DVCCⅡ The trans-conductance linearity loop is shown in Fig.4. 0

39 Fig4. the circuit of trans-conductance linearity loop I B is the bias current controlling the resistor of the terminal X. The trans-conductance linearity loop is formed by NM6-NM7,PM7-PM8. NM6 and NM7,PM and PM8 have the same parameter. From the fig.4, the voltage relationship between the C,D,E,X can be nown as: VCX = VDC VDX = VEC VEX The trans-conductance linearity loop conforms the KCL: (6) i = I I X (7) All transistors operate in saturation region. W id = K ( V GS VTH ) Where L Knp, = μnp, C OX i = V ( K W / L K W / L ) + V ( K W / L + K W / L ) I X CX p p p n n n CX p p p n n n B The PMOS and NMOS are matched. So from K p W p /L p = K n W n /L n = KW/L and V X =V C +i X R X can get: RX = VXC / ix = 4 I KW / L B (8) (9) 3. Gain turned current mode instrumentation amplifier Only one CCDVCCⅡ,one simple amplifier and one resistor form a current mode instrumentation amplifier. The proposed amplifier has simple topology than other current mode amplifier [3~4].Its suitable for IC applications because it occupies less area. In addition, it can offer advantageous features such as high slew-rate, high speed, and wide bandwidth compare with the voltage mode instrumentation amplifier. A is a voltage follower. A maes the circuit more stable. The CMRR of this circuit is higher than other amplifier. Straightforwardly analyzing the circuit in Fig. 5 and using CCDVCCⅡ properties, the output voltage and the gain of the circuit can be obtained as:

40 R W V = ( V V ) = 4 R I K ( V V ) (0) o o o B RX L W AV = 4Ro IB K () L Fig.5 the proposed gain tuned instrumentation amplifier From Eq. (9), we found the gain can be tuned by the input bias current I B. The resistor occupies more area in integrated circuit. We use only one resistor in order to mae the circuit suitable for IC and consume less power. The result shown in Fig.6 displays output signals versus input signals, while R=0KΩ,I b =0μA, 0μA, V in =0.sin(πf), f=mhz. Fig.7 shows the frequency response for input bias current I b =0μA, 0μA, 30μA.The ideal gain of the amplifier are.5db,4.5db,6.3db.fig.8 shows the frequency response of common mode rejection ratios (CMRR) for input bias current I b =0μA, 0μA, 30μA. The simulate result shows that the band width of the circuit is above 8MHz. The bandwidth is wider than the circuit in [3].The minimum input voltage is mv.fig.8 shows that the CMRR do not vary with the value of the I B..CMRR is more stable than the circuit in [3]. Fig.6 Transient response of the instrumentation amplifier Fig.7 Frequency response of amplifier

41 Fig.8 Frequency response of CMRR Fig.9 the novel multifunction filter 4. Multifunction filters The multifunction filter has one CCDVCCⅡ, one DVCCⅡ and one amplifier. The amplifier is used to reverse the phase. The multifunction filter is presented in Fig.9. I B is the bias current of the CCDVCCⅡ. Analyzing the circuit in Fig.9, the function of the circuit can be obtained to be: V o = Vs + s V + V 3 CR Q CCR XR + + s s CR Q CCR X R () Selecting S, S, S3, the nd order filter can be obtained from Eq.(0). The table shows that the filter types can be programmed by the controlled CMOS switch pattern. The pole frequency (ω 0 ) and quality factor (Q 0 ) of the filter can be expressed as follows: ω o = (3) CC R R X 3

42 Q C = RX CR X R (4) Response Table. The types of the filter for different values of the switch switch pattern switch S S S3 LP L L H HP H L L BP L H L BR H L H AP H H H The pole frequency (ω 0 ) and quality factor (Q 0 ) can be tuned by R X, while the R X can be tuned by I B. In a word, the ω 0 and Q 0 can be tuned by I B. The bandwidth of the response can be adjusted by R Q, the Eq.(3) is given: ωo BW = = (5) Q R C Q From the (), we found the high quality factor can be obtained by setting high R Q value. Using the equation y S x = ( x y) i ( x y), the sensitivities of the circuit can be expressed as follows: ω ω ω S = ; S = S = (6) o o o IB C C Q Q Q Q SI = S ; ; B C = S C = S R = (7) Q S BW RQ = S = (8) BW C The Fig.0 displays the response function of the filter by set I B =49μA, C =C =nf,r Q =Ω, R=Ω,.From () () (3), we calculate the ideal value of the circuit, ω 0 = rad/s,f 0 =3.8Hz,Q=0.88, B W =MHZ. The simulate value is f 0 =44.7Hz.It has an error of 9%. Fig. shows the response of band ass while R Q = 0.5Ω (Q=0.), 0.84Ω(Q=0.707),.9Ω(Q=),Ω(Q=.68),3Ω(Q=.5).The bandwidth of the filter is much wider than other filter. And the blocs in the circuit is simpler than other circuit. 4

43 (a) Band pass filter (b) All pass filter (c) Band reject filter (d) Low pass filter (e) High pass filter (f) The band pass filter of different values of R Q. Fig. shows the response of band 5

44 5. conclusion A novel CMOS current controlled differential voltage current conveyor (CCDVCCⅡ) has been introduced in this article. The proposed circuit enjoys several features in electronic controllability and differential signal availability, both in input and output ports to achieve more CMRR values. X terminal s parasitic resistance can be controlled by input bias current. The advantages of the proposed instrumentation amplifier are that wide bandwidth, high CMRR, low voltage and low power. The gain of the instrumentation amplifier can be programmed by the input bias current. The proposed multifunction filter has properties as follows: the pole frequency ( ω 0 ) and quality factor ( Q 0 ) can be tuned independently by the current I B. Different types of the function can also be obtained by different switches. And the bandwidth of the filter can also be tuned by the resistor in the circuit. Consequently, the proposed element is very suitable to use in analog signal processing circuits for instrumentation and communication systems. Reference. H.O.Elwan, A.M.Soliman, Novel CMOS differential voltage current conveyor and its application,iee Pro-Circuits Devices Syst, June 997,44, (3): Yehya H.Ghallab, A Novel Current mode Instrumentation Amplifier Based on Operational Floating Current Conveyor, Digital Object Identifier, 005,0.09/TIM Winai Jaila, Dual outputs current controlled differential voltage current conveyor and its applications, X/06, 006 IEEE 4. Mohsen AYACHI, A current mode CMOS IC for biological signals measurement in noisy environment, International conference on microelectronics, J.W. Horng, High-input impedance voltage-mode universal biquadratic filter using three plus-type CCIIs, Int. J. Electron, 004, 8, (3): H. Jianping, X. Tiefeng, Z. Weiqiang and X. Yinshui, A CMOS rail to rail differential voltage current conveyor and its applications, Proceedings of 005 International Conference on Communications,,005, Circuits and Systems 005, (6): B. Metin, E. Yuce and O. Ciceoglu, A Novel dual output universal filter topology using a single current conveyor, Electrical Engineering, , (3): W. Jaila and M. Siripruchyanun, Dual-outputs current controlled differential voltage current conveyor and its applications, Proceedings of The International Symposium on Communications and Information Technologies 006 (ISCIT 006) 9. Chaiyan Chanapromma, A Digitally Programmable Voltage-Mode Multifunction Filter Using CCDVCCs, 009, ISCIT 0. Wangweidong. Principle and Application of modern analog integrate circuits. Beijing:Publishing house of electronic industry.008. Behzad Razavi, Design of analog CMOS and integrated circuits. Xi an JiaoTong university press.00 6

45 ULTRA-HIGH-SPEED WLAN RESOURCE ALLOCATION DECISION ALGORITHM BASED ON CLOUD ZU YUN-XIAO, ZHOU JIE, ZENG CHANG-CHANG, WANG YU-TING School of Electronic Engineering, Beijing University of Posts and Telecommunications Beijing 00876, China SONG YU-TIAN, LIU XIAO International School, Beijing University of Posts and Telecommunications Beijing 00876, China Abstract: The cloud decision algorithm(cda) for ultra-high-speed WLAN resource allocation is proposed. CDA is a combination of cloud computing system with parallel genetic algorithm. Simulations are conducted to compare CDA with dynamic programming algorithm and simple genetic algorithm under cloud computing environments. The results show that the performance of CDA is better than that of the dynamic programming algorithm and the simple genetic algorithm. The transmission rate is increased maredly, the iteration number and computing time is declined significantly. CDA can meet the real-time requirement of resource allocation in ultra-high-speed WLAN system. The transmission rate of CDA with different nodes is also compared by simulation. The results show that the transmission rate is the biggest with moderate nodes, and the transmission rate will be decreased with too many or too few nodes. Keywords: ultra-high-speed WLAN, cloud decision algorithm, parallel genetic algorithms, resource allocation. Introduction With the rapid development of wireless local area networs(wlan) technology in recent years the research on ultra-high-speed WLAN become more and more popular []. Among these wors, how to reduce the computational complexity of resource allocation so as to meet the requirements of diverse multimedia services and solve the crowded WLAN user problem is a focal problem [~4]. Currently, the highest data rate provided by IEEE80.a and IEEE 80.g is about 30Mbit/s [5],and the spectrum utilization efficiency in 80.a/g can only achieve.7bit/s/hz [6]. Taing into account that the spectrum utilization efficiency in ultra-high-speed WLAN is greater than 3bit/s/Hz [7~9], transmission rate is higher than Gbit/s, traditional WLAN resource allocation algorithms as random allocation algorithm [0], greedy algorithm [], dynamic programming algorithm [] and injection algorithm [3] can no longer meet the real-time requirement of resource allocation in ultra-high-speed WLAN. So new real-time algorithms must be designed so as to solve the resource allocation problem. In this paper a cloud decision algorithm(cda), which is based on cloud computing and parallel genetic algorithm, is proposed. CDA focuses on the spectrum allocation problem of ultra-high-speed WLAN with transmission rate higher than Gbit/s and the spectrum utilization efficiency greater than 3bit/s/Hz. The performance of CDA with dynamic programming algorithm and simple genetic algorithm is compared by simulation. The results show that the performance of CDA is better than that of the dynamic programming 7

46 algorithm and simple genetic algorithm, the iteration number and computing time is declined significantly. CDA can meet the real-time spectrum allocation demand.. Ultra-High-Speed WLAN Resource Allocation Model. The Cloud Decision System Model of Ultra-High-Speed WLAN The ultra-high-speed WLAN mainly composed of three parts which are client station, access point (AP), and distributed system. The model of ultra-high-speed WLAN is shown in Fig.. Client station is wireless networ service target, which includes computers accessed to wireless networs, smart phones and other terminals. Access point is similar to the wireless base station, which is the transfer node of wired networs and wireless networs. A basic service set consist of an access point and client stations, while the distributed system is a networ component which is connected with a number of basic service sets, and usually is wired networs. Fig WLAN model Fig Master node and slave nodes in cloud computing system Ultra-high-speed WLAN has high spectral efficiency, but the complexity of spectrum allocation algorithm increases exponentially after using the high-order modulation. Thus, the traditional stand-alone computing algorithm is unable to meet the real-time requirements. So the cloud decision algorithm is developed in the distributed system of ultra-high-speed WLAN so as to use the existed idle hosts to solve the resource allocation problem.. The Establishment of Cloud Computing System As shown in Fig., one master node and several slave nodes are selected in the distributed system so as to construct a cloud computing system for resource allocation. The oval represents the master node,the rectangular represents the slave nodes and the circular represents the individuals in a node. The individual is the resource allocation scheme in the networs. The master node establishes the resource allocation model according to the resource information and distributes the tass of resource allocation to the slave nodes. The slave nodes compute the assignments simultaneously and eep on communication with the master node. After iterative calculation the master node processes feedbac information come from slave nodes and eventually selects an optimal allocation. 3. Cloud decision algorithm The parallel genetic algorithm is an improved edition of multi-population genetic algorithm. The traditional multi-population genetic algorithm runs on one host, which is unable to tae the advantages of parallel computing. The parallel genetic algorithm requires a fixed number of hosts. The number of hosts cannot be changed during calculation and the performance of each host must be basically same so as to get synchronization. These 8

47 restrictions of the above two genetic algorithms mae them cannot adapt to ultra-high-speed WLAN distributed system, because the number of host is vary and the performance of every host is different in ultra-high-speed WLAN distributed system. Considering above those the cloud decision algorithm(cda), which is the combination of parallel genetic algorithm and cloud computing system, is proposed in this paper. CDA taes full advantages of idle hosts in ultra-high-speed WLAN distributed system. Host group is constituted a cloud computing system to solve the ultra-high-speed WLAN spectrum allocation problem which has high computational complexity. CDA is able to adapt to the change of the number and the performances of hosts, and will distribute the assignments according to the performances of hosts. Because there is only one population traditional genetic algorithm has some problems, such as slow convergence, premature convergence, and so on. By population division, communication between nodes, niche selection and parallel computing, CDA can effectively improve global search ability, prevent premature convergence, improve computational efficiency, and shorten computing time. The ey steps of CDA include establishment of master node and slave nodes, encoding, initialization of population, population parallel updating, interaction between nodes, niche selection, crossover and mutation, etc. 3. The Establishment of Master Node and Slave Nodes A host is selected randomly from the distributed system as the master node of the cloud decision system. Other hosts are slave nodes. 3. Encoding For an ultra-high-speed WLAN with K active client stations and N mutually orthogonal sub-carriers in AP, the modulation and resource allocation matrix of the i th transmission antenna to the j th receiving antenna are shown in equation (). m, m, m, N m, N m, m, m, N m, N M ij = mn, () mk, mk, mk, N mk, N mk, mk, mkn, m KN, Where mn, represents the modulation method used by the th client in the n th sub-carrier from the i th transmit antenna to the j th receive antenna. The channel gain matrix of i th transmit antenna to j th receive antenna in AP are shown in equation (). Where an, A a a a a a a a a,,, N, N,,, N, N ij = an, ak, ak, ak, N ak, N a a a a K, K, KN, KN, represents the channel gain of the th client in the n th orthogonal sub-carrier. () 9

48 3.3 The Initialization of the Population In order to ensure initial population is randomly generated, logistic chaotic mapping is used to generate the initial individual in CDA, as in formula (3). y = μ y + ( y) (3) Where y represents chaos variable. When μ = 4 the system is in fully chaotic state and its chaotic space is (0,). After enough iteration times, the search spaces with random initial value have arrived at the whole (0,) space. According to the allowable highest modulation order R of ultra-high-speed WLAN, CDA will map the chaotic variables to the initial modulation matrix, as in formula (4). mi, j= [( R+ ) y] (4) Where [ ] represents taing the rounded number downward. The randomness of chaotic systems ensures that the initial individuals are randomly distributed in the whole solution space. 3.4 The initialization of the population In traditional genetic algorithms high fitness individuals in populations will tae crossover and mutation to produce next generations and update the populations. However, because of only one search space, early high fitness individual tends to fill the entire space rapidly. The algorithm tends to premature convergence and converges to the local sub-optimal solution. So the algorithm cannot obtain global optimal solution. In CDA, according to the number of host in the cloud decision system there are several populations which evolve synchronously. Each population evolves independently so as to avoid the premature convergence Interaction Between Nodes In the cloud decision system, different populations in slave nodes regularly inform the optimal allocation solution they found to the master node, exchange the high fitness individuals with other slave nodes through the master node, and use the high fitness individuals from other nodes to replace their own low fitness individuals so as to finish interaction and update between different nodes Niche Selection In traditional genetic algorithm individuals in a population usually have high similarity, which leads to the phenomenon of evolution stagnation. CDA dynamically adjusts the individual fitness according to Hamming distance between individuals in the same node. Hamming distance calculation is shown in equation (5), where P represents the number of individuals in a population, Q represents the number of elements in the modulation matrix. When individuals become similar each other, that is Hamming distance becomes small, then the selected probability of individuals with low fitness and high similarity will be decreased in similar individuals, so as to prevent these individuals from producing the next generation, and ensure the diversity of population. Z Z ( z z ) i=,,, P Q i j = i j = j = i+, i+,, P (5) 0

49 3.7. Crossover and mutation of modulation matrix in population We exchange the columns of modulation matrix to achieve crossover, and use roulette strategy to select the exchange columns randomly, as shown in Fig.3. Fig 3 Crossover in population Two new modulation matrixes are obtained after crossing over the two modulation matrixes M and M. Similarly, we exchange the rows of modulation matrix to achieve mutation, as shown in Fig.4. mi, mi, m i, N mj, mj, m j, N mj, mj, mj, N mi, mi, mi, N Fig 4 Mutation in population Mutation brings new genes and prevents evolution stagnation. 4. Resource Allocation of Ultra-High-Speed WLAN Based on Cloud Decision Algorithm 4.. Mathematical Model MIMO-OFDMA technology is used in ultra-high-speed WLAN. Because sub-carriers have narrow bandwidth and similar frequency their gain for same user is almost same and can be seen as flat. The allocation and modulation scheme of every sub-carrier is adjusted dynamically according to the channel gain of different user station with every sub-carrier by CDA. The aim of CDA is to mae the total transmission rate of user stations maximization with the condition of meeting minimum requirement of every user station. We investigate ultra-high-speed WLAN with N sub-carriers, K users, I transmit antennas and J receive antennas. The total transmission rate, that is the objective function is given by formula (6). I J N K max G B m = (6) i= j= n= = Where G is the total transmission rate, B is the bandwidth of sub-carrier and m n, is the modulation order of the th n sub-carrier to the th user station. th Let P( C ) be the upper limit of the total transmit power of AP, and a n, be the channel gain of the th user station on the n sub-carrier, then the total power of the system should be meet the constraint shown in formulated (7). n,

50 f( P, c ) I J N K e, n D P( C) (7) i= j= n= = an, Where f ( Pe, c, n) is the required transmit power of the th user station with transmission rate c n, and BER (bit error rate) P e. The objective of CDA is to enhance the transmission rate of ultra-high-speed WLAN with limited transmit power. 4.. Algorithm Steps The 4basic steps of resource allocation for ultra-high-speed WLAN based on CDA are as follows: ) Select master node and slave nodes in distributed system to build cloud computing system. ) Generate initial population with Chaotic maps in each node in parallel. 3) Calculate the individuals fitness in population on each node. 4) Select individuals with high fitness to accomplish crossover and mutation operation, and then use them to renew the population. 5) Compute Hamming distance between individuals in population and mae Niche selection according to the Hamming distance. 6) Exchange information among nodes through main node and update the population with higher fitness individuals from other nodes. 7) Chec whether the transmission rate of the user station demanding has been met. If the answer is yes then stop iteration and output the result, otherwise, bac to (3) and repeat the process from (3) to (7). 5. Simulation Results and Analysis In simulation, assume that the total bandwidth of ultra-high-speed WLAN is 40MHz, the number of sub-carriers is 4096 and the bandwidth of each sub-carrier is 0Hz, MIMO system has 4 transmit antennas and 4 receiveantennas. In CDA, the number of individuals in each population is 00, crossover probability is 0.7, variation probability is 0.06 and self-adaptation modulation order is 0-8 bit/s/hz. Fig.5 shows the transmission rate of user station by using CDA with one master node and eight slave nodes, dynamic programming algorithm and simple genetic algorithm, respectively, under the conditions of the SNR of 3 transmitter is 9dB and the BER is P e = 0. It can be seen that the transmission rate of CDA is higher than those of dynamic programming algorithm and simple genetic algorithm. Fig 5 Transmission rate versus iteration Fig.6 shows the minimum iteration number to reach the same transmission rate for eight nodes CDA, dynamic programming algorithm and simple genetic algorithm under the circumstance of the SNR of transmitter

51 3 is 9dB and the BER is = 0. It can be seen that iteration number of CDA is smaller than those of dynamic P e programming algorithm and simple genetic algorithm. So CDA has better real time ability. Fig 6 Minimum iteration number versus transmission rate Fig.7 shows the transmission rate of CDA with different slave nodes when the SNR of transmitter is 9dB and 3 the BER is P e = 0. From the figure we can see that the transmission rate of 8-node CDA is higher than those of -node CDA and 4-node CDA because 8-node CDA has high parallel density. However, the transmission rate of 64-nodes CDA is not better than that of 8-node CDA. The performance of CDA is affected by great communication cost between nodes because of too many nodes. So the number of slave nodes must be suitable. Fig 7 Transmission rate versus iteration number 6. Conclusions With the development of ultra-high-speed WLAN, the use of high-order modulation and multi-antenna technology, and the widen of system bandwidth, the traditional algorithm can not solve the resource allocation with high complexity. The CDA developed in this paper maes the computing time and the transmission rate improvement compared with the traditional dynamic algorithm and simple genetic algorithm by using the idle 3

52 resources in distribute systems, and the real-time requirement of resource allocation can be met. Meanwhile, the number of slave nodes must be moderate in order to get the highest transmission rate. Acnowledgements The authors wish to acnowledge the funding support from the research fund for joint China-Canada research and development projects of the Ministry of Science and Technology, China(grant No. 00DFA30). References. Bejerano, Y., Seung-Jae, H. and Li, L., Fairness and Load Balancing in Wireless LANs Using Association Control. IEEE/ACM Trans Networing, 007, 5(3): Salient, O., Giupponi, L. and Nasreddine, J., Spectrum and radio resource management. IEEE Vehicular Technology Magazine, 008, 3(4): Huang, W.L., Ben, L. and Zhang, Y.J., Joint Channel State Based Random Access and Adaptive Modulation in Wireless LANs with Multi-Pacet Reception. IEEE Trans Wireless Communications, 008, 7(): Li, J.D. and Roberto, B., Supporting service differentiation with enhancements of the IEEE 80. MAC protocol: Models and analysis. Sci China Ser F-Inf Sci, 007, 50 (5): Jae-Young, P., Yoon, K. and Kyung, H.J., Wireless measurement based resource allocation for QoS provisioning over IEEE 80. wireless LAN. IEEE Trans Consumer Electronics, 003, 49(3): Soung, C.L. and Zhang, Y.J., Proportional Fairness in Multi-Channel Multi-Rate Wireless Networs-Part I: The Case of Deterministic Channels with Application to AP Association Problem in Large-Scale WLAN. IEEE Trans Wireless Communications, 008, 7(9): Pollin, S., Mangharam, R. and Bougard, B., MEERA: cross-layer methodology for energy efficient resource allocation in wireless networs. IEEE Trans Wireless Communications, 007, 6(): Ramos, N., Panigrahi, D. and Dey, S., Quality of service provisioning in 80.e networs: challenges, approaches, and future directions. IEEE Networ, 005, 9(4): Liang, H.L., Fu, L.L. and Huey-Ru, C., Complete RF-System Analysis of Direct Conversion Receiver (DCR) for 80.a WLAN OFDM System. IEEE Trans Vehicular Technology, 007, 56(4): Matsumoto, Y., Shimizu, T. and Muraami, T., Impact of Frequency-Modulated Harmonic Noises From PCs on OFDM-Based WLAN Systems. IEEE Trans Electromagnetic Compatibility, 007, 49(): Kwa, D., Kwon, S. and Kim, C., Eulerian co-ordinated channel access for direct lin in IEEE 80.e WLANs. Electronics Letters, 00, 46(3): Daji, Q., Sunghyun, C. and Shin, K.G., Goodput analysis and lin adaptation for IEEE 80.a wireless LANs. IEEE Transactions on Mobile Computing, 00, (4): Jong-O, Kim., Ueda, T. and Obana, S., MAC-level measurement based traffic distribution over IEEE 80. multi-radio networs. IEEE Transactions on Consumer Electronics, 008, 54(3):

53 A DESIGN OF VEHICULAR SOLAR POWER SYSTEM SONG CHANG-YUAN, ZHENG WEI Henan Institute of Science and Technology Henan Xinxiang, , China Abstract: Based on the analysis of solar application, a vehicular solar power system was designed to field worer. The power of electrical and life equipments could be supplied in the field by the system, at the same time, the power could be supplied to car. Moreover, the adventure of power shortage could be avoided. The maret prospect of the system is favourable as its low cost and strong applicability. This applies a fresh solution of solar application. Keywords: Solar energy; Field Application; Vehicular Introduction As the rapid development of science and technology, improving people's living standard, outdoor sports become l a popular trend. In addition, geology, archaeological and art industries worers are need field assignments inevitably. However, people used to dependence of technology, the problem of filed power could not be ignored. The system is designed for that. Solar energy as a clean, efficient and never failure new energy, it is recognized as an important content of strategy of sustainable development by governments. But, in the vigorously support and the development of solar energy, the high cost leads that it is not popular. There are two solutions for the problem : On one hand, reduce the cost of products, because of the great amount of production of solar cells made in China, the technology of China are in the leading position, solar battery which is production domestically have greater cost advantages,on the other hand, let consumers accept the cost. Outdoor sports are high-end consumption, but also the high cost of fieldwor, the production of solar energy is easier to be accepted by the users. In addition, vehicular solar power system has great advantages: () Obtainment of solar is not limited by location; () The lifespan of solar battery is similar as vehicle; (3) compared to the wind, maintenance of solar battery is simple, (4) solar is an energy which has no pollution, this avoid environmental damage of outdoor activities []. Hardware design. Diagram of System design The design aims to supply power for electronic equipments and car battery under the situation of utilizing solar energy,to meet the needs of survival. Therefore, the system can be divided into solar cells, batteries, charging controller of solar battery, and inverter. Design diagram is shown in figure. 5

54 Solar cells Status and Alarm Controller of solar battery DC output Battary Inverter 0V AC output Fig Diagram of system design. In addition, considering the electricity at night and weather conditions, the power supply system is divided into four states: ()State of abundance, this state is used in the sunny day with strong sunlight, then full power of solar battery can supply electric appliances(such as small electromagnetism) ;()Basic state, in overcast conditions at night, solar battery power is wea, at the same time, should be proper charging battery needs to meet the basic wor as electricity requirements (e.g., GPS devices, noteboo) ;(3)Low power status, from the basic condition, then bacup battery has finished, but there is no consumption of the car battery ;(4)State of emergency, which is aiming for special circumstances at night. Car battery would be utilized to ensure power enough to the car.. Calculation of Battery capacity Battery is mainly used in basic condition, ensure basic power supply for equipments. Consider the cost, quality and woring applications, there are two common lead-acid batteries, one is belonged to the car, the other one is a bac-up battery, and two batteries are controlled individually. On the one hand, this could reduce the weight of system to save oil consumption, on the other hand, be lowering the cost of system. The bacup battery is chosen as V to match the car battery for simplifying the design of charging controller. According to the field wor, the general electric equipments need for lighting, satellite positioning and general entertainment. The pea power does not exceed 80w, and application time is approximately 4 hours after 0pm. Considering the conditions of battery capacity loss, temperature and weather. The battery capacity calculation method for BC is: BC = A QL NL TO CC(Ah). A is safety coefficients which is from. to.4; Q L means average electric consumption of load which is calculated as number of operating current multiplied the number of woring time, and is 7; N L is the number of rainy day, and NL equals ; T O, coefficient of temperature correction, equals. when temperature is above -0. C C is the depth of discharge, its value is 0.75 when lead-acid is used. [] The result of BC is about 95Ah. According to the capacity of car battery is above 40Ah, then the capacity of bacup battery is 60Ah 90Ah, which is chosen as the same capacity as the car battery for output control..3 The algorithm of the power of solar cell array Aspects of Choosing of solar battery considered as: pea power, pea voltage, pea current open circuit voltage, short-circuits current, open and solar panels of length, width, thicness and weight. Because of more than 80% of system cost from solar battery, power supply and cost are the main consideration. According to the 4 status of system introduced, State of abundance is the ideal status of solar cell-batteries which simples calculation. The pea power could be calculated as the load in abundant state, and is highly to 500W. Pea power of DC is 600W as the efficiency of inverter considered. Output is supplied by two batteries and solar cell-batteries, and in a short time, The P(pea power of solar battery) is calculated as: P = ( P max P0(W). ) CZ P max means pea power of DC which is consumed; The P 0 is the rational power of two batteries concatenated, 6

55 which value is 480W as that wored in hour. Comprehensive correction coefficient of solar battery is C Z which value is 0.8, and 0.7 for installation. 00w of pea output power of solar battery is enough, moreover 00w is the consumption requirement of solar battery in a day []..4 Solar battery controller design Solar battery controller mainly includes three functions: the battery charging and maintenance, woring status judging and alarm, output control [3]. Based on single-chip, through the relay output control realization. )Battery charging and maintenance The maintenance of batteries are mainly three aspects: firstly, the temperature protection in charging, and temperature sensor DS8B0 installed on car battery and bacup battery, mae bacup battery woring temperature does not exceed 40 degrees, car battery woring temperature under 50 degrees, once beyond temperature limitation turn system off in time. Secondly, after battery charged by solar battery, it is repaired by the current produce high-frequency pulse on batteries positive for hours. This could be responsible by maintenance program [4]. ) Judgement of status and Alarm The sates of battery are judged by these: abundant state, output voltage of solar battery is higher than 60% of pea voltage, and car battery and bacup battery are in charged state(this is judged by the signal of charger); basic state, output voltage of solar battery is about 0% 60% of pea voltage, the voltage of battery is higher than V; low power status, voltage of bacup battery is lower than 0.5V; state of emergency, emergency button was pressed and voltage of bacup battery is lower than 0.5V. There would be alarm in low power and emergency sates. 4 states are shown on LED, and alarm is responsible by buzzer [5]. 3) Programming of single-chip AT89S5 is applicator and programs are in C language as application and expand capacity considered, diagram of program [6] is shown in figure. Fig Diagram of program of single-chip Avoiding that engine cannot be started for low power of car battery, there are protections in emergency output program and AC output program which are achieved by capacity testing of battery, and it should be noticed that threshold voltage is set high enough and correction coefficient of temperature is introduced [7]. 7

56 .5 Output design The power voltages of most digital equipments are V and 5V, specially the voltage of some hand digital equipments is 9V. The problem of 3 different voltage output would be solved by direct output part. Besides, for supply of single-phase 0V AC, sine wave converter should be installed [8]. It should be noticed that output of solar charging controller is higher than the output voltage of two batteries concatenated. 3 Conclusions Based on the above, test system was created for testing. System adopts monocrystalline silicon solar panels which maximum output is 00w. There are two Fengfan lead-acid batteries (V60Ah), one is simulated as car battery. Full power system could supply that a noteboo and a LED light wor 6 hours, in sunny day, it supply enough power for a 500W induction cooer. At the same time, System could meet the need of field life if the car battery is charged. System weight and cost are: solar battery 7g weight, price 700yuan; controller with aluminium alloy, 4g, 450yuan respectively. The weight of system is about 3g which could be ignored compared with the weight of a car. Because its cost is less than 3000yuan compared with thousands yuan of general field equipments, the system has huge profit space. References. Li Shen-sheng. Characters of Solar. Solar Energy, 003, (5):0-.. Liu Zhen-quan, Power System Design of Solar on Highway. China ITS Journal, 009, (): Qian Jiang, Ling Chao-dong. Intelligent Management System of Lead-acid Battery. Microcontrollers & Embedded Systems, 009,(): Song Lei-ming, Mou Xiao-hui. The main factor if influencing Lead-acid battery service life and needing attention matters in use. The World of Power Supply, 009, (): Zhang Xiao-guang. V Solar Power Controller. Practical Electronics, 006, (9): Xue Jian-guo. Design that the Solar Cell Based on One-chip Computer Follows the System Automatically. Journal of Changchun Teachers College (Natural Science), 005, 4(3): Liu Qing-sheng. Influence of Temperature on the Accumulator. Hubei Electric Power,009, (8): Yu Zhi-gen. Design of the Inversion Device for the Mini, types Solar Power Supply. Power Electronics, 009, (7):

57 THE DESIGN OF CROSS-COUPLING FILTER WITH OPEN-CIRCUIT TERMINALS WANG HAN-JIANG, WU JIAO, YANG AN-SHENG, CHEN JUN, YANG WEI-MING School of physics and electronic technology, Hubei University, Wuhan, 43006, China Abstract:This paper gives the particular description of a theoretical analysis and practical design for rectangular-rod inter-digital band-pass filter. First, the self - capacitance and mutual capacitance of the inter-digital band-pass filter is obtained in according with the design theory of the inter-digital band-pass filter. Based on computer aided design, the parameters of filter are given. Filter with pass-band centered at.5ghz and percentage bandwidth is 70%, has been designed and simulated by HFSS-software, which greatly improves the efficiency and accuracy of the design. The simulation result shows good agreement with theoretical result, which proves the method is valid. Keywords: inter-digital filters; band-pass; self - capacitance; mutual capacitance; HFSS-software. Introduction Microwave filter have widely used In the communications of microwave, millimeter wave and satellite, radar, navigation, guidance, ECM, testing instruments and other systems. It is of the universal concern that how to accurately and rapidly design filter. The Inter-digital Filter have the following advantages: ) with compact and sturdy structure; ) with lower requirement of tolerances and easy to fabricate because of bigger interval of each resonator; 3) the resonant pole have λ 0 /4 length so that the center frequency of the second pass-band in 3ω 0, and have no spurious resonances; 4) with the larger stop-band attenuation and cutoff frequency for the higher-order attenuation pole in even several number times of ω=0 and ω=ω 0 ; 5) It can be realized in printed circuit form and also can be supported with a thicener rod without medium []. In the design project, in order to promote the accuracy and precision, microwave CAD tool is needed to aid the design. So far, there is already a lot of microwave CAD software. However, the effect of Ansoft Corporation is the best. It is very easy to obtain lots of physical models and mae an electromagnet to the model of emulation by this software. This paper calculates the original size of the inter-digital filter of rectangle rod. Then we optimize and simulate it by HFSS and design the inter-digital filter. Finally, the simulated result indicated that the feasibility and practicality of this method [].. The Theory of Inter-digital Filter Generally speaing, the inter-digital filter has three structures and types. They are terminal short-circuit, open circuit, loading capacitor. The figure is structure of inter-digital filter of terminal short-circuit. Fig. Setch-map of inter-digital filter 9

58 This structure is to put two overlapping rectangular pole parallel coupling array in two parallel ground plates, and each of the rectangular pole end with a short circuit at the end, the other opening. It is about λ0/4 length and carries the TEM mode. From the first pole to the pole N, including the two terminal poles, each serves as the resonator. We only need N poles to realize a low pass prototype consists of N reactive elements. This structure is very fit for the broad-band filter, when designing the narrow-band, we can find that there has extremely high resistance value between two poles and this method can t be realized. Because [3] of the effect of distributed capacitor, the actual length of the resonator is shorter than λ0/4 in inter-digital filter. In this type of the filter, the coupling of the resonator led by the edge field between the resonant lines. And coupling of the resonator is mainly the magnetic coupling effect [4]. After extracting the Normalized line capacitor by the design formula of the filter, we can calculate the value of self-capacitance and mutual capacitance after we have assigned b (the width of resonant cavity) and t (the width of resonator). When concluding the design formula of the coupling round bar, we neglect the effect of the edge capacitor, so it can use orthogonal mold of TEM which transmit along the structure to describe, that is odd-mode and even-mode. The two modulus of TEM have different characteristic impedance. It is related to the static-capacity of rectangular pole relative to GND, but static capacity have something with the self-capacitance Cg and mutual capacitance Cm. Therefore, the realization of the design of filter needs rectangular pole structure. The first step is to calculate the value of Normalized capacitance Cm /ε, +/ε. And then the structure of filter is divided into many small segments, and each of segments is made up of Normalized self-capacitance and Normalized mutual capacitance [5]. 3. Design instance Then the following demonstrate it by the filter of eight level in the L wave band. The mid-frequency is.50ghz and relative bandwidth is W=0.70,LAr=0.0dB. According to technique data, we choose low-pass archetyp filter function of chebyscheve to calculate the degree of filter n=8 and get component parameter of archetype circuit. Later, we can get the initial value of Normalized self-capacitance and Normalized mutual capacitance by adopting the design formula of rectangular pole inter-digital filter. Table Initial parameters of the filter of Based on the formula and the chart from the references [6~7], we can obtain the size of the rectangular pole inter-digital band-pass filter. This step is very important. The reason is that the option of initial value is in relation to the speed of the simulation in HFSS. The figure is the simulation mode of filter. Table Initial parameters of the filter 30

59 Fig. the simulation model of the inter-digital filter We have carried on the electromagnetism simulation based on the initial datum with HFSS. The simulation result as shown in Fig.3 and Fig.4, we can see that the pass-band center frequency is.5ghz and percentage bandwidth is 70%, the VSWR is small. It can meet the needs of the design target. Fig.3 The attenuation of the inter-digital filter Fig.4 The VSWR of the inter-digital filter 3

60 To comparison the simulated attenuations and the calculated ones of the weaen characteristic of filter, following the Table, they tally very well. Table is the comparison of the simulated attenuations and the calculated ones. Table Comparison of the simulated attenuations and the calculated ones 4. Conclusion This paper uses the HFSS software to unify the design example of the cavity inter-digital filter of L wave band. The simulation result has demonstrated the feasibility of this plan. The innovation spot of this paper lies in filter's resonant unit is /4 wave lengths, so that it can reduce the filter's size. The resonant unit end is short-circuits and the other end opening. The two ends are used overlapping layout among each resonant unit. Simulated results indicate that the wideband and the small insertion loss are obtained [8]. The method combined the traditional theory with the advanced computer technology. In the meantime, It can save the development cycle and the production cost greatly. So it is of great utility value. References. Gan Ben-bo, Wu Wan-chun. Structure and Design of Modern Microwave Filters [M]. Science Press, 973. Xiao J K, Chu Q X, Zhang S. Novel micro-strip triangular resonator band-pass filter with transmission zeros and wide-bands using fractal-shaped defection [J]. Progress in Electro-magnetics Research, 007 (77) : SHEN Kai, WANG Guang-ming, GU Guo-dong. Investigation on Double Inductive Post Filter Based on Substrate Integrated Waveguide ( SIW). Journal of microwaves, (3): 43~46 4. Xue Ling, Sun Man, Chen Da-ping, Meng Dan, TANG Ting-ting. Design of wideband inter-digital band-pass filter with ADS. Television technology, 009, 33():0~, (in Chinese) 5. Zhang Xiao-chuan, Xu Jun, Yu Zhi-yuan, BI Dan-hong, DONG Yu-liang. Wideband Substrate Integrated Waveguide Band-pass Filter. Microelectronics, (3): 439~44 6. Han Chi-zong, Zhu Jing. Design of Parallel Coupled Micro-strip Band-pass Filter With ADS[J]. Application of Electronic Design, 007, (9) : 94~95. ( in Chinese). 7. Deng Jian- ping, Hu Ze-bin, Zhao Hui-chang. ADS- aided Design of Parallel Coupled Micro-strip Band-pass Filter [J]. Journal of Projectiles Rocets Missiles and Guidance, 006, 6 () : 830~83. ( in Chinese) 8. Wei Feng, Huang Qiu-lin, Shi Xiao-wei, Chen Li, Gao Chang-jia. Design and Realization of a New UWB Band- Pass Filter. Journal of microwaves, 00, 6(3): 48~5 3

61 DESIGN AND IMPLEMENTATION OF A SIMULATOR FOR FREQUENCY DOMAIN CIRCUIT AND SENSITIVITY ANALYSIS KANG LI, YANG LEI, ZHANG ZHI-JIAN Daxue Rd. Songshan Lae Dongguan Guangdong, P.R.C angl@dgut.edu.cn, yangl@dgut.edu.cn, zzj@dgut.edu.cn Abstract:One of the most significant teaching challenge is the engineering students have not substantial math experience. For this situation in course circuit analysis, a Matlab based simulation tool is designed and implemented to address the stuents to computationed thining. A set of formulas is presented in this paper used for linear circuit frequency domain analysis, such as admittance matrix, output sensitivity with respect to differenct type of elements. Two typic ciructs are provided here to explain its application. The outputs of these two circuits from this simulator and PSpice are showed. The result comparison between the two simulaton tool demonstrates for the validation of this simulator. Key words: frequency analysis; Matlab tool; simulation. Introduction Computer simulation has gained more and more application over the past decades [~9]. In engineering, much of the experiment wor has been replaced by computer and computer-aided design. In this project s linear circuit simulator is written for frequency domain circuit and sensitivity analysis. Two subroutines are written in Matlab, one describing the frequency domain circuit analysis using modified nodal formulation and the other carrying out the frequency domain sensitivity analysis. The data is imported into the simulator through a netlist(data file). Validation is done by comparing the simulation results with the tool PSpice.. Formulation Description and Implementation. Frequency Domain Circuit Analysis Frequency domain circuit analysis is carried out using modified nodal formulation which is in the form as below [0]: Where Y n is the nodal admittance matrix for the elements which have an admittance representation; A is the incidence matrix for the elements wich do not have and an admittance representation; Y,Z,I and W represent the admittance matrix, impedance matrix, current vector and independent voltage source vector, repectively; V n is nodal voltages; J n contains current sources. Eq. can be written as Tx = W () () 33

62 Matrix T can be divided into two parts: a frequency-independent elements matrix GG and a frequency-dependent elements matrix CC, therefore, we have: In the frequency range of interest, the voltage and current response(including amplitude and phase)can be obtained by solving () and (3) using triangular decomposition methods. Frequency Domain Sensitivity Analysis The sensitivities are computed by, firstly, solving the equation of the given system which has the same form as (), and then solving the adjoint system defined as Where d is a constant vector, appearing in The equation for the frequency domain sensitivity analysis is If the parameter is an independent source, we have (3) (4) (5) (6) (7) Therefore, it was obtained that If the parameter with respect to which the sensitivity evaluated is a component value, (8) (9) (0) () Where V is one for reactive element and is zero otherwise; h is an element value; e i, e j, e and e l are elementary unit vectors. For two-terminal elements, I equals, j equals l. For four-terminal elements, i.e., controlled sources: As for CCCS: As for CCVS () (3) As for VCVS (4) 34

63 As for VCCS The normalized sensitivity is The semi-normalized sensitivity is (5) (6) (7) Based on the formulas described above, a main and two other subroutines are implemented in Matlab to form admittance matrix, doing triangular decomposition and compute the frequency domain sensitivity respectively. 3. Simulation Scenarios and Comparison with PSpice As shown in Figure. and Figure, two circuits are used to validate the simulator. For Figure., three outputs are plotted and shown in Figures. The amplitude response(figure 3), the sensitivity of V out with respect to L (Figure 5), The corresponding plots obtained from PSpice are shown in Figure 4, Figure 6, respectively, for comparison []. Fig 4 -node circuit Fig 9-node circuit After Figure. Was simulated by the simulator, four outputs were plotted. Phase response( deg.) is shown in Figure 7, the voltage transfer function sensitivity with respect to capacitor C 3 is in Figure 9. The corresponding plots obtained from PSpice are shown in Figure 8 and Figure 0 respectively. Fig 3 Amplitude response(db) in 4-node circuit by the simulator Fig 4 Amplitude response(sb) in 4-node circuit by Pspice 35

64 Fig5 Sensitivit of V out wrt L in 4-node circuit by the simulator Fig 6 Sensitivit of V out wrt L in 4-node circuit by PSpice Fig 7 Phase response(deg) in 9-node circuit by the simulator Fig 8 Phase response(deg) in 9-node circuit by PSpice Fig 9 Sensitivit of V out wrt C 3 in 9-node circuit by the simulator Fig 0 Sensitivit of V out wrt C 3 in 9-node circuit by PSpice 36

65 4. Results The simulation results obtained from the simulator described in this paper agree with the results obtained from PSpice, which indicates that the simulator wors correctly. References. Najm. Farid N. Circuit simulation, Wiley_IEEE Press, 00.. Lin Dong, Matlab Usage,Fundmentals,Development and Enginnering Application, Publishing House of Electronics Industry,ISBN: Michal Bialo, R. Crampagne, D. Andreu, Basic methods for microcomputer-aided analysis of electronic circuits, Prentice Hall, D. Brian Larins, William Harvey, Introductory computational science using MATLAB and image, processing, International Conference on Computational Science, ICCS J. Kepner, Parallel MATLAB for Multicore and Multinode Computers, Society for Industrial and Applied Mathematics (SIAM), Andrei Vladimerescu, The SPICE Boo, John Wiley & Sons, New Yor, 994, ISBN 7. TopSPICE/Win3, Mixed-Mode Circuit Simulation Tool, released in 007, http: //penzar. com/ topspice/ tw7brochure. pdf 8. A J. Scholten,etc., Noise modeling for RF CMOS circuit simulation,electron Devices, IEEE Transactions on Electron Devices,003,50(3): M. B. Steer, etc.,modeling of spatially distributed microwave and millimeter-wave systems," IEEE Trans. On Microwave Theory Techniques, 999, 60(3): J. Vlach, Basic networ theory: with computer applications. New Yor, N.Y.:Van Nostrand Reinhold, 99.. J. Vlach, Kishore Singhal. Computer methods for circuit ananlysis and design. New Yor: Van Norstrand Reinhold,

66 STUDY ON OUTPUT WAVEFORM CONTROL STRATEGY OF FUEL CELL POWER INVERTER SYSTEM GE WEI-QING, HUANG SHI-SHENG, LIU YUN-CHENG ) Department of Computer & Information Science City College of Dongguan University of Technology Dongguan, P.R.China gewq@dgut.edu.cn ) School of Mechanical & Automotive Engineering South China University of Science and Technology Guangzhou, P.R.China sshuang@suct.edu.cn Abstract Fuel cell s DC output must be changed into AC through the power inverter system. Harmonics will be generated in inverter system. The output voltage harmonics will be more serious while its load is nonlinear. Firstly the output current harmonics are analyzed and detected with vector control theory; secondly the mathematical model on three-phase SPWM inverter system is established according the Proportional control mode of current inner loop and the Proportional & Integer control mode of voltage outer loop. The controllers parameters are determined by the poles configuration method. Experiments show that the output harmonics are inhibited effectively using this control strategy in the three-phase SPWM inverter while nonlinear load is three-phase rectifier. The output voltage harmonics are better restrained, and THD can also be controlled below 5%. Key words: voltage harmonics; SPWM; Proportional control mode; nonlinear load. Introduction Fuel cell is a ind of green energy, which can be instead of thermal and/or other traditional power []. However, the output voltage range of the actual fuel cell is wide and output behaviour is soft. As fuel cell is DC power, but in many cases AC power is used. So DC is needed to inverter into AC []. Inverter system will generate harmonics that can cause electrical equipment to overheat, even to burn. In particular, the non-linear load will lead to so serious current distortion that it increases the output voltage harmonics. Researches of inverter control methods have done at international so much that there are many important achievements [3~7]. However, the nonlinear loads are not studied in these control algorithms and the harmonic distortion is seldom analyzed and detected. The following is the studies of detecting harmonic with vector control technology, of controlling harmonics with the double closed loop of output voltage and current. The experiments prove that DSP digital controller can perfectly control three phase SPWM inverter.. A Power Inverter System Fig. shows the schematic of inverter connected with the fuel cell. Fig. shows the control bloc diagram of the power inverter system. Fig The principle diagram of inverter connected directly to fuel cell 38

67 Fig Bloc diagram of inverter conditioning system The principle is: DC power of fuel cell is inverted into three-phase AC power through three-phase IGBT inverter module; then AC power is transformed and sent to the load. The ey to solve problem is how to detect the load s current and voltage, how to control the IGBT inverter module using DSP, how to achieve an allowable range of the load s current and voltage harmonics, and how to obtain a higher power factor. 3. Current Harmonics Detection According vector control theory [8~9], three-phase variables under static coordinate system can be converted that of the two-phase named αβ. So three-phase variable can be changed into two independent variables that can be equivalent to α phase and β phase inverter. Here focuses the current harmonic detection method shown in Fig. 3. Fig.3 The principle of current harmonics detection with d-q coordinate After abc/αβ transformation (three-phase coordinates changed into two-phase coordinates) and αβ/dq transformation (stationary coordinates changed into the rotating coordinate), the basic frequency and five/seven times harmonics of the three-phase load currents of i a, i b and i c under abc coordinates are equivalent to DC signals and four/six times signals under d-q coordinates. Four/six times harmonics signals can easily be filtered except the DC component through a low-pass digital filter. Meanwhile, in order to detect and control harmonic current synchronously, Phase-Loced Loop (PLL) technology must be used [0]. 4. Double Closed-loop Control System Here focuses the influences that current harmonics produced by three-phase rectifier nonlinear load effect output voltage of three-phase SPWM inverter, so the controlled parameters of the inductance s current as the inner control loop and the load s voltage as outer control loop is chosen. The wor principle is that temporal voltage U 0 of the output filter inductance compared to the given voltage U f ; then the difference signal is adjusted by the voltage controller. This result is considered as a given value I r of the filter capacitor s current. The difference value 39

68 of the capacitor temporal current I compared to the given current value I r is modulated with the triangle wave. The modulation wave generates SPWM switching signals that adjust the on-off time of power switches. Finally the system output voltage can be controlled. In order to achieve this purpose, feed-forward decoupling control strategy is applied, shown in Fig. 4. Fig 4 Bloc diagram of double closed-loop of voltage and current According to references [~], while α= not only the advantages of sampling capacitive current can be taen into account, including the impact of the load s disturbance, but also the current can be restricted by software. At β= decoupling can be achieved. Outer loop voltage controller wors Proportional & Integer (PI) algorithm. The controller s function is to mae the output voltage waveform trac a given value at any time. Outer voltage controller s transfer function is designed as: i G ( s) = p + s () Inner loop Current controller generally wors Proportional (P) algorithm that can increase the inverter s damping factor so that the whole system is stable and robust. Inner loop current controller s transfer function is set as: G ( s) = p () The transfer function of inner loop can be obtained: Gi ( s) = LCs C p + ( r + p ) Cs The transfer function of closed loop system can also be obtained: ( p + i / s) p G( s) = (4) LCs + ( r + ) Cs + ( + / s) The system s parameters are designed that filter inductor of L= 700uH, filter capacitor C= 80uF, the equivalent internal resistance r= 0.6Ω, switching frequency f=6 Hz. Because the system is controlled by DSP chip digital controller, so the transfer functions above necessary discretization according to discrete theory. p p i p (3) Z r / L e ( Z )ζ [ ] = ζ ( ) = s Ls + r rz s( s + r / L) r( Z e rt / L rt / L = ) Z (5) 40

69 T ζ ( ) = Cs C Put the types (5), (6) into equations (3), (4), so: p Gi ( Z) = Z G( Z) = p p [( p + i F( Z) ) Z i Z Z + Z ( Z + ) = Z Where F (Z) for the closed-loop transfer function characteristic equation is: p ] (6) (7) (8) F ( Z ) = Z + [ ( p i 3 = Z + AZ + BZ + C ( p i i p ) Z )] Z + p i p p The controller s parameters are determined with poles configuration method. Here ω r means natural oscillation frequency, ε means damping ratio. Then the closed loop dominant poles of the three-order double-loop control system are desired as s, = εωr ± jωr ε, and non-dominant pole is s = mεωr So the poles in the discrete domain of Z are: 3. (9) Z εωrt + ωrt ε εωrt ωrt ε = e, Z = e, Z 3 = e mεω T r (0) The discretization system characteristic equation can be obtained: D( Z) = ( Z Z Z Z Z Z () 3 )( Z Z)( Z Z3) = Z ( Z + Z + Z3) Z + ( ZZ + ZZ 3 + ZZ3) Here ω r =3768rad/s, ε=0.5, m=5. They are got into equations (0), () and (9), the controllers parameters can be determined as: p = , i = , p = Fuel Cell Inverter System Test of Three-phase Power This project is supported by Dongguan city Science and Technology project (No ). There is established a test platform of three-phase power inverter for fuel cell system. This study focuses on the system output performance in non-linear load conditions. Test conditions: input DC voltage V, output three-phase voltage 0V, 50Hz. Fig 5 shows the output waveform under mixed load conditions of a resistor and a fan. The influence of nonlinear inductive load affect on the system output is get better control from the oscilloscope. The output voltage waveform is phase voltage of.4v, frequency of 50.00Hz, THD of.9%. The output waveform shown in Fig. 6 is that a system is connected nonlinear load as rectifier type. Fig. 6 (a) show the case of a rectifier is connected a resistive load, Fig. 6 (b) show the case of a rectifier is connected mixed loads. Seen from the output waveforms, the output phase voltage is balance and stability, the sine degree is better, 3 4

70 the effective average output voltage is 8V ~ 0V with less variation. The THD of output voltage can be controlled within 5%, and its frequency is stability, so the power supply can meet quality requirements. Fig 5 Output waveforms and harmonic spectrum distribution under Resistor and inductance nolinear load (a)resitive load that connected rectifier (b)mixed load that connected rectifier Fig 6 Output waveforms and harmonic spectrum distribution of closed-loop system with rectifier load 6. Conclusions The output waveform of three-phase SPWM inverter power system determines the fuel cells power s output quality. It is mainly discussed that three-phase sine output waves are controlled by the double closed loop feedbac control strategy of voltage and current to reduce the output harmonics. The output current harmonics are 4

71 analyzed and detected with vector control theory, then the mathematical model on three-phase SPWM inverter system is established according the Proportional control mode of current inner loop and the Proportional & Integer control mode of voltage outer loop. The controller parameters are determined with the poles configuration method. Experiments show that the output harmonics are inhibited effectively used the control strategy with three-phase rectifier nonlinear load in the three-phase SPWM inverter. The output voltage harmonics are better restrained, and THD can also be controlled below 5%. Acnowledgements This project is supported by Dongguan city Science and Technology project (No ). References. Jia Lin, Automation of. Fuel cell application and development, 005, (): Jiang Z, Gao L, Dougal R., Flexible multi-objective control of power converter in active hybrid fuel cell/battery power sources, IEEE Transactions on Power Electronics, 004, (): Kawamura A.,Yooyama T,Comparison of five different approaches for real time digital feedbac control of PWM inverters, Industry Applications Society Annual Meeting, IEEE, 990, (): K.P.Gohale, A.Kawamura, R.G.Hoft, Deadbeat microprocessor control of PWM inverter for sinusoidal output waveform synthesis, IEEE Transactions on industry Applications, 998, (3): Zhuang Changfan, Wang Yaonan, Intelligent sliding mode control and its application, 00, : Chen Hong, Hu Yuwen, Repeat controller design for inverter power, 00, (6): B.R.Lin, Neural and fuzzy applications for converter control, 995, (5): Yamamoto, Hidehio, Wu Jiaju, Liu Guiying, Modern AC Motor Vector Control Theory and Design Practice, Nanchang, Aviation Industry Press, Ye Bin, Power electronic applications, Beijing, Tsinghua University Press, Roland E. Best, PLL design simulation and application, Beijing, Tsinghua University Press, 004. Chen Boshi, Power Speed Control, Beijing, Mechanical Industry Press, 000. Hu Shousong, Automatic Control Theory, 4th ed., Beijing, Science Press, 00 43

72 THE DESIGN OF FIREWORKS LIGHTING OFF SYSTEMS BASED ON USB COMMUNICATION LI FU-QIN, YANG QI-FENG Henan Mechanical and Electrical Engineering School XinXiang Henan, 45300,China Abstract:Based on USB communication, firewors lighting off system is designed using microcontrollers C805F30 as the main control chip. The firewors are let off through operating the software of upper machine, when the driven circuit is triggered by the lighting off control subsystem, according to different lighting model. Keyword:Universal Serial Bus; C805F30; firewors lighting off; firmware. Introduction With the development of economy,there are more inds of large activities, and firewors are usually set off to display festive air. As demands for firewors type,amount,pattern,and so on,is getting higher and higher, the manual lighting off operation is insufficient to meet the demand of the maret. According to the above, a firewors lighting off system is designed based on USB communication,using microcontrollers C805F30 as the main control chips. Many good excellence of this system, such as easy operation, powerful control function and anti-interference will mae it popular on the maret.. Hardware design of the system The hardware of the system is made up of three parts: personal computer with lightting off control software installed,communication control circuit(ccc) using microcontrollers C805F30 as the main chips,and some [~ 3,, 7~8] subsystems with electronic ignitor drive circuit.fig. shows the compositions. Fig Bloc diagram of the system The upper control-software was programmed on PC to establish the control platform (CP). Control command from CP was send to CCC though USB interface. After decoding,ccc delivery the control command to the following separate subsystems, thus triggering the driven circuit of electronic ignitor and setting light to firewors. 44

73 The system eliminates any need for an open flame, and allows the user to stand a safe distance away while he ignites the firewors in various modes...design of USB interface circuit As the lighting off control command from CP is sent though USB,it is very important to choose a reasonable design plan of the USB interface circuit. Integrated with USB transceiver and processor,c805f30 from American company Cygnal,is a system on chip for USB equipment. The 6K Bytes on-chip downloadable Flash ROMs and 304 Bytes RAMs allow the program memory to be reprogrammed In-System through an SPI serial interface or by a conventional nonvolatile memory programmer. And the microcontroller of C805F30 is compatible with MCS-5 Core and instruction set. The design of USB interface includes two main parts:the choice of power supply conditions for interface translation module; the connection of USB pins. Compared with similar USB devices,the merits of C805F30 are as follows:fulfilling USB.0 protocol having the ability to operate at full speed or low speed;3being integrated with a recovered cloc, which mae C805F30 operate without outer cloc;4 possessing high speed enhancement 805 MCU core,and the processing speed can reach as high as 5MIPS.So, C805F30 is a good choice for the design of USB interface circuit. Fig. is hardware circuit diagram for USB interface of CCC module. An outer 5 V power supply is used to improve the stability of the system, for the reason that the current is large when the electronic ignitor acts. Because pull-up resistors is integrated in USB transceiver, C805F30 can be attached directly to USB interface [4~5]. VBUS D - D + GND USB interface +5V REGIN VBUS D - D + GND C805F30 Fig circuit diagram for USB interface.. Design of lightting off subsystem After control command through RS-485 Bus is identified by C805F30, the driven circuit of the electronic ignitor is triggered, resulting in setting light to the firewors. Fig.3 shows the operation principle of the lighting off subsystem. Every unit has its own binary-coded decimal code. Under condition that each of the unit is allocated different code,the allowance number of the system's lighting off subsystem is 3. C805F30 is in a state of waiting for control command passed through RS-485 Bus. The instant that the control command arrives, C805F30 decodes and compares the binary number with its own to decide whether lightting off control command is executed. Ignition device Q +5V Encoder R RXD TXD P RO DI RE DE VCC A B GND +5V 8 R 6 R 7 R 5 A B 6 ignition device drive circuit C805F30 MAX485 Fig3 The electric circuit principle diagram for lighting subsystem 45

74 3. Software design of the system 3.. Programming for USB firmware Programming for the firmware is a major tas for USB device development,with the aim to set up a reliable communication channel between USB device and the host. The program includes foreground main loop and bacground interrupt service routine (ISR). The most important wors of the program are the definition of USB descriptor and communication interrupt handling. USB descriptor is a description language defined by USB protocol to describe a device s function and property. With the USB descriptor, the host identifies, configures, provides the driver for a device, and runs the client driver in upper layer of protocol stac, thereby realizing plug and play functionality. When USB interruption arrives,in the first C805F30 judges the origin by reading the three interrupt control registers(cmint,inint and OUTINT),then executes the relevant processing module according to the origin, and returns after execution. Endpoint 0,default communication point supported by every USB device, is mainly used by host to correct the wrong information about USB device configuration,status,and so on. Interrupt handling module of endpoint 0 contains the input control part and the output control part. Starting with transaction set, that transmission is judged as control input or output by USB standard command from transaction set data pacet. [5~6]. As design environment,silicon Laboratories IDE accesses to the low level hardware of USB by calling API function in upper application.fig.4 is the flow chart for USB communication the power-on reset of C805F30 calling API function in upper application N USB communication Y Initializing USB cloc by calling USB_Cloc_Start() enable USB by calling USB_Int() disable API by calling USB_Int_Enale() writing or reading data bloc to the host by calling Bloc_Read or Bloc_ Write end of USB communication? Y Calling USB_Suspend () to enter USB interruption waiting state N stopping USB interruption by calling USB_Disable() Program ends Fig 4 The flow chart for USB communication 46

75 3.. PC-side software programming As the upper machine for the system,the function of the PC software is to realize data transmission and device control. It mainly consists of USB driver and user application program. USB driver can be easily developed by USBXpress Development Kit from Cygnal/Silicon Laboratories Company,as the pacage can provide application program interface by using dynamic lin library and database function.the user application program was developed by Visual C++. Firstly, the program acquires the number of USB device;then according to the number acquired,enables the related device,and uses the handle as USB device label. Hence, the user application can call the API functions to read or write device and control the data transmission. The USB device drive should be installed before running the host application software When the communication card is connected to the host through USB interface,the software begins to enumerate, and translates data between USB device and the host through endpoint 0, and. In USB protocol,pacets from end point 0 are defined as control data pacets,pacets from endpoint as input data pacets,and those from endpoint as output data pacets Lighting off Control command sent by host,is passed to C805F30 through endpoint,then to the lighting off subsystem,realizing PC control of lighting off firewors. [8]. 4. Conclusion Automatic firewors lighting off system controlled by PC are characterized by good flexibility,stable and reliable operation,for the reason that USB interface is adopt to communicate with PC In addition, the system can be easily modified and updated,according to the user s practical needs. Once the above firewors lighting off systems is on the maret,it will produce enormous economic benefits and social benefit. References. Pan Zhuojin,The principle and application of high-speed Single Chip SOC C805F.Press of Beihang University, Beijing, 00.. Wang Tie liu,data acquisition and memory circuit based on USB interface and C805F30 communication. Shenyang website of Chip Microcomputer, He Limin,selected application technology of Single Chip. Press of Beihang University, Beijing, Liu Zheng,The principle and application of Single Chip C805F. Electronic Engiineering &Product World 009, (): Chen Zhiming,The communication protocols and System design of USB[J] Automation &Instrumentation006, (6): Guo Hong,The technical problem of C805F used. The application of of Single and embedded system 008, (): Liu Cuiling,Distributed control system (DCS) [C]. Press of Beijing University, Beijing, Yang Xinqiang,Data communication and Computer Networs. Press of Electronic Industry, Beijing,

76 DISCUSSIONS ON EMC OF COMPLEX BATTLEFIELD ELECTROMAGNETIC ENVIRONMENT LIN MEI-QING, GAO YU-LIANG Dept. of Information Countermeasure, Air Force Radar Academy, Wuhan China Abstract : Under information asymmetry, as one much important part of battlefield environment, battlefield electromagnetic environment impenetrate into land sea sy and universe battlefield. There are high density and extensive electromagnetic applications in battlefield electromagnetic dimension, it result into a complex and much diversity battlefield electromagnetic environment. As the battlefield electromagnetic environment is developing, EMC of weapon system is becoming more and more important. The paper provided an in-depth analysis of battlefield electromagnetic environment, and discussed on EMC of complex battlefield electromagnetic environment. In the end, the paper gave a new cognition about EMC problem of complex battlefield electromagnetic environment. Key words:electromagnetic environment;emc;electronic countermeasure;simulation. Introduction As human being deeps into electromagnetic theories, electromagnetic applications arise from inexistent, and head for battlefield from daily life. Electromagnetic application field is expanding unremittingly, and electromagnetic counter-applications appeared subsequently, then, complex battlefield electromagnetic environment came into being. Under information war, lots of Electronic Equipments and information weapon systems are used in battlefield. Then, electromagnetic space is becoming one indispensable major part of whole battlefield space, which impenetrate into other battlefield spaces including land, sea, air and universe. [] There is a good deal of electromagnetic eradiation in battlefield electromagnetic space. All inds of electromagnetic signals such as artificial and natural, hostile and sociable and so on, filled in battlefield electromagnetic space through multiple and diverse electromagnetic applications. In the end, battlefield electromagnetic environment is becoming much more complex. The confrontation of battlefield electromagnetic environment embodies as electromagnetic applications and counter-applications. It was contradiction between electromagnetic application and counter-application that resulted in the unending evolving of battlefield electromagnetic environment. In course of battlefield electromagnetic environment evolving and developing, Electromagnetic interference and counter-interference become an important electromagnetic application form, which demand much higher counter-interference performance for weapon systems. [] That is why EMC of weapon systems highlight day by day. Thus, electromagnetic compatibility problems become a focus of research on battlefield electromagnetic environment, and both related theories and technologies are highly valued. Currently,domestic and imported research on battlefield electromagnetic environment is incipient, unified depiction with much accuracy and approbation for battlefield electromagnetic environment does not exist. There have been lots of writings and papers on EMC, which are mainly theoretical and technological approach in-depth on specific electromagnetic compatibility problems. But, macroscopic discussions on electromagnetic compatibility problems considering complex battlefield electromagnetic environment are absence. [3~4] 48

77 In this paper, discussions on the essence of battlefield electromagnetic environment are provided firstly, thining for setting up of battlefield electromagnetic environment is mentioned secondly. Finally, battlefield electromagnetic compatibility problems are discussed with macroscopic inspect considering complex battlefield electromagnetic environment.. Connotation of Battlefield Electromagnetic Environment. Space and Environment Now, we have a loo at two statements as follows: ) Classroom is three - dimensional space; ) In classroom space, teacher is teaching earnestly, and students eep a close watch on tuition. Then, a classroom environment with much liveliness and ordinal comes into being. Of course, statements above are right. But, if we have replacements between space and environment,other two statements are as follows: ) Classroom is three - dimensional environment; ) In classroom environment, teacher is teaching earnestly, and students eep a close watch on tuition. Then, a classroom space with much liveliness and ordinal comes into being. Statements above are wrong obviously. Thus, we can conclude that space is a static concept which reflects the existence of object, but environment is a dynamic concept because of whose dynamic action, evolving and development. Environment can not get away space, an environment must correspondent a space, and environment can not also get away active entities, which are the incentive of environment evolve and develop. So, environment and space are interrelated each other, as it were, environment is made up by active entities and dynamic action of entities in mate space. When we study on environment related problems, we should mainly discuss active entities and dynamic action in mate space.. Battlefield Space and Battlefield Environment Battlefield space is five - dimensional space made up from land, sea, air, universe and information. Of which,land, sea, air and universe are visible battlefield space, information battlefield is invisible space. Information space is main part of battlefield space by covering other four - dimensional battlefield field. As is shown in figureand. Fig. composition of battlefield field Fig. structure analysis of battlefield field 49

78 .3 Battlefield Electromagnetic Environment As above, we can conclude that battlefield electromagnetic environment is made up from electromagnetic operation entities and electromagnetic application in electromagnetic space. In other words, battlefield electromagnetic environment is total electromagnetic actions and phenomenon which mae a difference on operation. In short, battlefield electromagnetic environment equals electromagnetic space added by electromagnetic operation entities and electromagnetic application. [] Battlefield electromagnetic environment is import composition of battlefield informational environment, thus an indispensable part of battlefield environment. It is an ensemble existence of close, complex and extensive electromagnetic signals. Electromagnetic actions with much richness and variation in battlefield electromagnetic environment impel it evolve and develop with more and more complexity and variety, then battlefield electromagnetic compatibility problems are much more stand out. Just as environment protection is an important measure for natural environment to re-sustainable develop, research on battlefield EMC is an effective measure to solve electromagnetic environment contamination because of EMC, and it have much significance for battlefield electromagnetic environment to re-sustainable develop..4 Electromagnetic operation system We construct a system with the function of disputing electromagnetic domination, which is made of associated each other electromagnetic operation entities through electromagnetic application. We name the system as electromagnetic operation system, which exist in battlefield electromagnetic environment. Battlefield electromagnetic compatibility problems in battlefield electromagnetic environment act on electromagnetic operation system, and operation effectiveness of electromagnetic operation entities is much influenced by their EMC. How to solve battlefield electromagnetic compatibility problems lies in electromagnetic operation system, of which each part results in EMC condition of battlefield environment. So,EMC of electromagnetic operation system is the main reason of battlefield electromagnetic compatibility problems, and study on EMC of weapon system is the beginning and basis of battlefield electromagnetic compatibility research. 3. Setting up of Battlefield Electromagnetic Environment 3. Composition of Battlefield Electromagnetic Environment Considering of the implication of battlefield electromagnetic environment, battlefield electromagnetic environment has compositions as follows: )Electromagnetic operation entities According to electromagnetic radiation and reception, electromagnetic operation entities should include electromagnetic radiation sources and electromagnetic radiation acceptors. Electromagnetic radiation sources include radar signal radiation sources, communication signal radiation sources and so on; electromagnetic radiation acceptors include radar signal radiation acceptors, communication signal radiation acceptors and so on. Concretely, electromagnetic operation entities include radar countermine weapons, communication countermine weapons and electro-optic countermine weapons and so on. )Electromagnetic application Electromagnetic applications, according to the object, can be divided into applications on purpose and applications without intention. According to the counterwor, it can be divided into counter-applications and non-counter applications. According to friend and foe, it can be divided into hostile applications and own 50

79 applications. According to the threat of applications, it can be divided into high threat as anti-radiation attac, middling threat as electronic interference, and low threat applications. In the concrete, electromagnetic application is made up of start point and destination of electromagnetic radiation, the aim and duration time of electromagnetic application, and so on. Applications on purpose and counter-applications are major electromagnetic applications, which including electronic reconnaissance and count-reconnaissance, electronic interference and count-interference, electronic demolish and count-demolish and so on. 3. Feature Analysis of Battlefield Electromagnetic Environment According to composition, battlefield electromagnetic environment has features as follows: )Cognizable It is mainly because of systematic feature of electromagnetic operation entities. Every electromagnetic operation entity in battlefield electromagnetic environment is a cognizable system having some function, electromagnetic operation SOS made up by operation entity is system with higher levels, and it is also cognizable. The condition of battlefield electromagnetic environment in which electromagnetic operation system exist is decided by electromagnetic operation entities and electromagnetic applications in it. Systematic feature of electromagnetic operation SOS and electromagnetic applications based on electromagnetic theories is cognizable, so battlefield electromagnetic environment can be cognized, developed and utilized effectively by human being. )Dynamic evolutional It is mainly because of evolutional and diversified feature of electromagnetic operation entities. Both electromagnetic operation entity and SOS are system, and a vigorous system is evolutional day by day. The development of battlefield electromagnetic environment urged electromagnetic operation entities to evolve, and the evolution of electromagnetic operation entities counteract on battlefield electromagnetic environment, mae it evolve further. It means that system and environment in which system exist act on each other. In course of action, both system and environment evolve further. The system which does not act on its environment is closed and in-animated. Battlefield EMC problem is essentially adaptation between electromagnetic operation system and correspondent electromagnetic environment. 3)Vigorous antagonistic It is mainly because of counteraction among electromagnetic operation entities. Typical feature of battlefield is antagonistic, which mainly embody as vigorous antagonistic actions among operation entities. Battlefield electromagnetic environment is one main part of the battlefield environment, and it also is antagonistic because of vigorous counteractions among electromagnetic operation entities in it. 4)Complex and inconstant It is mainly because of related features of electromagnetic applications. As electronic equipment and information weapon system are being extensively applied in battlefield, electromagnetic applications are becoming more and more diverse, dynamic and extensive. Thus, battlefield electromagnetic environment is tending to more and more complex and inconstant. 5

80 3.3 Simulation of Battlefield Electromagnetic Environment As simulation is well repeatable, low lost and high speed and so on, it is being extensively applied in weapon system development demonstration, battle and campaign rehearsal and combat training. Under modern information war, battlefield electromagnetic environment is one main part of the modern battle environment, simulation of battlefield electromagnetic environment is essential trend of military simulation technology. [~4] The purpose of battlefield electromagnetic simulation is as follows: )Study on electromagnetic operation entities development demonstration. It is mainly aim electronic equipment and information weapon, is study on electromagnetic operation entities in electromagnetic environment. )Study on campaign usage of electromagnetic operation entities. It is also mainly aim electronic equipment and information weapon, is study on electromagnetic operation entities in electromagnetic environment. 3 ) Study on combat training in complex battlefield electromagnetic environment. It is study on electromagnetic application in electromagnetic environment. 4)Study on EMC of electromagnetic operation entities and so on. It is study on adaptability between electromagnetic operation SOS and electromagnetic environment. According to above purpose of simulation, battlefield electromagnetic environment can be classified as follows: )Simulation for electromagnetic operation entities development demonstration, such as radar system performance simulation, radar system effectiveness simulation and so on. )Simulation for electromagnetic operation entities campaign usage, such as radar confrontation simulation. 3)Simulation for electromagnetic operation entities combat training. 4)Simulation for EMC and so on. According to above analysis, the development trend of battlefield electromagnetic environment simulation is as follows: )Under the condition of complex battlefield electromagnetic environment, integrated simulation including radar confrontation, communication confrontation, electrical and optical confrontation and so on. )Under the condition of complex battlefield electromagnetic environment, integrated simulation including performance simulation, effectiveness simulation, special topic simulation and so on. 3)Combination simulation with the feature of mutual communication and resource sharing among all inds of simulation systems. 4)EMC integrated simulation and evaluation under the condition of complex battlefield electromagnetic environment. In short, simulation technology is an important approach to research EMC of complex battlefield electromagnetic environment. 4. EMC for Battlefield Electromagnetic Environment 4. Problem Analysis for EMC EMC problem is mainly owing to electromagnetic interference, especially electromagnetic interference on purpose. As battlefield electromagnetic environment is being complicated, EMC problem is becoming much more highlight. [] In complex battlefield electromagnetic environment, electromagnetic operation entities perhaps subject to such main interferences as interferences on purpose from opposing side and interferences without purpose. For information unit or electronic unit of electromagnetic operation entities, if it has poor anti-interference capability, electromagnetic interferences is to influence performance of it. In result, electromagnetic operation entities can not complete electromagnetic applications successfully. Moreover, electromagnetic eradiation without purpose will come 5

81 into being inter-interferences among electromagnetic operation entities of one side of operation, which also influence effectiveness of weapon systems. In complex battlefield electromagnetic environment, the connotation of EMC is as follows: electromagnetic eradiation of operation entity itself have not interference on other electromagnetic operation entities; electromagnetic operation entity is not sensitive to electromagnetic interference on purpose and electromagnetic leaage, it means having strong anti-interference capability. According to system theory, EMC problem is indeed the relationship problem among electromagnetic operation entities and battlefield electromagnetic environment. So, it is important for electromagnetic operation entities to deal with all inds of relationships in course of curing EMC problems. [5~6] 4. Design of battlefield EMC As above discusses,battlefield EMC design should be considered as follows: )Considering relationship among electromagnetic operation entities ) Considering relationship between electromagnetic operation entity and battlefield electromagnetic environment. Additionally,EMC problem mainly result from performance of electronic equipment and information equipment, which is the inner reason and an decisive factor. Another reason of EMC problem is environment electromagnetic radiation which is the outer reason and an important factor. According to system analysis theories, inner reason decides outer reason. So, in course of battlefield EMC design, firstly, we should consider the performance of electromagnetic operation entities, than, we should consider the influence relationship between operation entities and battlefield electromagnetic environment. In a word,the design of battlefield EMC should be as follows: )The EMC analysis of electronic equipment and information equipment of electromagnetic operation entities, such as design of anti-interference performance, electromagnetic leaage and so on. )The considering of electromagnetic relationships of operation entities in battlefield electromagnetic environment. It includes dimension deployment relationship, time precedence relationship, frequency overlap relationship, energy comparison relationship and so on. 3)The considering of electromagnetic relationships between operation entities and battlefield electromagnetic environment. Main context of it is to cut down electromagnetic radiation without purpose. In the all, we should consider all inds of electromagnetic relationships from the angle of system, design the battlefield EMC scientifically. 4.3 Development Direction of Battlefield EMC Researches on EMC have accumulated resourceful theory and technology basis. For example, EMC technology has developed for about seventy years, then, there have been so many fruits as theories and technologies. And EMC simulation is also developing so much. Moreover, theory cognition for electric magnetic field and electric magnetic wave is progressing unremittingly, which mae electronic and information technologies innovate every day. [7~9] Development trend of battlefield electromagnetic environment mainly include follow two aspects: )EMC in battlefield electromagnetic environment integrated simulation and test )Overall EMC data fusion for battlefield EMC analysis. 53

82 EMC problem in complex battlefield electromagnetic environment is a research subject area which adapts the development of information war. According to overall integrated perusal hall thought and method of systems engineering, by integrating EMC technologies, information technologies, electronic technologies, simulation technology and so on, and combining experience of specialist and priori information, we can establish an integrated perusal pattern which adapt to the research on EMC of complex battlefield electromagnetic environment, and can propel the theories, technologies and methods of EMC in complex battlefield electromagnetic environment develop, then realize effective using, administration and control for electromagnetic resource. 5. Conclusions EMC problem in complex battlefield electromagnetic environment is an important research subject area in course of information war developing and evolving. When we discuss the battlefield EMC problem, we can consider electromagnetic operation SOS made up by electromagnetic operation systems firstly, then, in the angle of SOS counter, we can apply thoughts and methods of systems engineering to battlefield EMC research. Only when we consider fully the relationship among electromagnetic operation entities and relationship between battlefield electromagnetic environment and electromagnetic operation SOS, then, there is some basis to realize battlefield electromagnetic compatible condition. References. Wang Ru-qun.Battlefield electromagnetic environment [M] Liu Na, Shi Hai, Yang Jian-hua. Method of Radar Signa Modeling in the Virtual Battlefield Electromagnetic Environment[J].Command Control & Simulation,007, (3): Zhang Zhi-min, Lui Lin. Radar Electromagnetic Environment Simulation Analysis[J]. Shipboard Electronic Countermeasure,008(): Davis Paul K,Anderson Robert H.Prospects for composability of models and simulations [C] Proceeding of SPIE,Enabling technologies for simulation Science,Dawn A.Trevisani, Alex F Sisti Eds (3): Wang Xing, Hao Chong-yang, CHENG Si-yi, SHI Liang.Analysis on EMC Solutions between Airborne Radar and Electronic Countermeasure Equipment[J]. Telecommunication Engineering, (9): SHAO Tao, HU Yi-hua, SHI Liang, JIAO Jun-jun. Methods for Quantitative Evaluation of Battlefield Electromagnetic Environment Complexity [J]. Electronics Optics and Control 00, 7(): KAN De-peng, JIA Cui-xia. Research on Simulation Technique of Complicated Battlefield Electromagnetic Environment[J]. Journal of China Academy of Electronics and Information Technology, 009, 4(06): Ma Kuang-ping,L Min,James. L.Drewnia.Comparison of FDTD algorithms for subceluar modeling of slots in shielding enclosures[j].ieee Trans EMC.997, 39(): Bogdanor J L. Intra-system Electromagnetic Compatibility Analysis Program. AD-A00856,

83 FAST AND ACCURATE CAMERA CALIBRATION METHOD BASED ON GRID-BASED BOARD PLANE LUO GUI-E, YANG XIN-RONG, LIU XIAO-QUN, LIU WEI School of Information Science and Engineering, Central South University Changsha, Hunan province, 40083, China ; Abstract:One of the basic tass of computer vision is to calculate the geometry of objects that based on image information obtained from the camera in three-dimensional space, and thus reconstruct and distinguish object, while these geometric parameters which decide the relationship between the three-dimensional geometry location of a point on space of surface and the corresponding point in the image, is the camera parameters and including the internal parameters and external parameters. Camera calibration plays an important role in computer vision, the purpose of calibration is to accurately determine the camera intrinsic parameters and external parameters in order to locate objects. This paper introduce a calibration method based on grid-based board plane, the first step adopts linear approach, then the solution which gets from the first step is nonlinear refined based on the maximum lielihood standard. Finally considering the lens distortion, the linear method is the same used with the first step, and then the result is proceed to nonlinear optimization. Experiments show that this calibration method is simple and has high accuracy. Key words: image information; three-dimensional space; accurately determine; linear approach. Introduction Computer vision, whose research aim is enable the computer to have ability that cognizes three dimensional environmental information through two-dimensional picture, is used to realize the computer's visual function. The ability is to percept, recognize and understand the three-dimensional scene of the objective world by computer. When using the computer technology to percept, recognize and understand the three dimensional scenery, CCD camera is a basic measurement tool to carry on three-dimensional reconstruction of the physical world, so camera calibration and stereo vision sensor calibration are considered to be a basic and crucial step in order to realizing three-dimensional Euclidean space visual. The camera calibration can determine the internal parameters (namely geometric and optical characteristics) and external parameters (namely three-dimensional position and orientation that camera structure relative to one world coordinate system) of camera []. It not only can improve the measurement accuracy through accurate calibrating inside and outside parameters of the cameras, but also lay a good foundation for the follow-up of stereo matching and 3D reconstruction. Now the most commonly used camera calibration techniques can generally be attributed to be two types of traditional camera calibration method and camera self-calibration method []. This article focuses on researching traditional methods. This approach is between the traditional demarcation and the self-calibration, the computational complexity and accuracy of calibration are closely related to the geometric model of camera imaging. For example the most commonly used pinhole model, it is the basic model of the camera calibration, but in many cases this linear model can t accurately describe the geometry of camera imaging, lie in short-range, wide-angle time situation [3~4], so after considering the linear or nonlinear distortion compensation, it can be 55

84 rational as the pinhole model of imaging process, also can get higher precision by using the corrected three-dimensional reconstruction model. So the imaging model and distortion compensation is the most important researching into the camera calibration of a binocular stereo vision.. Camera's Projection Mathematical Model T Supposing space (in this template plane) a point p in world coordinates as M = ( x, y, z ), T corresponding to the coordinates of image pixels p u expressed as m = ( u, v), with homogeneous coordinates T expressed as M ~ = ( x, y, z ), m ~ = ( u, v,) T [5~6], the camera projection mathematical model can be expressed as: w w w ~ s m ~ = A[ R t]m () Where s is a scale factor, A is a matrix of the internal parameters, R is rotation matrix, t is the translation vector, f x c u0 A = 0 f v () y Where c means the migration because of the two camera axis be out of vertical. Supposing the plane demarcation template falls on the world coordinate system's zw=0plane, expressing the ith row vector of R with r i. Formula () can result in w w w u s v = A x [ ] yw r r r t = A[ r r t] 3 0 w x y w w x = H y w w (3) the introduction homography matrix (it has established a mapping between template plane's spot and its image point) h h h3 H = h h h 3 = A r h3 h3 h 33 [ r t] so camera's projection mathematical model can be expressed as sm ~ = H M ~ (4) If the size of template chess grid is nown, then we can get the coordinates of m and M, we can solve this H. Eliminating s from (4), we can get 56

85 = = h y h x h v y vh x vh h y h x h u y uh x uh w w w w w w w w (5) Ordering T h h h h h h h h h ] [ =, so = v u h vy vx y x uy ux y x w w w w w w w w (6) If there are four corresponding points, you can get eight equations to solving linear equations and obtain h. The actual calibration usually tae many corresponding points, and ordering T h h h h h h h h h ] [ =, then = h v vy vx y x u uy ux y x w w w w w w w w (7) This equation can be calculated using least square method to get the homography matrix H. In fact, it is difference a scale factor between the H that solved by this equation and the true homography matrix [7], ordering [ ] 3 h h h H = and then ] [ ] [ t r A r h h h H 3 λ = = (8) As r and r are unit orthogonal vectors, so there are = = T T T T T T h A A h h A A h 0 h A A h (9) 3. Solution Processing of Parameters The solution process of parameters is as follows: first carrying on the linearity solution, then the solutions of nonlinear refinement which based on maximum lielihood standards; second considering the lens distortion, using the linear method to solve as first, then carrying on the nonlinear optimization to improve the accuracy of calibration. 3. Linear Solution As = ) ( ) ( ) ( y y x y y y x y y x y y y x y y y x y x y x y y x x T f v f f f u cv f v f f f u cv c f f f u cv f v f f f u cv c f f f c f f c f f f u cv f f c f A A

86 Ordering B = A T A B = B B 3 B B B 3 B B B , h = i T [ h h h ], b [ B B B B B B ] i i i3 = T The result can be T hi Bh j = v ij b v = h h h h + h h h h h h + h h h h + h h h h Where ij i j i j i j i j i3 j i j3 i3 j i j3 i3 j3 From above two equations about the vector b can be as follow T v (v v b = 0 T ) If there are n images, and then stacing up the equations of these images, the result can be Vb = 0 (0) V is a matrix that is nx6. If n >, the solution of b has the proportionality factor; if n =, then the number of the equation is less than the number of unnowns. At this point assuming the angle between the minor axes of A is 900, that is c equals to zero, which provides b a new constraint [8]. [ ] b = 0 this equationb is the characteristic vector corresponding to the minimum eigenvalue of matrix After getting B, ordering V T V. ; In B = B = AA T b = b b 3 b b b 4 5 b3 b 5 b 6 a A = 0 0 a a 4 0 a3 a 5 a 6 A can be solved, then according to formula (8) and formula (9) we can get r, r, r 3,t and λ = A h = A h 3. Nonlinear Refinement Based On Maximum Lielihood Standard The above method requesting R is based on the minimum distance, and has no physical meaning. So next we carry on the nonlinear optimization to the results with maximum lielihood estimate. Supposing to tae n pieces of pieces of template image from different angles, each demarcation template has m calibration points as the same. Assuming that the coordinates of each point have independent and identically distributed noise, then the maximum lielihood estimate can be result from the minimum of the following formula.. C = n m i= j= m ij m ~ ( A, R,t, M ) () i i j 58

87 59 Where ij m is image point coordinate vector of the ith spot on jth image, i R is the rotation matrix of the ith image, ti is the translation vector of the ith image, j M is the space coordinate of the jth spot, ),,, ~ ( j i i M t R A m is the coordinates of the image point estimates that get from the already nown initial value. The solution of ),,, ~ ( j i i M t R A m is a classical nonlinear optimization problems, so A, i R, i t which minimizes the evaluation function are the optimal solution of this problem. The linear results that result from the first time can be as the initial value A, then using Levenberg-Marquarat algorithm [9] to solve{ } n i t R i i,...,, =. 3.3 Processing Lens Distortion Because the most of cameras have lens distortion, and the radial distortion has great impact on the imaging model. This article has only considered the first-order and the second-order radial distortion, and assumes the distortion factor of x direction and y direction to be the same. Here the distortion model [0] can be: = = ] ) ( ) ( [ ] ) ( ) ( [ u u u u u d u u u u u d y x y x y y y x y x x x () Where, is the radial distortion coefficient of the first-order and the second-order. And because of + = + + = d y d d x y v v cy x u u α α = + = 0 0 v y v u x u u x u x α α From all above, the result can be = = 0 0 ) ( ) ( )[ ( ) ( ) ( )[ ( u u u u u u u u y x y x v v v v y x y x u u u u (3) Giving m calibration spots of n pieces of the template image, we can get m n equations which can be written as the matrix form d D =. The linear least squares solution of this equation is d D D D T T ) ( =, when and are defined, the value of ),,, ~ ( j i i M t R A m can be recalculated by them, and then re-using the maximum lielihood estimation and Levenberg-Marquarat algorithm iteration to further optimize all the internal parameters. 4. Experiment Process and Analysis of Results 4. Experimental Procedure ) Printing a calibration template that lies flat board, and pasting it on a rigid plane. In the experiment the board calibration template of 7 9 is shown as Figure, the size of each chess is a square of mm mm

88 Fig Board calibration template Fig Corner extraction of calibration template )Constructing the system of binocular stereo vision In the experiment the camera has selected the CCD camera of DH-HV30UC-T in company of Beijing Daheng. Parallel binocular stereo vision system is formed by two parallel and flat cameras whose fixed baseline is 3 cm. The checerboard calibration template is putted in the front of two camera's photograph scopes. The photo source is the daylight lamp, turning calibration template, so taing some images of the camera calibration template from different angles by camera. Theoretically, the inner parameters of cameras that used in the experiment can be derived from just three pairs of calibration template images taen from the experiment. However, in order to improve the accuracy of the inner parameters of cameras, we get eight pairs board calibration template image pairs from different angles in the experiment. 3) SUSAN corner detection method is used to extract the coordinates of all the cross-corner of the template Fixing Z-axis and taing the top left corner of the calibration plate as the origin of the world coordinate, then the corner z w of calibration board is zero, the upper edge of the board is Y-axis, the left of the board is X-axis. In the experiment taing the corners between blac and white chess as the calibration spots, and using SUSAN corner detection algorithm to extract the corner of each pairs of image. Figure is corner extraction method of a piece of images. 4)Solving the internal and external parameters and distortion coefficients of camera According to the above calibration method, the intrinsic parameters and external parameters of camera, also the distortion coefficient of camera, can be solved out, then all parameters can be further optimized by using the maximum lielihood estimation. 4. Experimental Results and Analysis Using the checerboard plane to calibrate the template, the calibration results of two cameras by calculating can be as table 60

89 Table Results of camera calibration Left CCD Right CCD A A Taing the camera coordinate system of the left camera as the world coordinate system, then the rotation matrix and the translation matrix between two cameras can be expressed as table 3. Table Calibration results of sensor s Structural parameters R t According to the translation matrix t =[ ] T, we can see that the translation of the right camera in the X axis direction is pixels, which converted into centimeters is *0.005= cm, the result is almost the same with 3 cm that is fitted in the experiment. 4.3 Taing Templates of Zhang Zhengyou as Calibration Images Camera calibration has been taen the template of Zhang Zhengyou as calibration images which don t consider the distortion of the camera model, the results of calibration are not satisfactory. So using this algorithm in this paper, the results can be table 3. Table 3 Results calibrating the template of Zhang Zhengyou A R t Comparing to the camera model that doesn t consider the distortion and just considers the first-order distortion, the model in this paper not only improves the precision but also the speed of calibration. 5. Conclusion In this paper, a camera calibration method that based on grid-based board plane has been proposed. Because the calibration template as board plane of this method is easy to be made, and the calibrated position can be any place in anywhere, it s avoided to use the cube calibration bloc of high-precision that used in the traditional two-step method called Tasi, and the inconvenience and error which result from measuring the corner world coordinate of calibration bloc. This calibration algorithm is between traditional and self-calibration, also can get high accurate calibration results, and less demand on the experimental conditions, but is strong practicality. 6

90 References. Qiumaolin, Masongde. Camera calibration summary in computer vision[j]. Automation Technology, 000,6(): Zhang Y,Zhang Z,Zhang J.Camera calibration technique with planar scenes[a].machine Vision Applications in Industrial Inspection XI[C].Santa Clara,CA,USA:SPIE, Masongde, Zhangzhengyou. Computer vision- Computation theory and algorithm foundation [M]. Beijing: Scientific Publishing, Zhang Z. Flexible camera calibration by viewing a plane from unnown orientations[c]. ICCV, Song L M, Wang M P, Lu L, et a. High precision camera calibration in vision measurement[j]. Optics&Laser Technology, 007, 39(7): Kei, Masayui. Integration of real-time binocular stereo vision and whole bodyinformation for dynamic waling navigation of humanoid robot. IEEE Conference on Multisensor Fusion and Integration for Intelligence Systems, Toyo, July Q.-T.Luong and O.Faugeras. Self-calibration of a moving camera from point correspondences and fundamental matrices.the International Journal of Computer Vision, 007,(3): I.Shimizu,Z.Zhang, S.Aamatsu, and K.Deguchi. Head pose determination from one image using a generic model. In Proceedings of the IEEE Third International Conference on Automatic Face and Gesture Recognition, Nara,Japan,Apr Hongwei G, Chengdong W, Lifu G, et a. An Improved Two-Stage Camera Calibration Method[A]Proceedings of the 6th World Congress on Intelligent Control and Automation[C]. Dalian, China; IEEE, G. Q. Wei and S. D. Ma. Implicit and explicit camera calibration: theory and experiment[j]. IEEE Trans. Pattern Recognition and Machine Intelligence, May 007,6(5):

91 FAST RECURSIVE ALGORITHM AND APPLICATION OF A MULTICHANNEL CORRELATION COEFFICIENT FORMULA REN LI-MIN, CHEN HUA-MIN, HUANG DA-YONG Department of Mechanical and Electrical Engineering Nanyang Institute of Technology, Nanyang , China rlmchmrlm@63.com Abstract: Coherence technology is a ind of method which uses mathematic methods to highlight the similarity of the signal between two neighbouring channels in order to detect wea signal and reflect unusual characters. Fast recurring algorithm and application in wea signal detection of a multichannel correlation coefficient formula based on signal energy was introduced in this paper. The author developed a set of application software of coherence technology based on the discussion about the realizing method of the mathematic model. The tests on theoretic model and practical model proved the availability of the algorithm. Key words: signal energy;multichannel;correlation;wea signal detection. Introduction Wea signal detection is a new arisen course, the application of which covers various inds of fields. Wea signal detection uses the methods of electronics, information theory, computer and physics to analyze the cause and law of noises, to study the character and coherence character of the signal and measure the useful signal which is submerged by noises []. The purpose of wea signal detection is to collect useful signal from strong noises or adopt some new technology and methods to increase signal-to-noise ratio (SNR) of the output signal []. The study on wea signal detection theory, seeing new methods and developing new equipment of wea signal detection are the central issues in measurement technology field. The interference of noises is the main problem of information science. Extracting wea sine periodic signal is a synthetically technology and a advanced branch of signal detection. The devices of measuring amplitude and angle are widely used in various inds of scientific fields such as physics, bio-medical science, earthquae etc [3]. At present, methods in time domain have the shortcomings of high door limitation and wea resistance to noises. But coherence technology hasn t these shortcomings apart from many strong points. Coherence technology is a ind of method which uses mathematic methods to highlight the similarity of the signal between two neighbouring channels in order to detect wea signal and reflect unusual characters. In technique aspect, more and more attention is paid on coherence technology which is divided into three generations in the world. The algorithm of the first generation is based on correlation which has good signal distinguishing ability when the data has high signal-to-noise ratio but has wea resistance to noises [4]. The algorithm of the second generation is in view of similarity which is a better algorithm of calculating coherence character and has higher distinguishing ability compared with the first generation algorithm [5]. But the quality of the data still has effect on calculating coherence to some extent [6~7]. The third generation algorithm is based on character structure which is the highest level of coherence technology. In recent years, coherence technology developed quicly [8]. The author developed a set of application software of coherence technology based on the discussion about the realizing method of the mathematic model. The tests on theoretic model and practical model show that this method is effective in wea signal detection. 63

92 . Principle of -D Coherence Technology The principle of multichannel correlation coefficient formula based on signal energy is as following: firstly calculating the similarity coefficient of the vertical line and the horizontal line from a point of the space, then combining the calculated value to get the coherence value of the point. Secondly calculating the coherence value of each point along the time direction. Finally repeating this process to obtain the whole coherence body. Much time is needed according to this algorithm, therefore, the formula of multiple channels coherence coefficient and a faster algorithm started with energy of the signal is introduced. Assuming a signal as X j (n), j =,,..., M, n =,,..., ; N ; M is the total number of the channels; N is the number of points in the calculating window. Assuming a standard channel X (n), then the energy error between M N the standard channel and the Mth channel is Q, [ ] Q = X j ( n) X ( n),. To mae Q = 0, so that Q j= n= X ( n) M can reach the minimum value. At this moment X ( n) = X j ( n). According to the energy relationship between M J = the standard channel and the M th channel, the coherence value is got. R N M X ( n) j n= J = j= n= = M N ( M ) X j ( j= n= Bigger value of R indicates better similarity character of M channels signal, otherwise, the similarity character is worse. The calculating amount of this method is great and the calculating speed is slow. To change the cycling sequence of calculating, that is to calculate along to the horizontal line firstly, then to calculate along the vertical direction. Assuming the starting point and the terminal point of the glide window is i and N, then they will change to i + and N + after the window gliding one point. I and II can be successively deduced and calculated individually, i is the sequence number of the glide window whose original value is. Then formula () can be written as: I=I+ X j ( N + ) X j ( i) j j M N X n) II=II+ [ X j ( N + ) X j ( i) ] j j ( n) () From the formula above, the conclusion is reached. When calculating the coherence value of the next window, only to calculate the energy change of the two rows outside the overlapping part of the two windows and it is not necessary to calculate the energy of N points inside the window. The calculating amount of this method is reduced according to geometry progression and the calculating speed is fast. () 3. Tests On Theoretic Model The procedure of this method is composed and tests on the theoretic model are done on the basis of analyzing the formula above. The result of the tests accords with the theoretic result. In the tests, the total number of the channels of the data is 4 and the number of the points in each channel is 04 which is synthesized by half a period s sine signal and random signal. As figure to figure 4 shows. 64

93 Fig the input signal with S N being 0.5 (left) and the coherence figure (right) (glide window is 3 5 ) Fig the input signal with S N being 0.5 (left) and the coherence figure (right) (glide window is3 5) Fig 3 the input signal with S N being (left) and the coherence figure (right) (glide window is3 33) 65

94 Fig 4 the input signal with S N being (left) and the coherence figure (right) (glide window is3 65 ) Through the analysis of figure to figure 4, the conclusion is obtained. The character in the input signal is obviously reflected in the output signal. In order to show the comparison more directly, the output data is filled so that the number of the total channels and points in the input signal is completely equal to that of the output signal. Comparing the input wave and the output wave, the result is clear.. ) The completely same part of the st channel to the 4th channel in the input wave is reflected as a horizontal line in the nd channel to the 3rd channel in the output wave accordingly which means strong coherence character, as figure and figure show. ) If the length of the glide window is larger than the period of the input sine signal, then the outline and the period of the signal can t be accurately showed in the coherence wave. Generally speaing, the period in the coherence wave is longer than that of the original signal. 3) The size of the calculating glide window must ensure enough data in it because it has much influence on coherence calculating. Too large glide window will bring smoothing effect to the coherence value, greatly suppressing random noises and smoothing a part of wea signal which is not benefit to detect wea signal; small glide window will sensitively chec the small change of the wave which will enhance the resolving power to wea signal and accurately reflect wea signal but will increase the noises at the same time as figure 3 and figure 4 show. The length of the glide window in figure 4 is two times of that in figure 3, so the amplitude of valid signal wave is clearly smaller than that of figure 3. 4) The relay in the input wave is also showed in the output wave. In the input wave the 5th channel to the 0th channel individually has one eighth period s relay than the former channel. Accordingly in the output wave the 4th channel to the 9th channel also individually has a fixed relay than the former channel as figure to figure 4 show. 5) When the signal-to-noise ratio (SNR) is :, the signal is a ind of wea signal, however, the signal still can be obviously distinguished in the coherence figure as figure to figure 4 show. 4. Tests on the Practical model In order to further verify the validity of this method, examinations on practical model are done. The result shows that this method is effective in practical problems as figure 5 and figure 6 show. Figures below show that the results of practical model accord with that of the theoretic model. 66

95 Fig 5 practical data (left) and the coherence figure (right) (glide window is 3 5 ) Fig 6 practical data (left) and the coherence figure (right) (glide window is 3 33 ) Through the tests on theoretic model and practical model the wea signal detection ability of this method is verified. 5. Conclusions The coherence analysis between two signals can show the extent of their similarity. In sound emitting, in order to detect, distinguish and extract one or more relayed signal, the coherence technology is indispensable. Just as spectrum analysis in frequency field, the coherence analysis in time domain has wide application in signal treatment field. Considering this method in industrial practical application, the coherence technology in wea signal detection can be used to measure pipeline leaing and realize on-line monitoring of pipeline. With the improvement of the technology, the expanding of the application area, wea signal detection theory is continuously updated and the 67

96 methods are constantly improved and increased. In practical application, different methods should be used in different actual conditions. Wea signal detection has close relationships with many fields whose development is limited by solid ware conditions before. The maturing of wea signal detection technology will bring revolutionary development to this field before long in the future. References. Zeng Qing-yong, Wea Signal Detection[M], the Publishing Company of Zhejiang University Yang Xiang-long, JIANG Bo. Adaptive stochastic resonance technology in detecting wea signal[j].signal Processing,003,9(): GAO Jin-zhan, Wea Signal Detection[M]. The Publishing Company of Qinghua University Ma Xiao-yan, LI Guang-zhu. Improved radar signal to noise ratio method based on wavelet transforms[j].tsing hua University:Sci&Tech,003,43(3): Wang Chao-lu, Study on Aconitum Kusnezoffii Reichb and Its Processed Products by D-IR Correlation Spectroscopy[J], Spectroscopy and Spectral Analysis, 009, 9(7): Li Yi-bing. Estimation of sinusoidal parameters in powerful noise by multi-ayer autocorrelation[j].journal of Harbin Engineering University. 004,5(4), Wang Yan. Ascertaining the Optimal Quantitative Wave number Range of Gas with Two-Dimensional Correlation Infrared Spectroscopy[J], Spectroscopy and Spectral Analysis, 009, 9(7): Li Nan, Three nonlinear methods of wea signal detection[j], Electric Power Automation Equipment, 008, 8(4):

97 IMAGE EDGE DETECTION ALGORITHM BASED ON WAVELET TRANSFORM AND DYNAMIC THRESHOLD ADJUSTMENT WANG YAN NIU XIAO-KE School of Electrical Engineering, Zhengzhou University, Zhengzhou 45000, China Abstract: The image edge detection and extraction is essential for image processing However, the traditional edge detection method, which is generally based on space operations,is sensitive to noise. To solve this problem, we proposed a new method for figure edge detection which combined the two-dimensional wavelet transform method and the dynamic threshold adjustment method based on Kirsch operator. The simulation results show that this algorithm can effectively detect and extract the image edge, especially when the image is mixed with noise. Compared with the traditional method, the method we proposed can more effectively suppress the bacground noise of the image. Keyword: Edge Detection, Wavelet Transform, Dynamic Threshold. Introdution Image edge is generally defined as an assembly of pixel around which the image gray has a step or slope change []. It is not only the most important feature that the image segmentation relies on, but also contains major information of the image including texture feature and contour of the image. In addition, the analysis on image edge can provide new theories and methods for the restoration,enhancement and reconstrucution of image with the egde as the major image feature []. As a result it is essential for image processing, and widely applied in practical project,either, such as pattern recognition, image matching. applying in the area of medicine, aviation, military and so on. The traditional edge detection method is based on space operations, taing spatial differential operator template convoluted with the image [3]. There are different differential operators depending on the template size and value of different elements, for example the Robert operator, Sobel operator, Prewitt operator, LOG operator, Canny operator, etc. Although these method with traditional operators is easy to implement,and the extraction results are of better continuity, these methods are sensitive with noise and fail to give satisfactory effects when the image contains mess bacground. Wavelet transform featured with the "time-frequency" multi-scale decomposition can extract the edge information of different levels from coarse to precise [4], which is compatible with the characteristics of human visual system. This paper presents a new edge detection algorithm based on wavelet transform, by reconstructing the three high frequency components of wavelet decomposition [5], combined with Kirsch operator to obtain image threshold automaticly, which can effectively remove the possible emergence pseudo-boundary as well as noise, and also plays a certain inhibitory effect on the bacground image, maing the target image being more prominent. The method mentioned above is carried out by matlab programming. The simulation experiments result shows that this proposed algorithm can effectively detect and extract the image edge, especially when the image is mixed with noise this method is more effective in suppressing the bacground and noise of image compared with the traditional algorithm based on spatial operator (tae Canny operator for example). The new algorithm proves to have better noise immunity than the traditional method. 69

98 . Edge Detetion Theory Based on Wavelet Transform Wavelet transform is an excellent tool used for time-frequency analysis [4]. The information extracted through wavelet decomposition in various scales is non-redundant and direction-sensitive. The wavelet decomposition of a two dimentional image first decompose a two-dimensional image f into an approximate sub-image a and three detail sub-images d (),d () (3),d with the resolution of -, and then decompose the approximate sub-image a in the same way. Given the maximum decomposition level is J. Then the decomposition of layer J is made on the approximate sub-image a j- which is decomposed into four sub-images including an approximate sub-image a j and three detail sub-images d () j,d () j,d (3) j. The last three respectively represent the horizontal,vertical and diagonahigh high frequency components of layer j. The wavelet decomposition structure chart is shown in Figure. Fig Two-dimensional wavelet decomposition chart Given that the maximum decomposition layer of the image f is J, after the image f is decomposed for J times, those sub-images including low-frequency part a J and high-frequency part d j,j=,,j would be obtained. The edge information of the image is always contained in high-frequency part of the image [], so it can be reconstructed through those high-frequency parts obtained. The structure chart of two-dimensional wavelet reconstruction is shown in Figure : Fig Two-dimensional wavelet reconstruction chart The figure reconstructed through the method discussed above may contain a lot of noise(lie the bacground image) and much possible pseudo-boundary [6], therefore the result needs to be further processed to obtain a more smooth and prominent figure. It is the general way to complete this tas that those greater than the threshold which is set previously is considered as the image border and those less than being zero. As the gray-scale of the image is variouse from one to another, and there are significant differences between target and bacground, it is very difficult to set a proper value as threshold. If the value is too low, the extracted pixels would contain many points that are not the real edge, otherwise if the threshold is too high, those slowly changed pixels would be missed. 70

99 Therefore a new algorithm is needed to adjust the threshod automatically according to the overall gray level of different image. When identifying an image the visual system of human is always interested in the so-called target of an images [7].Therefore it is practical to extract the edge of the target image. And because the edge of the target picture is of obvious continuity and concentrate to a certain extent, it provides possibility to acquisite the threshold automatically. For an image of any size, the number of edge pixels of the target picture is relatively limited compared with the image size. For example,once the threshold is determined, if the edge pixels extracted is too many compared with the image size, the threshold is obviously not proper. In addition, Kirsch operator could preserve the details of the image and has certain noise immunity [8]. Base on these principle a method used to automatically obtain the threshold value is proposed, the basic idea of which is as follows: Firstly, define Kirsh operator for each pixel of the image: for any pixel of the image there are eight points around it. The difference between the weighted sum of three adjacent points and the weighted sum of the remaining five adjacent points is computed. Then tae these eight points shifted around this pixel and compute the difference in the same way. At last eight differences are obtained. The Kirsh operator is defined as the maximum difference [8]. Secondly, compare the Kirsh operator of each pixel with the default initial threshold which is set in advance as small as possible: those greater than the initial threshold is regarded as the edge points, meanwhile the number N (whose initial value is zero) plus one. When N goes larger than a certain amount, the threshold value should be renewed as the minimum of the Kirsh operator of all the edge pixels (as a result of every adjustment these pixels with the smallest value are removed, and any possible border will not be missed). Then compare once again in the same way until N reaches the preset requirement. Over. 3. The Implementation Approach Based on those principles mentioned above, the specific implementation approach of the algorithm proposed is as follows: ) For the given image f(x,y), compute the maximum decomposition level of the image f, suppose as J. ) The image f is decomposed with wavelet transform of level J. According to the theory of multi-resolution analysis, a series of wavelet sub-images would be obtained, namely {a J, d () J,d () (3) J,d J, d () J-,d () J-,d (3) J-,, d (),d (),d (3) }. 3) Discard the approximate sub-image on the Jth level, which means that set the low frequency coefficient matrix a J to be zero, and then reconstruct the other three high-frequency details images d () J,d () (3) J,d J, expressed as follows: A = d + d + d ( ) ( ) ( 3) J J J J () of which J is the decomposion layer,a is the new reconstructed coefficient matrix which is represent the approximate sub-image, d is high-frequency coefficient matrix which is represent the detail images. Then iterate reconstruction according to formula () until A 0 is obtained. A A d d, j = J ( ) ( ) ( 3) j = j + j + j + j d,..., 4) Dynamically acquire the threshold of the given image f based on Kirsh operator to remove any possible pseudo-edge and noise appeared in A 0, maing the the edge of the target image more smooth and prominent. The computing process is as follows: Suppose si is the sum of three adjacent points, and ti is the sum of the other () 7

100 five adjacent points around the ith pixel, Kirsh operator K(i) is defined as follows: K ( i) = max{, max[5* si 3* ti]} (3) Given that the initial threshold is TH 0, if K(i)>TH 0 then the ith pixel would be considered as the edge points. At the same time Num (its inicial value is zero) plus one. 3Once Num goes greater than the preset value(gennerally setting as 5*M,M=max(size(A 0 ))), the threshold should be renewed as TH 0 =K min. Then A and Num are both set to be zero and return the second () step until it is less than or equal to the preset value then end. 4. Simulation and Result The simulation experiment is designed to verify the effectiveness of the algorithm by taing the image cameraman (56*56)for example. The 'bior3.7' fuction [9] is chosen as basis functions of the two-dimensional wavelet decomposition and reconstruction. The maxmum decomposition level of both image is 3, namely J = 3. The detected results is shown in Figure 3. a. The image of Cameraman b.the result with proposed method c The result with canny operater Fig 3 The original image and edge detection result It suggests that the algorithm prsent this paper can detect the target image boundary effectively, and can also effectively suppress the bacground image, maing the egde of the target image being more prominent. In addition, in order to test the robustness of the algorithm, some noise is added to the image, and then the synthesized picture is analyzed with the proposed algorithm and the traditional operator(tae canny as an example) respectively. The comparison of the results is shown in Figure 4. As seen in Figure 4, The proposed algorithm is better than traditional edge detection operator in terms of noise immunity and bacground suppression. a.the image with noise b. The extracted result with the c. The extracted result with algorithms canny operator Fig 4 The image with noise and the results 7

101 5. Conclusion The image edge detection is a ey technology in image processing. Image boundary as an important feature of image is the basis of image analysis and pattern recognition. This paper presents dynamic threshold adjustment method based on two-dimensional wavelet transform combined with Kirsch operator to detect and extract the image boundary. The method proves effective through the computer simulation. The result shows that the algorithm proposed this paper is more effective and robust than the traditional method on inhibiting the bacground image and noise. In addition, there are several dissatisfactory about this algorithm: as the dynamic threshold we chose is a global one, some partial boundary information would be missed, which would be one of the causes for the discontinuity of the result. In the future wor this algorithm will be improved to get more complete and smooth results. Reference:. Rafael C. Gonzalez, Richard E. Woods, Steven L. Eddins. Digital Image Processing Using MATLAB [M]. Beijing:Publishing House of Electronics Industry Zhang Yujin. Image Analysis(nd edition) [M]. Beijing: Publishing House of Tsinghua University Canny J. A computational approach to edge detection [J]. IEEE Trans Pattern Analysis and Machine Intelligence, 986, 8(6): Li Bicheng, Luo Jianshu. Wavelet Analysis and Application [M]. Beijing: Publishing House of Electronics Industry, Yu Wei. The Application Research of Wavelet Transform in Image Edge Detection. China University of Geosciences Ma Chunmei,Zhao Jingxiu. A New Edge Detection Method Based-on Wavelet Transform[J]. Computing Technology and Automation.009,8(4), Lou Liantang. Research On Approach to Extracting Object Contour. Huazhong University of Science and Technology Yin Ping,Wang Runsheng. Adaptive Multi-Scale Edge Detection[J]. Journal of Software. 000,(8):990~ Guo Wei-wei,Huang Xian-wu, Ge Yi-min. A Method for Outline Detection of Image with Noise Based on Spline Wavelet [J].Journal of Computer Applications,003,(0):

102 DESIGN OF HUMANOID ARENA CONTEST ROBOT AND REFORM OF UNDERGRADUATE CREATIVE EXPERIMENTS DENG JI-CAI, GUO FEI, WU XIAO-HUI, CHEN HUI School of Information Engineering, Zhengzhou University, Zhengzhou 45000, China Abstract: Humanoid robot for Martial Arts arena contest is a new type of small smart robot, which consists of wheel base and upper body of humanoid robots. It has not only the characteristics of run fast, woring stable, but also the functions of humanoid robots. In this paper, the robot mechanical structure and circuit system are described combined with the experience to participate in China robot competition. In the meanwhile, the paper mainly analyzes the electronic information processing technology in humanoid robot design based on competition requirements, including sensor configurations and multi-sensor information fusion technology, driving circuit design, contest strategy design technology. Practice shows that choosing robots as teaching practice platform can exercise undergraduates comprehensive design and practical ability, and has obvious advantages in cultivating students' innovative consciousness and improve their professional sills. Keyword: Humanoid robot; martial art arena contest; embedded system; sensor;. Introduction Robot is a complex intelligent mechatronic device [~5]. Robot competition is a high-tech against activity with robots as the main body, which involves many technical fields, such as artificial intelligence, automatic control technology, visual processing, signal detection and communication. Intelligent electronic information processing technology is the ey technology for the robot contest. Now with the increase in student participation and the expansion of student audience in the competition, the project of robotics competition is gradually increasing. In Chinese largest robot competition, robot arena contest is one of the events with the largest teams. Practice is testified that choosing robots as teaching practice platform has obvious advantages in cultivating students' innovative consciousness and improve their professional sills. It is also important for training good-quality information talents. Combination of robot design, this paper will analyze the application of electronic information processing technology in intelligent robots, and meanwhile, the effect of cultivation of students' comprehensive practice ability is also discussed.. Current Development and Status of Intelligent Robot Contest Robot contest began at the end of last century. With the development of information technology, competition level is rising continuously, and the continuous updating and expansion of the game content. At present the contest is developing in the direction of diversification, large-scale and high-level [6~7]. Soccer match is the earliest robot contest. Now there are two major international organizations, One is RoboCup [8] (Robot World Cup), the other one is FIRA(Federation of International Robot-soccer Association). In 996, the RoboCup international federation was established. and the demonstration game was held in Japan in 996. The first RoboCup Competition and Conference was held in Nagoya, Japan in 997, which made a solid first step for the dream of robot soccer team beating the human soccer world champion. From then, the contest is held annually. 74

103 In 008, the RoboCup Competition held in Suzhou, China, was the first match held in China. In domestic, the first RoboCup robot soccer was held in Chongqing in 999. From then the competition held every year, and game content no longer limited to soccer, both including physical robot contest and robot simulation contest. Correspondingly, the name of the contest was changed to "China Robot Competition and RoboCup Open". Every year the competition attracts hundreds of teams from many domestic and foreign universities. The results show that the students' practical ability and innovation ability have been improved obviously through the competition. 3. Design of Humanoid arena contest Robot Humanoid arena contest robot is one of arena contest robots, which combines wheel base and humanoid robots. It has run fast, woring stable performance, and possesses the functions of humanoid robots. In the field of motion characteristics, because of wheeled platform, it follows the dynamic characteristics of wheeled robots, so PID controller can be used to achieve path following control. In the aspect of tas execution control, its control is necessary to consider the impact of lower mobile platform, so its basic control is different from the legs upright humanoid robot [9~]. According to the function, humanoid arena robot is divided into mechanical system and control circuit system. Mechanical system consists of two parts, namely wheeled platform and the imitation of the human body. Figure shows its structure diagram (a) and our prepared robot (b). (a) Structure diagram (b) prepared robot Fig the structure of humanoid arena robot Robot circuit control system include center controller, sensing detection circuit, signal processing and motor driving circuit. Central controller has two inds of design, that is the core design of single-chip microcomputer (SCM) and DSP core design. Considering the difficulty of the debugging of the design, we give preference to choose SCM scheme. In our prepared robot, Atmega8 was selected as the controller, which completed a variety of functions, including sensor signal processing, decision maing, implement of motion control algorithms and motor control etc. The circuit control system is shown in figure. 4. The analysis of information processing technology in Robot Robot competition arena is shown in figure 3. 75

104 Fig Control system diagram Fig 3 Contest field The arena is a square low table, which is 400mm long, 400mm wide and 50mm high. The table bacground color around the outside to the center was pure blac to pure white gray gradient. The arena s two corners have ramps respectively. In beginning of the game, robots start from the starting areas, then along with two different ramps onto the challenge to contest. The basic competition rule is that the two sides race to find the other one and hit or push each other. If one side leaves the arena area totally or can not continue operation, then the other side wins. 4. signal detection and multi-sensor information fusion technology The ey problem to win the competition is to get environmental information, that is own location and the other one s location. The method is to detect signal through the sensor circuit. The sensors used in robots include infrared distance sensors, infrared switch sensors, ultrasonic sensors and gray sensors. Infrared distance sensors are used to detect "enemy" and to get its position, and gray sensor to detect the signal from table to determine its own location, infrared switch sensors to detect the arena edge to prevent errors caused by falling. Ultrasound sensors are also used for distance measurement in conjunction with infrared distance sensors, which further improve the detection performance. For example, infrared switch sensors are used for detecting the table edge to prevent falling table. The sensor s detection volume is a Boolean value. To ensure the reliability of edge detection, infrared switch sensors were installed with a certain angle in front of the chassis, and meanwhile, adjusting the threshold value range, it 76

105 can determine whether the robot approach edge of the table. However, it should be noted that the slope of the table edge will lead to incorrect diagnosis, so many teats in the slant position can ensure good results. Table edge detection is shown in Figure 4. Fig 4 edge detection of Infrared switch sensors Therefore the installation of actual sensor circuit requires a comprehensive consideration of both robot structure and woring environment to determine. This wor requires repeated experiments, which is different from simple sensor experiment. In robot competition, because it can not be pre-informed of the environmental information, the robot entirely depends on sensor system to sense the real-time environment. All inds of sensor detection information are transmitted to the controller in time. Then controller needs to mae a comprehensive processing and analysis to determine the next step in the game strategy. This is multi-sensor information fusion technology, which needs to be done by programming. 4. Motor driving circuit design Robot arena contest is a attac dual meet, so we use a number of high-power motors to increase its offensive power in the design. As micro-controller output signal is small, we need to design the motor driving circuit. Humanoid robot chassis is equipped with four-wheel, each wheel is separately controlled by a DC motor. Motion control of robot is implemented mainly through the four motor-driven, including speed and steering control. The drive circuit designed with L98N chip is shown in Figure 5. Fig5 motor drive circuit designed with L98N 4.3 Strategy and programming Strategy is important for robot contest. All the programs are designed based on the analysis of strategy. It is necessary that strategy need to be determined by competition policy rules and possible climate change. For 77

106 example, if own attac power is greater than "the enemy", the program would tae the initiative to attac, in the contrary, defense program should be taen to avoid attac. 5. Conclusions In this paper we have presented the design of humanoid robot for martial arts arena contest combined with the robot competition requirements. We mainly analyzes the electronic information processing technology in humanoid robot design, including sensor configurations and multi-sensor information fusion technology, driving circuit design and contest strategy design technology. The robot scheme described can be used in the practice teaching. Robot is a complex intelligent mechatronic device. Humanoid arena contest robot contains a variety of electronic information technology, including signal detection, power drive circuit, SCM control system and program design, etc. Robot has a strong practical feature, that is to say that circuit designing and the procedure compiling can be verified in the laboratory. Therefore, the design and preparation of robot is important for the training of qualified personnel. Practice demonstrates that choosing robots as teaching practice platform has obvious advantages in cultivating students' innovative consciousness and improve their professional sills. So it is necessary and valuable to carry out robot innovative experiment. References. Oh J S, Par J B, Choi Y H. Stable path tracing control of a mobile robot using a wavelet based fuzzy neural networ. Int J of Control, Automation and Systems, 005, 3(4): SeungKeun Cho, TaeKyung Yang, MunGyu Choi, JangMyung Lee, Localization of a high-speed mobile robot using global features, 4th International Conference on Autonomous Robots and Agents, 009, (): Katrasni, J., Pernus, F., Liar, B., A Survey of Mobile Robots for Distribution Power Line Inspection, IEEE Transactions on Power Delivery, 00, 5(): Bagnell J.A., Bradley D., Silver D., Sofman B., Stentz A., Learning for Autonomous Navigation, Robotics & Automation Magazine, 00,7(): Salerno A., Angeles J., A New Family of Two-Wheeled Mobile Robots: Modeling and Controllability, IEEE Transactions on Robotics, 007,3(): Kawamura T., Tanaa T., Robot Contest Competition, An Approach to Venture Mind Education, ICM : Pastor J., Gonzalez I., Rodriguez F.J., Participating in an international robot contest as a way to develop professional sills in engineering students, Frontiers in Education Conference, 008, (3): Cai Zixing, Robotics[M].Beijing, Tsinghua University Press, Gong Gen-hua. Design and Research on the Control System of Wheeled Mobile Robot[D],Nanjin:Nanjin university of aeronautics and astronautics Zheng Hong, Navigation and SLAM system for mobile robot, Shanghai :Shanghai Jiao Tong University,

107 A MOBILE TERMINAL POSITIONING ALGORITHM USING REAL MEASURED RECEIVED SIGNAL STRENGTH PACHO INNOCENT T. HE FENG ) Department of EIE, Huazhong University of Science and Technology Wuhan, Hubei, P.R.China innopacho@gmail.com ) Department of EIE, Huazhong University of Science and Technology Wuhan, Hubei, P.R.China hefeng@mail.hust.edu.cn Abstract: This paper considers the problem of positioning the mobile station(mt) basing on the attenuation of the received signal strength in cellular networs lie GSM. At any instance a GSM mobile station can receive signal from many base stations, in most cases it has been noted that it receives signals from six neighbor base stations and one serving base station. This property maes it easy to locate any mobile station by just utilizing the received signal strength. This paper suggests a mobile terminal location estimation algorithm based on the attenuation of the received signal strength, which yield circles along which the mobile may lie. Then the place where the two circles intersect is the estimated position of the mobile station. The radius of a circle is the distance obtained from the Oumura-Hata formula due to the attenuation of signal strength. This method can be applied in existing system and it does not need any upgrade of system hardware. The performance of the proposed algorithm is evaluated using the real measured GSM signal strength data. So far the results demonstrate that this proposed algorithm can achieve a basic precision, and it still has great protential to enhance in the future. Key words: GSM mobile station; estimation algorithm; received signal; signal strength. Introduction Mobile locations could support many applications, such as emergency services, roadside assistance, location-sensitive billing, navigation, tracing and so on. Over recent decades, numerous studies have examined the mobile location estimations, which can be divided into five categories. The first category is the Global Positioning System (GPS), which provides accurate positioning based on satellite-transmitted signals. However, the GPS may fail when satellite signals are bloced, for example, in a setting when the mobile is used in indoors, in underground car pars, and in urban canyons. The GPS has been standardized in Global System for Mobile Communications (GSM) networs as the Assisted-GPS method, which requires hardware upgrade in both the mobile terminal and the networ. The second category estimates the mobile location based on received signal strength (RSS) measurements. This approach uses the relationship between the received signal strength and the distance from the base stations (BS) to the mobile station. Unfortunately, this approach may be inaccurate because of the complex propagation mechanisms. The third category locates the mobile via the angle-of arrival (AOA) [] of a signal from the mobile at several BSs. The AOA estimation can be used to draw a line of bearing (LOB) from the BS to the mobile; multiple LOBs intersect at the estimated mobile position. This technique requires no time synchronization between stations and can wor with as few as two BSs. However, the AOA estimation requires a complex antenna system and may suffer from non-line-of-sight (NLOS) propagation, maing it impractical for networs in urban environments. 79

108 The fourth category determines mobile location by measuring the time of arrival (TOA) [], which provides the estimate of the distance between the BS and the mobile since electromagnetic waves propagate at the speed of light. The estimated distance yields a circle, centered on the BS. The mobile location then can be determined at the intersection of circles using multiple TOAs. The simplest way for the GSM to measure the TOA is by using timing advance (TA), which measures run trip time between the BS and the mobile. Multiple TAs can be obtained by forcing the mobile to mae handover attempts from the serving BS to the neighboring BSs. However, the theoretical distance resolution of TA is 550 m, which may be too large to enable accurate location estimation. Another positioning technique based on propagation delay time, namely time difference of arrival (TDOA) [3], calculates the differences in TOAs of a mobile signal at multiple pairs of BSs. Each TDOA measurement yields a hyperbolic curve along which the mobile may lie. The mobile position can be determined at the intersection of these curves. Two TDOA techniques are standardized in GSM networs as the uplin TOA (UL-TOA) and the enhanced observed time difference (E-OTD). Nevertheless, potential disadvantages of the propagation-time based techniques are NLOS propagation and the need for timing synchronization between stations. The final category recognizes the channel status, such as path loss and the power delay profile, for mobile location estimations. The mobile position is identified by matching the actual signatures of the received signal with the entries stored in a database available at the networ. The location accuracy by using the channel status recognition depends strongly on channel status variations and the database size. However, the construction and updating of the large database is time-consuming [4]. This fingerprint technique is attracting increasing attention for indoor applications, for which database management is easier than in wide outdoor areas. The GSM provides measurement reports [5] about the signal attenuations from serving and neighboring BSs for managing radio resources. In this study, we proposes a mobile location estimation algorithm based on the received signal strength information contained in measurement reports of GSM. The rest of this paper is organized as follows: We detail our algorithm in section. In section 3, we give the performance evaluation results, and finally we give the conclusion and future wor in section 4.. The proposed positioning algorithm In this section we briefly explore the limitations of current research wor and contrast this with commercially accepted development practices. We then discuss anecdotal evidence that supports an iterative development process incorporating client-developer joint exploration of partial designs to facilitate the development of client understanding of their needs.. Genernal idea RSS-based positioning algorithm refers to the way of locating a mobile station based on the received signal strength. The main parameters required in accomplishing this algorithm are received signal strength(rx-lev), equivalent isotropically radiated power(eirp), downlin frequence, longitude and latitude of all the relative base stations etc. In additional to that we also need a well modified Oumura-Hata formula [6~7]. After having these parameters on hand, then we can use the distance derived from Oumura-Hata as a radius of the circle and then use the point of intersection of two circles as the estimated mobile position.. Positioning algorithm The positioning algorithm is divided as two steps. Firstly, the received signal strength is converted as distance between MT and relative base station by using the most used propagation model Oumura- Hata. Secondly, the idea in this algorithm is that the distance from the BS to MS are taen as the radius of the circle and then tae the circles formed from two different BS to find their intersection. As there are up to six neighbour 80

109 cell RSSs in one measure report message, more pairs of circles may be used to get more intersection points. Figure illustrates different conditions for these circles and corresponding dealing measures. Thirdly, all valid intersection points longitude and altitude values are averaged respectively as the final estimated location. This condition occurs most of the time, for this condition the average of the two points of intersection is taen as one valid estimation result. This condition occurs when the two circles do not intersect. When this happens, the corresponding pair of data are neglected. This occurs when two circles intersect at only one point. It gives an exact position of the mobile station. These two circles do not intersect. When this happens, the corresponding pair of data are neglected. Fig Illustration of different intersecting cases 3. Performance evaluation of proposed algorithm 3. Experiment conditions We use GSM real measured data to demonstrate the performance of proposed RSS-based positioning algorithm. These data were collected by TEMS terminal at Huangshi city, Hubei province. In addition, we got the support from local wireless operator to obtain all necessary wireless configration parameters of cells which include latitude, longitude, transmited power, BCCH channel, BSIC and so on. Figure. gives the scene of experiment in Huangshi city in which the sectors represent cells, and the yellow labels with the received signal strength from serving base station represent the trace of measurements. Fig Experiment scene 8

110 3. Experiment steps We implement positioning algorithm and the following estimation error statistics by C programming. Before executing positioning algorithm, we need export the log files recorded by TEMS T68 terminal and TEMS investigation 5. software [8]. Then we need extract the RSS values, MT s current precise position(obtained by GPS equipment ), BSIC and ARFCN index of the relative base station in GSM measure report messages from the exported text files. After that we need use the ARFCN index to loo up the GSM system information type 5 GSM system information type 5ter messages to get the real ARFCN. Then we loo up the local operator s wireless configration parameters file to match the BSIC and BCCH number to get the corresponding base station s information including precise position and transmited power. After getting the RSSs and relative base station s position, transmited antenna hight, transmited power and MT s current precise position, we use the Oumura- Hata to covert the path loss to distance between the base station and MT. Then our proposed algorithm will be executed to estimate the MT s position. Finally, we statistic the distribution of estimation errors. The diagram of positioning procedure can be seen in figure 3. Input the logfile in order to extract parameters Decode the Hexadedimal String from exported text file Output the error statistics Scan the arfcn,rxlev,bsic of the neighbout cells Calculate the error Input the file with true position of the MS Compare the BSIC and ARFCN to get the corresponding BS s geographical potition Calculate MT position Fig 3 Diagram of positioning procedure 3.3 Positioning results In this wor, over 600 positions have been estimated, and the positioning error statistic of each position is in table. Table Positioning error statistic Error(m) Below 00 Above 00 and below 50 Above 50 and below 00 Above 00 and below 50 Above 50 and below 300 Above 300 Percentage(%).5% 0%.% 37.08% 40.45% 9.% Cummulative(%).5%.5% 3.37% 40.45% 80.9% 00% 8

111 4. Conclusions and future wor In this wor we focus on the RSS-based GSM MT positioning algorithm and its implementation. We present a RSS-based positioning algorithm and demonstrate its performance by using real measured GSM RSSs. The algorithm that we has used can be improved in future wor. Firstly, in this study, we have not consider the radiation direction of each cell, however, most of the cells antennae are not isotropic antennae but beam antennae. So there should be a different path loss at different direction in the same distance. In future wor, we will use a enhanced propagation model which may consider the radiation pattern of the cell antenna. In this case, the radiation shape of a beam antenna will not be a circle but is similar as figure 4. Fig 4. Radiation shape of beam antenna Secondly, smooth average window could be applied to the estimated positions to reduce estimation error. Acnowledgements This wor was partially supported by the National Major S&T Project(00ZX ) and the National Major S&T Project(009ZX ). References. S. Saagami, S. Aoyama, K. Kuboi, S. Shirota, and A. Aeyama, "Vehicle position estimates by multibeam antennas in multipathenvironments," IEEE Transactions on Vehicular Technology, 99, (4): C. Drane, M. Macnaughtan, and C. Scott, "Positioning GSM telephones," IEEE Communications Magazine, 998, (6):

112 3. T. S. Rappaport, J. H. Reed, and B. D. Woerner, "Position location using wireless communications on highways of the future," IEEE Communications Magazine 996, (4): L. Tsung-Nan and L. Po-Chiang, "Performance comparison of indoor positioning techniques based on location fingerprinting in wireless networs," in Wireless Networs, Communications and Mobile Computing, 005 International Conference on, 005, (): GPP, "Radio subsystem lin control," GSM version 4.., March Y. Oumura, E. Ohmori, T. Kawano, and K. Fuuda, "Field strength and its variability in VHF and UHF land mobile radio service Rev," Electr. Com. Lab, 968, (6): M. Hata, "Empirical formula for propagation loss in land mobile radio services," Vehicular Technology, IEEE Transactions on, 980, (9): Ericsson, "TEMS," 84

113 DESIGN AND SIMULATION OF LOW VOLTAGE SELF-LIFTING-CIRCUIT AUDIO FREQUENCY POWER AMPLIFIER HU FANG, ZHOU CUI, HAN ZHEN-DUO, QIN ZHEN-JIE Air Force Radar Academy Wuhan 43009, China Abstract: The actual maximum output power of the audio frequency power amplifier and its efficiency are both lower than the theoretical value in ideal state because of the effect of saturation voltage drop, negative load and nonlinear distortion of the triode under a limited requirement to the nonlinear distortion. And it s clearer especially when it goes under low voltage. Self-lifting-circuit is a specific positive feedbac which can enlarge the dynamic output range of the amplifier. The circuit output voltage can be upgraded after two magnifying tubes are added into the OCL circuit to promote the maximum output power and efficiency. The simulated experiments show that the maximum output power and its efficiency in the OCL self-lifting-circuit can be promoted greatly. Key words: the audio frequency power amplifier; nonlinear distortion; the dynamic output range; maximum output power. Introduction OCL and OTL are two common forms of small low frequency power amplifier circuits. Tae OCL circuit for example, the maximum output power and its highest efficiency of the collector under ideal state show as follows [], P ( V V ) CC CE(sat) VCC omax = () RL RL π VCC VCE(sat) η π C max = = 78. 5% () 4 VCC 4 Of them, V CC - V CE(sat) = V om shows the amplitude of the maximum output voltage without distortion, and V CC is the power voltage. It is nown from Equations & that the effect of V CE(sat) is ignored, and there is nonlinear distortion with the triode. But in real applications, the actual maximum output power and the highest efficiency of the collector are both lower than the results gained under ideal state because of the effect of saturation voltage drop,v CE(sat), and negative load of the triode. It can also be nown from Equations & that the lower the power voltage V CC is, the greater the effect of V CE(sat) is. And the actual maximum output power and the highest efficiency of the collector may be evidently lower than the ideal value.. Some specific problems with the low amplifier of Class AB under low voltage. Factors affecting output power ) The saturation voltage drop cannot be ignored. The effect can be ignored while the power voltage is comparatively higher with V CE(sat) at the position of (0.~0.3)V. But at a low voltage run, if it s in OCL circuit V CC =.5V(or in OTL circuit V CC =3V), the effect of V CE(sat) cannot be ignored. At this moment, P omax and η are decreasing greatly. Cmax 85

114 ) The voltage gain at the end of the amplifier is less than when load is smaller. No matter it is in OCL or OTL, actually there exist two emitter followers which tae turns to wor. Under normal conditions, the voltage gain of emitter followers is less than, almost closer to []. When load is as small as a loudspeaer of 8Ω, the voltage gain is clearly lower than. It indicates that the amplitude of the output voltage without distortion will be lower than V CC -V CE(sat), so P and η Cmax will still get lower. omax 3) The nonlinear of triode limits the maximum non-distortion output voltage. When the output voltage of low amplifier is close to or reaches maximum value, its operating point may approach the saturation region or the cut-off region, at this point, the nonlinear of the amplifiers appear more evident, that is, the higher the amplitude of the output voltage is, the greater the nonlinear distortion is. For example, when V CC = V R L = 8Ω, the amplitude V om, the output power P o and the total harmonic distortion THD of the integrated audio amplifier LM380(the amplifier level is OTL circuit)are shown as Table [3]. Table. The output voltage, the power and the total harmonic distortion of the LM 380 output voltage V om (V) P o (W) THD notice >0% the state of maximum output 8 4 <0.5% 7 3 <0.% From the above, the amplitude of the output voltage must be restricted under the circumstance of a higher requirement to the nonlinear distortion. It can be concluded that the output voltage amplitude cannot reach it maximum, the output power is reduced and its actual efficiency is far lower than the ideal value by 78.5% with the effect of the saturation voltage drop, the load and the nonlinear distortion of the low amplifier Class AB under low voltage.. Simulated analysis of common low amplifier Class AB with low voltage When V CC =.5V R L =8Ω and the input signal frequency is sine-wave Hz by using software Pspice to do the simulated analysis of the normal OCL circuit, the simulation result is as follows if the nonlinear total harmonic distortion is demanded to be THD<%. When the maximum output voltage amplitude is V im = 0.78V, the output voltage amplitude is V om = 0.637V. Analyzing the DC component of single collector current I c0 = 6.mA, THD in the circuit is.8%. So, the actual voltage gain in the circuit is A v = 0.87, the output power is P o = 5.4mW, the supply power is P D = 78.6mW and the true efficiency is ηc = 3.3%. The OCI Amplifying Circuit is shown as Fig. R R 50 T3 50 T QN QN Vcc.5Vdc 0 VOFF = 0 VAMPL = 0.78v FREQ = K T4 QN907A RL V3 T 8 QN907A 0 R R4 50 Vcc.5Vdc 0 Fig OCL Amplifying Circuit 86

115 The simulation indicates that if THD is demanded, the maximum output power and efficiency in OCL circuit is lower the theoretical value under the ideal state. And it appears more evident especially when the low power voltage and the load resistance are both smaller. 3. the design of a self-lifting low amplifier 3. The basic principle of a self-lifting OCL circuit In order to improve efficiency and output power, many inds of low frequency power amplifiers are designed and utilized. Those amplifiers used many patterns such as a BTL pattern [4], D ind [5~6] or G ind [7]. Although these amplifiers can effectively raised the output power and efficiency, they used more components and the electric circuit is more complex. On the other side, in the application of Self-lifting circuit in OCL, the circuit is simple and it can solve a special problem such as efficiency of the amplifier woring under low voltage. Self-lifting circuit is actually a specific feedbac. It wors in the following way. Change the instantaneous electric potential at a certain position in the circuit by taing the advantage of the instantaneously unchangeable feature between the voltages at two ends of the capacitance,in other words, promote the electric potential at one end of the capacitance to control that at the other end. Applying self-lifting circuit can enlarge the dynamic output range of the amplifier. So, a self-lifting circuit is connected in an OCL circuit to enlarge the dynamic output range of the circuit and promote its maximum output power and efficiency. 3. Basic principle of self-lifting OCL circuit Ordinary a Self-lifting circuit in OCL (or a Self-lifting circuit in OTL ) only added the circuit to one power amplification tube, which results in the two tubes have different amplification capacity. The output waveform has a clearly nonlinear distortion [8]. To avoid this, we give each amplification tube a Self-lifting circuit. The amplification tubes will construct a double Self-lifting circuit. A double self-lifting circuit in OCL is shown in Figure. C 00u A R R T Vcc.5Vdc 0 T3 QN QN O VOFF = 0 VAMPL =.44v FREQ = K 0 V3 T4 R3 50 QN907A T QN907A R4 RL C 00u Vcc.5Vdc 0 Fig A self-lifting OCL amplifying circuit As shown in the figure, C R R consist of the self-lifting circuit of T, and consist of that of T. R R 3 are used to prevent a shortcut caused by the output signal passing through C C. Tae Tube T in the circuit in Figure for example, after a self-lifting capacitance C is connected, the electric potential at the static Point A is the component voltage of R and R V BE3. V V V + CC BE3 A = R VBE3 ( V CC + BE3) R + R = V (3) 87

116 But the electric potential at the static Point O. So the DC voltage of the self-lifting capacitance isv C = VA. V C Will eep constant in one period as long as the time constant C R is big enough. The electric potential at Position O will go up from the static 0V to V CC value, when the positive half-period of the signal is input and passes through T and the input signal amplitude is getting larger in static status, the output voltage amplitude is also increasing. And the static electric potential at Position A will be promoted as the potential at Position O is increasing, v A = vo + VC = vo + VA. When the input signal reaches its maximum or the output voltage reaches the maximum and is closer to V CC, the electric potential at Position A is, v A = vo + VA V CC + ( VCC + VBE3 ) > CC V (4) So, the input current is big enough to mae the operating point of T saturated and the output range of T even bigger. 3.3 Simulation analysis of the self-lifting OCL circuit When the condition and the requirement are the same with normal OCL circuit, use software Pspice to do the simulated analysis of the normal OCL circuit, the simulation result is as follows. When the maximum input voltage amplitude is V im =.44V, the output voltage amplitude is V om =.8V. It can be found that the DC current component of the single collector is I c0 = 65.6mA after the Fourier functional analysis on the current of amplifying collector, and meanwhile THD is equal to.87%. So, the actual voltage gain in the circuit is A v = 0.889, the output power is P o = 0.4mW, the supply power is P D = 96.8mW, and the actual efficiency is ηc = 5.0%. The comparison between an OCL circuit and a self-lifting OCL circuit is shown in Table. OCL Table the simulation comparison between an OCL circuit and a self-lifting OCL circuit V im (V) V om (V) P o (mw) P D (mw) η C theoretical % actual % Self-liftingOCL % The parameter analysis on self-lifting capacitances C C and the resistances R R 3 as shown in Figure 3 & 4 indicate that when R =R 3 = 50Ω and self-lifting capacitances C C are bigger than 50μF, it will not affect the output voltage much, when C = C = 00μF and the resistances R R 3 are less than 00Ω, it will not affect the output voltage, either. Fig 3 Parameter analysis of self-lifting capacitances 88

117 Fig 4 Parameter analysis of self-lifting resistances 4. Conclusion A Self-lifting circuit has been widely applied in a transistor circuit, and applied in a radio tube circuit [9]. It is especially used under low-voltage, The maximum non-distortion output voltage can be promoted in collecting with an OCL circuit in a higher demand of non-linear distortion, it also means the great promotion of the maximum output power and efficiency. The simulation of self-lifting circuit in OCL indicates that when the power voltage is ±.5V, the load resistance is 8Ω, the total harmonic distortion is lower than %, compared to OCL circuit, the output voltage of double self-lifting circuit in OCL will be doubled and its maximum output power can be tripled and the efficiency can be promoted by 0%. So, self-lifting circuit in OCL can largely prevent the limitation of saturation voltage drop to the output voltage and enlarge the dynamic output range in the circuit; meanwhile it can also reduce the effect of low load to the output voltage and promote the load capacity in the circuit. Especially in the operation of low power voltage, self-lifting circuit will greatly better the main functional index of the audio power amplifier which is of great practical value. References. Zhang Suwen. Low Frequency Electronic Circuit (Second Edition). Beijing, Higher Education Press, Feng Jun, Xie Jiaui. Electronic Circuit Linear (Fifth Edition). Beijing, Higher Education Press, Xie Jiaui. Electronic Circuit Nonlinear (Fourth Edition). Beijing, Higher Education Press, Wang Shaoang, Wu Jin, et al. BTL CMOS Audio Power Amplifier with Low Static Power Consumption. Electron Devices, 008, 3(): Du Qiang. Design and Simulation of D Kind of Voice-Power Amplifier. Electronic Component & Device Applications, 00, (): Sun Yuqing, Wu Chuanxin, et al. Design of Class D Audio Amplifier with High Efficiency and High Fidelity. Microelectronics & Computer, 00. 7(3): Xia Shouxing. Analysis and Design of High Efficiency G-type Audio Power Amplifier. Audio Engineering, 009, 33(8): Zhang Jinzhu. The Design of A Kind of Small Signal Voice-Power Amplefier Circuit Parameter. Computer & Telecommunication, 008, (3): Zhou Jinglei, Li Chengliang, et al. Design of High Fidelity Headphone Amplifier Based on Vacuum Tube SEEP Circuit. Audio Engineering, 009, 33():

118 TEST ANALYSIS VOLTAGE FLUCTUATIONS PERFORMANCE OF THE SINGLE-PHASE ASYNCHRONOUS MOTOR (BIS) ZHANG XIN-FANG Zhanjiang Normal University, Zhanjiang Guangdong, 54048, China Abstract: This article is to the impacts when the power grid voltage fluctuates on the single-phase induction motor s performance. Series of tests, include, Load Test Temperature experiment, Noise Test and so on; From experimental studies which analyse experimental curve of data, we can determine when the power voltage will affect fluctuation single-phase asynchronous motor s performance Key words: Single-phase asynchronous motor;voltage fluctuation;test analysis. Introduction Single-phase asynchronous motor is also called single-phase induction motor. Its power is supplied by single-phase AC power. It has a series of advantages, such as simple structure, low cost,reliable running and easy maintenance and so forth so that it is widely applied to all wals of life. In recent years, as power capacity is constantly changing and frequent voltage fluctuations caused by the changes of various load power, single-phase asynchronous motor is permissible to run within the ± 5% of rated voltage. If the voltage goes beyond this range, various function index and running index of the motor will go wrong, which has adverse impact on the economic running of motor and shortens the life span of it. In the course of the motor s usage, if the index of motor loss is under qualification, the supply of the power resources will be affected and the rate of the electrical power utilization descended [].. Outline In order to learn the influence of the voltage fluctuations to the parameter, performance and various index of the single-phase asynchronous motor, the author has made a lot of comprehensive tests about it. The tests have explained the influence of the power voltage fluctuations to the motor s performance. Be tested motor is CO90L-4 single-phase capacitor start motor, brand-name data U N = 0V, I N = 6.77A, P N = 0.75W, n N = 450rmin-, f = 50Hz, E-class insulation. Tests of U N, U N ±0% and U N ±5% have been carried out under five types of voltage.if we have nown the nown measured value of the insulation resistance, the real measured value of the cold-lie DC Resistance, the no-load test data of the single-phase asynchronous motor, and data of short-circuit test, the noise tests about the rising temperature of the single-phase asynchronous motor, load test and single-phase asynchronous motor can be carried out.through the test outcome, the influence of the voltage fluctuations to the single-phase asynchronous motor has been carefully studied []. 90

119 3. Comprehensive Experiment 3. Temperature rising Temperature data of measured temperature rising test can be seen from the Table. Tab Parameters of Temperature test No U I P R f Grid Rate V Grid Rate A Grid Rate W Ω 0 300/ / *0/ / / *0/ / / *0/ / / *0/ / / *0/ / / *0/ / / *0/ / / *0/ Load test Data of the measured load test can be seen from Table. Tab Parameters of load test No I P n Grid Rate A Grid Rate W r/min 80 0/ *0/ / *0/ / *0/ / *0/ / *0/ / *0/ revised rate of rising temperature can be seen from the calculation sheet 3 of the load test. I 6.9 Δθ t 0 = Δθ = = I N 6.77 Calculation sheet of load test can be seen from Table 3 9

120 Tab 3 Calculation sheet of load test N I P s s ref p w p w p s P cosφ η A W W W W W % Noise Test Table 4 Measurement Data of Noise Test R ref =3.Ω Tab 4 Measurement Data of Noise Test No P V 98 (V) 09 (V) 0 (V) 0 (V) 3 (V) 4 (V) Bacground noise V V V Table 5 Calculations of Noise Test Tab 5 Calculations of Noise Test No I V 98 (V) 09 (V) 0 (V) 0 (V) 3 (V) 4 (V) I P L W G Fig Comprehensive test curve of motor 9

121 Fig Comprehensive test data curve of motor 4. Analysis of test result When U N ;U N ±0%; U N ±5%;five types analyses of test date of motor ) summary of multi-performances of single-phase asynchronous motor in every voltage Summary of multi-performances of single-phase asynchronous motor can be seen from table 6, and the test made references measurement of insulation resistance, winding cold measurement and hot resistance measurement, no-load test, and data of bloced rotor test [3~6]. Tab 6. Summary of multi-performances of single-phase asynchronous motor Number Performance item Unit Test result Voltage values U V Voltage per-unit U* Starting current I st A Times of starting I st * Starting torque T st g.m Times of starting torque K st * Slip ratio s Efficiency η % Power factor cosφ Temperature θ Noise I p db )The temperature curve with the voltage fluctuates Figure shows the temperature curve with the voltage fluctuates 3)The noise variation curve of voltage fluctuations Figure 3 shows the noise variation curve of voltage fluctuations 93

122 Fig Voltage fluctuations of the temperature rise curve of the impact of changes in Fig 3 Data curve of Noise test 4. Summary Through a number of analysis of test results, electrical voltage in the range of performance parameters is studied ; though series of test data, the relationship between a series of parameters is analysed. When the voltage fluctuates downward, temperature rise rises with the voltage s dropping, which increaseds utilization of the material ; noise falls with the voltage s dropping. When the voltage fluctuations up, as the voltage increases, both temperature rise and noise rises, and single-phase induction motor s performance will reduce [7~8]. The analysis of combining single-phase induction motor load and short circuit test performance shows, whether single-phase induction motor applied voltage increases or decreases, there are some advantages and some disadvantages, so we should consider the application from a practical point of view. When electrical wor at the rated voltage, all its performance parameters can achieve a better state, so when designing, we should consider performance parameters and the power supply voltage and voltage to choose options [9]. References. Pan ChengLin. Practical Handboo of Small and Medium Motor. Shanghai: Shanghai Science and Technology Press[M].007, 0.. Zhang XinFang. Electric Traction and Control. Beijing: Electrical Power Press[M] Standard Number:[S]GB/T ,Stand Name: Basic Technical Requirement of Motor Control 4. Standard Number:[S]GB/T 57-00,Stand Name: General Technical Requirements for Small Power Motors 5. Standard Number:[S]GB/T , Stand Name: Single-phase Induction Motor's Test Methods 6. Standard Number:[S]GB ,Stand Name: Electrical Noise Measurement Method, etc 7. Zhang Fan. Apply MD3A to Have Integrative Test on Agricultural Submerged Motors Parameter[J].008, (4): Dan WenPei, Dan XinAn,WangBing, Electrical Equipment Testing and Troubleshooting Examples[M]. China Water Conservancy and Hydropower Press.006, (): Yuan GuanYi.Beijing: Electronic Industry Press[M].The First Edtion,

123 TEST ANALYSIS VOLTAGE FLUCTUATES IMPACTS PERFORMANCE OF THE SINGLE-PHASE ASYNCHRONOUS MOTOR (ONE) ZHANG XIN-FANG Zhanjiang Normal University, Zhanjiang Guangdong, 54048, China Abstract:The purpsose of this article is to analyse the impacts when the power grid voltage fluctuates on the single-phase induction motor performance, Series of tests, include Insulation resistance easurement, Winding cold and hot state resistance measurement No-load test Loced-rotor test ; Experiments study to analyse experimental curve of data, results from the analysis, we can determine the factors that affect fluctuation single-phase asynchronous motor s performance when the power voltage fluctuant Key words: Single-phase asynchronous motor;voltage fluctuation;performance analysis;test analysis. Introduction Single-phase asynchronous motor is also called single-phase induction motor, which is a drive power that is supply with single-phase AC motor.it has a series of advantages lie simple structure, low cost,,reliable operation, easy maintenance and it is widely used in industries and daily life.in recent years, networ capacity continue to change, due to the voltage fluctuations which are caused by changes in networ load,single-phase asynchronous motor in the bottom 5% rated voltage operation is allowed.if beyond this range,it will do harm to the functional indicators and the operational indicators,and it also harm the economic operation and shorten the engine`s life.during the using process,if the engine fails to meet the requirements,it will affect the electricity supply and decline the electric utilization. [].. Outline In order to mae sure that whether the voltage fluctuations will affect the motor parameters, performance and indicators,we will test the single-phase asynchronous motor integratedly.by this experiment,we can analyze the voltage fluctuations`effect on motor performance. [] Under these five voltages lie UN;UN±0%; UN±5%,we mae many tests.they are insulation resistance measurement; the actual state of winding DC resistance of cold determination; single-phase induction motor no-load test; single-phase asynchronous motor short-circuit test; With the results, we carefully study the voltage fluctuations on the single-phase asynchronous motor performance. Be tested motor is CO90L-4 single-phase capacitor start motor, brand-name data UN = 0V, IN = 6.77A, PN = 0.75W, nn = 450rmin-, f = 50Hz, E-class insulation. 3. Comprehensive Experiment 3. Insulation resistance measurement. The data of insulation resistance measurement is in Table, 95

124 Tab. Test data of Insulation resistance No. Type Object Cold state insulation resistance Thermal state of insulation resistance Primary winding and chassis Vice-winding and chassis Lord, Vice-winding The actual state of winding DC resistance in cold determination Data of DC resistance in Table. Tab. Test records of DC resistance Unit: Ω No. Resistance (Ω) The chassis` temperature( ) Cooling medium`s temperature ( ) The DC resistance under the actual temperature of the cold winding: R C = = No-load Test ) Records of No-loaded test is in Table 3 Tab 3 records of No-load test ( Ω) No. U o I o p o Case Rate V Case Rate A Case Rate W 8 300/ / / / / / / / / / / / / / / / / / / / / / / / / / / / / /50 40 Others U o I o p o Case Rate V Case Rate A Case Rate W / / / R O =.8(Ω) R om =.83(Ω) 96

125 ) Calculation of no-load test is in Table 4 Tab 4 Calculation of no-load test No. U o /U N (U o /U N )² p ocu (W) p o (W) p o (W) I o (A) ) Calculation of the test result: The alculation of rotor winding equivalent resistance: o r = om =.8 =. 64( Ω) p R I o 4)The no-load test characteristic curve is based on the experimental data and the calculated analysis data. When Uo=U N =0 V, p Fw = 3 W, p F e = 4 W,the no-load test characteristic curve is in figure. Fig no-load test characteristic curve 3.4 Bloced-rotor test The measurement data of bloced-rotor test is in Table 5. 97

126 Tab 5 Data table of bloced test No. The maximum current stall The minimum torque around wall U I U Gross weight Dead weight Case Rate V Case Rate A Case Rate V Kg g / / / / / / / / / / / / / / / The short-circuiting bar L=m The blocing test parameter calculation table is shown in Table 6. Tab 6 parameters of bloced test No. Project Net weight (g) T (g m) VoltageU (V) Note:T =net weight the length of the short-circuiting bar Indicated by the curve,when U = 0 V,T =.45 g m,i = 36.9 A,when U = U N = 0 V,T is T st;t st = T =.45 g m,i is I st, I st =I = 36.9 A.The bloced test characteristic curve is shown in figure. [3~6] Fig Bloced test characteristic curve 3.5 Summary of multi-performances of single-phase asynchronous motor and test data curve )Summary of multi-performances of single-phase asynchronous motor 98

127 Under these five voltages lie UN;UN±0%; UN±5%,we mae tests. summary of multi-performances of single-phase asynchronous motor,table is shown in Table 7. Tab7. summary of multi-performances of single-phase asynchronous motor Number Performance item Unit Test result Voltage values U V Voltage per-unit values U* Starting current I st A Times of starting current I st * Starting torque T st g.m Times of starting torque K st * Slip ratio s Efficiency η % Power factor cosφ Temperature rise θ Noise I p db Stator current I A )Fig3 is the curve of motor s the voltage fluctuation times with the change of the voltage fluctuation. 3)Fig4 is the curve of the starting current with the change of the voltage. Fig3 Motor torque curve with the voltage Fig 4 Voltage fluctuation on the impact 4)Fig5 is Voltage fluctuation on the impact of changes in slip curve, 5)Fig6 is Voltage fluctuation on the impact of power factor cosφ curve. 6)Figure 7 is the changing curve of the current I with fluctuant voltage. 7)Figure 8 is the changing curve of efficiency with fluctuant voltage. Fig 5 Voltage fluctuation on the impact of changes in slip curve Fig 6 Voltage fluctuation on the impact of power factor 99

128 Fig 7 The changing current curve on the impact of fluctuant voltage Fig 8 The changing efficiency curve on the impact of fluctuant voltage 4. Summary Through the analysis of tests' results and mae research on the motor's performance parameters under different voltages, and according to the tests data, get a series of parameters )When No-load and the voltage downward fluctuations, NO-load exciter current I0 increases with voltage, stator current I decreases with increasing voltage )Starting torque increases with the voltage increases, that is the multiple of starting torque increases with voltage increases. Starting current increases with the applied voltage increases and decreases with the voltage decrease 3)Slip decreases with the applied voltage increases 4)Power factor decreases with the voltage increases. 5)When U N is 0.95,I is minimum, under other voltages, whether the voltage is increasing or decreasing, current I increases with it. When voltage decreases, the rotor current I proportionally increases with the voltage decreases, I 0 decreases with decreases of voltage; 6)When current is at the lowest point, the voltage is U L. When U<U L, I proportionally increases with the voltage decreases, therefore, the stator and the p Cu will increase. When U>U L ;I increases with the voltage increases and p Cu gradually increases 7)Rotor Copper (aluminum) consumption p Cu: Maintained output power constant, if the applied voltage increases, p Cu will become larger with the voltage decreases 8)p Fw and p s have nothing to do with voltage,they are unchanging constants. 9)Iron loss p Fe : motor's iron loss p Fe 's loss increases as the voltage becomes larger [7] 0)Mar U L (voltage when the current at the lowest point)as the base point,regardless of increases or decreases of the applied voltage, the efficiency reduce. Motor's starting torque and starting current decrease, which maes the starting performance worse. Efficiency drops first and then increases with voltage decreases, which maes the wor characteristics of the motor better and then worse and cos ϕ subsequently increases to get better performance. Temperature rise increases with voltage drops, which made the utilization of the material increasing, and noise lower with the voltage drops. When the 00

129 voltage fluctuations up, with the voltage increases, the motor's starting torque and starting current rise, so will lead to temperature rise and noise increased(read the No-load test), but the efficiency and power factor are reduced with it. From this can own that, when the voltage increases, starting performance higher and utilization of materials increases, while other performances reduce. [8] All in all, whether single-phase induction motor's applied voltage increased or decreased has its positive side also has its negative side. So from the perspective of practical application, when motor wors at the rated voltage, its all performance parameters can achieve a better state, so various performance parameters and supply voltage should be taen into account to select the voltage in the design.the conclusion has guiding help for people, who engage in single-phase induction motor design, manufacture, testing, using, control, and college laboratory personnel, students major in electricity and engineering and technical personnel. [9] References. PAN ChengLin. Practical Handboo of Small and Medium Motor. Shanghai: Shanghai Science and Technology Press[M] ZHANG XinFang. Electric Traction and Control. Beijing: Electrical Power Press[M] Standard Number:[S]GB/T ,Stand Name: Basic Technical Requirement of Motor Control 4. Standard Number:[S]GB/T 57-00,Stand Name: General Technical Requirements for Small Power Motors 5. Standard Number:[S]GB/T , Stand Name: Single-phase Induction Motor's Test Methods 6. Standard Number:[S]GB ,Stand Name: Electrical Noise Measurement Method, etc 7. Zhang Fan. Apply MD3A to Have Integrative Test on Agricultural Submerged Motors Parameter[J]. 008, Dan WenPei, Dan XinAn,WangBing, Electrical Equipment Testing and Troubleshooting Examples[M]. China Water Conservancy and Hydropower Press Yuan GuanYi.Beijing: Electronic Industry Press[M].The First Edtion,

130 THE ANALYSIS AND DETECTION OF CT SECONDARY SIDE FAULT IN HIGH-VOLTAGE POWER MEASURING SYSTEM ZHANG SU-JUN, YAN LEI-BING, NIE YONG-FANG Department of Machinery and Electricity, Henan Institute of Science and Technology Xinxiang ,China CHENG JIAN-FENG Department of Foreign Languages, Henan Institute of Science and Technology Xinxiang ,China ZHANG LI-LI College of Information Engineering, Henan Institute of Science and Technology Xinxiang ,China Abstract:On the analysis of the faults, the detection means is presented in this paper. It can detect the faults that are inter-phase short circuit and opposing connection including one phase or two phases together in current transformers secondary side in high voltage power measuring system. And this detection means can judge the faults by use of the phase relationship of two-phase current that is phase A an C in secondary side. And it also can judge the types of the faults. And what's more, the detection circuit is simple, realized easily; furthermore, only two voltage values need to be measured. Key words: inter-phase short circuit; high voltage power measuring; detection circuit. Introduction High-voltage Power Metering System adopts the three-phase three-wire mode of connection through potential transformer (PT) and current transformer (CT), whose sophisticated mode can mae some users deliberately change correct connection to count less power or even no. This occurs mostly in secondary side of CT and PT s measuring system, whose low voltage and small current mae it operated easily without detection. It is given the model and simulation of short circuit of the primary or secondary side of current transformer for the high voltage electric power metering system []. At present,some literature, through the analysis of failure in reversed polarity of current transformer [,3,5,7], gets its measurement to compare with the normal one, however, this mentions few fault detection methods. By far, the most direct method is still using a lot of measuring tools as the 0

131 voltmeter, ammeter, phase, phase-sequence table to measure some parameters and draw a vector diagram for analysis after that. However, the result is not perfect for not meeting real time requirement. Although using standard vector chart [4, 6] may simplify the judging process, its premise is on the correct connection of voltage transformer, which still needs to measure seven parameters. The discussion of secondary inter-phase short circuit is less [], even without the proper test methods. As a result, to find the fault detection is very significant, on which the new test method, with simple circuit, less parameters and no vector diagram, is proposed in this paper. This structure is as follows: firstly, the analysis of faults in reversed polarity of current transformer and inter-phase short-circuit current transformers, then the commonly used method of reversed phase, and finally the new detection method.. The Analysis of CT Secondary Side Failure. The Reversed Polarity of Current Transformer The connection of current circuit will change its correct phase relationship in energy meter as well as the voltage and current phase relationship, maing the electric energy measurement incorrect. There are many ways of current circuit connection in CT secondary side, which may connect current transformer polarity reversely or exchange connections of two or three phase current. This paper focuses on the analysis of reverse connection in A current of CT secondary side with wiring diagram and vector diagram shown in figure and. Fig The Reversed Connection in A current of Secondary CT Secondary Side 03

132 U ab U a φ a I a U cb I c φ c U c I a U b Fig The Vector Diagram of Reversed Connection in A current of CT Secondary Side The measuring power is [8] : P = U ab I a cos( 0 + φa ) + U cb I c cos(30 = UI cos( 30 + φ) + UI cos(30 φ) φ ) c = UI sin φ () Type maes clear that the measuring value of energy meter will depend on power factors, so the actual electricity record may be positive or negative. U ba. The Secondary Inter-phase Short Circuit of Current Transformer The correct connection of three-phase three-wire energy metering system [9] is shown in Figure 3. Fig 3 The Wiring Diagram of Three-phase Two-component Measuring System 04

133 When the short happens between a- and c-phase circuit current, the voltage on electric wire of the measuring element I and II is secondary current they are U ab and cb I a and U respectively, and with the interphase short circuit in a and c circuit, the I c of transformer TA and TA pass through the current soil at the same time, so ( I + a I c ). The equivalent circuit diagram is shown in figure 4. I + A I C I A Ea I C Z Z a Ec c ( I + A I C ) ( I ) A + I C ZII ZI Fig 4 The Equivalent Circuit Diagram of a and c interphase Short Circuit In figure 4, on the left, E a, E c are potentials for TA, TA; Z a, Z c, impedance for equivalent simplified circuit of current transformer; on the right, the equal Z I, Z II are the impedance of electric energy meter currentcoil. When the interphase short circuit occurs between a and c, it is equal to TAand TA paralleled. Now ( I + a I ) provide power for energy meter current coil, and because c Z I = Z II, the current through the component I and II is ( I a + I c ). The vector diagram is figure 5, U ab U a φ a I a I + a I c U ab U a φ a I a U cb I c φ c ( I ) U a + I c cb U c I a U b I c φ c U b U ba U c Fig 5 The Vector Diagram of a and c Interphase Short Circuit so the measured power of I and II is: P = U ab ( I a + I c ) cos(30 φb ) () P = U cb ( I a + I c )cos(30 + φb ) (3) 05

134 Because the above three-phase three-wire current circuits are symmetrical, so the total power is: P = P + P = UI cos(30 φ) + UI cos(30 + φ) = 3UI cosφ (4) 3. The Commonly Used Method of Secondary Reversed Phase of Current Transformer Judging whether opposing connection of current transformer the polarity of current transformer is reverse or U ab and U cb, U ca and current I a, the I c. Its inspection criteria are decided by the following principles. not, it needs to detect the following parameters: line voltage amplitude and phase Angle of ) Considering the limit load cases, namely the capacitive or perceptual, the current and voltage phase sequence must be in a limited range, which is considered normal. So although this can ensure it without U cb lags behind I c misjudgment, some wrong phase faults may be missing. When the load is capacitive, by0 ; when perceptual, U cb advances I c by60, therefore the normal phase relationship lies between them. Similarly, when the load is capacitive, U ab lags behind I a by 60 ; when perceptual, U ab advances I a by0, therefore the normal phase relationship lies between them. Due to fluctuation of voltage and the allowed voltage unbalance, the misjudgments can be avoided by modify the phase angle. ) The premise of judging the current misphase is no pressure loss and flow, no CT fault. 4. The Detection Methods of Current Transformer Reverse Polarity and Secondary Inter-phase Short Circuit The proposed method in this paper only needs two parameters to detect the reverse connection of current transformer, including a reverse connection of current transformer, two reverse connections and inter-phase short. Detection circuit is simple as to achieve it easily. Detection design:in accordance with the phase relationship between be judged. Assumptions: the three-phase load is balancing and perceptual. Normally, by 0 0, but with the\reversed current transformer polarity, the phase relationship between I a and I c.the fault and its type can I c lags behind a I c is constant ahead of I a I a and I c is 60. I by 0 0 ; and when they are However, with the reversed polarity of both current transformers, in secondary side interphase short, the current of two components is ( I a + I c ). This shows that both their phase and amplitude are the same. Detection methods: it's easy to see from detection design that this method is simple for not needing many parameters to measure and drawing vector diagram to judge fault. Its detection circuit is shown in figure 6. 06

135 U ab U a I + a I c ( I + a I c ) φ a I a I c U cb I c φc U c I a U b U ba Fig 6 The Detecting Vector diagram of reversed polarity of current transformer and the short circuit for current loop between phases To lin a current transformer tester TA3 in the secondary loop current of current transformer TA, then to lin a current transformer tester TA4 in the secondary loop current of current transformer TA,. For the simpler one, two hoops can be used for current transformer tester to turn the measurement of I a and I c into the measurement of u and u. Because two R resistances are lined to TA3 and TA4, so only measuring u and u is enough to judge the fault and its type. Above all, this method can judge the above three faults by measuring u and u &. 5. Conclusion In this paper, the common secondary side faults in high-voltage power measuring system and its influence to the system has been analyzed, whose focus lies in the secondary short circuit such as the reverse polarity connection of current transformer and its inter-phase short. Then the detection methods on the phase relationship of two vectors are put forward, which are easy to judge and needs few measuring parameters, but confined only to the normal power. References:. Zhang Su-jun Kong Xiao-hong Ning Xin. Fault analysis and modeling for the high voltage electric power metering system technology and application of electronic information, 009, (0): Shi Xin-li, Du Xi-feng, Yan Ying, Xi Lei, Li Qi-lin. The analysis and calculation on short for current loop between phases of in one phase of electrical power measurement devices [J].Electrical Measurement & Instrumentation 005, 4(7): Zheng Zhong- fa, Liu Jian- hui, Liao Yong, Kang Guang- yong Analysis of three phase three wire electrical energy metering device commonloop breaing and inverse wiring of current transformer secondary circuit[j]. 07

136 Electrical Measurement & Instrumentation 007,44(7): Li Yin Wang Zhe.The analysis on the wrong wiring of the electrical energy measurement device[j]. Electrical Measurement & Instrumentation 006, 43(3) : Zeng Fan-hua Analysis on Several Wrong Coupling Line of Current Transformers Two Phase Star Coupling Method[J]. Metrology & Measurement Technique.009, 36(0): Huang Kai-lai.The Vector Analysis of Three Types of Wiring Error for Three - Phase Three - Wire Electric Energy Meter [J]. Metrology & Measurement Technique.009,36(): Du Wei-hua, Zhou Hong, Chen Hai-bin,Wang Hui. Influences of wrong secondary wiring of tap current transformers on electricity metering[j]. East China Electric Power.008, 36(): Qiu Guan-yuan, Luo Xian-jue, circuit[m], Beijing,Higher Education Press Liu Jie-cai,factory electricity supply[m], Beijing,China Machine Press

137 THE DESIGN OF AUTOMATIC IRRIGATION SYSTEM BASED ON PLC ZHENG YAN-LING, CHENG JIAN-FENG, ZHANG SU-JUN Mechanical and Electrical Engineering School,,Henan Institute of Sicence and Technology Xinxiang Henan, , China Abstract: This article presents the automatic irrigation control system with Programmable Logic Controller (PLC) as core system,the system combines irrigation system with automatic control, which maes the system irrigating without people based on the prescriptive program or the instruction through controllers. Besides couches, motor,water pump and pipes, this system has central controllers, solenoid valve, sensors and wire, and so on. The sensors send collecting-data to intelligent control unit,then send to upper monitor or control center to indicate, deal with and storage. The built-in procedure of the system inputs the signal of soil moisture measured by humidity sensor to PLC to compare with the value of optimal moisture for controlling the open and close of the electrical motor and water pump well to realize the automatic irrigation control. This design, for its low cost, simple management, maintenance and operation, can be used easily in the small irrigation system in vast rural areas. Key words: Programmable Logic Controller; automatic control; central controllers; the sensors. Introduction In our country, potential of saving hydroelectric resource is very huge. However, some irrigation systems abroad, because of its complex installation, maintenance, control and high cost, are not suitable for us. On the other hand, the irrigation equipments made in China, though the cost is relatively low, cannot achieve timing, quantitative irrigation for its ordinary relay control system maes it less sensitive and difficult to debug and maintain, so its maret share is very low. In this paper, the organic combination of PLC automatic control irrigation system can run automatically in accordance with the provisions of the program or command by the controller. The small self-control programmable logic controller (PLC) system, with its low cost, high reliability, low energy consumption, is suitable for operation in various conditions. Furthermore, it can meet various needs through the change of software configuration with hardware unchanged, so it is the ideal substitute of traditional relay control and has wide application prospects and use value in small pumping irrigation system when unattended or half [].. The Overall Design of Automatic Irrigation System The combination of PLC automatic control irrigation system can run automatically in accordance with the provisions of the program or command by the controller. In addition to emitters, pipe fittings, pumps and motors, this system also has a central controller, solenoid valves, sensors, wire etc. Firstly, the collected signals are sent to the intelligent control module by the sensor, and then they are displayed, processed and stored when arriving at the monitoring computer or the controlling center through the communication system. The whole controlling system of irrigation networ is divided into 3 grades []. 09

138 )The automatic measuring instrument In every round irrigation area, choose one watch-point with representative soil, sunlight, etc, in which a set of automatic measuring instruments with a soil moisture meter, a wet sensitive resistor is installed to automatically meter soil moisture and weather conditions. )The main controller(plc) The main controller (PLC) collects and analyzes the control index surveyed by the measuring equipment of automatic irrigation. When the index meets the crops irrigation, the main controller will issue orders to each sub control station and test its actual wor conditions automatically and continually, the result of which will be displayed through a video display terminal. 3)The sub irrigation control station Receiving and memorizing orders sent by the main controller, the sub irrigation control station controls the operation of electric gate valve and pump and delivers its actual woring condition to the main controller in the form of information which is displayed in the machine screen [3]. The diagram is shown as in figure... Upper PC Monitor 上位机管理 of PC 温度传感器 Temperature Sensor A/ D RS3 电磁阀 Solenoid valve 雨量传感器 Pluviometer FP-C40C M 水泵电机 Water pump motor. 控制按钮 Control Button Power supply 电源 Indication 指示 Alarm 报警器. Fig. Bloc diagram of automatic control system 3. The Design of PLC Irrigation System According to the design, the irrigation control system consists of PLC controller, dc 4V power supply, start / stop buttons; the data acquisition device includes soil humidity sensor, various buttons, while the electromagnetic valve and pump motor belong to the output execution components. The alarm device is an alarm flashing indicator light or an alarm bell, whose woring principle is when the system wors, the light is on. And through the communication in RS3 of PLC, centralized managements can be realized in large-scale irrigation areas. The C40C programmable controller input in this paper is 4 points(x0-x3),output 6 points(y0-y5).the former and the latter are distributed [4] as PLC wiring hardware diagram in figure. 0

139 .. K0 Y0 KMY 电机 switch KMY on of 接通 motor Start button of motor 电机启动按钮 X0 K KM switch on of motor Stop button of motor Y 电机 KM 接通 Manual indicator light Manual model 电机停止按钮 X K Y Automatic 手动显示灯 indicator light Automatic model 手动模式选择 X Y3 Solenoid valve Pluviometer 自动显示灯 K3 Solenoid valve Manual sound attenuation Y4 一号电磁阀自动模式选择 X3 Solenoid valve 3 Overload protection of K4 motor Y5 Operation 二号电磁阀 indication of valve Humidity sensor 雨量传感器 X4 Operation indication of valve K5 Y6 Operation 三号电磁阀 indication of valve 3 Switch of valve Switch of valve 手动消音按钮 X5 Y7 Power 一号阀运行指示 indication K6 Rain gauge Switch of valve 3 Y8 电机过载保护 X6 Soil drought 二号阀运行指示 indication K7 Y9 Proper 三号阀运行指示 humidity indication 湿度传感器 X7 Excessive water indication K8 YA 电源指示. 一号阀开关 二号阀开关 三号阀开关 K9 K0 X8 X9 XA PLC FPC40C YB YC YD YE COM COM 0V FR 雨量报警器 土壤缺水指示 湿度适宜指示 水份过量指示. Fig. Hardware wiring diagram of PLC 4. The Software Design of Automatic Irrigation System According to the actual situation, the communicative function must be realized between the system and the monitoring machine, so the software system adopts a client/server architecture, whose structure diagram is shown as in figure 3. Using Kingview software [5], a Human Machine Interface is drawn as in figure 4. State-collecting and PLC controling module Inquiry module of long range Communicatio n module Print module of report forms Monitoring platform Data collection Information statistical and automatic irrigation module Fig.3 Software system chart of automatic system Fig.4 Human-computer interface of control t In this process, put the soil moisture signal gotten by humidity sensor into the data register DT0 of PLC, and then put the upper limit (-50Pa)of soil moisture into DT4, the lower limit(-60pa)) into DT, as a consequence, when the soil is unwatered or appropriate, the relevant indicator will be on [6].

140 5. The Debug of Hardware and Software in Automatic Irrigation System Automatic irrigation control is a complex system with various valves, pumps, control units and other hardware [7]. The layout diagram of its use is shown as in figure 5. Solenoid Solenoid valve Solenoid valve Water pump Control center Cont rol unit of wor field Cont rol unit of wor field Fig.5 Totality layout chart of automatic irrigation control system Through field test, the ground data of TS-4 soil humidity is shown as in table. Table Data measured by TS-4 soil-humidity sensor Measure data Measure time Weather condition temperature/ Mercury column Point Point h /cm h /cm PF-value /-Pa Indicated value of instrument /-Pa Relativ e error Sunny Sunny Sunny Sunny cloudy day cloudy day Sunny Sunny Sunny Sunny Note:Relative error =( PF-value- indicated value of instrument)/ PF-value. verage relative error is -0.99%. When energized and commissioned, the system can wor according to the requirements. Pressing the start button, the pump motor can finish Y/ start in s, and then runs in the normal state. When setting the soil moisture detector into the dry soil, the detection shows that the humidity is lower, and the indicator is on at the same time, so the electromagnetic valve will open to irrigate. If setting it in the moist soil or in the swamp, the indicator is on, so there is no irrigation. When pouring some water into the rain sensor, the rainfall alarm wors. In this case, to press the alarm button can stop alarm manually. All of this shows that the design with high reliability can achieve the expected requirements [8].

141 6. Conclusion This article presents the automatic irrigation control system with Programmable Logic Controller (PLC) as its core system,whose built-in procedure inputs the signal of soil moisture measured by humidity sensor to PLC to compare with the value of optimum moisture for controlling the open and close of the electrical motor and water pump to realize the automatic irrigation control. Then, the overall scheme has been analyzed and certificated; the PLC hardware designed and programmed; the data, measured and tested. This design, for its low cost, simple management, maintenance and operation, has tried the use in water saving irrigation system, having a certain theoretical value and practical significance [9]. References. Wang Xiaoguang. Principle and application of PLC[M].Beijing:Engineering Industry Press Chang Douna. Principle and application experiment of PLC[M]. Beijing:Engineering Industry Press, Universal Automatic Software Science and Technology Limited Company of Beijing Kunlun.MCGS User Manual Xia Hong, Lin Gangyong,Zhu Zhaoyou and XU Wen. An Irrigating System Controlled by PLC. Journal of Machine Tool & Hydraulics. 007, 35(7): Che Xiu-bo, Che Yi-man and Chen Xi. Oil Tans Area Monitor System Based on PLC and Configuration Software. Journal of Automation Application.00, (): Deng Gang, Song Keling and Wang Dazhi. Design and Application of PLC in Elevator Control Model. Journal of Industrial Control Computer. 00,3(5): Liao Yuwu,Liu Kefei and Hu Jiaqin. Digital Temperature Monitoring System Based on Configuration Software. Journal of Coal Mine Machinery. 009, 30(8): Jiang Hai,Tian Chunyan. Application of MCGS Configuration Software in PLC Woring Monitor. Journal of Equipment Manufacturing Technology.008, (): Yu Zhongan, Liu Ying. Automatic Monitoring System for Material Level Based on PLC and Configuration Software. Journal of Mining & Processing Equipment.008,36():

142 STUDY ON THE EXPERIMENT OF ALL-WEATHER SOLAR WATER HEATER ZHONG CHENG-YAO School of Physical and Electrical Engineering, Hainan Normal University at Haiou Haiou Hainan, 57045, China Abstract: All-weather solar water heater, which maes the most use of direct and indirect solar can provide hot water in all weather. Heating at the day s highest temperature enhances greatly the energy efficient ratio,cooling at the day s lowest temperature enhances greatly refrigeration coefficient to save electric energy. In summer, it is able to supply hot water and relevant cooling, avoiding heat pollution and cooling loss. In winter, it is able to supply hot water and relevant heating. The water cycle system which is adapted to store and supply of heating and cooling, reduces the area of solar collector and lins of heat exchanging to reduce cost. All-weather solar water heater with advantages such as high conversion efficiency of solar energy and heat energy, initial cost, operating cost and power saving which are better than traditional solar water heater of the same volume, has a great potential for future applicatio Key words: All-weather solar water heater; highest temperature enhances; lowest temperature enhances; operating cost. Introduction What is the all-weather solar hot water system? Simply speaing, it is a solar hot water system and project which is always ready to provide hot water anytime. It allows users (including collective users and family users) never to worry about if it has hot water for bath now? Compared with the previous one which promises hot water everyday (actually, only have hot water at some times in everyday), its concept is clearer. At the same time, it guarantees user s trouble free at the bad weather such as cloudy, rainy, wind and snow []. Solar is a ind of widespread, abundant, clean renewable energy. Solar water heater directly changes solar to heat energy. It has great social and economic effect to use solar water heater world-wide. However, it is difficult to realize to supply hot water in all-weather. As solar energy is intermittent with low density, it needs high initial cost and large hot water storage tan and assistant energy and it is polluted and inconvenient to use oil or gas as assistant energy. If assisted by electric heater to heat large amount of bathwater, converting high-grade electric energy to low-grade low temperature thermal energy, it is not reasonable and needs great electric consumption. Indirect solar energy can be used for heating bathwater. It is defined as the low temperature thermal energy heated by solar in the air, surface seawater, surface ground. It is widely and evenly spread, supplying heat at inds of different temperature. Therefore, air heat pump [~3] is widely used all over the world. Nevertheless, air temperature varies greatly with regions and season rhythm which result in following problems during the usage: difficulty in startup in winter and low energy efficiency, evaporator needs large absorb heat area which result in mass air flow, easily frost which lost great heat. Comprehending the advantages of current technology of heat pump used by indirect solar energy and solar water heater used by direct solar energy while overcoming their disadvantages, all-weather solar water heater combined both technology of using direct and indirect solar maes the most use of solar energy to realize to supply hot water 4 hours everyday and four seasons all the year. At the same time, it supplies relevant cold to air condition in summer while supplies relevant heat to eep warm in winter. Both initial cost and operating cost of 4

143 all-weather solar water heater is less than common solar water heater with equivalent volume. In cloudy and rainy day, it saves electric energy no less than 80%.. Experiment of all-weather solar water heater The common solar water heating system is composed of solar thermal collector, a hot water storage tan, a pump, interconnecting pipes, assistant heater, controller and other components [4~6]. However, all-weather solar heater adds air thermal collector, air heat exchanger and cold water storage tan which can mae the most use of solar energy to supply hot water and cold water while reduces thermal pollution and saves the normal energy by a wide margin.. Experiment construction In all-weather solar water heating system, as depicted in figure, Fig Construction of all-weather solar water heating system the inlet of (solar thermal collector) is connected by an adapter under the 5 (hot water storage tan), while the outlet is connected by an adapter above 5 and 6 (nozzle) through 8(component throttle valve) and 7 (component pump), which forms a circle directly heating water by solar energy. The hot water inlet of (air heat exchanger) is connected by another adapter under 5 while the hot water outlet of is connected by another adapter above 5 through 3 (hot water input throttle valve) and 4 (hot water pump), which forms a water heating circle directly and indirectly used by solar energy. It heats water in 5 according to the program until the water reach to temperature supplied through 6 or pipes to hot shower or other usage. In the water cooling side of air circle, the cold water outlet of is connected by an adapter under 8(cold water storage tan) while the cold water inlet is connected by an adapter above 8 through (cold water input throttle valve), 0 (cold water input magnetic valve) and 9 (cold water input pump), which forms a water cooling circle. Another adapter above 8 is connected by (fan coil) and the cold water outlet of 5 (air absorber), while another adapter under 8 is respectively connect by the cold water inputs of and 5 through 6 (cold water output magnetic valve), 7 (cold water output pump), 3 (coil throttle valve) and 4 (absorber magnetic valve), which forms separated circulation of both cooling refrigerating air-container and air thermal absorber. (solar thermal collector) adopts separated solar convection collector to form flat-plated collector. Or adopts relevant flat-plated collector which is simple, low-cost, high efficient, with flat, light and thin surface easily installed on building, and anti-freezing. Both water inputs 5

144 above and understand the and 5 eep water temperature of tan well balance through water distributor to ensure high efficiency of water heating.. Experiment data Relevant date as showed in sheet. Sheet experiment data Standard Actual NO. Name value value NO. Name Standard Actual value value Solar collector area/m.94 3 Cooling supply/kw Air absorber area/m outlet temperature of fan coil(a)/ 3 hot water storage tan volume inlet temperature of fan coil(b)/ cold water storage tan volume water cooling flow/t/h input electric power of heat exchanger /KW water heating flow/t/h.5.8 depends on high average efficiency of solar thermal Hot water supplying flow/t/h difference and valve of collector /% fan nozzle 7 electric power of air absorber/kw.3 9 cold water supplying flow /t/h(a) heat capacity of heat exchanger/kw Hot water supplying flow /t/h(b) cooling capacity of heat exchanger /KW heat preservation of hot water storage(daily temperature) / /4h cold preservation of hot water storage (daily temperature)/ /4h water flow of solar collector/t/h air absorber flow/t/h Air exchanging efficiency/% Sensitivity of temperature Hot water supply/l/4h controlling / ±.5 From sheet we can conclude that all-weather solar water heater has high efficiency with cooling efficiency 3.9, heating efficiency 4.4, and total efficiency Experiment analyses 3. Hot water supplying As proved in experiment, all-weather solar water heater with solar thermal collector whose area is only 70% of the common one provides hot water totally by solar energy both in sunny and cloudy climate. In cloudy and rainy climate, 5 (air absorber) absorbs air thermal to heat water in 8 for supplying hot water, with electric consumption is no more than /4.4 of the common. Sometimes there is solar radiation. But when water doesn t reach to the right temperature, the sun and the air will complement with each other to heat water. The heating 6

145 efficiency will reach above 8.8 if preheated by air source. It can also design according to angle of sunshine, climate condition and user s requirement to reach to the temperature of heating and water supply, supplying (fan coil) with hot water and heating via pipes and exchanger. Since the thermodynamic efficiency of pump system is closed related with outlet hot water temperature, it is given theoretically by the following equation [7] : T COP = ξ T T () Where COP is the coefficient of performance, ξ is thermal perfectness of system, T is temperature of inlet air wind, and T is temperature of outlet hot water. The coefficient of performance is defined as the heat capacity in unit consumed power. Obviously, the higher the COP is, the more the system saves energy. As nown from formula, when the outlet hot water is at a certain temperature, the coefficient of system performance is affected by the temperature of inlet air wind. In this system, the air source water heater mainly wors at the highest temperature during a day, which means the COP will be higher while T-T is lower. The annual average temperature in Haiou, Hainan is 3.8 degree, with the highest average temperature is around 8 degree and the lowest average temperature is around 8 degree. Assuming that hot water is at temperature of 45 degree, that means T=45. According to the formula it will be Assuming T= T COP ξ T T ξ + = = = 45 8 ξ Assuming T= T COP = ξ = T T ξ = 45 8 ξ COP 8.7ξ = =.59 COP.78ξ We can find that the coefficient of performance at the highest temperature is.59 times as the lowest temperature.the main factors which influence the energy efficiency ratio of air-conditioner COP are outdoor temperature and indoor temperature. Figure displays COP changes with outdoor temperature at different loading ratio. When loading ratio is 0%, 50% and 90%, and indoor temperature is set as 0 degree, the rule of COP with outdoor temperature is showed in the figure: COP increases with increasing outdoor temperature. Known from previous analysis, when heat in winter, outdoor temperature reflects the changing of evaporating temperature while indoor temperature reflects the changing of condensing temperature. So, coefficient of performance COP increases with increasing evaporating temperature when condensing temperature remains constant [8]. 7

146 Fig COP changes with outdoor temperature at different loading ratio The ambient temperature is linear to COP as shown in figure 3. Fig3 Effect of ambient temperature on COP COP increases with increasing ambient temperature while increase degree is related to temperature of water. Ambient temperature varies directly with COP: COP decreases around 0.5 as ambient temperature decreases 0 degree [9]. According to above analysis, it saves energy greatly to heat at the day s highest temperature. 3. Cold water supplying When the temperature of 8(cold water storage tan) is higher than the temperature of cooling air-container, (air heat exchanger) wors to decrease the water of 8 to the desired temperature of air-container and also the hot water of 5 to the temperature which the design requires. It allows cold water supplying while cooling. The COP of cooling reflects the cooling capacity of refrigeration unit as shown in formula(), refrigeration coefficient increases with the evaporating temperature increasing and decreases with the condensing temperature increasing [0]. T0 ε = T T0 () Where ε is COP of cooling;t0 is evaporating temperature;tk is condensing temperature. When cooling, (air heat exchanger) wors at the day s lowest temperature to storage the cold in 8(cold water storage tan) to enhance the ε for saving electric energy. In summer of Haiou, Hainan, the average highest temperature above 3 degree is 33 degree while the average lowest temperature is 5. According to formula (), it has Assuming TK=33, 8

147 Assuming TK=5 T0 T0 ε = = T T 33 T 0 0 T0 T0 ε = = T T 5 T The ε wors at the lowest temperature is ( + ) times as wors at the highest temperature. 5 T 0 Assuming evaporating temperature and desired refrigerating capacity Q0 eep constant and gas in compressor is saturated, figure 4 [7] displays the related changing rate of ε and compressor power consumption when condensing temperature changes among 5-40 degree calculated by computer programming. Fig 4 Compressing circle performance changes with condensing temperature Both experiment data and computerized data show that ε decreases around % and compressor power consumption enhances around % relatively with condensing temperature TK enhances every degree. From above analysis, refrigerating at the day s lowest temperature saves electric energy greatly. 3.3 Heat supplying and Heating Heat supplying and heating can come true by connecting (fan coil) with hot water supplying circle through exchanger and controller. Computer automatically controls all woring progress of the all-weather solar water heater. 4. Conclusion The all-weather solar water heater realizes supplying hot water in all weather through maing the most use of direct and indirect solar energy. Heating at the day s highest temperature enhances greatly the energy efficient ratio, consummating little electricity to gain heat as much as possible and saving electric energy. Cooling at the day s lowest temperature enhances greatly ε to save electric energy. In summer, it is able to supply hot water and relevant cooling, avoiding heat pollution and cooling loss. In winter, it is able to supply hot water and relevant heating which water cycle system is adapted to store and supply of heating and cooling, reducing area of solar collector and lins of heat exchanging in order to reduce cost. All-weather solar water heater with advantages such as high conversion efficiency of solar energy and heat energy, initial cost, operating cost and power saving are better than traditional solar water heater of the same volume. This study of experience on a ind of high efficient solar water heating system has a great potential for future application. 9

148 References. Xu Changfu, Also Tal About All-weather Solar Water Heating System.Solar Energy, 004, (): Luo Huilong, Tie Yan and Li Ming, et al., Thermal Performance Study on a Solar Energy Water Heating System in Conjunction with Air-source Heat Pump. Building Science, 009, 5(): Lin angli, Hot water engineering design using air source heat pump integrated with solar energy and technical and economical comparison. Refrigeration Technology, 009, (): 5-4. Leng Tianjiu, Han Leitao and Xie Jian, et al., SWH Project Management Research. Solar & Renewable Energy Sources, 008, (3): Chen Su, Discussion on Optimal Design for Housing Centralism Solar Energy Hot Water System. Construction Energy Conservation. 009, 37(6): Zhang Lina, Zhang Yizhi and Tian Rui, et al., Energy Saving Benefit Analysis of Solar Water Heating System. Energy Technology, 007, 8(4): Huang Xunqing, Approach to Technical Design Solutions of Household Air-Source Heat Pump Water Heaters (Ⅰ). China Appliance Technology, 006, (): Xue Weihua, Liu Chuanju and Chen Peilin, Analysis of heating energy consumption of the VRV air conditioning system and its influencing factors. Hv & Ac, 00, 3 (4): Jiang Lvlin and Zhang Ye. Analysis of Economical Performance in Air Sources Heat Pump Water Heater. Journal of Jiangsu Polytechnic University, 009, (): Cai Wenhai, The Research On The Refrigeration Coefficient Of The Central Air Conditioning and Energy-saving Of Refrigeration Host. Energy and Environment, 004, (4): 8-3 0

149 THE DESIGN OF A EMBEDDED VEHICLE HAND-FREE PHONE BASED ON BLUETOOTH COMMUNICATION ZHANG DUO-YING, TU CHANG-YAN College of Information Science and Technology, Ji Nan University Guangzhou, 5063, China Abstract: A car hands-free phone was designed with embeded system.the system uses embedded systems as a platform,realizing voice and data communications with the mobile phone through Bluetooth wireless communication technology,and realize the vehicle communication networ, hands -free functions through the serial port send control commands and extract call information.the system has the friendly man-machine contact interface, and displays woring condition real-time.also the user can dial, answer,rejector adjust the volume through the friendly man-machine contact interface.meanwhile,system has strong expansion,supporting for GPS positioning,security and other vehicle electronic systems. Key words:embedded; Bluetooth; GUI; Driver. Introduction With economic development and social progress,cars began to enter the civilians, at the same time,driving safety naturally became a topic of concern.in the process of driving,the use of mobile phones is main problem which caused drivers distraction,and proned to traffic accidents.traffic laws also prescible that drivers can not use cell phones and other communication tools in the process of driving.the Bluetooth communication technology realizes mobile phone interconnect with the vehicle hands-free phone which achieve hands-free feature that can liberate the driver's hand and eye.it is convenience to people's lives, and ensure traffic safety [].. Bluetooth. Bluetooth Technology Overview Bluetooth is a open standards of wireless data and voice transmission.it will be a variety of communications equipment, computers,terminals,data system,even the home appliance connected wirelessly. It has transmission distance of 0cm-0m.It will have transmission distance of 00m,if increase the power or add some peripheral.it uses.4ghzism band,frequency modulation, frequency hopping, the right to use the error correction coding, ARQ,TDD and baseband protocol.bluetooth support for 64b / s real-time voice transmission and data transmission and use 48-bit global unified device ID [].Bluetooth has strong portability and wide range of applications as it uses the wireless interface instead of the limited cable.also Bluetooth is easy to promote because of Low power consumption,less harmful and application of simple [3].. Bluetooth Core architecture Bluetooth specification include Core Protocol and Application Specification. Logically,the protocol stac of bluetooth contains three components(figuer ): Transport protocol group which locates bottom layer, protocol group which locates intermediate layer and application group which locates higher level [4].

150 application group protocol group TCP/IP PPP IrMC OBEX AT Command TCS RFCOMM SDP transport protocol group LCAP HCI LM Audio BaseBand RF Fig protocol stac of Bluetooth Transport protocol group which locates bottom layer consists of RF,BB,LM,LCAP and the protocol of HCI.Its main function is to enable Bluetooth devices to identify each position each other and build,deploy, mainten and manageme logical lin to services for the upper layer protocol. Protocol group which locates intermediate layer contains some standard protocols, and some SIG developed specially protocols, namely,serial port emulation protocol(rfcomm), service discovery protocols(sdp),lrda interoperability agreement(lrobex), the telephone communications protocol(tcs) and so on.they provide some abstraction standard interface for application layer [5]. The specification profiles of application layer include some application protocol subset which corresponds to a variety of applications model and the protocols of practical application which is develop by user. 3. Bluetooth Hands-Free System 3. Specification Overview of Bluetooth Hands-Free Applications Bluetooth application specifications provide that technical standards which the two sides of the Bluetooth device should meet to achieve a certain application.the specifications include that provision of applied characteristics,definition of applied model,configuration of core protocol stac,some protocols which are defined to achieve specific applications on the core protocol,and other provision which meet the requirements of interoperabilitable [6]. Bluetooth application specifications provide process of establish Bluetooth data and voice connections between voice gateway and hands-free equipment,and how hands-free equipment control mobile phone remotely based the lin and access the external networ to realize communication [7].

151 3. Realization of Bluetooth Hands-Free Application Specification Figure is a configuration of protocol stac.sending the dedicated control commands through the RFCOMM to achieve hands-free criterion [8]. Application (Audio port emulation) Hands-free control RFCOMM SKP Application(Audio Driver) Hands-free control RFCOMM SKP LMP LCAP LMP LCAP BaseBand Audio Gateway side BaseBand Hands-free terminal Fig Protocol stac configuration These commands are a subset of AT commands set and add the special instructions. We can complete status display,answer,reject,hang up,remote volume control,control echo cancellation,noise suppression and voice recognition and so on through AT commands set. In addition,in order to meet the requirements of interoperabilitable, hands-free specification also made some provisions in aspect of the connection process of Bluetooth channel and security management.when voice gateway and hands-free devices are binding,hands-free specification provide that voice gateway should be the initiator.voice gateways query the device and hands-free devices inquiry and scan.voice gateway can found hands-free device within the effective range.then the voice gateway initiate binding process through establishing a connection with call equipment and hands-free device.in this case, the voice gateway can only be as the main equipment, hands-free equipment can be as slave.connection request is initiated by hands-free devices or voice gateway after binding.and hands-free devices and voice gateways have no fixed main equipment and slave. 4. System Hardware Design 4. System Framewor The system used a powerful ARM9 series CPU as hardware platform;because Samsung S3C440 chip can be applied extensively,and has complete development information and high performance,we chose Friendly Arm mini440 development board as a hardware development platform which uses Linux.6 core operating system and has a friendly man-machine interface through Qt/Embedded. The system uses BTM004CP Bluetooth hands-free module which is developed by JinOu Science and Technology Development Co., Ltd in Chong Qing.The module connect with development board through the serial port and achieve Bluetooth hands-free functionality through AT command.meanwhile, the Bluetooth module integrated RF transceiver, baseband transmission, audio codec, and DSP echo processing functions.the system of man-machine interface display woring status after connection module with the phone.users can achieve related operations through a touch screen and communicate by speaer and microphone in the car.the structure of the system shown in Figure 3. 3

152 Car Audio Control Interface Audio Interface Host Controller GUI Bluetooth Subsystem Audio Converter RF BaseBand UART SSI SSI Processor Control Interface Fig 3 System Structure 4. Bluetooth Module Application Circuit In practical we use car stereo and speaers.the system enable switch automatically betweem vehicle hands-free phone and mobile phone.in addition,the BTM004CP Bluetooth module provides a standard UART interfaces.the circuit uses MAX33 chip which convert the module's TTL level into the standard RS3 interface,then the Bluetooth module connected to the ARM9 development board directly through serial cable. 4.3 Serial Communication Software Design Bluetooth software flow chart shown in Figure 4. Bluetoot module initialization Query and read address of the Bluetooth Prepare to establish a connection with the device. Y Whether the equipment had been connected N Establish physical lins to the equipment and conduct the pairing process. Establish a connection with the device. Establish RFCOMM connection. Fig 4 Bluetooth software flow chart 4

153 When customers need to connect the Bluetooth,it only need to press the corresponding button on the touch screen,you can complete the primary pair.then Bluetooth module is authorized as "automatically connect equipment" in the mobile terminal, and that can automatically connect Bluetooth module afterward,and establish the connection.if you mae a call, press the dial number,then press the call ey,then you can connect.and the phone which matches with the Bluetooth module also has a corresponding demonstration.if another phone call the mobile phone which has been connected,the touch screen and mobile phone numbers shows the other's number at the same time.pressing the answer button on the touch screen can connect to phone,using headset and microphone on the Bluetooth module to conversation and achieve hands-free phone function;pressing the end button on the touch screen can end the call;pressing the reject button on the touch screento can resist the call.and users can adjust the volume accordingly during a call.at the same time,users can also switch from the system of hands-free phone to the phone.the system redial the last dialed phone number when users press the redial button.through pressing the voice dialing button,starting the voice dialing function,and saying "call to 'so and so'" facing the microphone of the system,the system realizes voice dialing feature,which requires the phone support for the corresponding function. 5. Conclusion This system uses the formidable ARM9 series CPU as the hardware core platform and Linux operating system,realizing the friendly man-machine contact surface through Qt/Embedded,and it has completed the touchscreen driver program.the system has realized Vehicle Hand-Free Phone s basic functions,it can connect paired mobile phone automatically,display woring condition real-time,display the telephone number,and has realized the pronunciation dialing.also the users can dial,answer,reject or adjust the volume through the frendly man-machine contact surface.what s more,this system can be separated from the platform,and realize the vehicle communication networ s hands-free functions through the Bluetooth technology. References. Qian Zhihong,Yang Fan,Zhou Qiuzhan.Bluetooth principle, the development and application. Bei Jing: Beihang University Press,006.. Shen Liancheng,Song Tiecheng,Ye Zhihui. Development and Application of Embedded System. Bei Jing: Electronic Industry Press, Sun Zhiyan,Chen Xihua,Li Jinghua.Bluetooth hands-free phone system application technology in the car.journal of Gui Lin College of Aerospace Technology,007, (3): Jin Chun,Xu Guangchen,Sun Rui. Bluetooth Technology.Bei Jing: Electronic Industry Press, Dai Shenghua. Embedded System[M]. Bei Jing: China Railway Press, Zhang Jianghong. Design of car hands-free phone based on S3C440 and Windows CE. Journal of Hunan University of Arts and Science(Natural Science Edition), Tong Li. Rong Sheng Electronics topic.[eb/ol] Wang Long,YAN Yonghong. Multi-vehicle Anti-theft and Bluetooth Hands-free Mobile Communication System Design. Journal of Xiangnan University,00, (): -5. 5

154 CONTROLLED ORGANIC LIGHT-EMITTING DEVICE DRIVING CIRCUIT WANG LI-ZHONG, ZHAO LEI, JIANG WEN-LONG, ZHANG GANG, HUANG TAO, GAO YONG-HUI College of Information &Technology,Jilin Normal University, Siping Jilin, 36000, China Abstract: This paper describes Light-Emitting Device Driver IC SSD303 performance characteristics and application of technology based on focused on using Solomon's products control the driver IC SSD303 OLED display and the microcontroller AT89C5 monochrome OLED display driver means. And described the realization of text, static image display software design methods, shows the system wors and the role of various control signals driving IC timing settings for the practical application of OLED provides a feasible method of driving. Key words: OLED; Program-controlled;driver;Pixels;Single-chip. Introduction Electroluminescent display (OLED) technology is the next generation of competitive flat-panel display technology. With low power consumption, low cost, self-luminous, wide viewing angle, simple process, low cost, good temperature tolerance, fast response, the manufacturing cost low and the advantages of flexible displays [~4]. Organic light-emitting device is the current flat-panel displays one of the hot research areas. Different ways according to their driving can be divided into passive drive (Passive Matrix, PM, passive drive) and active driver (Active Matrix, AM, active drive). Active organic light emitting display in each pixel are integrated after a group of thin-film transistor (Thin Film Transistor, TFT) and storage capacitors, composed of pixel driving circuit, OLED pixel drive circuit controlled by the TFT. Passive Matrix Organic Light-Emitting Devices driver control circuit exists, such as "crosstal" and the "cross" effect and more complicated circuit to connect a number of shortcomings. Since OLED is current-mode device, the luminous intensity is the current flowing through the device control [5~7]. Present, there are two inds of modulation methods: one pulse width modulation (PWM), or by controlling the current flowing through the device to adjust the length of time; second pulse amplitude modulation (PAM), that is by controlling the magnitude of current flowing through the device size to adjust. This article discusses the method of maing OLED matrix display and control the use of OLED drive circuit and microcontroller AT89C5 SSD303 OLED display driver is designed for practical application provides a feasible.. Structure and light-emitting organic light-emitting device array OLED screen used when the normal matrix OLED cross-arranged in the anode and cathode cross the middle, through the combination of anode and cathode can control each strobe light OLED's. Passive drive circuit shown in Figure. Cathode and anode cross the area of OLED light-emitting area, only if there is current only when light signals, the instantaneous intensity is proportional to the number of scanning lines with the cathode. If the panel the 6

155 average brightness of each screen 00cd/m, a cathode 96 scan lines, the pixel brightness of the wor must be 9600 cd/m, such as the opening rate of 80% must be multiplied by.5 times [5]. Fig Schematic diagram of passive circuit panel When Mou line shows the beginning, when the scan line is low, there is no current through the diode, but by the column driver circuit via the data cable to charge the parasitic capacitance, when the capacitor voltage reaches the diode turn-on voltage (about 4v) when, light-emitting diodes will, as shown in Figure, Fig structure of the device and its equivalent circuit device structure and equivalent circuit. Therefore consider the display, must pay attention to the rapid charging parasitic capacitance problem. For single-color OLED array dominion want to display text or graphics, reasonable choice of diode conduction should be achieved, the best way is through the integrated use of process control chips. SCM has a feature-rich, flexible control and so on, using AT89C5 microcontroller and the driver IC SSD303, the software can be achieved through the OLED display features. 3. The hardware structure of display driver circuit The system consists of microcontroller 89C5, power modules, control and drive circuit SSD303 OLED display composed of three parts. In this paper, 89C5 microcontroller as 8 64 OLED control of the core components, SSD303 driver IC dedicated to monochrome OLED (IC), text display and graphics to achieve static and dynamic displays [8~9]. Theoverall design of the hardware structure shown in Figure 3. Figure drawing dotted 7

156 lines to the overall selection Visionox's a screen VGG864G screen, you can also use separate chips and homemade SSD303 OLED. Fig 3 System bloc diagram 3. System wors Solomon Systech SSD303 is a single-color OLED driver launched the IC, using TAB pacage. It is based on CMOS technology with integrated driver IC row, column driver, oscillator, contrast control, and graphics data memory (GDDRAM), largely reduced the external devices and power consumption. Control commands through the MCU interface to control commands input to the command decoder for decoding, then the output cloc, line sync, and vertical synchronization signals to control the oscillation frequency of OLED display, display device, voltage conversion module and the rans of OLED display offset driver module; if display data (8 64bits), then display the data from the control circuit through the MCU interface input to GDDRAM cache, then local color decoder to decode the data, and finally decoded display data through the rans of drivers drive OLED display, OLED display on the show a stable effect. 3. SSD303 driver and interface circuit Figure 4 bloc diagram for the SSD303 shows that the chip logic and interface circuitry. Fig 4 Bloc diagram of SSD303 Just give use interface provides power, command signals and drives the display data signal, you can drive OLED screen, MCU interface, voltage and current controller needs is its specially designed interface and drive circuit. 8

157 In order to achieve display driver chip, programmed to display text and graphics, to communicate needs and 89C5 microprocessor [0], Figure 5 for both communication lin circuit. Fig 5 AT89C5 communication lin with the SSD303 Circuit 3.3 Power circuit To microcontroller and driver chips to wor, choose as the reference voltage 5V power supply module, power supply to the MCU, and on this basis, using LM595- switching regulator will be 5 v input voltage to provide + V output voltage, use of external hardware circuit DC-DC converter Used TPS7333 chip will convert the 5V power supply voltage of 3.3V [8], as the whole system needs to 3.3V and V power supply, power supply output voltage and current control signals control the voltage and the SSD303 current. 3.4 Various control signals SSD303 and MCU interface pins are: DO ~ D7 interface with the MCU data bus, R / W (RW #) to read and write select signal, when CS # is low, the falling edge of literacy in their effective; D / C for the data / command select signal; CS # for the chip select signal, when the CS # low when the MCU can be connected with the driver IC communication; E (RD #) To enable signal; RES # for the reset signal, when the return time low All control registers were set to factory default state, while the image registers cleared; microcontroller manufactured by ATMEL low-power, high-performance AT89C5, AT89C5 and the SSD303 and display hardware wiring as shown in Figure 5, P.0, P., P., P.3, P.4 respectively SSD303 the R / W (RW #), D / C, CS #, E (RD #), RES # lined, P0 population and SSD303 data bus. By changing the D / C, WR # and RD # 3 interface level, microcontroller on the control of four state OLED may be shown in Table. Table List of read-write state 9

158 Through procedures to control these pins, but also understand the timing of read and write, so OLED display characters or graphics needs. 3.5 Read and write timing To mae it easier for data and command successful reading and writing, in the C programming language defines the type xdata pointer type, which is the point to off-chip memory through assignment to the pointer to access off-chip data storage area, when accessing off-chip memory time, / RD and / WR will be automatically changed to read and write low, single chip set reuse mode, as long as CS # is low, the WR # (RD #) of the falling edge of the write (read) data or command can read and write effectively complete the wor. Timing waveform diagram shown in Figure 6. Fig 6 Timing Waveforms 4. Software design SCM OLED display program with C language, the main program flow chart shown in Figure 7. Fig7 the main program flow chart 30

159 MCU initialization including the closure of the watchdog, cloc initialization, the port initialization, and the timer and interrupt initialization. OLED initialization including the opening show set the display mode, set the contrast control, contrast settings ( ~ 56), set the rans of the starting address, the specific location to set the color, set the serial port pin configuration. Clear OLED screen and OLED display are GDDRAM in writing to the data, including read status, write command, write data routine, clear OLED screen on the entire writing "0, OLED display as long as written by the text or image to display the character code that be. each write (command or data) must be read before the state, to see whether the highest bit D7 "0" or "busy" test, if it is ", indicating" busy "; contrary to" idle "in" busy "situations can write. 5. The display of text and pictures VGG864G built-in 8 64 bits of display memory for storing display data. RAM capacity of 8 64 = 89 bits, it is divided into 8 pages, just the first column is a byte, low in the last, high in the next; screen display of each pixel on the status of you and display binary data memory one correspondence, display memory directly as a graphical display of data drive signal. Data is displayed as "", the corresponding pixel display; data "0", the corresponding pixel is not displayed. The display text or image character library using the "font extraction V." software. OLED display according to the data RAM address structure select vertical modulus way, because OLED module structure is the high byte low in the next, so be set to byte reverse order, character fonts, font, size, and display ( underline and striethrough) can be adjusted as needed, then tae C5 format, modulo the lattice generated display a single character code, and finally required in the OLED screen on the display, adjust the code required can be obtained character library. Acnowledgements Designed based on AT89C5 microcontroller as a controller, drive through the software program sends the control signal to drive the output to drive OLED light, in order to achieve OLED display method. For its functions and features to address the relevant parts of the circuit design, and implemented on the system developed by the text, static image is displayed. The simple circuit design, the system greatly reduces the cost, so that the system can be used in small devices. In the design process by the strong support of colleagues, expressed appreciation. This paper is sponsored by: Jilin Science and Technology Development Program (005053,008058); Jilin Province Department of Education research project ([003] 5, [004] 54, [007] 54); Siping Technology project (four subjects in the first word No.,005,007, four subjects in Zi No References. HeieR,TillmanA,suegfriedK,etal.Roleofcopper phthalocyanine in multilayer organic LEDs based on small molecules[j]. proc.spie, 003, (8): Wang Yuan-min,Teng Feng,Ma Chang-qi,et al. Green to with to blue OLEDs by using PBD as a chrcity-tuninglayer[j].diplays,004,5(5): Li Feng,Chen Gang,Zhaoyi,et al. White-electro phosphoresce-cence.devicesbased on rhenium complexes[j].appl.phys.lett.,003,83(3): Lei Gang-tie,Wang Li-dao,Qiu Yong. Blue Phosphorescent dye as sensieizer and emitter for withorgain light-emitting dodes[j].appl.phys.lett.,004,85 (): Donggui Fang, QIU Yong. Dot matrix OLED driving circuit. Modern, 007, (3): Chen chin-bsin Huang Xiaowen. "OLED Organic Light-Emitting Materials and Devices." Tsinghua 3

160 University Press, Fengyong Mao, Rui-Guang Wang, Luo Jin, Xi-Feng Zheng. No cross-effects of passive OLED Driver Circuit. LCD and Display. 003,8 (5) : Shuang-Qing Li, Chiu Ying, Wang Xiangrong. "Universal Integrated Circuit Handboo for Manual." Electronics Industry Press, Xi-Feng Zheng, Pu Yan, Liu Via. Electroluminescent display structure and the drive circuit theory. Liquid crystal and show that in 000,5(): Shuhua, way bac On, Yao Wansheng. "Chip Microcomputer Principle and Application." Harbin Institute of Technology Press,

161 DESIGN OF GENERAL MODULATION AND DEMODULATION MODULE BASED ON SOFTWARE DSP_BUILDER WU YOU-FEN School of Physics &Information Engineering, JiangHan University, Wuhan, , China Abstract: Modern communications technology requires a universal, miniaturized and programmable communications system. With the rapid development of FPGA chip and continuous upgrading of EDA tools, it has become one of predominant design methods to adopt FPGA chip for ey module design of communications system. Based on general quadrature modulation method, by means of software tools such as DSP_BUILDER, this paper designed a general full-digital modulation and demodulation module based on FPGA chip, and presented system model, simulation result and analysis. This will provide favorable conditions for the development and structural optimization of various modulation and demodulation systems. DSP_BUILDER has effectively simplified design process of core development model. Key words: General modulation and demodulation module; simulation; DSP_BUILDER. Introduction Modulation and demodulation module is a significant component of communications system. Modern communications technology requires a universal, miniaturized and programmable communications system. In Software Radio technology, the design of general modem combines DSP and ASIC in most cases [~]. However, in the actual radio communications system, DSP shall accomplish mass and complex signal processing. In this case, some simple modulation and demodulation algorithm can be assigned to FPGA chip. Due to parallel processing of FPGA chip based on hardware circuit, compared with DSP, FPGA chip has the advantages of faster arithmetic speed and lower power consumption in terms of parallel multiply-add algorithm and distributed algorithm. Meanwhile, FPGA chip is dynamically configurable. With the rapid development of FPGA and continuous upgrading of EDA tools, it has become one of predominant design methods to adopt FPGA for ey module design of communications system. Based on general quadrature modulation method, by means of software tools such as DSP_BUILDER, this paper designed a general full-digital modulation and demodulation module based on FPGA chip, and presented system model, simulation result and analysis. The whole design is based upon visual design platform at algorithm level, distinguished from tedious design and debugging at RTL level, which can greatly simplify the design process.. General Modulation and Demodulation Model There is a variety of communication signals in modern communication system. However, theoretically speaing, almost every modulated signal can be decomposed into two quadrature component signals. Therefore, quadrature modulation method almost applies to every modulation system. [] As we can see from Fig. (a), the general modulation model consists of two parts, i.e. baseband signal generating circuit and quadrature modulation circuit. According to the required modulation mode, output 33

162 corresponding baseband signals I(n) and Q(n), and then multiply them with two quadrature carriers respectively and sum up, finally obtain modulation signal S(n). Fig : Digital Quadrature Modulation and Demodulation Model See Fig. (b) for the corresponding digital quadrature demodulation model, i.e. coherent demodulation model. Theoretically speaing, it applies to almost every modulation model. The main design of this paper is digital quadrature modulation and demodulation modules, involving Numerical Controlled Oscillator (NCO), quadrature modulation circuit, coherent demodulation circuit and filter circuit, etc. Each module generally adopts special chip. FPGA chips can integrate all these functions, dramatically reduce the volume of modules and form a small-sized and integrated system. 3. Implementation Method and Tools: DSP Builder DSP Builder produced by Altera Company is a system-level (or algorithm level) design tool. Based upon several software tools, DSP Builder combines design tools of system level (algorithm simulation modeling) and RTL level (hardware implementation) together, bringing their advantages into full play [3]. DSP Builder software is built in Matlab/ Simulin as the sub-module of Simulin. DSP Builder software consists of design processes from establishment of DSP (Digital Signal Processing) design model, to simulation test, HDL translation, logic synthesis, structural optimization, compiler adapting, and finally to hardware implementation. After Matlab/Simulin modeling and system simulation, Signal Complier Bloc carries out HDL translation, logic synthesis and compiler adapting; ModelSim conducts function simulation verification on TestBench. Only after Quartus II finishes a series of procedures, including adapting optimization, timing simulation, pin loc and download test, can hardware design finally accomplish. The whole design process combines system description with hardware implementation together, which fully demonstrates the features and advantages of modern electronic design automation development. Altera has provided designers with plentiful IP resources. Combined with the powerful simulation environment of Simulin, designers can accomplish the digital system design in a very short time. This paper aims to put forward FPGA design method distinguished from circuit-level method. The whole design is free from tedious program design. By means of DSP Builder tool, the design of general modulation and demodulation modules is conducted on Simulin simulation platform. 34

163 4. System Configuration and Implementation 4. Quadrature Modulation Circuit As we can see from Fig. (a), quadrature modulation circuit mainly comprises Numerical Controlled Oscillator (NCO), multiplier and adder, among which, NCO is the core of this circuit. NCO can synthesize digitally controlled frequency. It mainly consists of phase accumulator, phase modulator and ROM loo-up table. Place a pair of quadrature signals into two ROM loo-up tables respectively, e.g. one in sin table and the other in cos table. Input frequency FM can be determined by the following formula (): in FM in f N fout = () cl There into, N is bit width of phase accumulator; f cl is system cloc; f out is set output frequency of NCO. As long as the control word A can be changed, the output frequency f out can be controlled. The minimum step size of output frequency changes, namely, frequency resolution, is determined by the bit width of accumulator. If the bit width is 3 bits, then: fcl Δ fout = 3 () According to the system structure in Fig. (a), the simulation structure of general modulation module established by DSP_Builder in Simulin is shown in Figure [4~6]. Fig : Simulation Model of Quadrature Modulator Add two baseband test signals at the modulation part to simulate modulation circuit. Add sinusoidal wave and saw-tooth wave as baseband signals, and obtain simulated quadrature amplitude modulation signal. As we can see in Fig. 3, three signals are shown on oscilloscope. The one in the middle is modulated signal from baseband signals at the top and bottom, equivalent to Quadrature Amplitude Modulation signal (QAM). 35

164 Fig 3: Simulated Signal of Modulator 4. Design of Coherent Demodulator Coherent demodulator uses local NCO to produce and input quadrature LO signals with the same intermediate frequency, and multiplies them coherently with modulated signal S (n) obtained by A/D sampling, and then apply low pass filtering algorithm to the above result, and obtain baseband signals I (n) and Q (n). Without considering channel distortion, modulated signal S (n) obtained by A/D sampling is as follows: S ( n) = I cosω n Q sinω n (3) ' ' ' ( n) 0 ( n) 0 Multiplied by quadrature LO signals, and then obtain the following result: ' ' ' ' S ( n) cos ω0 n= I ( n) + [ I ( n) cosω0 n Q ( n) sin ω0n] ' ' ' ' S ( n) sin ω0 n= Q ( n) + [ I ( n) sin ω0 n Q ( n) cos ω0n] (4) Obtain low frequency part by low pass filter, namely, baseband demodulated signals ' I ( n ) and Q ' ( n. The ) performance of the filter directly determines the quality of demodulation output. See Fig. 4 for the design of the whole demodulation module. In this Fig., lpfw sub-system is low pass filter. Fig 4: Simulation Model of Coherent Demodulator 36

165 Low pass filter adopts FIR digital filter. DSP Builder can facilitate the design of FIR digital filter in graphical programming environment. Meanwhile, the calculation of filter coefficient can be accomplished by virtue of Matlab s strong computing capability and existing filter design tools [7~8]. In view of FPGA resources, this design adopts 6-Order Direct I FIR filter with 9-bit filter coefficients [9~0]. As for simulated test signal in this paper, the spectrum characteristics of modulated signal from sinusoidal wave and saw-tooth wave have gone through specific filtering design. See Fig. 5 for the filtering effect. Fig 5: Simulated Signal of Demodulator The above three waveforms shown on the oscilloscope are same-phase multiplication signal of coherent demodulator, filter output signals, namely same-phase and quadrature baseband demodulated signals. As we can see, demodulation module can demodulate signal correctly. Increasing filter coefficient and order and adopting optimal structure can further improve filtering and demodulating effect. 5. Conclusions In this paper we have accomplished modulation and demodulation module system modeling and simulation. This design focuses on implementation methods and approaches without any high requirements for signal parameters. If necessary, the performance of the system can be improved by optimizing module parameters and algorithm. The adjustable parameters have added great flexibility to this design. This design can be used as frequency band processing module of general modem, and then specific baseband transforming circuit can be designed to realize carrier modulation and demodulation. Therefore, this design can be universally applied. The whole design is based upon visual design platform at algorithm level, distinguished from tedious design and debugging at RTL level, which can greatly simplify the design process. References. Ye Fang, Li YiBind, LV Wei. The design of general platform software about modulation and demodulation with software radio,information technology 005, (3): Guo LiLi, Li ChuanQin, Tian Ye. Design of Digital Modulator Based on Software Radio, Applied Science And Technology 003,30(): Corp A. DSP Builder reference manual[m]. San Jose: Altera Corp, Pan Song, Huang JiYe, Wang GuoDong. Modern DSP technology[m] Xi an Xidian University Publishing house,003 37

166 5. Luo XiaoQiao, Wu Di, Dong JiCheng, Fan WeiLiang. Design of Qam modem based on modern DSP technology, Electronic measurement technique,009 3(): Li PanFeng, Wang ZiTing. Design of Orthogonal Signal Generator Based on DSP Builder and DDS, Taiyuan Science and Technology 008, (): Dai YiMing Liang XiaoWen, Pei XiaoPing. Design of the modern electronic system based on DSP. Beijing. Publishing house of electronics industry, Liu Wei, Gao Yong Implementation of the 6 QAM differential modulation technique, Journal of Tai Yuan university of technology. 008,39(5): Fan HanBai, SI JiaZhen. Design of 6-taps FIR filter based on DSP Builder, Modern electronic technology, 009, (): Guo HaiLi, Wang ZiTing, Design and Implementation of FIR Digital filter based on Matlab/Simulin. Power electronics 008, 7():

167 DESIGN OF TRAFFIC LIGHTS BASED ON LABVIEW YANG YONG-SHUANG, CHEN YAN Zhengzhou University Of Light Industry, Zhengzhou, 45000, China Abstract: For the urgent demand of intelligent management at intersections in many cities, this article proposed that the intelligent traffic light could be controlled by the LabVIEW software, which can instantaneously detect the transportation system's woring position and mae the corresponding setting to the woring pattern of the procedure according to the actual transportation condition. It can mae sure the safety of the vehicles and pedestrians without the massive police forces. This simple, flexible and highly reliable design with low cost and high economic efficiency could carry out the intellectual and user-friendly control to the street intersections signal light truly. Key words: Traffic light, LabVIEW, Woring pattern. Introduction Recent years, in the influence of the fast urbanization and economical development, the urban transportation glowed explosively and the question of the transportation has become the common failing that puzzled many metropolis development and has become the stern international question day by day. Meanwhile, the subject matter which causes the traffic jam is the intersection. In China, various developed city is positively exploring the methods that how to exert capacity of the road and reduce all inds of losses that creates by the traffic jam as much as possible []. The closely combination of computer and instrument is an important direction for the instrument s development presently. The hypothesized instrument uses the computer software to replace the traditional instrument's hardware to realize the signal analysis, the data processing and demonstration and many other inds of functions, which broe through the fixed pattern of the traditional instrument that the functions is defined by the factory and the user is unable to change. The hypothesized instrument has many merits such as flexiable setting up, short development cycle, low cost, easy to maintain, convenient expansion, rich software resource and so on []. LabVIEW software which was developed by American NI Corporation has the revolutionary development environment of the hypothesized instrument. It mainly applies in many domains such as instrument control, data acquisition, data analysis and data demonstration and it is suitable in many inds of different operating system platform. Differently from the traditional program language, LabView uses powerful graphical language which faces tests engineer, but not the non-specialized programmer. The program is very convenient, the friendly user interface, and it also has features such as formidable data visualization analysis, instrument control ability and so on [3]. the software was the instrument has reflected the hypothesized instrument technology s substantive characteristics.. Hypothesized instrument's development platform LabVIEW LabVIEW (Laboratory Virtual Instrument Engineering) is a graphical programming language. It is widely accepted as a standard data acquisition and instrument control software by industry, academia and research 39

168 laboratories. LabVIEW integrates all communications functionality that can meet the GPIB, VXI, RS-3 and RS-485 protocol hardware and data acquisition. It also builds in standard library functions which can apply the software such as TCP/IP, ActiveX and so on easily. LabVIEW is a powerful and flexible software, which lets you easily create your own virtual instruments [4~5]. The program that compiled by the LabVIEW Development Platform is called the virtual instrument (VI). VI includes the following 3 parts [6] : ) front panel: that is, the user interface; ) program diagram: including the graphical source code which is used to define VI function; 3) charts and wiring board: identifying VI interface, using to call another VI when create VI. LabVIEW describes the procedure behavior through the graphics symbol. When using the LabVIEW language to program, it usually does not need to write the procedure codes, what can displace is the flow chart. Moreover, LabVIEW does not need to install the hypothesized instrument software environment. In the process of demonstrates, it is possible to run the procedure by operating the execution document directly. Therefore, it simplified the hypothesized instrument' development process, reduced developing and debugging cycle and raised the programming efficiency greatly.now, It is the most widely used and most powerful hypothesized instrumental developing platform [7~8]. 3. Overview of traffic lights The common method of the traditional intersection traffic control lamp usually is after the vehicles current capacity's investigation, establishing the two direction traffic lights' time delay in advance with the statistical method. However, the traffic flow magnitude s change is often indefinite. Some street intersections even have very large differences in different time interval. Even a long-term undergoing and practical plan still will have such phenomenon: it does not have any vehicles in the green light direction, but the red candle direction actually lines up, waitting for pass. The fortuitousness of this ind of current capacity change is unable to establish the accurate model. The statistical method has not been able to adapt to the rapid developing transportation situation. The more realistic need is to have one ind of adaptive control traffic light which can control the traffic according to the current capacity s changes. Currently, the method of fixed conversion time interval is widely used in the crossroad traffic lights control in most cities. Since the current capacity is very completed and uncertain at different time for the crossroads, the fixed time control methods often waste effective time, mae empty waiting phenomenon and affect the smooth of the road. Thus, using the traffic lights which can change its time and condition under a variety of traffic conditions, could solve the problem better. 4. Designs the traffic light with LabVIEW There are many methods to realize the intersection traffic light's control. We may realize it through the plans such as monolithic integrated circuit, programmable controller PLC, standard logical component and so on. However, the revision and debugging of these control methods function need the support of hardware circuit, which increases the degree of difficulty in design to a certain extent and enhances the cost. But we can realize the intersection traffic light's control conveniently by using LabVIEW. 4. Design proposal In this design, the situation which meets frequently in the daily life need be considered separately. For instance: the transportation is quite busy at daytime, so the traffic light need to change quicer to raise the transportation efficiency and reduce the traffic jam; On the contrary, the transportation is sparse at night, so it could change slowly somewhat. Also, some certain road sections need to carry on traffic control sometimes and so 40

169 on. For all these situations, we can adopt five inds of patterns : at night to go, the normal speed, the trouble shooting, the north and south to pass through, the east and west to pass through to realize separately. 4. Front panel design The front panel of the intersection traffic light consists of Boolean lamps, two value inputs controllers, two value demonstration controllers, one under- pull menu tabulation and some beautification line. Choose the circular indicating lamp in the control board, the circular approaches the signal light, and the three Boolean lamps arrange from the top downward. Choose its attribute which respectively is red, yellow and green. Insert the five items : at night to go, the normal speed, the trouble shooting, the north and south to pass through, the thing to pass through into the under-pull menu tabulation s edition item. Then, decorate the front panel with the separation line. The front steps namely constituted the intersection traffic light's front panel that is under complex condition. Its front panel shown as Figure : Fig intersection traffic light front panel 4.3 The design of flow chart The crossroad traffic lights flow chart consists mainly of the event structure, conditional structure, tiled sequence structure, looping structures, wait time and Boolean true and false constants [6]. The design mentality is: in normal speed, the east and west traffic light and north and south traffic light does not conflict at the crossroad street intersection. When the east and west traffic light is bright to the red candle, north and south traffic light is bright to the green light, that is to say that this time the north and south direction passes through smoothly; When the north and south traffic light is bright to the red candle, the east and west traffic light is bright to the green light, that is to say that this time the east and west direction passes through smoothly. And join the yellow light in the red candle and the green light to glitter alternately three times to play the caution role. Add the surplus time to demonstrate the time that is away from the next conversion. Its flow chart shown as Figure : 4

170 Fig intersection traffic light normal speed pattern program flow diagram It s debugging results as shown in Figure 3: Fig 3 intersection traffic light normal pattern movement result When driving in the evening, the ray reduces, which causes traffic visibility dropping. In order to remind drivers to drive slow down and pay more attention to safety, the yellow light stics blining at the crossroads. Its bloc diagram shown as Figure 4: When trouble shooting, all the traffic lights at the intersection should be in power-off condition to mae it possible for the servicemen to carry on the overhaul. Its flow chart shown as Figure 5: 4

171 Fig 4 crossroad street intersection traffic light at night pattern flow chart Fig 5 crossroad street intersection traffic light trouble shooting pattern flow chart When the north and south direction passes through or the east and west passes through, the east and west traffic light or north and south traffic light and north and south traffic light or east and west traffic light does not conflict. When the vehicles of the north and south direction go slowly and the traffic jam appears, the east and west should have no entry to relief the stream of vehicles in north and south direction temporarily. When the vehicles of the east and west direction go slowly and the traffic jam appears, the north and south should have no entry to relief the stream of vehicles in north and south direction temporarily. Certainly, we may continue to increase the corresponding patterns to control path's passing through according to the actual situation, for instance, some path implements the traffic control, some path is single line and so on. 5. Conclusion Traffic control has become an indispensable composition in our daily life. In this text, the innovation is that it designed an intelligent traffic lights control based on LabVIEW. You can instantaneously monitor the status of the traffic system and set the program's operating mode appropriately in the traffic control centre according to the actual traffic conditions to control the traffic, which needn t a lot of manpower to command the traffic safety of both vehicles and pedestrian. Thus, it realizes intelligent and user-friendly traffic control at the intersection truly. 43

172 References:. Lu Pei Liu Xiaoyong. Lu Xi Intelligence street-traffic control lights control system design and labview simulation. Electronic technology, 009, (3): Broome, LabView programming style. Electronics industry publishing house Wu Chengdong, Sun Qiuye, abundant branch. LabVIEW hypothesized instrument programming and application. Beijing: People's posts and telecommunications publishing house Bi Xiaopu.LabView 8 practical tutorial. Beijing: Electronics industry publishing house Xu Xiaodong.LabView 8.5 common functions and programming example of refined. Beijing: Electronics industry publishing house Tong Gang. Virtual instruments and practical programming techniques. Beijing: China machine publishing house Nguyen Chi Ching. I and LabView an NI engineer's ten years of programming experience. Beijing: Astronautics Robert H.Bishop [US], Joe ruiping. LabView utility such as translation tutorial [M]. Beijing: Electronics industry publishing house

173 STUDY OF THE MODEL OF STRONG ELECTROMAGNETIC ENVIRONMENT EFFECT OF THE ELECTRONIC SYSTEM YU DAO-JIE, ZHANG CHANG-FENG, PANG XUE-MIN, LIN XIN, PENG PING Zhengzhou Information Science and Technology Institute Zhengzhou, 45000, China Abstract:The rapid development of information technology and its applications in military field have important practical significance on the evaluation of the effectiveness when electronic information system deals with the strong electromagnetic environment. This paper focus on the connotation of the electromagnetic environment and electromagnetic environment effect, the methods on solving effect assessment ey problems that electronic information system exposured in strong electromagnetic environment, and the developmnt of the electronic information systems effectiveness evaluation, such as the analysis and establishment of electromagnetic environment effect (E3) model of electronic information system and the preliminary research on strong electromagnetic environment system networ effect, etc. Key words: electromagnetic environment; electronic information system; electromagnetic environment effects. Introduction Early study on the electromagnetic environment mainly aims at the problems of electromagnetic interference among the electric, the inner equipment of electronic and the equipments and electromagnetic compatibility. Its purpose is to ensure that electromagnetic environment of the coexistence of system, equipment and its components wor normally and have mutual influence in allowable scope. At present, with the development of science and technology, the appearance of various military electromagnetic radiation, such as radar, high power microwave (HPM), ultra-wideband (UWB), hane-about electromagnetic pulse (HEMP) weapons of new concepts, etc, with the increasing power sources, the amount multiplied and the spectrum wide, mae the electromagnetic environment in the high technology battlefield become complicated and deteriorating. The property of the electromagnetic environment has changed, which energy change from wea to intense, frequency spectrum change from narrow to width, effects of interference became damaged. Modern power electronics system is mostly the result of machine-electricity-instrument integrated technology combining with automatic control technology with the electromagnetic sensitivity become much higher, but the strong electromagnetic environment maes its performance lowered, damaged and destroyed. Therefore, the study of electromagnetic environment effect and analysis methods and improving survival ability of electronic equipment in the strong electromagnetic environment become urgent tass [~].. Study Development of Electromagnetic Environment Effect Foreign related research can be traced bac to the 950s, then with the deep understanding of nuclear electromagnetic pulse and the appearance and practicability of all inds of electromagnetic pulse weapons, the research of electromagnetic environment effect become hot. In America, a dozens of research institutions, such as the Florida state laboratory, the Philips laboratory and so on, participate in related topics. In aspect of the experiment, the effects of the experiment ability vary from the electronic components to small electronic equipment, until such large weapon system such as aircraft and missiles. American do large experimental 45

174 researches not only on electronic components, optical fiber transmission system, and digital communication cable networ, but also on the sin electric current and inner sensitive components interference response of aircraft and missiles large complicated systems in strong electromagnetic environment. In aspect of the effect model analysis, scientific and technological personnel do a lot and in-depth researches on hole tacing coupling, field lines coupling, leptotene scattering, rotary scattering, shielding effect, reduction model, multi-conductors transmission line and its networ, jamming modeling analysis and electromagnetic reinforcement technique of complicated electronic systems and related aspects of transmission line method, the integral equation method, the singular point expansion method, the characteristic root expansion method, and the electromagnetic topological research methods and so on. In 965, C.W.Harrison.etc, based on cylindrical antennas scattering model with inhomogeneous differential equation method, calculated the missile sin electric current distribution [3] with plasma efflux. In 97, C.M.Bulter, based on thread model with integral equation method, calculated the plane surface incentive electric current [4] under the action of plane. In 977, C.L.Yu.etc, based on elliptic cylinder model, analyzed the aircraft sin electric current [5] under the action of plane. In 97, C.W.Harrison.etc, based on the theory of transmission line with integral equation method, analyzed the impedance load response [6] of multi- conductor transmission line containing n conductors under the action of the field. In 977, C.E.Baum.etc, based on multi-conductor transmission line theory with BLT equation, studied the solution [7] of the question on the multi-conductor transmission line networ with closed loop. In 975, F.M.Tesche.etc, put forward the concept of electromagnetic topology and applied it to the complicated structure internal interference analysis [8]. C.E.Baum and other scholars deeply studied this concept, maing it become the electromagnetic topology theory. Then, many scholars applied this theory to complicated electronic system effect modeling analysis and succeeded, for example, in 993, J.P.Parmantier etc, using the theory, analyzed EMPTAC (an experimental aircraft) electromagnetic interference problems under the action of the field,compared with the experimental data, and made the unanimous conclusion [9]. 3. Electromagnetic Environment Effect Modeling Analysis Electromagnetic environment effect modeling analysis is the main content of environmental effects research, applying the theoretical modeling and calculation simulation theory and other technology means to do development research on electronic system, analyzing the operational capability of electronic system, and improving the decision-maing scientific [0~].Through the simulation, the comprehensive evaluation and analysis of sensitivity analysis, we can analysis the electronic system whether satisfies the military requirement, the electronic system structure and the wea lins, so as to guide the construction direction and ey pieces of electronic system, to optimize the system structure. In terms of effect modeling analysis, we mainly adopts the method of transmission line method, integral equation method, singular point expansion method and characteristic root expansion method, electromagnetic topology research methods [0,,3] and so on. On the study of the effect modeling of complicated system, we mainly apply multi-conductor transmission line networ analysis method and the analysis methods based on the theory of electromagnetic topology. The analysis methods based on the theory of electromagnetic topology has the basic thought that it do space decomposition of electromagnetic interference dissemination way, and divide according to the actual shielding layer by external to internal, then gradually establish interference coupling model, maing the complicated electromagnetism coupling problem decompose into one group of relatively independent and small electromagnetic problems to solve. Electromagnetic topology theory mainly solves two inds of problems, one is the interference which is formed due to that external electromagnetic field enters into internal system through external power supply of electronic system, signal lines or other exposed wires, the other interference [4] is formed due to the bad shielding of electronic system. 46

175 It can obtain higher adaptability of confidence with better cost-benefit ratio that studying the electromagnetic environment effects by establishing evaluation system based on the model and the analysis, using the system structure, the mission planning, expected electromagnetic environment, system effect analysis model and evaluation criteria. On the evaluation study, based on system uses, the structure characteristics and expected nowledge understanding of the electromagnetic environment or priori nowledge mastering, with certainty views and statistical analysis two aspects, we can mae the system evaluation on the electromagnetic environment effect more objective and complete. 3. Construction of Electronic System E3 Model Constructing electronic equipment E3 model and forecasting and analysis, can provide important reference for system definition, design, development, assessment, helping designers, managers the most effective position antenna system, frequency and the parameters (transmission power, antenna gain, receiving sensitivity), detailed understand E3 and EMC performance requirements and forecast potential interference problem, damage degree and the measures, which can better deal with battlefield strong electromagnetic environment and guarantee the system effectiveness. Through the analysis of the electromagnetic environment effect, we can predict the potential E3 problems and adopt effectively corresponding techniques and procedures to change the design, to prevent and reduce utmost the E3 problem occurrence and influence. Therefore, it is necessary to consider the problems which mainly include:firstly,the system electromagnetic environment;secondly,electronic and electrical theory, methods and techniques of system constituting application;thirdly,the system tas needs, functional requirements; Forthly,electromagnetic characteristics of interface, equipment, systems;fifthly,the system signal flow, power distribution and the terminal layout;finally,the EMC design standards, etc. Among them, the electromagnetic compatibility indexes which are closely related to the strong electromagnetic environment and its effect are mainly the military equipment and the system sensitivity, typically including CS03,CS04, CS05, etc transmission sensitivity index and RS03, RS05, etc radiation sensitivity index. These indexes describe the ability to bear when military electronic equipment and system are influenced by the electromagnetic environment. 3. Analysis of Complicated System Networ Effect Model In military application, the system composed of electronic equipment operational platforms, control, command and communication networ is very complicated. Its interaction diagram will be very complicated and it needs us to describe the binary relation described by topological with the graph theory method and analysis the problem of complicated electromagnetic effect with electromagnetic topology method. Corresponding to the electromagnetic topology, we can use tree diagram to describe the logical relationship and the corresponding relationships of the complicated system. Corresponding to the interaction graph, we can use digraph to describe the interaction between the electromagnetic systems. If the weight function model of electromagnetic environment interference, the graphic elements constitute model and electromagnetic parameters are nown, we can use the graph theory method to analyze the complicated electromagnetic interference effect and evaluate the integrative influence that the environmental factors affecting of the electronic warfare platform and the factors mae on the platform weapon system. The electromagnetic environment effect analysis and model of complicated electronic information system mainly have means such as field road synthesis, electromagnetic field topology which reach a target of predicting the electromagnetic environment effect of complicated system by establishing the association interactions diagram model of electromagnetic interaction among space volumes of systems, node routing and so on. The 47

176 networ effects model of complicated system which is established with the electromagnetic topology theory is shown in figure. Fig Complicated system networ structure model which the nodes represent the user terminals, the local area networs represent some platform communication stations and local networs, the networ center represents the center of command and control and the routes composed of lin represent the wired and wireless lins between electronic devices and systems. The comprehensive performances of the networ structure model of complicated system mainly consist of system node usability, routing of smooth general characteristic, networ reliability. Evaluating the final performance of the networ model in strong electromagnetic environment, we need to consider the number of nodes composed of the unit electronic equipment model and other effect model and the node effect indexes, the data lin number and corresponding routing effect. 4. Dynamic States and Trend of Strong Electromagnetic Environment Effect Study 4. Dynamic States of Electromagnetic Environment Effect Study Firstly, from the harm to ordnance of radio frequency (HERO) to the E3 questions study, the United States and the former Soviet early in the 960s began to study the question on that the weapons systems was jeopardized by electromagnetic, from the early study of the HERO gradually expanding to the study of weapon system electromagnetic environment effect for now, which the study updates and expands constantly on the concept and in the research scope. And the object of experiment, from small electronic components to F - 6 fighters, B5 bomber etc. large weapon equipment, is carried on the electromagnetic pulse simulation test. Weapons electromagnetic pulse effect experiment database is established while doing the effects test and research of threshold. Secondly,electromagnetic pulse simulation technology improves continuously. Taing nuclear electromagnetic pulse simulation for example, foreign technologies have made great progress, which can produce the nuclear electromagnetic pulse environment where the highest intensity of electric field can reach x 05V/m. And the pulse rise time by the original 0ns has shortened to.8-80 ns. American army standard MIL-STD The system electromagnetic environment effect requirements have put forward some general requirements in electromagnetic environment effect on the process of whole life of weapon system. 48

177 Finally,with protection technology in-depth research, the United States and the former Soviet Union pay much attention to the weapon equipment electromagnetic environment effect and protection strengthening technique research while they studied and developed the electromagnetic pulse weapons and simulation equipment. Aiming at electromagnetic function failure mode of the sensitive electronic device in circuits, they did deeply research on the electromagnetic damage mechanism and the way of energy coupling, and promulgated the relevant military standards. American relevant research institutes also carried out research on the basic theory and microscopic mechanism in the respective area, directing at the problems that electromagnetic pulse made circuit potential out of wor. 4. Trend of Electromagnetic Environment Effect Study Firstly,the method of electromagnetic environment effect experiment will change from a single factor method to the effect studies under the action of various electromagnetic fields and the equivalence and correlation studies of all inds of test methods. Secondly,the research focus will change from the electromagnetic compatibility researches of system level and subsystem level to the combat mode researches under the conditions of strong electromagnetic environment effect and strong electromagnetic environment. Thirdly,the new theory, new methods and new technologies will emerge constantly (such as the platform level electromagnetic compatibility top design method, potential failure mechanism, open-sounding room technology, broadband electromagnetic pulse field test, etc.). Finally,the means of electromagnetic shielding will change from shielding, protection from the ground, filtering and other traditional passive protections to active protections (such as evolvable hardware technology, electromagnetic bionic technology, etc.). 5. Conclusions With the development of science and technology, microelectronics devices, electric explosive devices and the electromagnetic radiation source are widely used to weapons systems, causing the electromagnetism sensitivity of electronic equipment greatly improve. At the same time, with the rapid development of information technology and its applications in military field and civil electromagnetic radiation sources numerous, conducting electromagnetic effect researches on strong electromagnetic environment and its affecting electronic information system,grasping their laws and adopting corresponding countermeasures are beneficial to improve the adaptability of strong electromagnetic environment effect of electronic information system, to solve the reliability design of electronic components and systems, to brea the technical bottlenec of strong electromagnetic environment adaptability requirements. References. Liu.S.H. The electromagnetic environment effect of weapons and its development and trend [J]. Journal of Equipment Command Technical College, 005, 6(): -6.. Anon. Elect ronic warfare [EB/ OL]. ( ) [007--]. Http: / / www. dtic. mildoctrine/ jel/ new _ puba/ jp 3-3. pdf. 3. C.W.Harrison. A Preliminary Report on the Interaction of An Electromagnetic Field With A Missle Having An Ionized Trail [J].Interaction Note, 965, 06: C.E.Batler. Integral Equations For Currents Induced on A Wire Model of A Pared Aircraft[J]. Interaction Note, 97, (9):

178 5. C.L.Yu. High Frequency Surface Current and Charge Densities Inducded on Aircraft by a Plane Electromagnetic Wave [J]. Interaction Note, 977, (4): C.W.Harrison. Generalized Theory of Impedance Loaded Multiconductor Transmission Lines In An Incident Field [J]. Interaction Note, 97, (8): Baum,C.E. Numerical Results for Multiconductor Transmission line networs[j]. Interaction Note, 977, (): Tesche,F.M. Topological Concepts And Needed Model Improvements[J]. Interaction Note, 975, 4, (8): J.P.Parmantier. An Application of the Electromagnetic Topology on the Test Bed Aircraft [J]. Interaction Note, 993, 50, (6): Ianoz, Michel. Comparison Between High Altitude EMP and High Power Electromagnetic Effects on Equipment and Systems[C].Electromagnetic Compatibility, 007. EMC 007. International Symposium on,3-6 Oct. 007:-5.. Department of Defense USA. E3 and SM Assessment Guide for Operational Testing. 3 June 00.. Wei J.C,Zhang J,Yang F,Mao Z.J. Weapon system operational capability evaluation research based on simulation [J]. Journal of System Simulation, November 007, (3): Rocville MD, Haifa, Israel. Analysis and modeling of E3 on combatant topsides. Interference Technology.com. EMC TEST & DESIGN GUIDE Kodali V.P., engineering electromagnetism compatibility: the principle, test, technology and computer models (The Second Edition) [M]. Beijing Publishing house of Post,

179 CURRENT TESTING BASED ON FAULT DETECTION FOR MIXED-SIGNAL CIRCUIT ZHANG CAN-BING, PAN QIANG, SUN BI-WEI Electronic Engineering School, Navy University of Engineering, Wuhan, , China Abstract: Current,an important parameter of circuits, is implying a lot of circuit topology information. Compared with voltage testing, the strongest point of current testing is free from the influence of the test points during the test, and the selection of the test points is just right a difficulty of integrated circuit testing; The neural networs has a series advantages, such as abreast distributing processing, memory ability, fault-tolerance and approaching complicated non-line relation adequately []. Depending on Pspice modeling, simulation, analyzing and the data acquisition, the paper applies the merits of current testing and neural networ to the fault testing of a mixed signal circuit and accomplishes the neural networs designing, training and testing with Matlab. At last, it proves that this method had advantages of high fault convergence and high accuracy. Key words: Mixed Signal Circuit, Current Testing, Neural Networs, Fault Detection. Introduction With the rapid development of technology and manufacturing process, the integration of integrated circuit is being improved with each passing day. The system chip includes more and more mixed signal circuits according to the decreasing of chip size. The widely use of integrated chips maes people s life much more convenience; however, it also brings an unprecedented challenges to the designer, equipment user, maintainer of chip. So the detection signal circuit in mixed-signal is attracting highly valued with the rapid development of Mixed-signal circuit in electronic products. BP networ is a multilayer feed forward neural networ. The transfer of the neuron is S function and the output of it is 0 ~ consecutive quantity. The function can realize the output from the input to the arbitrary nonlinear mapping, weights adjustment using propagation learning algorithm. It has very good pattern recognition and classification and plays ey role in networ. Current test technology includes the static electricity measurement technique and transient current testing technology. [] Applying in mixed signal circuit fault detection, Current test not have to distinguish analog circuit and digital circuit in the test, and does not need to consider the fault information transmission. It just input appropriate excitation signal and test the signals in resource output power, then judge the circuit by the data processing. In this paper, we tae fault detection for mixed signal circuit basing on the method of combining neural networ with current test.. Fault Detection Process of Mixed Signal Circuit The ey point is getting test information in this process. The power source and load current information are observed in simulation circuit modeling by using Pspice 9., and characteristic parameters are extracted. At last, the circuit states are judged by training and classification under BP neural networ. 5

180 ) Data acquisition and characteristic parameters extraction. While the test circuit in normal mode, power source and load current information are collected. As the tolerance of resistance and capacitance are 0%, Monte Carlo, sensitivity, and worst analysis of the circuit are done in order to find the best test analysis parameters. ) BP networ structure parameters. The input and hidden-layer points of BP networ lies on the characteristics of the circuit parameters. False characteristic parameters of the dimension is N; input nodes for N. There are two inds of detecting state circuit that is normal and fault, so the output layer node number is ; Hidden-layer points pre-selected N + +a (N for input layer node, a = -0), if it cannot satisfy the requirements of networ training process, the hidden-layer points can be increased (decrease) one by one [3]. By analyzing, the excitation functions of hidden layer and output layer are nonlinear log-sigmoid function and nonlinear tan-sigmoid function respectively. 3) Training BP neural networ. BP neural networ training is necessary for the BP networ to identification circuit. Tae characteristic parameters for the training sample input vector, the training sample set standards for the output circuit: the dimensions of circuit characteristic parameters for N, only N dimensions completely meet normal conditions the circuit goes in normal and networ output "", Any dimension not satisfy normal conditions the circuit is in fault and networ output "0". This paper is mainly for fault detection of mixed signal circuit and achieves the expected error range by training networ refers to fault samples in dictionary. 4) Results. To judge the circuit according to the output result, from which by inputting the characteristic parameters of the test circuit to the trained BP neural networ. 3. The Examples of Fault Detection 3. Detection Circuit Tae the mixed signal circuit composes of 7404 inverter for example for fault detection as in figure, and simulation modeling of circuit by using Pspice 9. [4]. V Vdc R R 0 C 0u C Q UA 0u 7404 VOFF = 0 VAMPL = v FREQ = 00 V QN R3 C3 0p Fig : the circuit diagram for mixed signal Through analyzing the circuit transient and sensitivity, you will find the R, R, R3, C and C3 have relatively large influence to the current amplitude where power V, V and the current load R3 staying, and in extreme cases, C is also great influence on current amplitude. 5

181 Under the environment of both resistance and capacitance tolerance for 0%, 000 times Monte Carlo and worst analysis have been done and found that the current detection range in less than 0%. The detection current amplitude are obviously difference when a single component tolerance for 0%. From figure and 3, the current detection amplitude difference can be seen as R3 is K and. K condition. So the current amplitude in the three points can be used as test parameters for fault detection. 0A -0.5mA -.0mA -.5mA 0s us 4us 6us 8us 0us us 4us 6us 8us 0us us 4us I(R3) Time 0.0mA Fig :The current information at R3 while load R3 for -0.mA -0.4mA -0.6mA -0.8mA -.0mA -.ma 0s us 4us 6us 8us 0us us 4us 6us 8us 0us us 4us I(R3) Time Fig 3: The current information at R3 while load R3 for. From the above analysis, the structure of BP networ which the paper needed can be consist of 3 neurons in the input (the dimension of characteristic parameters), neurons in output layer (circuit state: normal and fault) and 3- neurons in Hidden layer. 53

182 3. Test Results MATLAB7. is used. The BP networ structure is 3-- through designing, training and testing, in order to get better classification, hidden and output layer are selected logsig and tansig nonlinear function respectively, training function is trainlm, learning rate lr=0.05, momentum factor MC = 0.90, learn error err_goal = The testing results, obtained by many training and testing, displayed in figure 4 Fig 4: training and testing result In the figure, Red Cross says expectation object, the green line expresses the training result, and the blue line shows test results. Training vector includes 5 groups, of which the 8 groups in front are expected output for ""which stands for the circuit in regular, and the others expectation output all for "0"; test vectors includes 6 groups, but only 35 groups vector (including 0~ 5, 3~59) represent the circuit in normal, i.e. the expectation output for "", the rest of the expected output as "0". We get the following results by using tools function in matlab7.: in trained BP neural networ, the undetected vector is groups; virtual screening is 7 groups and error detection rate is 3.9%. Therefore, BP networ can well realize fault detection for mixed signal circuit. 4. Conclusion The paper studies the current testing method on the basis of mixed signal circuit which composed of 7404 inverters, then uses Pspice to get circuit modeling, simulation and analysis, at last uses matlab7. to design, train and test BP neural networ. Simulation results prove that the method owning high fault coverage and fault detection rate (96.%), it not only detects circuit fault in resistance and capacitance components, but also can detect the faults in triode, inverter and power. The method realized the fault detection for mixed signal circuit, so it will play important role in electronic equipments applying and maintenance. Reference. Xia Wei, Li Chaohui, Chang Chunteng, etc. MATLAB Control System Simulation and Example Explanation[M]. Bei Jing The People's Posts and Telecommunications Press Min Yinghua. The Review for COMS Circuit Current Tests. [J] Journal of Computer Research and Development. 999, 36():9~ Zhu Da Qi,Shi Hui. The Artificial Neural Networ Theory and Application [M] Beijing Science Press,

183 4. Wang Fu Chun. electronic circuit CAD and OrCAD Tutorial [M].Bei Jing, China Machine Press, M.R.A shouri. Fault detection of analog circuits using neural networs and M onte-carlo analysis. Proc. 44th Midwest Symposium,Aug 00, (): 4~7. 6. F.Aminian, M.Aminian. Analog fault diagnosis of actual circuits using neural networs. IEEE T rans. Instr&Meas,00,5(3):544~ Zhu Yanqing, He Yigang, Yang Hui. The Mixed Signal Circuit Fault Detection and Location Based on the Current Test.[J] Journal of Systems Engineering and Electronics, 007-0, 9(0): 768~ Wang Cheng, Chen Guang, Xie Yongle. Simulation/Hybrid Circuit Fault Detection Based on the Radial Basis Function (RBF) Neural Networ. [J] Circuit and System Journal ():65~ Chehab, A. Kayssi, and A. Ghandour. Transient Current Testing of Gate-Oxide Shorts in Cmos. International Design and Test Worshop (IDT), Cairo, Egypt, 007, (7):

184 TEMPERATURE MONITORING SYSTEM FOR WIRELESS NETWORKS BASED ON EMBEDDED ZHANG DUO-YING, ZHANG WEN-QIANG School of Information Science and Technology, Ji Nan University, Guangzhou, 5063, China Abstract:This design uses CC50 and ecog set up a temperature monitoring wireless networ system. This system consists of nodes and control centers to monitor, Node communication protocol currently used in various hot technologies-- ZigBee protocol,using MESH networ structure,have Ad hoc and self-healing capabilities. The monitoring system can automatically detect the temperature of each monitoring point, and transmitted the measurement results to the monitoring center at the same time. The system has low power consumption, low cost, easy networing and maintenance, scalability and good features, Has practical value and maret prospects. Key words: ecog; CC50; ZigBee; Wireless sensor networs; Temperature Monitoring. Introduction Along with the development and improvement of living standards, People get rid of cords for wireless technology has become increasingly demanding. This article briefly describes a wireless temperature monitoring based on embedded systems. ZigBee technology currently rising due to its low power consumption and self-networing functions mae it suitable for industrial monitoring. We have adopted CC50 and ecog formed with the wireless temperature monitoring system.. Functional Description With the ZigBee wireless sensor nodes placed on the need to capture the local temperature, used to collect the temperature data. Put some wireless routing node in place. Using ZigBee networing functionality to form self-wireless networ, System uses the ZigBee protocol for wireless transmission. As shown in Fig.. Fig System Bloc Diagram Finally, the temperature data to the computer terminal display, so as to achieve the purpose of temperature monitoring. 3. Hardware Design System from the MCU, ZigBee wireless transmission module CC50, temperature sensors, power supply modules, control centers display module. 56

185 3. MCU-eCOGK The ecog microcontroller is a low-power microcontroller based on a 6-bit Harvard architecture with a 4-bit word code linear address space (3Mbyte) and 6-bit word linear data address space (8Kbytes). It s the microcontroller which embedded communications applications for low-cost and low-power. The ecogk have powerful computing capability and low-power sleep mode, you can meet the ZigBee transmit data burst characteristics of the composition of low-power systems [~]. 3. Wireless communication module The CC50 is TI's second generation ZigBee /IEEE RF transceiver for the.4 GHz unlicensed ISM band. This chip enables industrial grade applications by offering state-of-the-art selectivity/co-existence, In addition, the CC50 provides extensive hardware support for frame handling, data buffering, burst transmissions, data encryption, data authentication, clear channel assessment, lin quality indication and frame timing information. These features reduce the load on the host controller. In a typical system, the CC50 will be used together with a microcontroller and a few additional passive components [3]. 3.3 Temperature Sensor The DS8B0 digital thermometer provides 9-bit to -bit Celsius temperature measurements and has an alarm function with nonvolatile user-programmable upper and lower trigger points. The DS8B0 communicates over a -Wire bus that by definition requires only one data line (and ground) for communication with a central microprocessor. It has an operating temperature range of -55 C to +5 C. 3.4 Power Modules System with four battery-powered, ecogk chip and CC50 modules require 3.3V voltage, we dropped by AMS7 3.3V to 6V for the CC50 to provide the required voltage. 3.5 System Connection CC50 requires minimal external components, the connection is very simple. Its peripheral circuits, including RF input / output matching circuit and the crystal cloc circuit. As shown in Fig.. Fig Controller Interface Circuit 57

186 CC50 4-wire SPI Bus by (SI, SO, SCLK, CSn) to connect the SPI module ecog chip, which can set the chip in the woring mode, and achieve read / write cache data and read / write status register. In order to prevent drift input, CSn, SI, SCLK pin to set up a pull-up resistor [4~5]. 4. Software Design 4. About ZigBee ZigBee is an emerging short-range, low-rate wireless networ technology for formation of low-cost, low-power wireless networs. ZigBee wireless sensor networ is based on technical standards and IEEE ZigBee networ protocol designed for wireless data transmission networ. ZigBee protocol stac is based on the IEEE wireless networ standards, by a group of sub-layers. Each floor to provide a specific set of its top service (a data entity to provide data transmission services, a management entity to provide all other services) [6]. ZigBee protocol stac architecture is shown below. Fig 3 ZigBee architecture model [7] CC50 supports IEEE wireless networ protocol, and the TI Company to provide a ZigBee protocol stac (Z-Stac TM ), provides a powerful and complete solution. The system consists of a networ based on ZigBee protocol coordinator RAN equipment and multiple sub-nodes FFD, which set up a MESH-based LR-WPAN networ. This LR-WPAN networ components and topology is shown below. Fig 4 LR-WPAN MESH topology relationship 58

187 4. Sensor node software design The design of the terminal nodes using the temperature sensors, which sense the temperature of the surrounding environment, and access to the signal conversion processing by ecogk, then control module CC50 to send out the use antennas.sensor node software design flow chart is shown below: Fig 5 The process flow chart of Sensor node 4.3 Process Design Networ The design and implementation of the system functionality from the networ: the master node is the coordinator of the wireless networ administrator, it is responsible for the establishment of the networ, address the distribution and sub-node joins, node equipment data update, data forwarding, equipment associated with the table maintenance and the status of the networ automatically updates. Coordinator broadcast queries by way of the master node to find child nodes within a certain space, and networ node number to each child, when the find will add a node into the networ, or to delete it. Routing node is responsible for participation in route discovery, message forwarding, allowing other nodes associated with the networ through its functions. Networing software design flow chart is shown below: 4.4 The design of wireless communication software In Figure 5 and Figure 6 shows the software flow chart, the wireless communications protocol software implementation is an important tas. Because TI offers a complete set of the CC50 device to achieve using Z-Stac ZigBee protocol stac, we only based on the protocol stac (physical layer and MAC layer), which calls the corresponding interface module and its parameters to do some modifications so that it can better achieve our desired function. In view of this, we have omitted the description of the process [9]. 59

188 Fig 6 The process flow chart of networing 4.5 Serial communications control center PC and MCU with SPI Serial Communication, PC-side programming using C++ serial communication communications software (Figure 7), set the baud rate of 500, in order to achieve client PC machine and ZigBee transceiver communication. Fig7 Display of temperature data on PC 5 Conclusion We designed an embedded wireless temperature monitoring system. The communication networ using MESH topology, the networ has the ability to self-organization, the node abnormal automatically tae measures to ensure the normal operation of the system to meet temperature control requirements. Temperature monitoring with traditional wired networs, compared with the design of wireless temperature monitoring system, installation is simple, does not involve cabling; short construction period, in the construction process without affecting the plant's normal operations. And by adding at the end sensors and software upgrades, you can mae more types of data collection and monitoring. 60

189 References:. ecog User Manual Peng Xuange, Zhu Bing, Zhang Jun. 6 Principles and Applications [M]. Beijing University of Aeronautics and Astronautics Press, Texas Instruments.CC50 DateSheet Jiang Ting, Zhao Chenglin. ZigBee and Its Application [M]. Beijing: Beijing University of Posts and Telecommunications Press, He Na, Huang Zhiwei. Based on the CC50 ZigBee / IEEE transceiver circuit [J]. Industrial control computer, 009, (3): TI Inc.CC50 datasheet.4 GHZ IEEE /ZIGBEE RF transceiver TI Inc.CC50 errata note.4ghz IEEE /ZIGBEERF transceiver SUN Limin, Li Jianzhong, Yu Chen, Zhu Hongsong. Wireless sensor networs [M]. Tsinghua University Press Li Wenzhong, Duan Chaoyu. ZigBee006 wireless networs and wireless positioning combat [M], Beijing University of Aeronautics and Astronautics Press,

190 DESIGN OF A NEW SWITCHED-CURRENT BIQUADRATIC FILTER ZHANG YONG, WANG WEI-DONG School of Information and Communication, Guilin University of Electronic Technology, Guilin, 54004, China zhangmyc@63.com; wangwd@guet.edu.cn Abstract:The Switched-Current (SI) technology is a new type data sampled technology. In this paper, the principle and error of the SI memory cell is analyzed, especially the cloc feedthrough effect. To reduce the cloc feedthrough effect, a new type of switched-current memory cell which adds a flipped voltage follower (FVF) circuit is introduced, this switched-current memory cell exhibits some characteristics of low power, low error, and high performance. Using this switched-current memory cell, a new switched-current bilinear integrator is designed, which constitute the switched-current biquadratic filter. This switched-current biquadratic filter is a standard part of the general filter. Select different coefficients, it can become a second-order low-pass, high-pass, band-pass, and all-pass filter, as well as Chebyshev, Butterworth, elliptical and other different types of filters. In addition, it can be easily cascaded to form high-order filter. All the circuits in this paper have been simulated with Cadence IC, using SMIC 0.8um library under the voltage of.8v. The simulation results indicate that the biquadratic filter has perfect performance and useful application value. Key words:si memory cell; FVF; bilinear integrator; biquadratic filter. Introduction The switched-current (SI) technique is a new analog sampled-data signal processing technique of current mode that aims to replace switched-capacitors (SC) []. In contrast to the SC technique, which requires a nonstandard digital CMOS process to realize floating linear capacitors, SI can perform accurate signal processing functions in a standard digital CMOS process without the direct use of any capacitor. Moreover, the SI technique does not utilize CMOS op-amps but rather performs its entire analog signal processing with much simpler current mirrors. In a word, The advantages of the SI is its simplicity of implementation, potential for high speed, low-voltage operation and compatibility with digital CMOS processes which is an attractive feature due to the tendency for the integration of large analog/digital systems in a single chip. However, the SI circuit is still not satisfactory in the performance of speed and precision because of the finite output resistances of the MOS transistors, mistaes in the current mirrors, some parasitic capacitances, and cloc feedthrough effect in the switches []. This paper firstly analyzes the cloc feedthrough error. To reduce the cloc feedthrough effect, a new type of switched-current memory cell which adds a flipped voltage follower (FVF) circuit is introduced. Using this switched-current memory cell, a new switched-current bilinear integrator is designed, which constitute the switched-current biquadratic filter. All the circuits are simulated with Cadence IC under the voltage of.8v,. Analysis of Cloc Feedthrough Figure is the basic first-generation switched-current memory cell. Suppose the switch transistor woring in the saturation, the channel charge Qc of the switch transistor Ms can be written in the following form: Q = C A ( V V ) () c ox s φ Tn 6

191 Where C ox and A S (W S L S ) are the unit gate capacitance and effective area of the switch transistor, respectively. V φ is the switch transistor gate voltage, V Tn is the threshold voltage of the NMOS. When the switch transistor is turned off, most channel charge of Ms will be transferred to the gate capacitance of M, so the gate voltage of M is increased by the channel charge redistribution can be approximated as: Q Cox As ( V - VTn ) As ( V - VTn ) c φ φ VCFT = = = () C C A A gs ox Where the A is the effective area of the M. Assume that M matches with M, their leaage current equation can be respectively expressed as follows: i = J + i = β ( V V ) d in gs Tn i AJ i A V V V d = out = β ( gs Tn + CFT) (3) The β is gain factor; A is the area ratio of M and M. The Eq (3) can be rewritten as: = + = β + + (4) iout id AJ A ( Vgs VTn VCFT) AJ From the Eq (4), i out contains an item and second item of the cloc feedthrough voltage V CFT, therefore the output is influenced by the cloc feedthrough effect, causing the bias of the actual output current. In addition to the cloc feedthrough error, there is also mismatch error, adjustment error, conductance ratio error and noise error, which seriously affect the performance of SI circuit. Fig The basic first-generation SI memory cell 3. SI Memory Cell with FVF In order to reduce the above error, a new type of SI memory cell is proposed. Figure is the flipped voltage follower (FVF) [3, 4], in which the current passes the M is constant, dose not depend on the output current. Fig The flipped voltage follower (FVF) 63

192 Ignore the short-channel effect, VSGM is constant, the voltage gain is. The circuit can draw great current because of the very low output resistance, which is / (gmgmro), the gmi and roi is the transconductance and output resistance of Mi, respectively. Figure3 is the SI memory cell with FVF, M, M, M3 and Vref constitute the FVF. M7-M constitute the two cascaded cascode current mirror, which could increase the resistance of output, thus reduce the transmission error of SI memory cell. M4 -M7 are the CMOS switches [5]. The supply voltage is.8v, Vp is 0.5V, and Vn is.v. W/L ratios are set in table. Table W/L ratios of MOSFET MOSFET M M,M5,M6 M3 M4 M7,M8 M9,M0 M,M M3 M4,M5,M6,M7 W/L 00u/300n 89u/.u u/300n 7u/300n.u/300n u/300n 5u/300n 3u/300n 350n/300n Fig3 The SI memory cell with FVF Simulate the circuit with Cadence IC, using SMIC 0.8um library under the voltage of.8v. The input is sine wave of 60uA, frequency is 5 KHz. The sampling frequency of switch is 5MHz. Simulation waveforms are in figure4. Fig4 Simulation result of the SI memory cell 4. SI bilinear integrator 4. Shunt SI circuits are current-mode circuits. In the design of the circuit, need to use the current mirror to get two or more equal current, as well as proportional current. The shunt can achieve it [5]. Here is a simple shunt in figure5. 64

193 As figure5 shows, adjust the coefficient K, equal or proportional current could be get, and which can be easily cascaded. This shunt is widely used in the bilinear integrator and biquadratic filter. 4.. Design of Bilinear Integrator Fig5 Shunt Bilinear integrator is the core unit of the SI biquadratic filter [6~7], the bilinear integrator transfer function is as follows: Z + H(Z)= (5) Z The systems bloc diagram which implements the function (5) is shown in figure6. Fig6 System bloc diagram of bilinear integrator Fig7 The bilinear integrator As shown in the figure6, the two outputs of the shunt have equal and the same direction current as the preamp input current. This guarantees the current of each branch will not interfere each other. Shunt divides the input into two; bring in Ii into the A, B nodes at the same time. Shunt separates the output io and if. Due to the transfer function of the SI memory cell is H (Z) =-Z -/, cascades the two memory cell can form Z -. Realization of the circuit is shown in figure7. 65

194 As shown in figure7, M-M7 and M8-M34 are two SI memory cells, M35-M38 are connected into cascode structure, used for the output of the integrator. M39-M48 implement the shunt. Simulate the circuit with Cadence IC, using SMIC 0.8um library under the voltage of.8v. The input is sine wave of 60uA, frequency of 5 KHz. The sampling frequency of switch is 5MHz. Simulation waveforms are in figure8. Fig8 Simulation result of bilinear integrator Fig9 S-domain bloc diagram of biquadratic filter As shown in figure8, the simulation result indicates that the input current shift phase 90 through the bilinear integrator. Sine wave is changed into cosine wave. The output waveform is without distortion, which shows the good performance of the integrator. This bilinear integrator can be used for filters, Σ-Δmodulators and the basic module of other systems [8]. 5. SI Biquadratic Filter 5.. Design of SI Biquadratic Filter This switched-current biquadratic filter is a standard part of general filter, select different coefficients, it can become a second-order low-pass, high-pass, band-pass, all-pass filter, as well as Chebyshev, Butterworth, elliptical and other different types of filters. In addition, it can be easily cascaded to form high-order filter. The construction method of the filter is as follows [9]. The S-domain transfer function of biquadratic filter is as follows: io () s as + as+ a0 H() s = = (6) ii () s ω0 s + s+ ω0 Q Where a 0, a, a is constant, ω 0 is cutoff frequency, Q is quality factor. The S-domain bloc diagram of the KHN structure biquadratic filter is shown in figure9 [0~3]. iol () s is the low-pass output, ioh () s is the high-pass output, iob () s is the band-pass output, the iol () s and ioh () s is connected to form the band-stop output. There transfer functions are as follows: a0 iol () s = i() s (7) ω0 s + s+ ω0 Q as ioh () s = i() s (8) ω0 s + s+ ω0 Q 66

195 as i s i s OB () = () ω0 s + s+ ω0 Q Use the SI integrator to synthesize filter, need to change the S-domain into Z-domain, due to the bilinear transform is most perfect of the four transforms, we use the bilinear integrator to synthesize the filter. Let Tz+ =, we can get the system bloc diagram in figure0. s z (9) Fig0 S-domain bloc diagram of biquadratic filter As shown in figure0, we can get the coefficient i as follows: ω0t ω0t 0 = = Q at at = (0) 0 = 3 ω0 = a 4 The advantages of this method are that characteristic frequency ω 0 and quality factor Q of the filter can be adjusted. By adjusting the feedbac coefficient 0, the ω 0 is changed. When the ω 0 is fixed, we can change quality factor Q by adjusting. 5.. Realization of the Second-order Butterworth Low-pass SI Filter Through the analysis of 5., tae the second-order low-pass Butterworth for example. Using above components to construct the filter, and simulating the filter with Cadence IC. Looing up the table, we can get the normalized polynomial of the filter as follows: H() s = s + s + According to figure0, 0, is coefficients of the filter. Using Eq. (0), when the cutoff frequency is 50 KHz, sampling frequency is 5MHz, we can get 0 =0.0945, = Of curse, the 0, is theoretical value. We should debug these two factors in the process of debugging the circuit. Connect the circuit on the basis of figure0, we simulate the circuit with Cadence IC, using SMIC 0.8um library under the voltage of.8v. The input is sine wave of 0uA. As the SI circuit must be driven by the cloc, when simulating the filter with Cadence IC, the cloc must be described by time-domain parameters. However, the amplitude-frequency characteristic of the filter is frequency-domain problem. While analyzing frequency-domain of the circuit with Cadence IC, we can () 67

196 not control the cloc signal. So we must simulate the circuit at different frequencies, and then portray these points with Matlab. The simulation result is in figure. As shown in figure, the cutoff frequency of the filter is almost equal to 50 KHz, but some errors are existed. Fig Simulation result of the second-order low-pass Butterworth SI filter 6 Conclusion This paper designs a new type of SI biquadratic filter, the characteristic frequency ω 0 and quality factor Q of which is only related to the W/L of the MOSFET. By adjusting the W/L of the MOSFET, the parameters of the filter can be changed. Simulation result shows that the performance of the filter is good, but some errors are existed, the reasons are as follows: ) If the current signal is completely passed to the next level, the output impedance of the circuits must be infinite. It is impossible to achieve, the signal will be weaen during the transmission. ) The error of the bilinear integrator is existed. 3) The coefficient precision of the filter should be corrected to 5 decimal places, but the SI circuits do not reach such a high accuracy. References. HUGHES J B, et al. A new technique for analogue sampled-data signal processing [J].IEEE Int Symp Circ System, 989, 43(8): Weidong Wang. Principle and Application of modern analog integrated circuits [M]. Beijing: Publishing House of Electronics Industry, M.Fahfah, S.Masmoudi, M.Loulou, E.Tlelo-Cuautle. Synthesis of voltage followers and design of switched current memory cells[c]. Cairo, R. G. Cavajal, J. Ramirez-Angulo, A. Torralba. The Flipped Voltage Follower: A Useful Cell for Low-Voltage Low-Power Circuit Design [C]// IEEE. 005, 3(9): Phillp E Allen, FENG Jun Etc translate. CMOS Analog Circuit Design [M], Publishing House of Electronics Industry, J. B. Hughes, K. W. Moulding, J. Richardson, etal. Automated Design of Switched-Current Filters [J]. IEEE J. Sol Sta Circ. 996; 3(7): J. B. Hughes, I. C. Macbeth, D. M. Pattullo. Switched current Filters [J]. Circuits, Devices and Systems, IEE Proceedings G, 990;37(): M. Pavli, J. Haze, R.Vrba. Switched Current -Bit Capacity to Digital Delta-Sigma Modulator [A]. 68

197 Advances in Electronics and Micro-electronics, 008. ENICS '08. International Conference on[c]. Valencia, Sawigun,C. and Serdijn,W.A V micro-power SI memory cell with feedthrough error reduction. IEEE Electronics Letters, 008, 44(3): Fahfah, Mourad and Loulou, A Novel Design of a Fully Programmable Switched-Current Filter[M], Internation Journal of Electronics, 00, 97(6): Lenian He, Yi Wang. Analog IC Design and Simulation [M]. Beijing: Science Press,008. Fahfah, M., Masmoudi, S., Tlelo-Cuautle, E., and Loulou, M.,Synthesis of Switched-Current Memory Cells Using the Nullor Approach and Application to the Design of High Performance SI Sigma Delta Modulators. [M]WSEAS Transactions on Electronics,008, (5): Sawigun,C. and Serdijn,W.A. Low-voltage, low-power, low switching error, class-ab switched-current memory cell. IEEE Electronics Letters, 008, 44(3):

198 THE REMOTE CONTROL SYSTEM BASED ON THE TELEPHONE NETWORK ZHAO MING-FU, YANG TIAN-MING, TIAN XI-YAN, DU LIU-FENG, WANG CHAO School of Machinery and Electricity Henan Institute of Science and Technology Xinxiang Henan, , China Abstract: Intelligence and networ can greatly increase the performance of the electric appliance, and is also the inevitable developing trend of the future. A ind of remote control system based on the telephone networ is introduced in this paper. The system is mainly made up of microcomputer AT89C5 and dual-tone multifrequency decoding chip MT8870. The user can telecontrol the electric appliance by means of the fixed telephone or mobile telephone. Thus it can telecontrol the household appliance or other equipments. Key words: remote control system, telephone networ, telecontrol, dual-tone multifrequency decoding. Introduction With the development and advancentment of the society, more and more intelligent and networ electric appliance come to the people s life, which brings a lot of convenience and enjoyment. Because of the popularization of telephones, it is a trend to realize the romote control by means of telephone networ. It is also the only way to realize intelligentized house. A ind of remote control system based on the telephone networ is introduced. The user can telecontrol the electric appliance conveniently by means of the telephone networ. For example, the user can open his houshold electric rice cooer, air conditioner and water heater ahead of time []. The rice has been ready, the temperature in the house is just fine and the water has been heated when he returns home, which is comfortable and convenient. In addition, the user can chec the utilization and change woring condition of electric household appliance. The user can also monitor and control the condition around the outlet in the house. Next we will introduce the structure and principle of this system.. System Structure The system is shown in figure. Fig.. System schematic diagram 70

199 When the user wants to control household appliance, he just needs to pic up the phone or mobile phone to dial the home number. Ring signal will arrive at the home phone through the telephone networ. At that time, the ring detect circuit begins to detect the ring signal, a ring gives a pulse, and the pulse is sent to the single chip computer (MCU) to calculate the signal number []. To prevent the system from conflicting with the phone networ and misoperation when someone answers the phone or the ring signal is less then 5 times (the practical number can be set by the software). The system will regard it as a phone call or a wrong operation. When the ring times is large than 5 times, The system begins to control the outlet and the appliance, CPU sends control signals to pic the phone And givoice guide, it will require the user to input the code. At the same time, MT8870 converts the input signal into the digital one, and sends the signal to the CPU to mae judge. If the code is wrong, CPU will as the user to enter again, and then loop for 3 times. When the user is still wrong after entering 3 times, the system will hang up. As the code is right, the voice guide system will as the user if he wants to control the appliance or just wants to now the state of the device, or wants to monitor the device environment, and ass the user to enter the corresponding number [3]. When the operation is finished, the system will hang up automatically. When it lasts too long during the user operates it, the system will also hang up automatically. 3. System Hardware Design 3. Cpu The CPU of this system is AT89C5, all the commands are sent out from it. The interface circuit is shown in figure. Fig.. SCM interface circuit When the system power is on, the system will be reset automatically, and then CPU will always detect the ring signal. When a valid signal is detected, the counting program is initiated. When the number amounts to the set value, CPU sent out signals to pic the phone, and the control circuit pics up the phone and sends guide voice to as the user to enter the password. And the CPU will also detect the STD signal sent from MT8870. When STD is 7

200 valid, the CPU will read the code from MT8870 and compare it with the set code. If they are different, the CPU will hang up automatically. Otherwise the user can perform the operation according to the guide voice. For example, setting the device state, etc [4]. 3. Ring detection circuit Ring detection circuit is shown in figure 3. Fig.3. Ring detect circuit When the ring signal is inputted through C, C, the 75±5V, 5Hz voltage on the phone line was converted into dc through D4, and filtered by C8. D5 will mae the voltage more stable. The DC voltage maes the photoelectric coupler at a state ON. +5V power voltage charge C3 through the photoelectric coupler, R, D3. When the voltage on C3 reaches the on-state voltage of 74L08, 74L08 is on. It will convert the analog signal into digital signal, then input it through T0 to the AT89C5 to count the pulse. Every ring signal produces a pulse. When the number adds up to 5 times, the software will mae pin P. of AT89C5 low voltage to finish picing up the phone. 3.3 DTMF decoding circuit The decoding circuit is shown in figure 4. Fig.4. DTMF decode circuit DTMF decoding circuit is to convert the audio signal into digital signal, and then sends it to CPU for data processing to perform the control function. MT8870 can finish this tas. It is an integral DTMF receiver. It can be used as a filter and a decoder. The filter part is used for converting the high and low frequency of the C, the 7

201 decoder part is used for digital inquiry, and also used to convert the 6 bit DTMF signal into 4 bit code. The minimum value of the outer counting number can be set by input amplifier and cloc oscillator and the latched 3-bit register. The signal on the phone line can be inputted through C3, R3, and R4 to pin and 3 of MT8870, then convert dial signal into digital signal [5]. The signal that the user dials the phone eyboard will be sent out by audio signal through the phone line [5~8]. 3.4 Voice guide and monitor circuit The ISD series voice chip uses analog data direct storage technology in semiconductor memory, namely, let analog voice data write into individual storage unit directly without the transform of AD or DA. Therefore, this can reproduce the natural effect of voice more perfectly, without the phenomenon of quantification noise and distortion in solid voice circuit, which caused by quantification and compression. The ISD 560 voice circuit includes EEPROM which is used as data memory. It can preserve data more than 0 years without battery. Data erasing and writing can be complete automatically inside the chip without external instruments. The ISD560 provides the user with direct address operation on voice information. But as to the microcontroller, as long as 0-bit address lines occupy too much port line and give rise to problems of expanding connection. Moreover, direct address operation of recording and playbac is a bit inconvenient. But the operation pattern of ISD voice chip can provides practibility and flexibility for designer. When the designer carries on the operation of voice information section and voice combination, he only needs to now the relative serial number of the sound section, without needing to now its address. When the highest address bits A8 (pin 9), A9 (pin 0) of ISD560 are set for high level, namely, the chip goes into the operation pattern. The operation pattern is divided into 6 inds of patterns according to the different combination of the high and low level of Pin A-A8 to achieve different function. The voice guide circuit consisting of ISD560 and the microcontroller is simple, which can withdraw a section of voice signal from the inside of chip without using complicate address data line. The system receives the password from the user, for example, the password is,, 3, 4, If the password is correct, then the voice guide the password is correct is given out. The microcontroller only deliver the relative series number of sound section to ISD560. When the monitor function is initiated, only changing corresponding port electric level can transform scene sound to electric signal, and deliver its to telephone lines. This electric circuit is simple and easy to operate. 3.5 Picing,hanging telephone and drive circuit The analog picing and hanging telephone circuit is shown in figure 5. Fig.5. Analogous hang on/up telephone circuit 73

202 In general, when telephone ring off, two telephone lines are in open condition. In the telephone line, the 48 voltage (old style telephone are 60 V) is added to both sides of the ringing circuit. The ringing circuit is open when the telephone is piced up. When the telephone is switched on, the resistance valve is about 300 Ω. When you dial the telephone, high voltage ringing signal from telephone line produces square-ware pulse signal through ringing detection circuit. And then deliver it to port p3.5 of AT89C5 to count the ringing pulse. When ringing number reach 5 times, the microcontroller procedure controls port p. to output a low level, the high level of p. is delivered to pin of integration switch driving circuit MC43 to carry on enlargement, then pin 6 outputs high level and delivers it to the base of triode 903, causing the triode to be saturated and turned on, then the positive 5 V power source is connected to ground through the relay winding and triode. The relay coil turns on and causes its normally open contact to close.300 mega resistance is connected in circuit and the telephone is switched on. When the user inputs a wrong password or the operation is over, the system software controls port p. to output a high level through MC43 driving circuit, then pin 6 output a low level, controls 903 to be closed, and then the relay winding loses electricity.electronic contact separation. The telephone line returns to open state again, and that analog hanging up telephone is realized. 4. Software Design and Debugging After the control system completes picing telephone, the system prompts please input the password. If the input password is not correct, the system will prompt to input again. You can input three times at most. When you surpass three times, the system will automatically hang up the telephone. If the password is correct, the system produces operation prompt according to the function menu. In order to facilitate the user to operation, the system sets a return ey. When you press down it, you will return to the upper level menu. After all sets are completed, you may press down # to end set. The system automatically hanging up the telephone. The system flow chart is shown in figure 6. Fig.6. Program flowchart 74

203 5. Conclusion The design of the intelligent telephone remote control system uses microcontroller AT89C5 as the control unit and combines with software programming to realize voice interface and safe authentication mechanism, the system function has been enriched and it conforms to the development trend of electric appliances intellectualization and networ. Using this system can realize long distance control to air conditioner, lamp, electric cooing pot and other household appliances and equipments by the fixed telephone or mobile phone, which can turn on air conditioner before reaching home, and enjoy a cool world after entering home. When the user goes out, he can turn on/off lamp, TV in the living room through this system, which produces a pseudomorgh of someone in home. The system not only enhances the family security but also realizes monitor function. You can be familiar with home condition when going out. In addition, the system can also use in industrial and agricultural production to realize long-distance control of the unmanned post. Acnowledge This wor was supported by the Science and technology project of Henan Provincial Department of Education( ) References. Mao Zhao-rong, Xu Hua: The system design based on telephone remote telemetry. Electronic Technology, 000, (3): Yu Gao-xiang: A Simple Method To Realize Voice Function In Single Chip Microcomputer System. Electronic Technology, 00, (9): Guo Yao-hua, Yao Ming-lin: The Remote Temperature Communicating Monitoring System Based on Field bus Technology. Measurement & Control Technology 003, (): Li Hai-zhou, Yu Shou-qian, Li Jun: Research and Implementation of Video Surveillance System Based on Can Bus. Measurement & Control Technology 004, (5): Xiao Jin-zhuang, Wang Yan, Wang Hong-rui: Intelligent Remote Control System Based Telephone Net. Intelligent Remote Control System Based Telephone Net 007, (4): Jia Yong-qiang: The Design of the Experiment Equipment of the Telephone Long-distance Control System. Sci-Tech Information Development & Economy 007, (9): Liu Xiao-yan, Wang Zhi-gang, Yu Hui-jun: The Design of Telephonic Remote Intelligent Control System. Microcomputer Information 00, (4): Xiao Liao-liang, Deng Mu-sheng, Jiang Feng-wu: Telephonic Remote Intelligent Control. Telephonic Remote Intelligent Control 007, ():

204 INTELLIGENT PHOTOELECTRIC SENSOR AND ITS APPLICATION YANG TIAN-MING, TIAN ZE-ZHENG, GAO YIN-HAO, TIAN XI-YAN, WANG CHAO Henan Institute of Science and Technology, Xinxiang Henan, , China Abstract: A ind of photoelectric sensor measuring electric circuit that can recognize people s in and out is introduced, and it can be applied in the situation of the automatic record and display the dynamic number changing in the maret, the exhibition building, libraries and the classroom in the schools and so on, and it is convenient for the administrative department to plan and manage. Key words: photoelectric sensor;counter;measuring of in and out;automatic record. Introduction Photoelectric sensor widely used in automatic counter and photoelectric alarm. In this paper, the intelligent photoelectric sensor that can recognize people s in and out was introduced. The intelligent photoelectric sensor incorporated the counter and display can show not only the number of people s in and out but also count the number of people remained. So, it can be used in the situation of the automatic record and display the dynamic number changing in the maret, the exhibition building, libraries and the classroom in the schools. It is convenient for the administrative department to plan and manage [~].. The component of circuit The circuits conclude the direct-current stabilized voltage power supply, the intelligent photoelectric sensor and it s applied circuit [3~5]. The intelligent photoelectric sensor primarily mae up of the infrared light emitting circuit and the photoelectric measuring circuit and distinguishing people s in and out circuit.. The direct-current stabilized voltage power supply that concludes the power supply transformer, bridged rectifier, filter capacitor and three-end manostat supply the steady direct-current power supply for emitting and chec of signal.. The circuit of emitting of Infrared light is shown in figure. V D 448 R K D U 3 R4 300 DL R 00K R3 0K C 0.0u Fig. the infrared light emitting circuit. 76

205 It primarily concludes 4 resistances(r-r4), capacitors (C), diode (D), Infrared light emitting diode (DL) and timer (555). It is shown in fig. Fig. the setup of photoelectric sensor..3 The circuit of photoelectric chec and distinguishing people s in and out are shown in figure 3. V DL LEDA R5 50K C 03 R7 0K 3 UA * R9 0K U3A CLK EN 7 R 458 Q0 Q Q Q A DL3 LEDA R6 50K C3 03 R8 3K 5 UB 6 * 7 R0 0K U3B 9 CLK 0 EN 5 R 458 Q0 Q Q Q3 3 4 B Fig 3. The photoelectric measure and distinguish circuits. They conclude photoelectric diodes (DL DL 3 ), resistances (R5-R0), capacitors (C ~C 3 ), voltage comparator U(LM393)and decimal counter U 3 (CC458). LM393 is double-voltage comparing circuit. The two anti-phase ends pin and 6 pin of comparators are connected and set a fixed voltage. Two in-phase ends respective connect two photoelectric diodes and the outputs pin and 7 pin of comparators respective connect counters cloc input end CLK of U3A and reset end R of U3B. CC458 is a double-decimal counter circuit. In this circuit, CLK is an input pin of counter cloc and R is reset pin and EN is counter control pin and Q0~Q3 are output ends of BCD code..4 Figure 4 shows the applied circuit, it is counter circuit that primarily concludes decimal add-subtract counter CC400 and nixie tube. It is shown in Fig 4. 77

206 Fig4 add gate countercircuit 3. The process of wor 3. The process of emitting of Infrared light The circuit of infrared light emitting functions as emitting infrared light that is demanded of photoelectric measuring circuit. Figure shows the infrared light emitting circuit. To saving energy, the circuit is narrow pulse happening. Choosing different resistance values of R and R3 can change occupy-empty ratio. Changing the value of C can change surging frequency [6~7]. The values as shown in figure, the occupy-empty ratio about is 0% and surging frequency about is. The output end of circuit through R4 drives the infrared light emitting diode DL that emit high-frequency infrared light pulse signals supplying the photoelectric measuring circuit. 3. The process of photoelectric measure and distinguish circuits (as shown in figure 3) The photoelectric measure and distinguish circuits can measure and distinguish people s in or out., A pin outputs a high level pulse when people come in and B pin outputs a high voltage pulse when people go out. The latter counters memorize that how much people come in and go out and remnant. The setups of photoelectric sensor are shown in figure. Photoelectric diodes DL and DL3 put the side of passage and the infrared light emitting diode DL against DL and DL3 puts another side. When no people pass exit-entrance shaft of signal measuring, the infrared light of DL irradiate DL and DL3 at the same time so that the resistances of DL and DL3 are decreased. As pulse light from DL and higher the time constant of R5C and R6C3, the level of both 3 pin of UA and 5 pin of UB is higher than that of pin and 6 pin. The level of pin of UA and 7 pin of UB is also higher. Because pin of UA connects cloc pin ( pin) of U3A and reset pin (5 pin) of U3B, 5 pin is high level (reset situation) and the output end B of U3B is low level. The 7 pin of U3A connecting the 9 pin of U3B is high level. So the output end A of U3A is low level. In this time, the output ends A and B of counters U3 are no outputs. As shown in figure, body firstly blocs the light from DL to DL When people pass the exit-entrance shaft of signal measuring. The level of 3 pin is lower than that of pin of UA and the output end pin becomes low level. The situation of 5 pin of U3B connecting pin of UA changes from reset to counter. Here, putting a high level pulse to 9 pin of U3B, the output end B outputs a high level. When people continue going forward, body blocs the light from DL to DL and DL3 at one time. The level of 5 pin of UB is lower than that of 6 pin of UB and 7 pin of UB also becomes low level. The situation of 7 pin of U3A connecting 7 pin of UB changes 78

207 from reset to counter. At this time, putting a high level pulse to pin of U3A, the output end A output a high level. As going on, body firstly leaves the light from DL to DL. 3 pin and pin of UA all become high level and 7 pin of U3A is still low level. Putting a high level to cloc end of U3A, the output end A becomes high level. When people leave the photoelectric measuring zone, the infrared light from DL irradiates DL and DL3 at one time. The counters U3A and U3B are all reset situation and the output ends is all low level. In conclusion, A outputs a high level pulse when people enters and B outputs a high level pulse when people leaves. The wor process of circuits is analyzed according to the same principle when people go out. 3.3 The example of applicable circuit The adding-subtracting counter of decimalism (CC400) can be used.the CPU is the cloc end of adding.the CPD is the cloc end of subtracting.the CR is the end of restoration.the CT is the control end of count.the Le is the prepared end of flip-latch.the a~g is the output of sever-segment code.the Bo is the output of borrow. The Co is the output of carry. The figure 4 is the circuit of three-digit counter.the point A and B in the figure 4 is respectively connected with the pointa and B in the figure 3.When a man enters the signal chec section, a high- electricity impulse comes from the point A and a number is added in the counter. While a man moves out, a high- electricity impulse comes from the point B and a number is subtracted in the counter.therefore, the counter in the figure 4shows the present number, that is, the balance of ins and outs [8]. If you want to record the number of entering, a counter circuit listed in the figure 4 can be added. The point A is connected with the point A in the figure 3. When a man enters, a number is added in the counter. Because the point B is not connected, the counter can only add.therefore, the new counter can only record the total number of entering. If you want to record the number of leaving, a counter circuit listed in the figure 4 can be added. The point A is connected with the point B in the figure 3. When a man moves out, a number is added in the counter. The counter can only add.therefore, the new counter can only record the total number of leaving. The above we analysize is the condition of only one. If there are two or three,each one must be set the equipment for transmission and reception, the counter records the each gate s data of enetering and leaving.the data of each gate can be added by adding counter and shown in the LED. 4. Concluding remar The photoelectricity transducer can mae a precise measure and count, whether the speed of men is high or slow. But if two enter or leave at the same time, the counter will mae a mistae. Therefore, the passage of photoelectricity measure is not too wide in order to avoid errors. The photoelectricity transmission and reception canal must be set correspondingly,and the setting location is not too high or too slow, which maes sure that a number is counted as long as a man passes. Reference. Zhang Xian-fu, Su Li-qiu, Zhao Ming-fu: The Principle and Application of Intelligent Photoelectric Sensor. Journal of Magnetic Materials and Devices 009, (): Xia Yujie; Xiong Zhongchao: Design of a control system for photoelectric sensor-based stereo garages. Hoisting and Conveying Machinery 00, (4): Xu Wei: The Reaserch and Application of Photoelectric Sensor. Science and Technology Innovation Herald 00, ():

208 4. Yuan Yong-qiang, Wang Li-gang: The Design of Intelligent Photoelectric Sensor. Science Information 007, (): Ge Peng-fei Zheng Jian-li Liu Xiang-fei: Research of autonomous tracing in intelligent vehicle based on photoelectric sensor. Foreign Electronic Measurement Technology 007, (8): Yan Xiao-he; Dong Ling-jiao; Su Shao-xing: The Development and Application of Photoelectrical Sensor. Equipment for Electronic Products Manufacturing 006, (): Gao Yang,Zhang Hai-yan, Zhang Xu-peng: Research on application of photoelectric transformer on relay protection. Journal of Shenyang Institute of Engineering(Natural Science, 006, (3): Jia Cheng-gong;,Wang Kai, Wang Zhi-gang, Liu Zong-xin: Angle Association Technology of Electro-optic Sensor. Electro-Optic Technology Application 003, (4):

209 STUDY ON SOLAR AIR-CONDITIONING SYSTEM OF TEMPERATURE DIFFERENCE ZHONG CHENG-YAO School of Physical and Electrical Engineering, Hainan Normal University Haiou Hainan, 5758, China Abstract: In the solar air-conditioning system, it maes chilled water reduced to the lowest temperature in the night of the day without any form of energy consumption, and then maes use of water-cooled chillers of air conditioning to refrigerate further in the valley period of electricity consumptions. By doing this, it can improve the refrigeration coefficient of the air-conditioning system, and save energy and cost of electricity substantially. It will mae the cost of solar air-conditioning lower than conventional air conditioning, and furthermore provides a broad way for the popularity of solar energy and solar air conditioning. Key words: solar air conditioning, chilled water, refrigeration coefficient, save energy. Introduction At present, the earth is faced with a sere of problems including the increasing of energy consumption year by year and environmental degradation. According to the research which international refrigeration institute of Paris maes, about 5% of global energy is used to drive all sorts of refrigeration and air-conditioning equipments, furthermore the energy consumption of air conditioning in building accounts for 45% []. For one thing, the widely-using of air-conditioning system and increasing of electricity consumption bring great pressure to electrical networ; for another, greenhouse effect caused by a large amount of carbon dioxide emission destroys the ecological balance. This has seriously threatened the human survival and development. Owning to this, solar airconditioning system of temperature difference is developed. It maes chilled water reduce to the lowest temperature in the night of the day, stores chilled water in tan of eeping warmth, and uses water-cooled chillers of air conditioning to refrigerate further reducing temperature. By doing this, it can provide refrigerating output required. This highly efficient ind of air-conditioning system is of environmental protection and energy-saving. There is profound significance in environmental protection especially in our country which is lac of energy and significant influence on the sustainable development of the human. Besides using temperature difference of day and night to improve the efficiency of the whole system, air conditioning can adjust the flow between water tan and unite as well as the flow between coil of fan and tan in order to improve the refrigeration coefficient of the system and reduce the cost of system according to water-cooled chillers of air conditioning. In many Chinese cities, the phenomenon of electricity shortage in summer is serious. This has affected the local economic development and people's living in recent years. Because electricity consumption of air-conditioning equipment increases successively in summer and even about 40% of consumption offered by urban electric power is used up in the period of pea, saving electricity is imminent []. Solar air conditioning can refrigerate in the period of valley and store the refrigerating output in water tan of eeping warmth. This can save electricity bills and play the role of pea load shifting. 8

210 . structure of solar air-conditioning system Solar air-conditioning system of temperature difference mainly consists of radiator, chilled water tan of eeping warmth, water-cooled chillers fair conditioning and refrigerating output. The bloc diagram of principle is shown in figure. Fig constitute of solar air-conditioning system of temperature difference In the solar air -conditioning system, the chilled water in tan of eeping warmth is frozen to the lowest temperature by the radiator along with natural circulation.it doesn t consume any energy.the water-cooled chillers of air conditioning refrigerates efficiently at the lowest temperature of the day. It maes chilled water refrigerate further reaching refrigeration temperature needed; finally, the frozen water is outputted in order to meet the requirements of refrigeration. 3. the advantages of air-conditioning system The advantages of the air-conditioning system are following: Firstly, maing full use of the temperature without consuming any energy to freeze water naturally; Secondly, water-cooled chillers of air conditioning refrigerates efficiently at the lowest temperature of the day; Thirdly, maing full use of the favorable price in the valley period of electricity consumption. 3. Maing use of the energy of temperature difference In the areas with a little temperature difference,as for the water, quality of l50g,temperature difference by 6 degrees Celsius, the lowest temperature of water at 6.5 degrees Celsius, the heat is 900ca. The living room or hotel room of 5 square meter needs 3000ca refrigerating output.900cal energy is equivalent to a third of air-conditioner cooling for hour,or the supply of cooling in living room for 0 minutes. In area with more temperature difference,temperature difference by, sometimes even 5. The lowest temperatures at 9, the water of 50g is of 650 cal. It is more than 50% of the cooling in living room for hour. Generally speaing, the temperature of air conditioning is above 5.After naturally cooling the water s temperature is 6.5, and by using auxiliary energy again temperature can be reduced to 0. By doing this, cool air of 5 is obtained [3]. Central air -conditioning system of Carp jiang power plant is designed with the river water as cold source, this system services for all living area and offices. The total cold load designed is 4350w and total hot load is 3970w. The air-conditioning system provides cooling for the whole plant directly using the drainage from Dongjiang river reservoir as refrigeration supply without refrigeration host in summer. In winter, the system maes full use of stream to Heat River when the plant uses steam turbine to generate electricity, considering for supply of domestic hot water. This system was designed initially in 997, installed and debugged at the end of 999 and put into use officially in May 000. Since the system wors stable in the past two years, all indexes have met the designing requirements. The total investment of project is up to 745 million Yuan. Compared with ordinary air-conditioning system, it saves investment for 000 million. The effect of saving energy is significant without pollution [4]. 8

211 As above analysis is showed, using the method combined with temperature difference energy can greatly improve the efficiency of air conditioning. In the areas with a little temperature difference, refrigerating of temperature difference save electricity consumption for 0 minutes every day; in the areas with more temperature difference, it can refrigerate directly with the energy of temperature difference without any energy consumption basically. 3. Using water-cooled chillers of air conditioning with large refrigeration coefficient At present, the solar air-conditioning system both at home and abroad mainly contains solar absorption refrigeration, solar solid adsorption refrigeration and solar spray refrigeration, etc [5], but there are common shortcomings in the various forms of solar air conditioning including lower refrigeration coefficient, higher cost. This limits practicability and industrialization of the solar air-conditioning system to large extent. Wan Zhongmin with some people have proposed a new solar air-conditioning system which is of hybrid absorption refrigeration. In hybrid absorption refrigeration circulation, high-voltage generator is added to overcome the shortcoming of low entire efficiency. The refrigeration coefficient increases to 0.6 and the whole efficiency improves 94.5% than that of two absorption system of solar air-conditioning [6]. Due to low efficiency of adsorption air-conditioning COP and collectors, the COP of system is usually less than 0.3. Under the circumstance of same refrigeration efficiency, number of collector not only increases, but also extra cooling towers and cold storage tan are needed in the adsorption air-conditioning system. This leads to the increase of initial investment. According to the survey of the European SACE research,the total cost of various solar adsorption air-conditioning system is (3.5~7.7) 0 3 euro and that of solar absorption system is (.7~ 6.0) 0 3 euro, but the compression refrigeration is only 0. 03euro.And therefore, solar solid adsorption refrigeration system can t compete with compression refrigeration system and absorption refrigeration system currently []. B.J.Huang thought,using R4b can obtain higher spray refrigeration coefficient of performance. The result of experiment shows that the performance coefficient of refrigeration system can reach 0.5 at most in the condition of occurring temperature of 90, condensation temperature of 8 and evaporation temperature of 8 [7]. The changeable trend of maret gross about water-cooled chillers in china is shown in table, and grade index of energy efficiency about water-cooled chillers (heating pump) is shown in table. Table. The changeable trend of maret gross about water-cooled chillers in china Classification of water-cooled chillers piston chillers screw chillers centrifugal chillers libr absorption chillers air-cooled chillers

212 Table. Grade index of energy efficiency about water-cooled chillers (heating pump) classification rated output efficiency grade(eer,w/w) of refrigeration(cc)w air-cooled and CC evaporative cooled CC> CC water-cooled 58<CC CC> May now from the two tables, refrigeration coefficient of water-cooled chillers of air-conditioning is 3.8~ 6..Compared with refrigeration coefficient of solar absorption refrigeration, solid adsorption refrigeration and spray refrigeration (0.3~0.6), it is larger. The system of using water-cooled chillers of air-conditioning combined with energy of temperature difference can improve refrigeration coefficient and save energy. 3.3 woring of water-cooled chillers of air conditioning at the lowest temperature of the day Using conventional air conditioning to refrigerate refers to refrigerating directly at woring temperature of chiller. As for solar air conditioning of temperature difference is concerned,it needs to freeze water to the lowest temperature of the day, then drops to the final temperature needed by means of water-cooled chillers of air conditioning. By doing this, it can improve refrigeration coefficient of air- conditioning system and save energy. Cold/heat source temperature has certain effect on efficiency coefficient of air conditioning. The ideal refrigeration cycle is inverse Carnot cycle. Its efficiency coefficient is only relevant with high source temperature (T)/low source temperature (T) of cycle. As for the air conditioning of refrigeration, the refrigeration coefficient ε obey the formula. That is, ε=t/ (T-T). ε rises along with the dropping of outdoor cold source temperature T when the room temperature T is certain. For air conditioning of heating, the heating coefficient εr obeys the formula. That is, εr=t/ (T -T).The higher the heat source temperature of outdoor evaporator is, the larger the heating coefficient is when temperature of heating room is certain. The efficiency coefficient of actual refrigeration cycle is lower than ideal refrigerating or heating coefficient of circulation, but it is consistent with changeable trend of cold/heat source temperature [8]. Refrigeration coefficient reflects the refrigeration capacity of chillers. From the formula (), refrigeration coefficient of chillers will increase along with the increasing of the evaporation temperature T0, and will reduce as condensation temperature T rises [9]. T0 ε = T T0 () ε refrigeration coefficient T0 evaporation temperature ( ) T condensate temperature ( ) When refrigerating, the air device of converting heating wors at the lowest temperature of the day, then stores cooling in the water tan. By doing this, it can improve the refrigeration coefficient and save energy. In HaiKou of Hainan province, the average of the highest temperature is 33 whenever it is 3 or higher. The lowest average temperature is 5 in summer. According to the formula (), 84

213 When T is equal to 33, When T is equal to 5, T0 T0 ε = = T T 33 T 0 0 T0 T0 ε = = T T 5 T ε ε 0 0 T0 5 T 8 0 = = + T 0 5 T0 33 T 0 When woring at the lowest temperature refrigeration coefficient is as highest temperature. 3.4 Using electricity price in the period of valley 8 ( + ) 5 T 0 The power price in Anhui, Zhejiang and Shanghai are shown in table 3~5 respectively. times as that of the Table 3. The electricity price from pea to valley about electrical power in Anhui province electricity price classification of electricity consumption less than v ~0v flat residential electricity valley electrical heating boilers and ice themal storage of air conditioning July, August, pea September other flat valley (Yuan/w.h) price of valley or pea 53.0% 40.0%-4.5% Table 4. The non-summer price of electricity on sale about electrical power in Shanghai classification of electricity consumption electricity price less than v 0v 35v business and other pea valley agricultural production (trial) pea valley residents in different periods pea 0.67 valley (Yuan/w.h) price of valley or pea 44.6%-47.9% 53.7% 49.8% Note: pea (6:00AM~:00PM), valley (:00PM~ 6:00AM next day) 85

214 Table 5. The price of electricity on sale about electrical power in Zhejiang province (Yuan/w.h) classification of electricity consumption residential electricity voltage grade electricity price in different price of periods valley or price of price of price of pea flat pea valley monthly electricity consumption one family (less than 50 w.h) % one meter monthly electricity consumption of less (5-00 w.h) % than v Monthly electricity consumption (0 w.h and more than 0 w.h) % users (less than v, shared meter) users ( ~ 0 v and more than 0v, shared meter) rural users ( ~ 0v) Note: pea (6:00AM~:00P),valley (:PM~ 6:00AM next day) From the table, the electricity charge needed is only 40.0%~58.% of the charge in rush time when it refrigerates in the valley period of electricity consumption. 4. Conclusion In solar air-conditioning system of temperature difference, it reduce the temperature of chilled water in the night to the lowest temperature without any form of energy consumption; Using water-cooled chillers at the lowest temperature to refrigerate further can improve refrigeration coefficient of air-conditioning system and save energy. Refrigerating in the valley period of electricity consumption can save more than 4.9%- 60.0% of the electricity charge in the flat period. Combined with several aspects of the effect it can save energy electricity charge greatly. This will mae the cost of solar air conditioning lower than that of conventional air conditioning, and provide a broad way for widespread use of solar air conditioning. References. Chen Chuanjuan,Wang Ruzhu and Xia Zaizhong. Review of Solar Adsorption Refrigeration System for Air Conditioning. Journal of Refrigeration, 008, 9(4): -7. Yu Bingfeng. New Technology and Application of Central air-conditioning. Chemical Industry Press, Fu Caimei. Analysis of Experiment on Temperature Differential Air-conditioner. Mechanical and Electrical Equipment, 005, 4(4): Jiang Aihua and Mei chi. Application of the Energy of Reservoir Temperature Difference to Refrigerating and Air Conditioning. Hv & Ac, 004, 34(3): Zhou Jianrong and Pan Yiqun. Summary of Solar Air Conditioning System. Refrigeration, 00, (4): Liu Guilan. The Solar Energy air Conditioning Technology Development and Application. Guangxi Journal of Light Industry, 008, (): Wu Xiaoqing, Tian Qi and Liu Yuna. Solar Energy Injection Type Air Conditioning. Shanxi Architecture, 009, 35():

215 8. Ma Yitai, Liu Shengchun and Tian Hua. Concept on Establishing Theoretical Platform of Refrigeration and Air-condition Energy Efficiency Standard. China refrigeration association conference, Cai Wenhai. The Refrigeration Coefficient of Central Air Conditioning and Energy Research of Refrigeration Host. Energy and Environment, 004, (4):

216 PLC AUTOMATIC CONTROLLING SYSTEM OF FLUSHING TOILET ZHONG CHENG-YAO School of Physical and Electrical Engineering, Hainan Normal University Haiou Hainan, 5758, China Abstract: A ind of PLC automatic control system which is used to flush toilet consisits of programmable controller, proximity switch sensor and solenoid valve. By means of proximity switch sensor receiving input singnal with the core PLC, PLC gives motion instruction to control solenoid valve carrying out flushing toilets automatically. In addition, this paper presents controlling procedure of ladder diagram.in the practical process of application, the system is of high sensitivity and good stability. At the meanwhile, the hardware circuit is simple and easier to be maintained. As far as the system is concerned, the system can be applied to different places with appropriate designs of procedure. Owning to the good univeisity and low cost there is better prospect of application. Key words: automatic control system, PLC, proximity switch sensor, programmable controller. Introduction Along with the progress of the society, the development of science and technology, continuous development and innovation of automatic controlling, the automatic controlling concept is gradually applied to life, industrial production and scientific research. According to accuracy and reliability of detection and location, all the sensors of proximity switch are often nown as the " the sense parts of automatic controlling system "and play a very important role. Various functions of proximity switch mae all sorts of novel controlling concept into the possibility.along with the rapid development of computer technology, chip manufacturing technology and sensor technology, promixity switch develops towards miniaturization, intelligence,high sensitivity, high stability, low price and low power consumption,and more and more powerful promixity switches appear constantly.with its powerful functions such as high reliability and anti-interference ability, PLC with proximity switch as the parter has been widely used in aviation,aerospace technology and industrial production in the field of automatic controlling.in daily life, there is certain application in hotels and restaurants.in adddition,the security devices composed of PLC and proximity switch are used in many important places such as data filing, accounting, finance etc. As for proximity switch, it is not only used to measure length and position in the field of measuring, but also used as the measurement and controlling of displacement, velocity and acceleration []. PLC [, 3] (Programmable Logic Controller) is a ind of electronic system carrying out digital operation.it uses programmable memory to store operation instruction executing logical operations, sequence controlling,timing,counting and arithmetic operation,then input and output in the digital and analogous model to controll various types of machinery or production process. Because of the widely-applying,powful function and convenient use, the PLC has become one of the pricinpal controlling equipments in modern industrial automation and is used widely in all areas of industrial production with developing rapidly both in automation of civilian and household. PLC automatic controlling system of flushing toilet consists of proximity switch sensors, solenoid valve and PLC carrying out the automatic flushing and cleaning toilet instead of people It is of high anti-interference ability,good adaptability to the environment and high sensitivity of detection to body.compared with the 88

217 traditional controlling system of flushing toilet, PLC controlling system is of higher stability and controllability.the device selected is easy to buy and maintain in daily life and production,and therefore the system is of good commonality, low cost and high ratio of price- performance.. The hardware circuit In this system, by means of proximity switch sensor receiving input signal, PLC as the core gives motion instruton to control movements of solenoid valve carrying out flushing toilet automatically.. Constitute of the System The diagram of PLC automatic controlling system of flushing toilet is shown in figure. Fig 3 PLC automatic controlling system of flushing toilet The system includes PLC of Mitsubishi Fx series, proximity switch sensor E3JK-DS30M [4~7] and directly driven solenoid valve of -position -way [8~0]. When people use the sysytem, proximity switch sensors will induct,then PLC will receive signals and begin to time. When opening time of proximity switch is 3 seconds longer than setting time, internal auxiliary relay of PLC will motion and maintain. When people leave, PLC will drive solenoid valve open and flushing for 3 seconds. After 3 seconds, the solenoid valve will close and stop fiushing.when opening time of proximity switch is less than 3 seconds, solenoid valve will not move waiting for receiving signal of switch sensor in order to exclude misoperation and save water when people pass. Time and frequency of flushing are designed by the PLC procedure of ladder diagram according to the different requirements and different situation.. I/O distribution Taing eight controlling positions for example, I/O distribution of the system is shown in table. Input Tab I/O distribution of the system Output signal Component and function input port address of PLC signal component and function output port address of PLC proximity switch X000 solenoid valve Y000 proximity switch X00 solenoid valve Y00 proximity switch 3 X00 solenoid valve 3 Y00 proximity switch 4 X003 solenoid valve 4 Y003 proximity switch 5 X004 solenoid valve 5 Y004 proximity switch 6 X005 solenoid valve 6 Y005 proximity switch 7 X006 solenoid valve 7 Y006 proximity switch 8 X007 solenoid valve 8 Y007 89

218 .3 Hardware circuit of the system Hardware circuit of the system is shown in figure. Fig Hardware circuit In figure, the common end of the promixity switches ~8 is positive pole of DC 4V power, negative pole of which is connected with COM of PLC, the other end of the promixity switches lin with input port PLC X000 ~X007 in sequence;as for the two ouput ports of PLC, Y000 ~ Y007 join with solenoid valve ~8 respectively, and the other output com ties with live wire of AC0V.In addition,the other end of solenoid valve lins with null line of AC0V. 3. The design of software 3. Procedure of system Procedure of the system is shown in fig 3. Fig 3 Procedure of system 90

219 Procedure of the system is shown in fig 3. After the starting of the system, timing begins from the moment of the sampling.it is needed to compare time of sampling with setting time. It will return to sample and time if timing doesn t finish,else solenoid valve will move. Once the timing of movement begins, wheather it is up to setting time is judged. solenoid valve will go on with the movement if timing doesn t finish,else solenoid valve will stop and return waiting for the movement next time. 3. The procedure of single function 3.. Controlling procedure of lavabo When someone washes hands,proximity switch will move.at that moment X000 and Y000 will open leading to the opening of valve;after washing proximity switch stops, X000 and solenoid valve will close with the stopping of water. Controlling procedure of lavabo is shown i Fig Controlling procedure of urinal Fig.4 Controllling procedure of lavabo When someone uses, proximity switch will move. At that moment normally opened contact of X000 will open and of normally closed contact X000 will close with the starting of the timer T0.If the counting time is over, auxiliary relay M0 will start, move and maintain by oneself. Comtrolling procedure of lavabo is shown in Fig 5. Fig 5 Comtrolling procedure of urinal When someone leaves, normally closed contact of X000 will open and Y000 will move, then solenoid valve will open to flush; at the same time, T start to time.if the counting time is up, normally closed contact of T and M0 will close with the stopping of Y000. This leads to the closure of solenoid valve and the stopping of flushing.meanwhile, all contacts reset waiting for the next movement. 9

220 3..3 Controlling procedure of bowl When someone uses, proximity switch will move.at that moment normally opened contact of X000 will open and of normally closed contact X000 will close with the starting of the timer T0. If the counting time is over, auxiliary relay M0 will start, move and maintain by oneself. Comtrolling procedure of lavabo is shown in Fig 6. Fig 6 Comtrolling procedure of bowl When someone leaves, normally closed contact of X000 will open and Y000 will move, then solenoid valve will open to flush; at the same time, T start to time.if the counting time is up, normally closed contact of T and M0 will close with the stopping of Y000. This leads to the closure of solenoid valve and the stopping of flushing.meanwhile, all contacts reset waiting for the next movement. Procedure of the system Comtrolling procedure of lavabo is shown in Fig 7. Fig 7 Procedure of the system 4. Conclusion Along with the progress of the society,and the development of science and technology,economy has been more prosperous and the condense of urban population also increases.there are more and more various public places of leisure, entertainment, shopping mall, airports, railway stations, schools, factories and so on. 9

221 However,toilet is required in these places and the internal cleaning of toilets is quite important Under the condition, automatic controlling system of flushing in toilet is more important. In the PLC automatic controlling system of flushing toilet when the control unit increase,cost will reduced a lot.in the process of experiment and practical application,the system is of sensitive induction, accurate controlling, fast response, high reliability and anti-interference ability. Time and frequency of flushing are designed according to the different requirements and different situation.the system is suitable in public places. With the enlarging of the imension, ratio of performance - price will improve and there will be good prospect of application. References. An Yuhong, Gao Jing and Miao Guoying. Proximity Switches Application. Electric Age, 005, (7): 0-. Liao Changchu. The Foundation and Application of PLC. Beijing: The Mechanical Industry Press, Chen Jianming. Electric Controlling and Application of PLC. Beijing: Electronic Industry Press, 006: Jiang Huihai. The Principle of Photoelectric Switch and its Application. Copper Engineering, 009, (): ZhouQing and Li Wenxu. The Principle and Application of Travel Switch. Electronic Component & Device Applications, 007, 9(6): Guan Cunhu. The Principle and Application of Travel Switch. Low Voltage Apparatus, 993, (): Zhang Xianfu,Su Liqiu and Zhao Mingfu. The Principle and Application of Intelligent Photoelectric Sensor. Journal of Magnetic Materials and Devices, 009, 40(): Zhou Chaoqun. The Electromagnetic Valve Principle and Its Application in Engineering Design. Automation in Petro-Chemical Industry, 006, (5): Liu Zexiang, Kang Min and GUO Mingjiang. Dynamic Property and Parameter Determination of Water Solenoid Valve. Journal of Magnetic Materials and Devices, 009, (): Cao Jing,Hong Xuefeng and Shi Jinhua. Innovative Design of In fall Solenoid Valve Lea Characteristic Test System. Development & Innovation of Machinery & Electrical Products, 009, (6):

222 ACTIVE ADJUSTMENT OF HIGH FREQUENCY SKY WAVE RADAR TRANSMITTING ANTENNA ARRAY ZHONG ZHI-FENG, LIANG YI, YE LAN, LIU ZHONG-LIN, LI TAO School of Physics and Electronics Technology, Hubei University, Wuhan, 43006, China Abstract: Using phased-array transmitting antenna s measurement and adjustment technology to measure adjust and compensate the value of magnitude-phase between the antenna array units is necessary in order to ensure antenna array s performance in the HF sy wave radar system. A technique proposed in this paper that using a set of antenna to emit the signals with same frequency and different phase, and measurement adjustment and compensation to the value of magnitude-phase using the piced up signal s frequency-phase characteristic in receiver. Theory analysis and database model experiments show the validity of this technology and the applicability for practical projects on the end of this paper. Key Word: High Frequency Sy Wave, Transmitting Antenna Array, Active Calibration. Introduction: Phase-array radar is a multifunctional high-performance late-model radar system along with the surge of technology and the maret demand [~3]. It consists of antenna units with controlled magnitude stimulation and controlled phase value. It s extraordinarily significant of putting to use magnitude-phase measurement of phased-array antenna adjustment technique and compensation to get high performance [4~6]. The technique to control the error of magnitude and phase mainly in two theories: first one is strictly control the production precision. Another one is the real-time adjustment. The former basically constraint by wormanship production procedure measurement means and the devices, it s unfeasibly to immoderately increase the manufacture precision considering about the costs. So, the emphasis is the real-time watching and adjustment. According to the produce and arrangement of stimulus signals, the watching method classify in two: external watching and internal watching []. For the high-power, HFOTHR usually use the transmission arrays, and with accurately controlled magnitude and phase of the transmit units to obtain requested wave shape and wave direction [4~6]. In Coherent Radar system, using the coherent sources the best method to adjust magnitude-phase value, and towards the microwave radar system, the external field is so close that should adopt the external watching. Moreover, in the high-frequency radar system, the wavelength is too long to transmit as far as 0 ilometers away. For those reasons, a technique using serial antennas array that transmit the signals with same frequency and different phase, and using measurement technique to pic up frequency-phase characteristic in receiver. According to theory analysis and database model experiment, it tells the feasibility and engineering applications. Additionally, this thesis mostly wors on the theory calculation, not on the engineer application, it s necessary to improve by practice.. Theories to calculate the error using magnitude-phase characteristic. Research in a cycle of a sin signal Assume the transmit signal without phase change is: So, the signal in the receive channel is: y = j t e ω () 94

223 j( t ) y = e ω α Here, α is the phase change across transmitter channel to receiver channel. The signal in receiver channel is: j( t ) y = e ω α β γ Here, β is the phase error between channel and channel, γ is the error produce by channel and instrument, regard as a random error in receiver channel. Assume the transmit signal with phase change in channel: Here, φ is the phase change in one movement. So, the relative signal is: y y ' j( t ) = e ω φ ' j( t ) = e ω α φ y '' j( t ) = e ω α φ β γ As to the ideal signal (without relative error between channels and without error between channel and instrument), the combined relative phase changed signal in receive channel is: ' y0 = y+ y j( ωt α) j( ωt α φ) = e + e = φ cos( ) e φ j( ωt α ) The maximum magnitude value of the combined ideal signal in receive channel at φ π ωt α = is: φ MaxAmp0 = *cos( ) (8) As to the real received signal (with relative error between channels and with error between channel and instrument), the combined relative phase changed signals in receive channel is: ' '' y0 = y+ y j( ωt α) j( ωt α φ β γ) = e + e φ+ β+ γ φ+ β + γ j( ωt α ) = cos( ) e (9) The maximum magnitude value of the combined real signal in receive channel at φ +β+γ MaxAmp = *cos( ) The phase error between ideal signal wave pea and real signal wave pea is: () (3) (4) (5) (6) (7) φ+β+γ π ωt α = is: (0) 95

224 β +γ θ= So, β+γ=θ. Θ is the result by sampling after a MF matched filter. The flow chart of receiver below is shown in Fig. () Fig, received signal process flow chart 3. calculate the error between channels using received signal s phase. According to the formula,β+γ=θ. The θ can be obtained by sampling after a MF matched filter. But, affecting by the channels and instrument s precision, there should be errors. To mae sure of the minimum errors, here is a solution: Fix up the phase in channel, and calculate the phase shift length according to the referent phase error in channel s. Then shift the phase value depend on the phase shift length until π, record the pea value of the received signal at the same time. Obviously, those pea values meet the transmitted signal in frequency distribution. Therefore, it s available to draw the points with sin signal, and then got β+γ value depend on the value of φ and the average value. Finally, decrease the relative error β between channels, as well as random error γ and the system measurement error. Here is an experiment, assume α=00;shiftphistep=0 0 0 ; β= 30 ; 0 γ=± 0. Attention: within different value of φ,shiftphistep>α+γ. As illustrate below: until the 50th cycle, the average error is Average PhiError= variance is: Var = 0.005, which is shown as Fig. Fig, Curve fitting with the same frequency. In spite of simple calculation and ideal effect, the synchronization is hard to carry out because of the sensitiveness of the phase. The latest receiving antenna mostly adopt super heterodyne pattern, namely mixing at 96

225 the same time at receiving. For the long distance of transmit channel and receive channel, the phase of mixed signal is hard to synchronize. Even if using GPS cloc trigger, it s highly inconvenient. 4. Calculate the phase error between channels using magnitude of received signal. The result of the analysis above, it s relative between the maximum magnitude and phase error when two channels transmit a sin signal with single frequency. The maximum magnitude value of received signal is measurable, so that the relative phase error can calculate by the corresponding pea value: According to formula (8): MaxAmp0 φ= *arccos( ) () According to formula (0): MaxAmp φ+β+γ= *arccos( ) (3) The result is: β+γ= MaxAmp MaxAmp 0 *(arccos( ) arccos( )) The method to accurately measure the MaxAmp : Two separate sin signal composted one sin signal with same frequency. We can get the frequency spectrum by repeat sampling from this composted signal and with Fourier transform; the corresponding pea value is the accurate MaxAmp.The ideal value of MaxAmp0 can be φ got by formula cos( ). Similarly, Fixed phase in channel, and calculate the phase shift length according to the referent phase error in channel s. Then shift the phase value depend on the phase shift length until π, record the pea value of the received signal at the same time. Obviously, those pea values meet the transmitted signal in frequency distribution. Therefore, it s available to draw the points with sin signal, and then got β+γ value depend on the value of φ and the average value. Finally, decrease the relative error β between channels, as well as random error γ and the system measurement error. Stimulate the model with the same date given above: 0 AveragePhiError = 30.5 Var = The angle changes is shown as Fig 3. (4) Fig 3, Angle changes Result is: The precision of error calculation depend on signal s phase is higher than the one depend on signal s magnitude; the variance of error calculation depend on signal s magnitude is larger than the one depend on 97

226 signal s phase. Absolutely, as a method to project applications, the one depend on signal s magnitude should be the best one. 5. Multi-channel adjustment based on channel. Real-time Multi-channel adjustment use the principle of time-sharing and PM process in transmit channel. Namely transmit channel emit sin signals that modularly. The transmitted signal pulse illustrated as Fig 4. The first pluse The eighth pluse Ann Ann Ann3 Fig4, Multi-channel simultaneous calibration Note, channel and other channels launch at the same time, and the initial phase of the transmitted signal maintain consistency. 6. stimulation experiment. Uniform linear array monopole antenna with 8.Assume distance between units is 5 meters, the frequency of radar is 3.33 MHz, and sampling time is 5. In the ideal condition, antenna array come into being the direction map illustrate in In magnitude-phase error condition, the magnitude error form g to g8 is [ ] based on referent channel ; the phase error fromφ to φ8 is[ ] based on referent channel. Finally, after adjusted by the method depicted above, the magnitude is[ ];the phase is[ ]. illustrated in the Fig 5. Fig5(a), Ideal array pattern 98

227 Fig 5(b), Array pattern with amplitude and phase error Fig5(c), Array pattern been calibrated amplitude and phase error 7. Conclusion. It brings a solution of adjustment of magnitude and phase in high frequency sy wave radar transmit antenna system. By the means of theories analysis and database simulation experiment, it was proved the solution s feasibility and project application value. Additionally, this thesis mostly wors on the theory calculation, not on the engineer application, it s necessary to improve by practice. References. Zhang Guangyi, ed. Principles of phased array radar. National Defence Industry Press, Cai Qingyu, ed. Phased array radar data processing and simulation technology. National Defence Industry Press, Zhang Mingyou, Wang xuegang, ed. Radar Principles. Radar system. Electronic Industry Press, Zhang Zuji, ed. Radar Antenna Technology. Electronic Industry Press, Liu echeng, ed. Antenna Theory. National Defense University Press, Jia Yongang; Bao Zheng; Wu Huan, A New Calibration Technique with Signal Sources for Position, Gain and Phase Uncertainty of Sensor Array. ACTA ELECTRONICA SINICA,

228 A RESEARCH ON THE USE OF SEC CODES IN DOUBLE ERROR CORRECTING. Introduction ZHU HONG-WEI, ZHOU CUI, ZHANG JIN-LIN, SONG XIAO-MEI Air Force Radar Academy Wuhan, , china Abstract: In a coding system, if the Hamming distance is d, we can detect any d- bits code errors or correct an error maximum to (d-)/ bits. SEC code is a d=3 parity chec code which has single error correction and double error detection capability. But the code can t locate double error. This paper discusses the realization of detection and localization of double errors by the parity chec equations. The result shows that the error code have three inds of combination when a double errors appeared. Key words:sec code, double error, localization, parity chec equations In modern digital systems, error correction technology is important in error correction, location and tolerance. The technology can increase reliability of data flow in digital systems, effectively. Parity chec code is an extensively used code in error location and correction. The code is more effectively used in the error detection during the process of the storage and transmission of data flow. SEC(Single Error Correcting) [,] codes are parity chec codes which Hamming Distance is three. It has the ability of location and correction for single error. This paper presents a method for the location and detection in single error especially in double error through the discussion of the SEC parity chec equation and generating matrix.. Parity Chec Equations and Generating Matrixes Parity chec codes have many inds of coding ways, such as LDPC-SPC code. They are consist of some information bits and chec bits. The chec bits will insert the information bits. There is a code with bits information bit, where b=b b - b (b i =0 or ). We built a Parity chec code V with n+ bits by adding the new chec code with n bits [3] (B,B, and B n ( n n++)). The code format of V is: V=V n+ V n+- V V l =b b B 3 b B B l () B i will insert the information bit in its i- bit (V t =B i (t=i-,i=,,3,,n)). Since parity chec code is a linear code, the relationship of information bits and chec bits are linear. We can use a set of linear equations to show the relationship. The value of B i is determined by the following equation. VP = 0 () P is a matrix with n+ row vectors p i (p i =i).. The parity code which Hamming Distance is three is consist of 7 bits information bit and 3 bits adding chec bit. We can get the format of the code from equation. V=V 7 V 6 V 5 V 4 V 3 V V l =b 4 b 3 b B 3 b B B l (3) p 0 0 p 0 0 p3 0 The matrix of P is P = p4 = 0 0 p 0 5 p6 0 p7 (4) 300

229 The equation is the chec equation of parity chec code and the generating matrix of chec bits [4]. 3. Failure Detection and Location We will discuss the chec equation and the generating matrix in the equation. And the error detection and location method will be present. B = The generating code V is (000) if the information bits is (0). We can get B = 0 from equation. B3 = 0 3. Single error V 4 has an error if V * changes into (00) after transmission. We can use the chec equation to perform a parity chec. It is V 4 has an error if VP=(00)=4. We can rectify V 4 to 0. If V*=V then VP=0, it can fit the equation. There is no error in the code. 3. Double error In order to enable the parity chec code has effective ability to detect and locate the double error effective, we added one chec bit V 8 and indicating bit C to the code. This will improve its efficiency in the chec and location of double error. V 8 and C aren t included in the calculation of the chec equation and generating matrix. In circuit design, we must indicate the states of V 8 and C in the transmission terminal and receiver [5]. V 8 = V7 V6 V5 V4 V3 V V C = V8 V7 V6 V5 V4 V3 V V In the equation, the parity code is consist of V 8 and V 7 ~V. We just investigate two cases: single error and double error. The discussion is in the following. Case : If C=, there is no single error in V 8 ~V. At the same time, if the chec equation VP = 0, there is no error in V 7 ~V but V 8 has an error. If C= and VP 0, there is an error in V 7 ~V and we can rectify it by the equation. Case : If C=0, there are two possibilities. There will be no error or double error in V 8 ~V. If the indicating state of V 8 isn t consistence, V 8 has an error and V 7 ~V have a single error. We can rectify it by the equation. On the other hand, if the indicating state of V 8 is consistence, we can use the equation to chec and locate the error. If VP = 0, there will be no error in V 7 ~V. There will be a double error in V 7 ~V if VP 0. We can locate the error by the results of the chec equation. From the equation, we can get: We assume VP=(00) after decoding, V 4 V3 V V = 0 VP = V 6 V5 V V = 0 (5) V 7 V5 V3 V = 0 V 4 V3 V V = 0 VP = V 6 V5 V V = 0 (6) V 7 V5 V3 V = 30

230 If there is a double error, one of the two error codes will appear in the third formula of the equation 6. Two error codes will appear in the first formula or the second formula of the equation 6 at the same time. Possible error combination will be V 6 V 5,V 4 V 3 or V V. There will be no error in V 7. Through the same argument, we can get the possible double errors and impossible errors when VP =00,0,00,0,0 and, which are listed in the following table. 4. Conclusions Table The location of double error VP Possible double error combination No error bit V 6 V 5 V 4 V 3 V V V 7 V 5 V 4 V V 3 V V 7 V 6 V 4 V V 3 V V 7 V 3 V 6 V V 5 V V 7 V 4 V 6 V V 5 V V 7 V V 6 V 4 V 5 V 3 V 7 V V 6 V 3 V 5 V 4 Although QC-LDPC code and LDPC code could detect error [6~0], This essay presents a double error location method in parity chec code which Hamming Distance is three. The method use the parity chec code equations. We can find out the impossible error bit directly when there is a double error in a code. We can also locate the double error basically. Combination of the double error will be located in three cases. V 7 V 6 V 5 V 4 V 3 V V References. Zheng, C.X. Diagnosis and Integrated Digital Systems. Xi'an Jiaotong University Press, Qiao, H., Lin, G.R., Wang, D., Dong, M.K. and Xiang, H.G. LDPC-SPC Product Codes. Acta Scientiarum Naturalium Universitatis Peinensis, 44(): Huang, Y.S. and Lin, B.S. Research of a New Error-correcting Codes. Journal of Yanbian University:Natural Science, 005, (): Yang, S.Y. The Fault Diagnosis Design for Testability. Tsinghua University Press, Zhu, H.W. Ability of Error-correcting Parity Code. Naval Academies, 007, (5): Chen, Y. Implementation of an LDPC on DSP. Journal of Huaqiao University, 005, 3(): Zhao, L., Zhang, X.L. and Zhi, G. Design and Implementation of Multi-rate Quasi-cyclic Low-density Parity-chec Code Decoder. Journal of Beijing University of Aeronautics and Astronautics, 008, 34(4): Jiang, M., Zhao C.M., He, S.B. and Shan M. LDPC Codes with Low Complexity Joint Decoding Method of Construction. Jouranal of Communications, 00, 6(): Wang, F., Ni, K.S.and Guo, Z.R. Construction of Low-density Parity-chec Codes Based on Cyclic Difference Sets. Computer Engineering, 00, 36() Jutta Stahl. Error detection and the use of internal and external error indicators:an investigation of the first-indicator hypothesis. International Journal of Psychophysiology, 00, 77(3),

231 MSP430-BASED SINGLE-PHASE SINE WAVE INVERTER LIU ZI-XI, FANG EN-XIN, SHI WEI, LUO JIN-WEI ). School of Information Engineering, Wuhan University of Technology, Wuhan ,Chain ). Zhicheng College,Fuzhou University,Fuzhou 35000,China Abstract: This paper describes a design of a MSP430 microcontroller based SPWM inverter. Through the boost section and the SPWM inverter section, it can give high-quality AC whose frequency and voltage is set. The design is based on Boost topology principle and uses high-performance voltage PWM control chip TL494 to drive the MOS tube in the main circuit. MSP430 microcontroller is the center of the whole system. It cooperates with the -bit high-precision D/A module to control the output voltage accurately. The system has a good over-current protection and can detect the load conditions intelligently. Adopting SCM technology to control this power maes the whole system simpler and also achieves digital intelligence. It provides a ind of high-quality AC power for equipments with high performance requirements. Key words: Inverters; MSP430; single chip; sinusoidal pulse width modulation; voltage negative feedbac. Intrduction In recent years, with its advantages of environmental protection and energy saving inverter has been more and more widely used in modern industry. This ind of inverter can transform the + V DC input voltage provided by battery into AC voltage with variable frequency and size. It can be used in automobiles, household appliances, office equipment and computers, etc. With the PWM technology more and more widely used in frequency conversion and frequency inversion, and the rapid development of power switch devices such as IGBT, PowerMOSFET, the PWM-controlled high-voltage power supply is developing toward the direction of small, high frequency, intelligent and efficient [~]. In this paper, voltage PWM control chip TL494, the high suspended driver IR0 and the power switch devices IGBT module program are used to achieve hith-frequency inverter [3]. In addition, the system uses low power consumption and high efficiency design to maximize system efficiency. The inverter part uses digital SPWN control mode in order to minimize harmonics as much as possible.. System design As shown in Figure below, the program uses special high-performance switching power supply controlled chip and MSP430 MCU to constitute the control section, which can be divided into the front level DC-DC module and after level DC-AC inverter module. The front level adopts Boost topology. Control circuit uses voltage PWM control chip TL494, built a voltage and current double closed-loop feedbac circuit,while achieving voltage stability and over current protection function; The after level DC-AC s transformation uses special driver chip IR0 to drive the bridge inverter circuit, the SPWN signal used for driving is generated by the MSP430. After low-pass filter, the bridge inverter output section then can be an ideal sine wave. The whole system constitutes a closed-loop control structure, using PID control algorithm to achieve accurate numerical surge. MSP430 [4] is a 6-bit microcontroller with the characteristics of low Power consumption, rich built-in resources, fast instruction execution time, which the other traditional 6-bit machine can not match. Its own -bit A/D and -bit D / A, to some extent improve the design accuracy and mae the external circuit more simple. Meanwhile, MSP430 JTAG emulation support for debugging interfaces for online debugging program is very suitable for low power, high efficiency products for embedded control 303

232 Fig Entire System Bloc Diagram 3. Hardware design 3. Boost circuit module design and analysis Use non-isolated Boost structure [5]. This boost style can achieve high power utilization and can be easily controlled. The specific circuit is shown in Figure. Fig DC-DC circuit This circuit use high-performance integrated switching power supply control chip TL494 [6] as the core and adopts hardware PI closed loop control. It builds voltage and current dual feedbac circuit and plays a role in regulating the output voltage. The voltage and current dual feedbac loop constitute the first layer of feedbac; And software constitute the second layer of feedbac loop. This design improves the system's output voltage precision and stability. The comparison voltage Ref used to control is given by the MSP430 after the microcontroller has analyzed the latter level s voltage sampling signal. By constantly changing the comparison voltage output by the MSP430 microcontroller buil-in -bit high precision D/A, the TL494 output duty cycle is changed. So that Boost circuitry can achieve output voltage regulation, which would achieve the level voltage 304

233 after the purpose of real-time correction. Main circuit choose low-impedance devices as the power devices, it can reduce the system loss to the largest extent. If the output current is up to A,set the circuit into over-current protection. As with the voltage feedbac design the over-current protection also has both hardware and software two levels of protection. Error amplifier is used for the hardware over-current protection. In case of over-current, TL494 can cut off MOS tube s drive output automatically. Before the output there is also a current sampling circuit to do system current real-time monitoring. If it occurred a over-current phenomenon, then promptly cut off the circuit, protecting the user s and device s safety. The breadown voltage of main devices in the Boost circuit should be greater than the output voltage. To ensure voltage and current can be passed smoothly, the main circuit diodes uses MUR000 a Schotty Diode which has a 0V rated-voltage and a 0A rated-current. To improve efficiency and reduce pipe damage, choose IRF 640 as the switch which has a mere 80m resistance when it wors. Even in the over-current state, the opening state power of it is also quite small. 3. Main circuit module design and analysis In the main circuit the IR0 drives the full-bridge inverter circuit. The D-A;D-B port of last level s output are connected with HIN;LIN ports of IR0. Since the entire bridge to be driven is alternately conductive, the HIN;LIN ports should be connected crosswise lie D-A;D-B/D-B;D-A to ensure the whole bridge is alternately conductive. In order to prevent bridge faults, add current measurement resistor at the input, playing the role of over-current detection and protection with the coupler together. Once the current is too large, the IR0 realize hardware protection firstly, while an interrupt signal is given to the microcontroller so that microcontroller alarms and automatically resets. If you need to change the protection current you simply need to change the current measurement Resistor R6. The main circuit chooses IRF640 MOS tube whose durable pressure and permissible current are both met. When woring the upper and lower leg of the whole-bridge is alternately conductive to achieve the DC to AC transformation. IR0 drives power devices, using the bootstrap drive mode. Floating channel design maes it possible to drive power tube whose bus voltage is less than 600v. Using only one power supply to drive the whole-bridge s four tubes can avoid the trouble of too many independent power supplies what is happened in the old bridge driver. It can also use the same GND port with the main circuit. The choice of the bootstrap capacitor should tae the Widest and narrowest conduction time into account. C>Qg(Vcc-0-.5).As the MOS tube s conduction time is usually less than cut-off time, it is often easy to mae the bridge shorted in the alternate conduction moment. In this design the drive arm is in parallel to a diode N448 to speed up the current returning. So as to accelerate the MOS tube s closing function. In order to prevent the MOS tube from breadown in the switching moment by pea voltage, add diodes, resistors and capacitors in the bridge, playing the role of a buffer clamping. Especially when the inverter output is high, the function of these resistors and capacitors is particularly distinct. Diode D is mainly used for blocing the high-voltage of the direct current lines, whose bear current is the product of the gate charge and switch frequency. So we should choose a diode which has a low reverse leaage current, whose bear voltage is higher than the pea voltage and the power consumption is as small as possible. So Diode HER8 is chosen. At the same time the resistor on the driver arm also determines the driving ability of IR0. Too small resistance may easily lead to the bootstrap capacitor discharge too quicly, directly affecting capacitance drive time. On the other hand it may mae the diode used to 305

234 accelerate current returning nominal. After actual commissioning, the bootstrap capacitor is taen as 0.Uf, the resistor on the drive arm is taen as OM. The inverter circuit diagram is shown in Figure 3. Fig 3 inverter main circuit diagram 3.3 Hardware Anti-dead module design and analysis The module circuit is shown in Figure 4 as follows: Fig 4 hardware anti-dead circuit diagram For the full-bridge circuit, the dead time is an indispensable part. Otherwise if the upper and lower tubes of a same bridge arm turn on at the same time, it will lead to disastrous consequences even if it s only a few ns time. In order to reduce the complexity in software and improve the stability of the whole system, we use a hardware dead protection circuit. Under normal circumstances, the circuit only reverses the input level. If the two pulses are at the same time low, then SPWM outputs high level. And the SPWM s output is low, so that preventing the situation of both high levels. Although this part of the circuit is simple, but the bridge played a very good protective effect. 3.4 Filter Circuit Module Design and Analysis The system uses symmetric LC low-pass filter structure to get sine wave, the filter s cut-off frequency is obtained by the following formula: 306

235 f s = π LC () For the 50Hz inverter, LC filter s harmonic frequency is usually chosen between 50Hz and 500Hz, ie 5 to 0 harmonics around. In order to inhibit the inductor ripple current, the L is generally at least several hundred uh. And to control the 50Hz fundamental, the sampling frequency is generally at least 000Hz. Otherwise the sampling points for each fundamental are too few, can not achieve a good control effect. Reducing the pea inductor current is also needed to reduce the filter circuit s impact on the former Boost circuit. For the above reasons, we set 360 sampling points, so the sampling frequency is 8000Hz, use 4,7Uf filtering capacitors and.mh inductance.the filter module circuit diagram is shown in Figure 5: Fig 5 filter circuit diagram 3.5 voltage, current and frequency detection circuit design and analysis [7] The detection circuit consists of current and voltage detection two parts. Since the voltage and current detection have the same principle but an added resistor. Here we only illustrate voltage detection as an example. Using high precision instrumentation amplifier INA8 in the signal amplification circuit can amplify the voltage signal precisely. INA8 magnification G=+50K/Rg, Rg=7K, so G=.85. By the K and 00K divider resistor, the INA8 input maximum voltage difference is The circuit bypass capacitor reduces the circuit clutter s affection to accuracy detection. Of course, the detected intersection still can not be directly converted by the microcontroller A/D module. The detection voltage yet needs to be elevated by the follow-up additive circuit until there is no negative pressure in the detection range and the maximum output voltage does not exceed 3.3V. Hereto the A/D sampling can accurately collect the detection data. The concrete circuit is shown in Figure 6. Fig 6 Voltage detection circuit diagram 307

236 4. Software design In this system design software has played a significant role besides providing the normal display. The advantage in this system software lies in adding software PID regulation, formed feedbac by sampling. Compared with the hardware PID regulation, the software PID regulation is more convenient. Cooperating with the first level feedbac circuit, it reduces the complexity of the whole circuit. Software and hardware two levels of feedbac improves the stability of the system output. Meanwhile the system also uses software to generate SPWN wave. It can regulate the whole-bridge alternative conduction to achieve the transformation from DC to AC [8~9]. 4. The generation of SPWM Wave The basic principle of the inverter power system is transforming the SPWN wave into a sine ware by the filter. Therefore, the most important thing in software development is to mae the MSP430 chip output SPWM Wave that changes according to sine wave. Through theoretical comparing and practical test we can produce the PWM wave according to the following formula. Q/360(sin(n3.45/80)) () The n is the number of sampling points in half a sine period, ranging from to 80; The Q is the time period of the timer, changing as the frequency of output AC changes. The formula is By the anti- function we can get the opposite polarity waveform output, thus obtaining bipolar SPWM wave as shown below: Fig 7 Bipolar SPWM waveform chart 4. voltage, current and frequency detection Using MSP430 chip s own A/D conversion function we have successfully completed the converter system s voltage and current detection. Because the system s output is AC, the sampling is also AC. In order to obtain the voltage and current RMS, we tae the AC definition formula to calculate the RMS. V= U + U + U3 + + UN (3) I I I I I = N (4) The N is the number of sampling points in a period. N=360. That is there are 360 sampling points in a unit sine wave period. 308

237 4.3 Voltage and frequency digital regulation. On voltage regulation we choose the Boost circuit DC voltage regulation. Because of the MSP430 built-in -bit high precision D/A we can output the reference voltage directly. When the voltage set by the system changes, the system output PWM waves. Then the TL494 s reference voltage changes and the output DC voltage is also changed accordingly. When the sampling voltage does not match the setting voltage, the system will automatically regulate the reference the output voltage, so that stabilize the voltage to be around the setting voltage. 4.4 Software flow chart The diagram blow is the microcontroller s software flow chart 8: Fig8 The microcontroller s software flow chart 5. Conclusion Through the above theoretical analysis and the practical test results. The design uses a high-performance switching power controlling chip TL494, and by the hardware and software two levels feedbacs, the PID algorithm and the SPWN wave regulation etc. the system output voltage s stability has been improved greatly. Tests show that the power s load regulation is only 0.9% around, while being full loaded the power s conversion efficiency is about 87.5%.It shows that this design is a highly efficient, highly stable power supply. Under the dual-phase over-current protection of hardware and software, the power is very safe. After testing the 3A-current protection can be absolutely achieved. When the output voltage is 36VAC, access in an 8-ohm resistor, the system can smoothly output an AC whose pea is A, and can achieve over-current protection when it arrives 3A. References. Shan Hong-tao, Li Peng,Kong Xue-juan, Hui Ouyang, Liu Zhao,Wang Shu-hui.Effect of Digital Process on the Performance of Pulse Width Modulation Inverter[J].Proceedings of the CSEE,009,9 (6):

238 . HU Xue-feng,LI Shao-ming,Zhang Jia-yan.Research on the Integrated Control Strategy for Inversion Power Supply[J].Power Electronics,009,43(): Wang Ling-ling,Wang Yi.The Design of Circuitbreaer Control Power Supp ly based on TL494 and IR0[J].Telecom Power Technologies,008,5(): Shen Jian-hua. MSP430 MCU 6 ultra-low power practice and system design [M]. Beijing: Tsinghua university press, Xie Yun-xiang,Demystifying Switching Power Supplies[M].Beijing:Posts&Telecom press, Zhang Guodong,Functions and Checing Methods of TL494,China Education Technique and Equipment,003,(): Xie Zi-mei. Electronic circuit design [M]. Wuhan: Huazhong university of science and technology press, Kong Xuejuan.The ey techniques research on the digital controlled PWM inverter[d].wuhan:huazhong University of Science and Technology, LI Zi-xin,,Wang Ping,,LI Yao-hua, Zhu Hai-bin,,Sheng Xiao-song,,Gao Fan-qiang.400 Hz High-power Voltage-source Inverter With Digital Control[J].Proceedings of the CSEE.009,9(6):

239 RESERACH ON THE MODEL OF EMERGENCY EVACUATION BASED ON AGENT MA LI, LIU GAO-YUAN, LIAO MENG-YI Pingdingshan University Pingdingshan, , China Abstract: Studying the process of emergency evacuation, and analyzing the existing microscopic models, a new evacuation simulation model based on agent was presented to maximize the performance of the emergency management system. The system was supported by a mathematical optimization model of large-scale evacuation. With the introduction of many factors, the model can simulate evacuation dynamics under various situations. In this model, we introduced a variety of factors in evacuation process, and simulated crowd dispersal state in real situation. The model was lined to an agent model, which provided real-time data and implemented visualization of output. Compared with modern models, it can be used for evacuation simulation of many inds of emergencies, and optimize simulation results. This proposed system is useful for devising evacuation plans in advance as real-time management under disaster. Key words:emergency operation; dynamics analysis; pedestrian safety; agent model. Introduction In recent years, the process of urbanization of every country has gradually sped up, the city size has expanded, and the population has increasingly been density, So inds of emergencies within the city have been also on the rise [~]. Because emergencies can not be truly tested, so it is hard to build a mathematical model of movement rule of human evacuation. With the help of computer simulation technology, we can build a model to research emergency evacuation. Building a simulation environment of affected area, researching personnel psychology, behavioral characteristics in the situation of emergency evacuation, simulating the evacuation process in densely populated areas, we can estimate the evacuation time and the number of people evacuated to safe areas at different times [,,3,5]. This is a great significance of improving the emergency response capacity of city; reducing disasters caused casualties and property losses. The method of modeling based on Agent The complex system is composed of many individuals which interact each other. Modeling and simulation methodology can describe the behavior and relationship of simulation entities in complex system [4~5]. Agent can get messages from other environment, and use these messages to update its state and send messages to other environment. Through inds of interaction, the overall behavior which just in object system entirety can appear.. Agent 3

240 Simulation modeling technology of evacuation based on agent treat staff as a collection of individuals, which is a microscopic model. So, every one is a mapping of agent in model, which autonomously maes decision and acts [6].. Environmental space The problem of emergency evacuation is how to brea away from dangerous area and get to a safe area. So, a spatial location and environment is an important factor. And it comprises the environmental space in simulation world. In the evacuation simulation based on agent physical space which is a base play an important role [6~7]. In this paper, we use Cartesian coordinate representation of continuous to display two-dimensional space. The virtual space exists in simulation world is a direct mapping of actual physical space. Using continuous space and xy coordinate without any changes of express method [,3,7,8]. Simulation Modeling Based on Agent 3. Environment model In order to maintain the advantages of continuous space simulation, and reduce the difficulties of computer simulation, we use continuous and discrete models respectively. For the individual variables within the state and its inematics, we use physical coordinates of continuous space ( x, y ), which consist with Cartesian coordinates. We use two-dimension grid space model to display the individual external performance and visual simulation. The grid coordinate is ( xi, yi ), which represents rows and columns of individual agent in a grid. Obstacles in space environment which are external manifestations of matter to individual agents are also uses grid space, and it is easy to feeling [8]. We use grid coordinate ( xi, yi ) to express every grid in a grid space, and status of every grid is when it is an obstacle or be occupied by others, and it is o when it is empty. According to the agreement above we now that when the statues is it indicates that the grid represents the total area of non-empty, and when it is 0, they are all empty. On the other hand, when a physical coordinates ( x, y) in a grid, we treat that agent occupies the entire area of the grid and only within the grid. So, when coordinates xy of individual Agent locate in a target cell, it indicates that Agent reached the destination. Computing the location of target, we choose the center of target grid [6,9]. 3. Individual Agent Model In the process of an Agent moving from the current location to the target location, the location is changing following the speed which is a vector indicating the changes of an agent location in the direction and size. The speed of agent bases on observations from the environment and changes both their own internal state, which changes the nowledge in agent. So, aesthesia is called Generate nowledge action [0]. We use shortest path planning algorithm in this model combining the characteristic of space discrimination and set a new method for a sub object of algorithm. Setting up a separate point as a sub object near the border of building, it will cause evacuation certain time when many individuals will see the same point as their own current 3

241 target, neglecting that point nearby more available passage regional, forming unrealistic crowded. So, we can use any obstacles to the formation of two narrow channels as the beginning and ending as the office entrance, and the composition of their grids are optional sub-objectives. Fig. illustrates a path planning based on sub targets [7]. Fig. Path planning based on sub targets D grids in picture are target grids, which includes final destination and sub target on the way. In picture it proposes a path project using three agents. Sub objects were previous set and individuals move towards to sub objects with little margin. So, it can avoid the influence of obstacles []. When target is fixed, moving behavior of individual agent is determined by inematics model of evacuation. Every individual Λ is composed of moving direction of any time θ ( x, y, t) and speed ν ( x, y, t).the direction of movement θ ( x, y, t) and speed ν ( x, y, t + ) next time is calculated by formula. The direction of movement and size of this process constitute the tactical level of individual decision-maing Agent, also nown as the local path planning. In direction select model, we need consider the influence of obstacles which in the direction. When it is bloced, we propose that individuals with a probability set to adjust their direction of movement, and the definition of direction angle is: π π Δθ = R random[, ] () When R is 0, it means that it can reach the nearest grid on the motion direction without obstacles, and it does not need to be adjusted. On the other hand, when R is, it needs to be adjusted. Maybe the direction of a random adjustment is still bloced. So, we set a constant m for simulation system which means the number of times individuals can try to select. For example, if m =5, any individuals can try the random direction many times when the obstacles appeared. If failed at the fifth times, we can set direction and speed of individual lie this: θ( t + ) = θ( t) v( t + ) = 0 After a strategic level and tactical-level decision-maing individual Agent can not guarantee completely avoid conflict with dynamic obstacles, especially the movement of conflict with other persons. Conflict in () 33

242 movement in general will change original decision-maing of individual Agent, and it needs to adjust strategy temporary which is collision detection and avoidance. In order to avoid collision detection and conflict resolution to bring the computational, we tae three steps. means action, and decision-maing includes tactical decision-maing and it may include strategic decision-maing. Agent maes a decision at t time, and three steps later it will mae a decision again at t+3 time. Between t+and t+ times, if detect the conflict of dynamic obstacles, individual agent will be forced to abandon the results of the original decision. At this point, people often tae protective action reflexively, slightly adjusted, and re-planning. This model sets that individuals should stop before the next decision, and adjusts. To a small enough time step Δ t, it meets people s actual behavior. So, when detects the obstacles, and means stay still, and when detects obstacles, means stay still. Starting to mae a decision at and when it comes to, maing a decision again. Through strategic and tactical decision-maing, nowing the direction and speed, we can use Lagrange method to describe personal action: x( t + ) = x( t) + νxδt (3) y( t + ) = y( t) + νyδt Thereafter, if the obstacles occur, adjust action temporarily before maing the next step, and stay still. The action eventually realizes the movement of the individual position. Individuals first update xy coordinates of their property. If the focus of individual agent in a new grid, individual agent will update xy coordinates and set new state of grid. 4. Conclusions Innovation in this paper: Building an emergency evacuation simulation based on Agent, and expounded its principles, elements and methods. Establishing a simulation model of emergency evacuation based on Agent, which can simulate the evacuation under different situations. From simulation we can see that this model has practical value. References. Fran Griffel, M. Tuan Tu, Malte Mune.Electronic Contract Negotiation as an Application Niche for Mobile Agents[J].IEEE,000. Mathieu Gorge, Vigitrust. Crisis management best practice where do we start from? [J]. Computer Fraud & Security (S36-373), 006(6): Helbing. D, Traffic and related self-driven many-particle system. Reviews of Modern Physics, 00,73(6): ZHU Wen-xing, JIA Lei, ZHAO Jian-yu, LIU Hong-bo. Modelling and Simulation on Path Optimization in Urban Traffic Networ [J]. Journal of System Simulation, 005, 7(7):

243 5. Elba Urbina, Brian Wolshon. National review of hurricane evacuation plans and policies: a comparison and contrast of state practices [J]. Transportation Research Part A (S ), 003, 37(3): Gupta A K, Yadav P K. SAFE-R: A New model to study the evacuation profile of abuilding[j]. Fire Safety Journal. 004,39(3): Cova T, Johnson J, Jus tin P. A ne tw or f low m ode l for lane based evacua tion routing [ J ]. Transporta tion Resea rch Pa rt A, 003, 37 (7) : O a R idge N a tional L aboratory. Responding to energyre la tedem e rgenc ies [ J ]. O a Ridge Na tiona l Labora tory Review, 00, 35 () : J. A. Kirland and A. A. Maciejewsi. A Simulation of Attempts to Influence Crowd Dynamics, IEEE International Conference on Systems, Man, and Cybernetics, Washington Li Fengzhi, Li Changji, Long Yunfang, et a l. Psychology analys is of drive r s aggress ive driving behavior[j]. Journal of Sichuan Unive rsity:medica l Science Edition, 004, 35 (4) : Wolshon B Emergency transportation p reparedness, management, and response in urban p lanning and development Journal of Urban Planning and Development, 007; 33 () : - 35

244 THE APPLICATION OF DS CONTROLLING IN THE SOFTWARE SYSTEM DESIGN OF LASER CARVING MACHINE NING XIN, NING LI-PU, MAO XIN-HUA, ZHAO GAO-LI, MIAO QING-LIN Henan Institute of Science and Technology Xinxiang Henan, , China Abstract: The traditional ways are almost inefficient contact machine wor in which the contact between tools and circuit board can cause pollution. This paper mainly deals with the point which uses DS controlling technique to finish the control of laser carving machine. This device mainly research the functions of controlling laser carving machine to mae electronic component jac and serial number on circuit board. Based on DS controlling, this paper mainly studies the software system design of laser carving machine, including the design scheme flow diagram of DS controlling system, the woring procedure of carving machine s controlling device, the implementation of design function, the edition of interior points of controlling device, the execution of the program and so on. The merits of using laser carving and cutting are simple procedure, high efficiency, low pollution, convenience application and widespread availability. Key words: laser carving machine, DS controlling, software system design, electronic component jac. Introduction The processing of circuit boards requires a lot of process and each process need to install lots of electron components or electron bloc. In order to better manage we mared different numbers for these parts. These numbers named serial number, which is essential for many industries producing. Electronic board production were previously sprayed in to write serial number, so not only wastes in, but also it is also liely to become blurred if time is slightly longer. Engraving serial number in the circuit board with laser is not only to save in, but not cause pollution. That meets the requirement of the green production [~3]. The traditional control method that engraving serial number on the circuit board is: PLC (or a motion control card) + servo drive + servo motor + gear. Its programming and debugging is tedious, and equipment development cycle is long, further more demand to the electrical control and mechanical personnel. Japan [A] company's DS series of [A] controller will made multi-part into one- part. It facilitates the design and installation:, the traditional PLC combines with servo drive by [A] controller; the traditional motors combines with drives device by [A] machine handle [4~6]. Simple programming language maes programming handy. Plus table and fixation devices mae equipments run. So that mechanical designer is easily to design the support and drive parts. This reduces a lot of issues that be must considered in equipment planning, and shorts the equipment cycle and improves the stability of the equipment. This design mainly studies such as functions how to control the laser engraving machine to perforate or play serial numbers in the circuit board.by using laser engraving and cutting, the process is very simple, just as using computers and printers to print on paper. It can tae advantage of a variety of graphics software to design and scan graphics, Vectorization graphics and CAD files can be easily "printed" to the engraving machine [7~9]. 36

245 . Design of Software System. Design of program flow chart In order to laser engraving machine control system can meet the basic control needs, the system should have functions such as procedures controlling dotting, inching micro-adjustment, the circuit board fixed and clamped and relaxed, and lighting control. Accordingly, SEL Language PC-Software for Windows programming software is adopted to program design and debugging. According to the needs of motor control, program design flow chart is as follows (Fig.) shows. This procedure flow chart only shows the basic movement sequence of laser engraving machine. Fig. Design flow of the DS language program. Edit of running programs controller running.. Activate editing software ) Close controller and the computer power, the computer will connect controller with filiated standard RS3C cable. ) Open controller and the computer power to activate Windows. 3) Use on-lin emode to activate the software. 4) When a omputer want to connect two sets (X-axis and Y-axis) or more controller units, select the purpose controller ports. 5) The screen will show the main menu of this software, the initial functional screen is shown in Fig.. Fig. Initial functional screen 37

246 .. Set of controller parameters ) Select parameters (M) in options Procedure (P). ) Start the program parameters of the window (as Fig.3), select the appropriate parameters to revise its parameter values. Fig. 3 Window interface of process parameters Fig. 4 Program editor window interface 3) After amending to press OK button, it will open the program parameter inputting window, press (Y) can change the contents of the inputting controller, pressing CANCEL ey values without changing the contents of the case comes to a close. Due to changed parameter are the effective settings, requiring once again the RESET action. (Other parameters set the same)...3 Creation and edit of program controller ) New programs Selection process (P) Editing (E) from the options in the (or clic), it will display program editor window on the screen. (As the following Fig. 4) ) Edit or modify the program use the DS language 3) After editing program stored in the computer a suitable location for later use or read into the controller..3 Realization of design features SA-S5H-type DS-axis belong to single-axis control, each axis has its own independent controller, which can act independently. Because the multi-axis joint controller s price is high, so we use two-axis motion controller to complete the requested action under meeting the requirements and saving the investment. Axis controller has abundant input-output ports to exchange communication signals, so that the two-axis fit closely. Achieve single-axis s point movement of X and Y on plane, through the X direction and Y direction of movement Because the different distance between each axis and the next objective point, and the different required time of moving to the respective target point, so using time control methods will be complex and difficult. The time control methods as: following the speed and distance among the target point to computation time, waiting for the appropriate time delay, and start to issue the next command signal until two-axis reach the target point at the same time, and then. The design of such a control scheme is very complex and difficult; the reality is almost impossible on the DS single-axis controller. The system control program use the ideas of notifying each other in place, that is, the first axis arrive at the destination point and wait temporarily, and then the latter axis is in place and send a signal to the first axis that I have put in place, they can move to the next step. So it form the interloc, they can move to the next point, after each plane coordinates of two points are in place. 38

247 .3. Design of interloc We realize interloc using the 306input ports and the 006 output ports of two-axis. The methods are as follows: X axis : Y axis: BTOF 306 BTOF 306 BTOF 006 BTOF 006 Fig. 5 Schematic diagram of interloc port.3. Design of multi-step operation If the Y-axis is the first to reach the target location, Y-axis began to wait for the in place signal from X-axis. Once X-axis is in place, the 306 output controller will set ON, and enter into a wait state. The 306 output port of X-axis controller is connected to the 006 input port of Y-axis, X-axis send the in place signal to the Y-axis controller. When the 006 input port of Y-axis controllers receive this signal, it would begin to move to their target points. Once the Y-axis controller is in place, its own 306 output port will set ON, and enter into a wait state. The 306 output port of Y-axis controller is also connected to the 006 input port of X-axis, Y-axis will too its in place signal to the X-axis controller. This cycle will continue to achieve interloc..3.3 Set of mechanical origin Most of the control device need to conduct post-zero on self-test after power up (namely mechanical origin), It also needs contains of the wor piece in the actual processing in addition to mechanical origin (namely operating the origin). It usually sets the origin on plane table. Use the tool setting to establish contact and mechanical origin when machined worpiece..3.4 Design of inching function Installing the wor piece or setting tool need to use a small amount of displacement, and eep the wor piece in the appropriate position. So this machine needs to design the inching function move features point. Inching function in DS-axis controller software programming interface is also a step can be achieved follow clicing on the button, but the action function is a fixed point moving, whose step is large, and can not meet the minor adjustments requirements. The machine designed to tae four steps jog magnification: 0.0mm, 0.0mm,.00mm, and 0.00mm.Once point of press the clic button, they ll changes in these four values. The specific design program is as follows: ) Select four inds of magnification with the branch. If the variable is 00 =, the selected step volume is 0.0 mm; if the variable is 00 =, the selected step volume is 0.0 mm; if the variable is 00 = 3, the selected step volume is.0 mm, otherwise the selected step volume is 0.00 mm. ) Realize the inching. After selecting the steps, once correspond the axis to adjust the direction following pressing the clic button, the slider will shift one step to adjust the direction follow the above options..4 Edit of controller point 39

248 ) Select the Point (R) Editing (E) in options (Or clic ).It displays Controller Point data Windows. The following diagram shows Fig. 6. Fig. 6 Window interface of controller point editing Fig. 7 Schematic diagram of processing point position of circuit board ) Set and save the point.drill 9 holes in the specified location (As the Fig.7).Need to set the controller as follows Tab...5 Implement the procedures Tab. Setting table of the controlled point X-NO. Acc Vel Position Y-NO. Acc Vel Position )Implement the program (P) implementation (U) in the option. The screen will show the wor (tas) status window, in this below window: ) Choose to run programs and clic. After editing, we use the automatic activation process, which will set up auto-running programs, and disconnect the DS controller and the controller software.ds will run the setting program automatically after it is on power. Show as Tab. : 3) The operator should pay attention to the automatic activation: This machine use automatic activation mode. Once the system is power on, it will run the controller program automatically. Such action would activate the servo-drive device suddenly, and let the users do not prepared psychologically. For security reasons, we install the interloc device; the signal was confirmed after the implementation procedures. 30

249 3 Conclusion This paper studied that the DS control system achieves a laser engraving machine table motion control; you can easily change the program to complete the point to point control process. DS controller system is a new type of widely used in mechanical control system with simple structure, strong anti-interference, convenience programming and so on. The DS control system there are some shortcomings designed in this paper: there are no corresponding protection program design and lighting control design. They need further refinement. References. N.Yee, J.Linnartz, and G. Fettweiss, Multi-carrier CDMA in indoor wireless radio networs[j].ieice Trans. Commun, 994, 77(3): Cao Feng-qiong. Numerical control machine tool improvement for laser carving[j]. Journal of Zhengzhou University of Light Industry(Natural Science),008, 8(4): Wang Zongjiang. Design and Debug of New Digital Control System for the Laser Maring. Microcomputer Information,008, (7): Ren Xin-bo; Wang Ke; Xu Chang; Chen Ai-hua; Li Qin; Zhang Jian. Design of Profiling Laser-engraving Machine for Bamboo[J]. Journal of Zhejiang Forestry Science and Technology,008, (6): Li Cheng and so on. Modern mechanical and electrical control systems[m]. Xi'an: Northwest Industry University Press, LI Li-min; ZHU Cheng-de; XIA Li-li; ZHU Ning-feng. Creation design and optimization of the critical part of laser engraving machines,machinery Design & Manufacture,008. 8(8): Seitz,S.M.and Dyer,C.R. Photorealistic scene reconstruction by voxel coloring[j].int. J. Computer Vision, 999, 35(): P. Riviale, Eugène Boban ou les aventures d un antiquaire au pays des Americanistes. J. Soc. Am. 00, 87(4): Bíza,J.,Niedermeierová,H.,Pavingerová,D., homas, C.M., Klimyu, V.I., Jones, J.D.G.: Transposition patterns of unlined transposed DS elements from two T-DNA loci on tomato chromosomes 7 and 8.-Plant J., in press,

250 EFFECT OF THE STRUCTURAL PARAMETERS OF AIR-CORE PHOTONIC BANDGAP FIBERS ON PROPAGATION CHARACTERISTICS WANG FANG, SONG YAN Henan Normal University Xinxiang Henan, , China LU WEN-JUAN Beijing University of Posts and Telecommunication, Beijing China Abstract: In this paper, A finite element method (FEM) method is used to explore the propagation characteristics of air-core photonic bandgap fibers (PBGFs) with 9-cell theoretically and numerically. The dependence of structural parameters on effective index of the fundamental guided mode, and chromatic dispersion in PBGFs have been investigated by the FEM technique respectively. we employ the topology optimization method to improve the inner glass ring thicness and the corner of the inner glass ring in the PBGFs, so we can get a good transmission bandwidth. To improve numerical precision, the anisotropic perfectly matched layer (APML) is used as an absorbing boundary condition in simulation. Numerical results show that the initial driving source, APML and difference lattice are important optimization parameters in FEM, will mae a great impact on the precision and accuracy of results. It shows that the FEM approach can be effectively used in the analysis and design of the PCF with special purpose. Key words: PBGFs, FEM, APML. Introdution In the past few years, photonic crystal fibers (PCFs) have been intensively studied due to their specialized properties which are not realized in conventional optical fibers. And the design flexibility of the structure and much larger index contrast between the core and effective cladding relative to the conventional fibers have inspired a lot of interest in fiber-based devices. As a novel microstructured fiber, photonic crystal fibers (PCFs) have been applied in optical fiber communication. So far, there are many potential applications of PCFs or PCF-based devices in telecommunications. One application that seems quite close to being implemented is the use of solid-core PCF or hole-assisted single-mode fiber (SMF) for fiber-to-the-home, where the lower bend loss is the attractive additional advantage offered by the holey structure. [ ~ ] Other possibilities include dispersion-compensating fiber and hollow-core PCF for long-haul transmission. Additional opportunities exist in producing bright sources of correlated photon pairs for quantum cryptography, parametric amplifiers with improved characteristics, highly nonlinear fiber for all-optical switching and amplification, acetylene-filled hollow-core PCF for frequcncy stabilization at 550nm. [3~4] There are also many possibilities for ultrastable in-line devices based on permanent morphological changes in the local holey structure induced by heating, collapse, stretching, or inflation. Because we can control the array and size of air holes in PCFs, we can design the propagation characteristics of PCFs as requirements. Microstructural design of PCFs has been the focus of research recently. Researchers have devoted considerable efforts to the microstructural design of PCFs from a certain point of view, such as SMF with large-mode area, highly birefringent fiber, and so on. But few reports on 3

251 integrated design of PCFs are found. [5~7] So it is significative to discuss the fundamental propagation characteristics of PCFs synthetically. In this wor, we focus on the study of Photonic-bandgap fibers (PBGFs) with a 9-cell core defect region surrounded by multiple air holes and several important propagation parameters of PBGFs.. Simulation model and methods We calculate the fiber modes and their propagation constants using Comsol Multiphysics, a commercial full-vector mode solver based on the finite-element method.the accurate description of the fiber geometry is essential to obtain accurate simulation results. We assume that the fiber cross section consists of undoped silica and air, separated by smooth interfaces. The PBGFs under study contain a circle core surrounded by a glass core wall, in turn surrounded by six rings of circle cladding cells. Berenger s anisotropic perfectly matched layer (PML) are positioned outside the outermost ring of holes in order to reduce the simulation window for the PBGFs. correspond to the core, meaning that 9 air holes have been removed to form the core before the drawing process. Figure (a) shows a plot of a fiber cross section where silica is red. Figure (b) details the following three fiber geometry parameters: the hole pitch Λ (cladding lattice constant, measured between the centers of opposite struts in a cell) and the hole diameter d, inner glass ring thicness t, and the corner of the inner glass ring is rounded with radius d p and d c. [8] Using the topology optimization method to improve the corner of the inner glass ring in the PBGFs, we get d c = 0. 37d and d p = 0. 4d. Fig. (a)the simulation domain, which equals one quarter (b) Enlarged fiber detail, showing the four fiber geometry parameters: of the fiber cross section. The boundary conditions are shown along the edges. ring radius d p and pitch Λ, the hole diameter d, the corner of the inner glass d, and core surround thicness t. Fibers of the ind shown in Figure(a) possess six rotational reflection planes in addition to the point symmetry about the origin and hence belong to the point group C6v. Nondegenerate eigenmodes of the fiber can be found by computing the field in just one 30 o symmetry sector and continuing the field by repeated reflection and rotation. The most relevant (fundamental) mode is HE -lie and so is two-fold degenerate. [9] So only a quarter of the geometry is used in modeling PBGFs for convenient because of the symmetry of the fundamental core mode, around which we choose the following boundary conditions: perfect electric conductor (PEC) on one inner edge and perfect magnetic conductor (PML) on the other inner edge, as shown in Figure a. We note that this choice of boundary conditions excludes numerous modes such as TE 0, HE, TM 0 and many higher-order modes, which are not the focus of our present study since they are not so well concentrated in the central core and consequently experience much higher attenuation and nonlinearity than HE. c 33

252 3. Results and discussion In this section, we analyze the effect of the structural parameters of PBGFs on effective index of the fundamental guided mode and chromatic dispersion respectively. 3. Effect of the structural parameters on effective index of the fundamental guided mode In order to investigate the characteristic of chromatic dispersion, we should analyze the variation of effective index of the fundamental guided mode with the structural parameters first. As shown in Fig : (a) (b) (a) Variation of the effective index with λ when Λ (b) Variation of the effective index with t when d/λ is.0μm and t is 0. μm with d/λ as parameter; is 0. 5, Λis μm ; Fig. (c) (c) Variation of the effective index with Λ when d/λ is 0. 5, t is 0.5μm. Variation of the effective index of guided mode with the structural parameters of PCF and wavelength. As we can see in Fig(a), the wavelength dependence of the refractive index of the silica material and also the effective index of the fundamental guided mode for different values of the ratio d/λ. From Fig(b) we get that when the wavelength less than 0.8μm the refractive index almost no change with different t, and the wavelength between 0.8μm and.4μm, with small t we have big refractive index, but when the wavelength large than.4μm reverse, small t corresponding small refractive index. Fig(c) shows the mode is more confined in the core region when Λ is equal to a relative large value. 34

253 It may be noted from this Figure that the effective index will experience a steady decrease with increasing of the wavelength. Therefore, it is evident that at shorter wavelengths the mode tends to be more confined, while at longer wavelengths the mode becomes less confined to the core region. We have also found the effective index will decrease as increasing the value of d/λ. This can be interpreted as follows. When the ratio d/λ increases, the gaps between the holes become narrower, which isolates the core more strongly from the silica in the cladding. Thus, there will be more guided modes in the fiber. Higher-order modes will obtain energy from the fundamental mode, which leads to the reduction of effective index of the fundamental guided mode. 3. Effect of the structural parameters on chromatic dispersion Chromatic dispersion is a variation in the group velocity of light with respect to wavelength. We focus on second-order chromatic dispersion, also referred to as group velocity dispersion (GVD). Higher order dispersion will liely be the subject of future wor. To determine the chromatic dispersion, the effective index n eff of the fundamental mode of the PCF is computed as a function of wavelength. The dispersion is then calculated from the second derivative of the mode index using the following expression: dn eff λ D = c dλ where c is the velocity of light in vacuum and λ is theoperating wavelength, and and waveguide effects. neff including both material The computed chromatic dispersion values include both material and waveguide dispersion. The refractive index of silica is calculated using a Sellmeier polynomial approximationwith. [0] The chromatic dispersion is then calculated using a Taylor expansion: d n eff [ n ( λ + Δλ)] eff 0 dλ 4( Δλ) λ = λ 0 Fig3(a) presents the chromatic dispersion D for the case of Λ=.0μm, d/λ=0.5 and three different values of the thicness t. Also, the dispersion in the case of eeping the ratio d/λ=0. 5, t=0.5μm and for different values of Λ is shown in Fig3(b). Fig3(b) shows that we can obtain positive, nearzero, and negative dispersion just by adjusting the values of Λ at λ=.μm. We can also see that the zero-dispersion point can be easily shifted to a desired wavelength by changing the geometrical parameters of PBGFs. As may be observed from these Figures, the pea value of the dispersion strongly depends on Λ rather than t. This may be a ey point for designing dispersion-flattened PBGFs. 35

254 (a) Λ is.0μm and d/λ is 0.5 with t as parameter; (b) d/λ is 0.5 and t is 0.5μm with Λ as parameter. Fig3. Variation of chromatic dispersion with the wavelength when 4. Conclusions We have discussed the effect of the structural parameters of PBGFs on propagation characteristics theoretically by means of numerical simulation technique. In order to model PBGFs accurately, we adopt finite element method(fem). The variations of effective index of the fundamental guided mode and chromatic dispersion with the structural parameters of PBGFs with wavelength are obtained. It is noticed that the design of PBGFs is fairly flexible. According to the hole pitch Λ, the hole diameter d, and the number of hole rings N, we can design PBGFs for specific purpose at our desired wavelength, such as low-loss dispersion-flattened PBGFs, single-polarization single-mode PBGFs and so on. Finally, this investigation may be a reference for integrated design of PBGFs. Reference. F.Brechet, Marcou J, Pagnoux D, et al,opt. Fiber Technol., 000, 6(): M.Koshiba. IEICE Trans. Electron, 00, 85(4): R. Amezcua-Correa, N.G. Broderic, M.N. Petrovich, F. Poletti, D.J. Richardson, Opt. Express 006, (): R. Amezcua-Correa, N.G. Broderic, M.N. Petrovich, F. Poletti, D.J. Richardson, Opt. Express 007, (3): M.Qiu, He S L. Phys. Rev. ( B), 000, 6 (9): 87~ P. Russell. J. Lightw. Technol, 006, 4(): J.S. Sanghera, I.D. Aggarwal, L.E. Busse, P.C. Pureza, V.Q. Nguyen, F.H. Kung, L.B. Shaw, F. Chenard, Laser Focus World Jonathan Hu, Curtis R. Menyu, OPT COMMUN 009, (): C. Anastassiou, G. Dellemann, O. Weisberg, U. Kolodny, Photon. Spectra 004, (4): Mourad Zghal, MEMBER SPIE Rim Cherif OPT ENG 46, 800 _December

255 SOLIDWORKS BASED WORM'S PARAMETRIC DESIGN AND FINITE ELEMENT ANALYSIS TIAN FENG, YANG HUI, NING XING School of Mechinery and Electronics,Henan Institute of Science and Technology Xinxiang, China Abstract: With solidwors as the secondary development platform, a plug-in unit which can be loaded and unloaded automatically was generated by maing use of visual basic 6.0, so that parametric design of Eorm can be realized. Taing a particular Worm as an example, the present thesis made a static finite element analysis of one of its tooth surface by using the plug-ins of solidwors: cosmos/wors. Achieving the rapid modelling of Worm, the application of the plug-in unit can thereby shorten the design cycle-time of Worm and save the time and design cost as well. Key words: Visual basic 6.0; Solidwors; Worm ; secondary development. Introduction Worm is one of the important spare parts in mechanical transmissions. And the parametric design was at first proposed for the inconvenience of processing and manufacturing it by traditional methods. In order to realize the parametric design of Worm, the present thesis put forward to use visual basic 6.0 to conduct the secondary development of solidwors with which as the platform. In addition, an appropriative solidwors plug-in was also established. Raising the accuracy of design, a finite element analysis was carried out by maing use of cosmos/ wors on the basis of a built-up model so that the whole process of designing Worm can be more perfect. An abstract example was used to illustrate that in this thesis [].. Theoretical Basis of Parameterization Based on the Windows, solidwors is a destop integrated system of CAD, CAE and CAM and it is also a mechanical three dimensional CAD software developed by the American Solidwors Corporation. This software supplies hundreds of API functions and interfaces lie OLE or COM of solidwors in order that users can have the convenience of developing it by using many high-level languages, such as VB, VC and Delphi and so on. This is why it was chosen as the platform of secondary development [ ~3].. Mathematical Model of Archimedes' Worm The Archimedes' Worm is most frequently in the process of Worm drive, and the formation of its thread xuan noodles is got by scanning the column helical line with a trapezoid section, which is similar to the formation of the screw thread. The section of the scroll bar's alveolus is shown in Figure, and its vertex coordinates are as follows [4]. The basic circle of the column helical line is the reference circle of screw, the radius of which is r=mq/, the helical line leads T = Z. px = π mz. In the above-mentioned formulae, m is the module, z is the number of threads of Worm, q is diametral quotient of Worm and a is the pressure angle. 37

256 Fig Section of The Scroll Bar's Alveolus (). Mathematical Model of Involute The profile curve of the end face if the involute of the Worm gear. As there is not the function of plotting the involute in solidwors, the coordinates of the points on the involute have to be calculated. Results of the calculation can be used to plot the spline to tae the place of involute approximately [5]. (See Figure ) Fig The Profile Curve of the Involute In the formula θ= tan a a, a= arccos( rb/ r), φ= π/ z tan a+ a are the radii of the reference circles of Worm and Worm wheel respectively and rf r ra. After the closed wire frame that is enclosed by the underscore from one single alveolus fixed, the alveolus can be got by scanning the excision characteristics. In the process of scanning and excising, the lead is the helical line of the Worm. And modelling of the Worm wheel can be gained by using the circumference array. 38

257 3. Programme and Realization of Parameterization Modelling 3. Introduction of API Function of Solidwors The object model of solidwors is a multilayered object networ. The top-class objects are that the solidwors can access all the other objects of solidwors API directly or indirectly. Many methods, including OpenDoc,ActiveDoe,CloseDoe,ExitApp and so on, are encapsulated in this object. During the process of solidwors' secondary development, the object of solidwors' connection and establishment and new part drawing or assembly drawing should be set up firstly. And other steps followed include selection of the operation object, insertion and plotting of setch and establishment or fitting of entity. The present thesis mainly employs the Create Circle,Createline,CreatePoint of the ModelDoc object, and FeatureExtruesion,InsertSetch of the PartDoc object which are used in the entity modelling Structure Design and Finite Element Analysis of 600HP Drilling Pump Cranshaft [6]. 3. Design Procedure The parameter turns to design flow chart as follows: Fig 3 he parameter turns to design flow chart 3.3 Procedure Design Compile to form a DLL text.a DLL text has to be called in the solidwors in order to realize add of the menu. To open the solidwors and create a part. Open to open a born DLL document of one step in the document options in the spare parts window way. Then a new item of manufacture of theturbine Gua pole be added in the toolbar, and clic it to see Worm, and then clic it to see the formerly-designed form, then clic confirm to form the Turbine Gua pole. 4 Finite Element Analysis of Model of Worm and Worm Wheel Worm are the standard parts that can be used in many places, so it is necessary to do the finite element analysis (FEA)in order to test the accuracy of design. The basic concept of FEA is to discrete the continuous solution area into a group of Unit combination which is finite and can be connected together in a certain way. 39

258 A hole (diameter: 0 cm) should be made in the above-mentioned model so that the FEA can be done by maing use of cosmoswors [7~8]. Fig 4 Generation Figure of Worm Fig 5 Generation Figure of Worm Wheel Steps of cosmoswors FEA: confirm the analysis style;define the material of parts(select in the material ban or define a new one by oneself);3confirm the constrains;4confirm the loading condition;5confirm the division type of grid and divide the grid;6run the procedure to get the analysis result and generate the report. Suppose one tooth is under the uniform external force of 000N/m and then analyze the static force following the above steps. The stress diagram (See Figure 5) shows that the maximum stress which one tooth hold is 3.94e+003 while under the pressure of 000N/m. Bend dint5.300e+008 is beyond the stress range which means the pressure is too heavy. And the Displacement map, Deformation map and Safety factor graph can all tell us that the supposed pressure is too heavy. Therefore, the gear made of this material is not safe while under pressure of 000 N/m. A suitable external force can be found through more experiments. 5 Conclusion The present thesis tries to generate the plug-in that can be used by the solidwors to realize the Parametric Design of Worm by maing use of DLL function of VB. In this way, the time of designing the Worm canbe saved so that seamless interface of VB and solidwors is achieved. Furthermore, FEA of one tooth of the Worm by the cosmos/wors brings advantages lie: accuracy of Worm wheel s design, shortening of the design cycle, decrease of test cost and increase of profit. References. Li Chong-de. VB-based SolidWors Involute Gear Developing method. Mechanical & Electrical Engine -ering Technology.008():3-5.. Wei Yao-bin.SolidWors-based Parametric Design of Helical Gear. New Technology & New Process. 008 (): Shang Yao-jin,Cao Ru.Solidwors 3D design and application lectures. BeiJing. China Machine Press Hao Hai-chao. SolidWors Modeling Based Optimal Design Of Cylindrical Cam. Journal of Zhongyuan university of technology.008(): Liu Song,Wu Shu-fu.Spur-gear Parametric Design and Finite Element Analysis Based on Solidwor. 330

259 Science&Technology Information.008, (5): Xu Long. The Cylinder-Cam Organization S M odeling Assembly and M ovement Analysis in Solidwor. Development& Innovation of Machinery& Electrical Product.008, (): Yang Xing-chao,Huang Yang. Structure Design and Finite Element Analysis of 600HP Drilling Pump Cranshaft. Development &Innovation of Machinery& Electrical Product.009, (9): Hong Jiang,Chen Liao. The limited dollar is analytical solid example to analyze of Solidwors.BeiJing. China Machine Press

260 MONTE CARLO SIMULATION OF LEAST SQUARE SUPPORT VECTOR REGRESSION ESTIMATION METHOD FOR THE WEIBULL SHAPE PARAMETER ESTIMATION ZOU XIN-YAO Department of electron and information engineering, Guangdong AIB Polytechnic School, Guangzhou 50507, China Abstract: The Weibull shape parameter is very important in lifetime extrapolation and forecast for the time dependent dielectric breadown (TDDB) study of oxide breadown. A least square support vector regression estimation method (LSSVR) was proposed to determine the shape parameters β of the two-parameter Weibull distribution according to the scarcity of failure data in reference 8. This paper demonstrates the effectiveness of the LSSVR approach by Monte Carlo simulation. Maximum-lielihood estimation (MLE) is also compared with the LSSVR method. The simulation results show that the LSSVR method has good generalization and high accuracy of estimation for small samples. Key words: Time-dependent dielectric breadown; Weibull distribution; Parameter estimation; Least square support vector regression. Introduction Generally, oxide breadown characteristics such as time-to-breadown obtained from time-dependent dielectric-breadown (TDDB) experiments obey a Weibull cumulative distribution statistics. The importance of statistical accuracy of distribution parameters, especially for Weibull shape parameter β has received a great deal of attention, which is extremely important for lifetime extrapolation [~4]. So β has to be estimated accurately, any potential inaccuracy on this parameter may lead to increase lifetime uncertainties. Traditionally, there are several methods for the estimation of the Weibull slope, such as the traditional graphical method and maximum-lielihood estimation (MLE). Recently, a proportional difference estimate method was proposed [5]. In general, these estimators are developed from large samples based on classical statistics, and it is recommended to acquire sufficiently large data sets to facilitate accurate estimation. However, for real reliability data, it is becoming impossible to obtain sufficient data before a new product requires reliability assessment as product life cycles based on new technologies become shorter than before especially in nano era [6]. Way Kuo [7] firstly used neural networ to estimate Weibull distribution parameters for small reliability data samples. Recently, least square support vector regression (LSSVR) also was used to estimate Weibull distribution parameters for small reliability data samples [8]. In this paper, Monte Carlo simulations are used to demonstrate LSSVR, and for comparison, the maximum lielihood estimation (MLE) method is also used to estimate Weibull parameters with the same small samples.. Monte Carlo Simulation. Example In this simulation, we use the LSSVM software pacage [9] based on Matlab to perform the model training and testing. A complete sample is generated from the two-parameter Weibull distribution with β=.5 and η=30. The sample size is 0 and the failure times are as follows: 33

261 7.8s,.3s,3.8s,5.9s,7.4s,9.4s,0.6s,.3s,3.5s,4.9s,6.6s,8.5s,9.7s,3.s,33.4s,34.5s,37.0s, 38.8s, 4.5s, 5.4s. F(t) is estimated by Bernard s median ran estimator: i 0.3 F ( t) = () n Where i is the cumulative failure number of samples at time t, n is the total number of samples. After the ernel parameter chosen, the optimal LSSVR model obtained are linear ernel with γ=54.6. The regression straight line is shown in Fig. and the estimates of the characteristic parameter obtained by LSSVR and MLE are presented in Table. Fig. Regression straight line by LSSVR method for Example Table Comparison of Weibull characteristic parameters estimates for example Parameter estimator β η MLE LSSVR It can be seen that the LSSVR estimator perform quite well and its estimate is closer to the true value of β than MLE estimate.. Monte Carlo simulation Monte Carlo simulation has been carried out to investigate both of the generalization and effect of small samples of the LSSVR method. The simulation conditions are: sample size n=5,0,5,0; parameter true values still are: β=.5 and η=30. For each combination of simulation conditions, 0 different samples are randomly generated. Fi is also estimated by Bernard s method. We use the same LSSVR model (i.e. linear ernel with γ=54.6) to test the samples and estimate the shape parameter β according to the obtained regression straight line. MLE method is used simultaneously to estimate β for each sample. Bias is calculated based on the following formula, which is used as criteria to assess the generalization of the LSSVR method: 333

262 bias ( ˆ) β = ˆ β β () The calculation results are shown in Fig -4. Fig Bias comparison of MLE and LSSVR for estimate β with sample size n=0 Fig 3 Bias comparison of MLE and LSSVR for estimate β with sample size n=5 Fig 4 Bias comparison of MLE and LSSVR for estimate β with sample size n=0 334

263 In addition, these random samples are generated by pseudo random number generator and there must be some error, so we calculate the bias between the average estimate value and the true value of β based on the following formula. The calculation results are shown in Table. bias ( ˆ) β = β β (3) β = (4) 0 0 ˆ β i i= Table Bias comparison of MLE and LSSVR method Bias of β n=0 n=5 n=0 LSSVR MLE Discussion From the simulation results shown in Fig.-4, the following conclusions can be observed. ) The LSSVR model has good generalization for small samples. The reasonable estimate value β can be obtained for independent samples with the same LSSVR model. ) The estimate value of LSSVR method is closer to the true value of β than that of MLE method, and the smaller the sample size, the greater the difference between MLE estimate bias and LSSVR estimate bias. 4. Summary In conclusion, LSSVR method can be used to estimate the shape parameter of Weibull distribution with small samples data. Monte Carlo simulations show that LSSVR has higher accuracy of estimation and less bias than MLE when dealing with small samples. So LSSVR method can be used for TDDB study for small samples. References. Wu Ernest Y, Vollertsen RP. On the Weibull shape factor of intrinsic breadown of dielectric films and its accurate experimental determination part I: theory, methodology, experimental techniques. IEEE Tran. On Electron Devices 00; 49(): Oabe S., Tsuboi T., Taami J.. Reliability evaluation with Weibull distribution on AC withstand voltage test of substation equipment. IEEE Transactions on Dielectrics and Electrical Insulation. 008,5(5): Cousineau D. Fitting the three-parameter Weibull distribution: review and evaluation of existing and new methods. IEEE Transaction on Dielcectrics and Electrical Insulation. 009,6(): Li Hai-bo, Zheng-ping Zhang, Yan-ping Hu.et al. Maximum lielihood estimation of Weibull distribution based on random censored data and its application. The 8th International Conference on Reliability, Maintainability and Safety. Chengdu, China Mu fc, Tan ch, Xu MZ. Proportional difference estimate method of determining the characteristic parameters of monomodal and multimodal Weibull distributions of time-dependent dielectric breadown. Solid-state 335

264 Electronics 000, 44(8): Way Kuo. Challenges Related to Reliability in Nano Electronics. IEEE Transaction on reliability 007; 55(4): Way Kuo,Tep Sastri. An exploratory study of a neural networ approach for reliability data analysis. Quality and Reliability Engineering International 995, (): Zou Xin-yao and Yao Ruo-he, Application of support vector machine to reliability evaluation of small -sample IC(in Chinese). Journal of South China University of Technology(Natural Science), 009, 37(): Pelcmans K, Suyens JAK and Gestel TV, LS-SVM Software[online] 336

265 DESIGN AND IMPLEMENTATION OF HENAN PROVINCE TOURISM INFORMATION SYSTEM BASED ON ARCIMS TANG SHU-ZHUAN Henan University of Urban Construction Pingdingshan, China HE WEI-NA Pingdingshan University Pingdingshan, China Abstract: According to the tourism development in Henan province, and maing use of the previous study, a tourism information system based on ArcIMS was designed. The system adopted the implementation method of Geographic Information System technology, and consequently made tourist to obtain interactive and dynamic tour map including maps, words. This paper also presented a technology method which combining Internet and geographic information system, and maing geographic information and Tourism professional information together to construct the travel geographic information systems. We introduce the building process, technical route, the function design, the system characteristics and the problems of the travel geographic information system. In the practical application, it realizes map zoom, map indication, statistic search, map level control and statistic output. So the system will provide reliable information and evidence for the management and development tourism of Henan province. Keywords:Geographic Information System; ArcIMS; Map symbols; tourism information system. Introduction Henan is one of China's historical and cultural cities and was rated the best tourism city in 007. It has unique tourism resources, lots of scenic spots and beautiful natural scenery, attracting countless visitors. Tourism industry plays an important role in economic development in Henan. While tourism has an extremely close relationship with geographical position, the distribution of the tourist attractions, the location of the tourism facilities all contain geographic coordinates, the topological relation. Using the GIS spatial data processing ability, combining Web GIS and releasing geographic information on the Internet, the acquisition, release, sharing and operation of GIS has a broad prospect, at the same time, the application system based on the map is widely used. [,].. System Design. System design goal Designing and developing of tourism information system aims: using WebGIS technology, ArcIMS technology, ASP technology, database technology and multimedia technology, etc, to provide information and tourism scenic images. ASP calls ArcIMS pacet to publish vector map of Henan and allow users to operate some function, such as amplifier, narrow, roaming and query etc. [,,3]. It displays text, image maps, symbols by multimedia forms, which maes users to now the abundant tourism resources of Henan province.3system interface has Human-Computer Interaction function and information dynamic update capabilities, and it can accurate and timely storage and upgrade the text, pictures, maps, and digital information. [4]. 337

266 The presentation layer design: The presentation layer refers to the client browser layer. When the user clics map or tools, the browser sends HTTP requests to web server.the server responses the requests and returns HTML pages. Users can interact with server in the client. The logic layer design: This layer is primarily responsible for the user requests data analysis and processing, and returned the results. Web server is responsible for handling the HTTP requests, GIS components and loading data. The data layer design: Data layer is mainly responsible for storage and management of related data and attribute data. When GIS server receives the tas from web server, it uses every functions provide by GIS components in GIS server to extract, analyse, compute, handle data, and finally returns the results to client by general pages. [,3,4].. System function design Based on the basic case, the Henan province tourism information system is divided into three modules: spatial data management module, system inquires module, system data maintenance module. ()Spatial data management module: It mainly analyses and handles the space data and attribute data, including graphic display module, layer management module, spatial analysis module, networ analysis module and multimedia display module. Graphic display module: It can archive graphic amplification, reducing, roaming, selecting, etc. So, it realizes the tourist attractions. Users can use tools to select the region of interest, and highlight areas selected. Layer management module: As the space object on the map is a certain type on a layer, layer management functions can select interesting layer. For management information, we use the layer chec box to display the information of layer, and dynamically update the display. Spatial analysis module: Map search radius can be achieved simply, and the main use of object is generally tourist attractions and hotels, restaurants, etc. Tourism management department can determine the protection of scenic areas, roads, etc. Meanwhile, the tourists can select the appropriate range and route of travel. Networ analysis module: It can analyse the path so that visitors can choose the best path to travel. Multimedia display module: Through multimedia, the main attractions can be multi-media presentation with images, video, audio, photos, maps, text and other multimedia information [5]. () System query module: It is divided into attribute query and spatial query according to query mode. Attribute query: Finding an attribute data of a space object on the map. Through the browser, users can directly clic information points on the map, and system shows the corresponding details, such as attractions, the level of tourism traffic routes, fares, etc. Spatial query: Given the attribute values of space object, users can find the space to meet the conditions of the object, and the exact location of the object is highlighted in the map. System provides query conditions which can be used by users. Users can get the results of inquiries by clicing query in the browser. (3) System Data Maintenance Module: Maintaining and managing system data. System can add, delete, and modify data dynamically at any time. In addition, the system also implements database bacup to prevent data loss. 3. Key Technologies WebGIS is the Internet-based platform for information publishing, data sharing, exchanging and cooperating. Client uses WWW protocols, and it implements GIS implementation and business information online query. The 338

267 core is HTTP and TCP/IP standard application system embedded in GIS, and it achieves spatial information management based on Internet environment. [,,5,6]. ArcIMS is the internet-based geographic information system, which supports Web-based map services, and shares GIS information with traditional non-gis users. ArcIMS is running in a distributed environment, including client and server-side components. ArcIMS can be used to design and produce a geographic information Web site and maes it provide GIS services. ArcIMS application server can be extended at any time to meet the increasing requests. A complete service of process can be simply described as: The client sends a request message to the server, and server processes the request and returns information to the client. Finally, client presents information to users. [5,7,0]. ArcXML which is the specific mar-up language corresponding to XML specification is the core module of ArcIMS, It is designed for the ArcIMS to communicate between different components, and it is open and scalable. ArcXML provides the ability to access all features of ArcIMS, and it realizes the information exchanging between browser and server [8]. In the ArcIMS, ArcXML is responsible for data networs transaction which publishes vector or data formatted by image, such as data definition, graphics properties, displaying characteristics, sending and receiving data. ArcSDE which is a spatial data engine, connecting to oracle is relatively a mature and stable spatial data management technology. Its main function is that it can be used as an interface between the relational database management systems and geographic information systems. It can shield differences between different operation platforms and databases, and achieves seamless connectivity between spatial data and attribute data. [6,8,9,0,]. 4. System Implementation We adopt ArcIMS 9. as web server to achieve tourism information publishing on the Internet. Clients can use IE 6.0 and above to access data. When starting ArcIMS service on server-side, users on the client just enter the correct URL address, and they can browser map, and find information published by map []. As in figure Data is from Henan tourism information Fig Operation Interface. The map is divided into five areas: operating map area operated by selecting the tools, map display area providing direct display, eagle eye display area providing the location of the current map area, legend display area easy to distinguish the various objects, information display area returning the attribute information queried by query tools such as inquiry or identify. 339

268 5. Conclusions This paper focuses on the current development of tourism and the demand of Web GIS technology, and designs travel information service system based on ArcIMS 9. platform to realize the basic functions of tourism GIS. Meanwhile, the system has good portability and scalability and can be the appropriate extensions according to tourism development in Henan. Using Web GIS to display tourism resources, geographic information, it can not only achieve the purpose of serving the people, but also play the role of foreign exchange and finally it has potential significance to economic boom of Henan. References. Zhou Feng, Zhao Yinghui,Fan Wenyi. Design and Development of A WebGIS-based Management System for Forest-fire Database Classification[J].Journal of Northeast Forestry University;009,6(3): Malczewsi A GIS-based approach to multiple criteria group decision-maing[j]. Geographical Information System, 003,0(8): T Schen From pointbased to featurebased aerial triangulation[j]. ISPRS Journal of Photogrammetry & Remote Sensing, 004, (58) 4. Staab S, Werthner H. Intelligent Systems for tourism[j]. IEEE Intelligent System,00,7(6): T Schen. From point-based to feature-based aerial triangulation [J]. ISPRS Journal of Photogrammetry & Remote Sensing 004,(58). 6. Cost R S. Fini Tim, Joshi Anupam, etal ITTALKS: A case study in DAML and the Semantic Web[J]. IEEE Intelligent Systems,005,7(): SCOTT R LOBAN. A framewor for computer-assisted travel counselling [J]. Annals of Tourism Research, 007,4(4): ESR L Getting Started with ArcIMS[M]. USA:ESR I,004: MENG Qingxiang,FU Zhongliang,HOU Chen,ZHANG Wenyuan;Study of Map Service Methods Based on Images[J];Bulletin of Surveying and Mapping; SONG Yang, WAN You-chuan. Application of WebGIS on electronic-government information system based on ArcIMS [J];Engineering of Surveying and Mapping; WAN Jian-hua.Foundation of land and house management information system in high school based on ArcIMS[J];Engineering of Surveying and Mapping; LI Yu-xia,YANG Wu-nian. Development and application of real-tunewater situation monitoring system based on arcims[j];science of Surveying and Mapping;

269 THE APPLICATION OF MATLAB IN EXPERIMENTAL TEACHING OF ELECTROMAGNETISM AND WAVE BIAN LI Heilongjiang Institute of Science and Technology Harbin, 5007,China Abstract: This paper gives the reason why we introduces the computer simulation into the experimental teaching process of Electromagnetic Field and Wave in Electronic Information Engineering. With the aid of an example such as the calculation to distribution of voltage, the diffractive experiment of the electronic wave and the protracting to the direction graph of antenna array to prove the essence to these theories. At last it describes the practicability and convenience of using MATLAB and it can inspire the positive factor of the students to deepen the comprehension and cognition. Key words: electromagnetic field and wave; MATLAB; computer simulation. Introduction The subject of Electromagnetic Field and Wave in the Basic Course of Electronic Information Engineering seems to be more abstract than others. Frequently, the analysis of Field and Wave relates to complex graphics and calculations in a very large number.the analysis in the previous lessons is usually achieved by setching by hand on the blacboard and deducing. There is more sermons to the students. Many of the conclusions are achieved without verification.this situation maes students feel tedious; it influences their emotion of learning and reduces the results of learning. As all about, the importance of the experimental teaching combined with classroom teaching of Electromagnetic Field and Wave is obvious. Introducing the simulation technology of MATLAB into the experimental teaching process of Electromagnetic Field and Wave is very helpful to the classroom teaching of Electromagnetic Field and Wave and change the conclusions from abstract into acceptable to the students. In the next sections,we will introduce the specific application of using MATLAB into experimental teaching process of Electromagnetic Field and Wave.. About MATLAB language MATLAB language is released by MathWors Company in USA. It is an excellent language combined with the functions of numerical calculation, symbolic computation, visualizing, simulation and graphic processing. We can use it into either about solving equation, solving polynomial, minimax value calculation or simulation system of finance or industry. It can be used in the field of statistics or others, too. In the processing of experimental teaching,the simulation about Electromagnetic Field and Wave is completed by MATLAB. It full plays the features of MATLAB language and describes complex conceptions in a vivid way. Simultaneously, it offers a new way to the classroom teaching and experimental teaching process. 3. The plotting of field graph To the students, one of the difficulties in the lessons of Electromagnetic Field that the conception of the field is too abstract to understand. The solution of this situation is maing the field figuratively. By describing the 34

270 regular pattern of field profile, the teachers could use the image function to draw the Vector lines (Power Lines, magnetic lines), contour (equipotent line), and arrow diagram. Students could understand the field better In this way. Teachers may use the functions such as plot, ezplot, contour, quiver, etc. For example, a grounded metallic conductor, the size of which is a b. On the conductor is a metal lid which is insulation but compacting to the slot. Electric potential= +00V.If the Electric potential on the depth direction has no change, beg the function of potential Φ. The program files using MATLAB has shown below: tic NL=50; NM=50; u=zeros(50,50); t=(cos(pi/nl)+cos(pi/nm))/; opt=/(+sqrt(-t*t)); u(:,:)=0; u(,:)=00; =0; while e=0; for i=:nl- for j=:nm- t=(u(i,j+)+u(i,j-)+u(i-,j)+u(i+,j))/4; d=t-u(i,j); d=d*opt; e=max(e,abs(d)); u(i,j)=u(i,j)+d; end end =+; if(e<0.00) brea; end end contour(u,00) fid=fopen('d:\wangzi.doc','w+'); j=0; for i=:nl if (i>j)&(j~=0) fprintf(fid,'\n'); end fprintf(fid,'the potential of line %d' is,i ); fprintf(fid,'%.f \t',u(i,:)); j=j+; end statues=fclose(fid); toc Figure shows the simulation results, we could plot the potential distribution inside the conductor under the help of MATLAB. This helps the students understand the potential distribution in a vivid way. It is show in fig. 34

271 b = 0cm a = 4cm Fig the grounded metallic conductor groove Fig the distributing chart of voltage in metallic conductor groove 4. Simulation of Fraunhofer diffractive experiment 4. The equipment of experiment From the basic optical we now, the fraunhofer diffractive of any diffractive screen could be implemented by two convex lenses. As figure 3 shown, P θ will be the highlight when the lights which through the two convex lenses fit the condition of Constructive interference; P θ will be dim spot, when it is Destructive interference. All the highlights and the dim spots build up the figure of Fraunhofer diffractive, it is shown in fig 3. S λ a B P θ P 0 A f Fig 3 the equipment of diffractive experiment z 343

272 4. direct simulation )Single slit: the width of slit is given as a = 0.0;the focal length of convex lenses is f = 0000;wavelength of is λ = 0.00; The program files using MATLAB has shown below: clear; t=-000:0.00:000; a=input('please input your a= '); f=input('please input your f= '); r=input('please input your r= '); format long e sin=t./sqrt((t.^+f.^)); w=pi.*a.*sin./r; y=sin(w).^./w.^; subplot(,,); plot(t,y,''); subplot(,,); imagesc(y,[0 ]); colormap(gray); it is shown in fig x 0 6 Fig 4 the intension distributing chart and the diffraction candy strip of light to single slot 344

273 the results is shown as figure4.it describes Single slit diffraction phenomenon in an accurate and complete way. ) Long Qin grating: the width of the slit is given as 0.0( a = 0.0);the width of the opaque space between the two slits is given as b = 0.0;the focal length of convex lenses is given as f = 000;the amount of slit is given as n =;the wavelength is λ =0.0. The program files using MATLAB it is shown in fig 5. clear; t=-000:0.00:000; a=input('please input the width of the slit a= '); b=input('please input the width of the opaque space between the two slits f=input('please input the focal length of convex lenses f= '); n=input('please input the amount of slit n='); r=input('please input the wavelength r='); format long e sin=t./sqrt((t.^+f.^)); w=pi.*a.*sin./r; y=sin(w).^./w.^; v=pi.*(a+b).*sin./r; y=sin(n.*v).^./sin(v).^; y=y.*y; subplot(,,); plot(t,y,''); subplot(,,); imagesc(y,[0 ]); colormap(gray); b= '); x 0 6 Fig 5 the intension distributing chart and the diffraction candy strip of the langqin diffraction grating 345

274 the simulation results is shown as figure5,diffraction fringes will be achieved if we change the amount of slit.through this way, Long Qin grating is shown vividly. 5. Plotting of complex directional antenna Directional characteristic is one of the important features of antenna. There are three parameters to describe the antenna orientation: Directional function, directional Map, directivity. Since we could estimate reading out all inds of directivity and analysis the spatial distribution of the field from Directional Map, it is a very important parameter. As the radiation pattern of the antenna distributes in the whole space, generally, the directional Map of the antenna is Three-dimensional, and it s hard to plot. So the teachers often meet difficulties at this part in the classroom teaching. By means of MATLAB, teachers could plot E plane and H plane in a accurate and complete way, and this plays a significant supporting role in students understanding of radiation pattern. For example, to plot the directional Map of which the space between the four balance coaxial dipole is λ / and power fed with antenna array of the same current. The program files using MATLAB has shown below fig Fig 6 the direction graph of the four balance coaxial dipole antenna array max=0; for theta=0.0:0.00:*pi rho=abs(cos(pi./.*cos(theta))./sin(theta).*sin(.*pi.*cos(theta))./sin(pi.*cos(theta)./)); if rho>max max=rho; end end theta=[0.0:0.00:*pi] rhoh=ones(size(theta)); rho=abs(cos(pi./.*cos(theta))./sin(theta).*sin(.*pi.*cos(theta))./sin(pi.*cos(theta)./)); rhoe=rho./max; subplot(,,);polar(theta,rhoh,''); subplot(,,);polar(theta,rhoe,''); 346

275 Simulation results are shown as figure 6. All of the parameters of the antenna could be plotted in the picture. 6. Conclusion MATLAB offers a new way to the experimental teaching process of Electromagnetic Field and Wave.By means of this tool, we could get both convenient analysis method and imagine, vivid graphics demonstration.it also offers a platform of learning, arouses the studying interest of student s.maing it more imagine, clear, accurate to understand the abstract conceptions. References. Zhang Zhiyong.Carefully edit of matlab[m]. Beijing: Beijing University of Aeronautics and Astronautics Press,003.. Wang Jiali, Zhu Manzuo, etc. Electromagnetic Field and Wave [M]. Xi'an: Xidian University Press, Xie Jianing, Zhao Jianlin, etc. COMPUTER SIMULATION OF Fraunhofer diffraction [J] College Physics 004, (3): Bi Xiande, Etc. Electromagnetic Field Theory [M]Beijing: Electronic Industry Press He Hongyu Electromagnetic field numerical calculation method and MATLAB Implementation[M], Huazhong University Press, Guo Peiying Lanhua,etc, Analysis and Calculation of Electromagnetic Field Based on MATLAB, Northeast China Electric Power University, 004, 6(): Liu Yingxiong, Teaching Methods of Electromagnetic Field and Microwave Technology, South China University of Electronic and Information Engineering, 007, (): Zhou Xilang, The basis of electromagnetic theory and microwave technology, Southeast University Press, Yang Erbing, Electromagnetic Field Fundamentals and Applications, China Electric Power Press, He Yuhong, Electromagnetic field numerical calculation, Huazhong University Press,

276 The Design of Low Noise Amplifier in Mobile Communication Base-station CHENG JUN College of Electronic Information Engineering,Wuhan Polytechnic, Wuhan, , China Abstract: In this paper, the low-noise amplifier (LNA) applied to the front-ends of mobile communication base station receiver is designed by using PHEMT ATF Firstly, the appropriate DC point and bias networ are selected according to the design specifications requirement. Secondly, the value of the shunt resistor and inductance are optimized to ensure the stability of the amplifier. Then the input and output matching networs are designed based on the minimum noise figure and maximum gain guidelines. The simulation results indicate that the power gain of the LNA can reach 5 db at.9ghz~.98ghz, the noise figure is less than 0.365dB, VSWR is lower than.5, and the value of the compress point of db is -dbm, the OPI3 is 4.36dBm. These performances can all meet the need of the base station. Key words: Matching, PHEMT, Low noise amplifier.. Introduction The low-noise amplifier (LNA) is the main components in the radio frequency receiver, it is in the front of receiving system, receive and enlarge the wea radio frequency signal from antenna, but also bloc all inds of noise as much as possible to interference on the receiving system. Since the role of a special place of LNA in the receiving system, the design of it has very important implications in the performance of the receiving system. The LNA must balance the specifications of noise figure, bandwidth, dynamic range and VSWR. In this paper, the PHEMT transistor ATF36077, which has good noise figure and gain, was selected for low-noise amplifier design, and a good simulation result was obtained. []. Selection of Device The overall technical parameters of the LNA is given as follows. Frequency.9-.98GHz Source Impedance 50Ohm gain flatness <0.5 db Gain >5 db Noise figure <0.5 db VSWR <.5 ATF is an ultra-low-noise Pseudo-morphic High Electron Mobility Transistor(PHEMT), pacaged in a low parasitic, surface-mountable ceramic pacage. Properly matched, this transistor will provide typical GHz noise figures of 0.5 db, or typical 4 GHz noise figures of 0.3 db. Addition-ally, the ATF has very low noise resistance, reducing the sensitivity of noise performance to variations in input impedance match, maing the design of broadband low noise amplifiers much easier. The premium sensitivity of the ATF maes this device the ideal choice for use in the first stage of extremely low noise cascades. The repeatable performance and consistency mae it appropriate for use in Ku-band Direct Broad- cast Satellite (DBS) Television systems, C-band 348

277 Television Receive Only (TVRO) LNAs, or other low noise amplifiers operating in the -8 GHz frequency range. At this design we choose the bias point of ATF36077: Vds=.5V,Id=0mA.,It is topology structure of bias circuit showsfig. Fig.. Topology structure of bias circuit 3. Design of LNA ) Design for unconditional stability; The stability of an amplifier is very important. From the S parameters of the device, we can easily find out that the transistor wored in potential unstable case, A potentially unstable transistor can be made unconditionally stable by either resistively loading the transistor or by adding negative feedbac resulting degradation in power gain, noise figure and so on. Here, we use the shunt resistor on the output. also in the device source together with the inductance feedbac in addition to improve the stability of the device outside the zone have an important role, that is, so that the conjugate can be matched with the lowest noise figure close to match point, so that at the same time to achieve low noise figure and good input VSWR possible. it is the unconditional stable circuit and simulation showsfig. (a) The unconditional stable circuit. (b) The simulated result. Fig. The unconditional stable circuit and simulation ) Choice of reflection coefficient point; The best point from the constant gain circle and constant noise figure circle should be selected. Here, we choose the minimum noise figure point (0.87/4.). the dot of constant gain circle and constant noise figure circle almost in the same place. It is the constant gain circle and noise figure circl shows Fig.3 Then the maximum gain point and minimum noise figure point is almost coincidence. So we can get good noise factor while the input VSWR is small 349

278 Fig.3 The constant gain circle and noise figure circle Then we can use the tools named smith chart in ADS to design L-C networ in the input circuit, then wored on the output, which should done by simulation,this time we must let the reflection of port equal zero (db(s)equal Infinitesimal). Fig.4 is the input and output matching circuit. 4. Simulation of LNA Fig.4 input and output matching circuit Basing the above circuit structure, we add the DC-design and micro-strip in the circuit which is required in the actual circuit board. Here we choose FR4 broad (h=mm,εr=4.3), every Series of micro-strip connecting components should be done carefully because it will change S parameters, fig.5 showed the results of complete circuit. This is always done by the optimization design in some software. Fig.6 is the simulate results from the circuit (Solid line), It can be seen that the power gain and the noise figure is consistent with the theory. In the graph, the power gain equals 5.33 db, while the noise figure is 0.36 which coincide absolutely with the minimum noise figure we required. In order to obtain better input VSWR, we usually sacrifice noise figure. The actual noise is higher than the minimum noise we can get. At the center frequency the input VSWR is.4, while the output is., they are all suffice the target. 350

279 Fig.5 the whole circuit structure. (a) Simulated gain (b ) Simulated reflected figure (c) Simulated noise figure Fig.6 the Simulated results of LNA. (d) the curve of P db point 5. Conclusion A ind of low noise amplifier was designed using the microwave simulation tool ADS005. The LNA was complimented on the FR4 substrate using pacaged ATF36077 and micro-stripe lines. This LNA resulted in noise figure of 0.365dB, and 5dB gain over.9 GHz to.98 GHz range. The VSWR is less than.4 at the input and output port. and the value of the compress point of db is -dbm, the OPI3 is 4.36dBm. This sort of LNA is fit for the front-ends of the base-station of mobile communication system. 35

280 References [] Taris, T., Begueret, J.B., Deval, Y A low voltage current reuse LNA in a 30nm CMOS technology for UWBapplications, Microwave integrated circuit conference, 007. [] [3] D.Henes, LNA Design Uses Series Feedbac to Achieve Simultaneous Low Input VSWR and Low Noise, Applied microwave and Wireless October 998, (): 8 5. [4] Yang Weiming, Chen Jianxin, Xie Wanbo. The Design of SiGe HBT Direct-coupled LNA. The 7th Asia-Pacific Microwave Conference Proceedings. Suzhou, 005. [5] GE Guanding, KANG Hongyan, LI Si-min; Design of GHz ultra-broad band low noise amplifier, Microcomputer Information, 008, (8): -8. [6] H.H. Hsieh, etc., Gain-Enhancement Techniques for CMOS Folded IEEE Trans.M.T.T. Vol.56, pp , Aug. 008, 56(4): [7] Lee Y S, Lee M W, Jeong Y H. High-power amplifier linearization using the Doherty amplifier as a predistortion circuit[j], IEEE Mircrow.Wireless. Compon. Lett., 008, 8(9): [8] Ruey-Lue Wang; Min-Chuan Lin; Cheng-Fu Yang; Chih-Cheng Lin; A V GHz Full-band Cascoded UWB LNA with Resistive Feedbac Electron Devices and Solid-State Circuits, 007. EDSSC 007. IEEE Conference on 0- Dec [9] Dong Hun, Jaejin Par, and C. Patric Yue A low power, 3-5GHz CMOS LNA Using transformer Matching Technique, Solid-State Circuits Conference, 007 ASSCC '07. IEEE Asian, -4 Nov

281 ANALYSIS OF Q-LDPC CODES IN THE APPLICATION OF DEEP SPACE COMMUNICATIONS WEN LEI, LEI JING, WEI JI-BO School of Electronic Science & Engineering, National University of Defense Technology, Changsha, 40073, China Abstract:In the design of deep space communication system, the most important things are improving efficiency of power and probability of error correction. Q-LDPC is a technique that exceeds B-LDPC. Based on these, this paper presents Tanner graph of Q-LDPC and general encoding algorithm. FFT decoding algorithm which balanced between complexity and performance is researched. By comparing the simulation of error performance of Q-LDPC and B-LDPC, it shows that the Q-LDPC is better than B-LDPC. Such wor is foundation of application of Q-LDPC in satellite communications. Keywords:deep space communications; Q-LDPC; belief propagation; FFT 多进制低密度奇偶校验码在卫星通信中的应用研究 文磊雷菁魏急波 国防科学技术大学电子科学与工程学院军事通信工程系, 湖南长沙中国 摘要 : 在卫星通信中, 如何提高功率利用效率及抗差错能力是通信系统设计最重要的问题之一 多进制 LDPC 码是新发现的较二进制 LDPC 码性能更优的信道编码技术 本文从卫星通信的应用角度出发, 介绍了多进制 LDPC 码的图模型结构以及通用编码算法, 在综合考虑复杂度和性能的情况下, 研究了基于 FFT 的多进制 LDPC 码频域译码算法 对多进制 LDPC 码纠错系统的纠错性能进行了仿真, 测试结果表明多进制 LDPC 码的性能优于信源信息速率和码率相同的二进制 LDPC 码, 为多进制 LDPC 码在卫星通信中的应用奠定了基础 关键词 : 卫星通信 ; 多进制 LDPC 码 ; 置信度传递 ; 快速傅立叶变换. 引言随着我国载人航天工程取得举世瞩目的成绩, 向卫星探测领域进军是很自然也是很有意义的事情 在卫星通信中, 由于通信距离的大幅提高, 通信信号从卫星探测器传回地面时, 衰减很大, 地面系统很难对这种极为微弱的信号进行处理 而纠错编码则是一种有效的提高功率利用率的方案, 在目前发射的所有的卫星探测器中, 都无一例外地采用了有效的纠错编码方案 近年来, 低密度校验 (LDPC) 码由于其接近信道容量的纠错性能而受到人们的极大关注 [], 关于二进制 LDPC 码 (B-LDPC) 的研究已经有了大量的工作 Davey 和 MacKay [] 研究发现通过合理设计 Q 进制校验矩阵得到的多进制 LDPC(Q-LDPC, Q>) 码的性能可以超过 B-LDPC, 且 Q-LDPC 码还具有很强的抗突发错误的能力 [3~4], 其性能超过了同码参数下的 RS 码 Q-LDPC 码的高性能, 是以更高的译码复杂度为代价的 多进制 LDPC 码的译码仍然采用迭代算法来实现, 采用快速傅立叶变换在频域进行译码能够使译 353

282 码复杂度从 O(q ) 降到 O(pq) [5] 相对来说其编码部分的处理更加麻烦, 原因在于随机构造的 LDPC 码具有最好的性能, 然而通过校验矩阵计算出的生成矩阵非常稠密, 破坏了稀疏特性 本文安排如下, 引言部分指出研究多进制 LDPC 码的意义, 第二部分介绍多进制 LDPC 码图模型结构及通用编码算法, 第三部分研究了迭代译码原理, 给出了可简化译码算法的傅立叶变换译码, 第四部分将多进制 LDPC 码与二进制 LDPC 码在卫星通信中的性能进行对比, 指出下一步研究方向. 多进制 LDPC 码图模型结构及通用编码算法. 多进制 LDPC 码图模型结构 与二进制 LDPC 码类似, 多进制 LDPC 码也是由低密度奇偶校验矩阵或者 Tanner 图来表示, 如图 所示 [6] 变量节点 置换节点 交织器 校验节点 图 多进制 LDPC 码的 Tanner 图表示 Fig Tanner graph of Non-binary LDPC Codes 其中置换节点表示变量节点按照多元域的运算法则转换相应的排列顺序, 这是二进制 LDPC 码 Tanner 图中所没有的 将 Tanner 图中置换节点与校验节点之间的连接看成一个交织器的结构, 为了使得校验矩阵的围长尽可能的长, 构造 Tanner 图时必然希望连接同一校验节点的置换节点之间距离越大越好 [7] 在多进制情况下, 图 给出的 Tanner 图中的元素不再是简单的 0 和, 而是从多元域中取值 因此在多进制 LDPC 码中, 一个码元不再只是代表一个比特的信息 考虑 GF( p )= {0,,..., p -} 上的多进制 LDPC 码, 每个码元由 p 个比特组成 联系信度传播迭代译码算法, 可以通过与校验节点相连的置换节点的正确信息, 经过一定次数的迭代运算, 来纠正信道传输过程中出现的错误 并且当译码器纠正一个码元时, 它将不正确的码元替换为正确码元, 不管这个错误是由一个比特的错误还是 p 个比特的错误引起的, 这就赋予了多进制 LDPC 码相对于二进制 LDPC 码更好的纠错能力. 多进制 LDPC 码通用编码算法如前所述, 现有的构造方法大多基于两个考虑 : 一是追求好的纠错性能, 二是使其具有特定的结构从而能进行快速编码 [8] 二者往往不能兼得, 通过随机构造法构造的码尽管具有很好的性能, 但编码复杂度太高而没有实用价值 考虑 GF( p ) 上的多进制 (n, )LDPC 码, 将校验矩阵分成 [A,B] 两部分, 其中 A 是 (n-) (n-) 的满秩矩阵, 码字则对应为 [t,s] 形式, 其中 t 代表校验符号,s 代表信息符号, 由于码字空间即为校验矩阵的零空间 : 354

283 T t T T [ AB, ] = 0 T, 即 t = A B s () s 式中乘法与加法运算都在多元域上进行, 编码即通过解上面方程组得到校验符号的过程 然而矩阵求逆的运算非常复杂, 并且 A - 是稠密矩阵, 直接对其进行处理会呈指数级地增加硬件开销及系统时延 如果 A 可以分解为 L U 两部分 A=L U,L 为下三角矩阵,U 为上三角矩阵, 通过引入中间变量 v, 方程 () 变成如下两组 : T L v= B s () T U t = v (3) 利用 L 和 U 的三角结构,() 式采用前向迭代算法 (3) 式采用后向迭代算法能够快速计算出方程的解, 这样可以避免矩阵求逆等效率极低的繁杂运算 [9] 对于多元域上的稀疏矩阵, 其 LU 分解最重要的目的就是要尽量保证分解矩阵的稀疏性, 以及分解过程的稳定性, 否则就失去研究价值 同时考虑到 LU 分解只需通过计算机软件进行运算, 得到的 L U 能够以稀疏矩阵的形式存储到编码器硬件设备中, 每次进行编码时, 可以直接调用这些矩阵实现连续编码 3. 多进制 LDPC 码的快速译码算法 Q-LDPC 码采用置信度传递译码算法 [0] 设变量节点用 n 表示, 校验节点用 m 表示 ;M(n) 表示变量节点 n 参与的所有检验的集合,M(n)/m 表示除校验节点 m 外变量节点 n 参与的所有检验的集合 ;N(m) 表示校验方程 m 检验的所有变量节点的集合 ;N(m)/n 表示除变量节点 n 校验方程 m 检验所有变量节点的集合 置信度传递译码步骤如下 : ) 将校验节点 m 给变量节点 n 的对数似然比信息矢量 Lr mn 置 0, n N, m M, 对于 H m, n 0 的校验节点 m, 变量节点 n 给其相邻校验节点 m 的对数似然比信息矢量 Lq nm 置为 LQ n ; ) 尝试译码, 每个变量节点的后验 LLRV 用 Lq n 表示, 则 Lq n = LQ n + Lr mn (4) m M( n) x n 的值取后验对数似然比信息矢量 Lq n 中最大值所对应的标号, 如 Lq n 中第 3 个值最大, 该最大值对应的标号为, 则 x n = 若 Hx T =0, 则说明矢量 x 为合法码字, 译码成功, 译码过程结束 ; 若迭代译码次数达到设定的最大迭代次数,Hx T 仍不为零, 则宣告译码失败并停止译码, 将此时所得到的 N 长符号序列的后 K 位作为译码结果输出 3) 水平步骤用于计算变量节点 n 传递给其相邻校验节点 m 的似然比信息矢量,m M(n): Lqnm= LQn+ Lr mn m M ( n) / m (5) 4) 垂直步骤用于计算校验节点 m 传递给其相邻变量节点 n 的信息 要计算对数似然比信息矢量 Lr mn, 首先要将 Lq nm 从对数域变换到普通的似然域,n N(m), 即 q nm =LLR - (Lq nm ), 将 q nm 内元素进行适当的排 序后得到 q nm, 再计算似然域的信息矢量 r mn : 355

284 q (6) r mn = IFFT FFT ( ' nm) ' n N( m)\ n r mn 经过相应的排序得到 r mn, 再通过 LLR(r mn ) 转化为对数似然域的信息矢量 Lr mn 后进入下次的译码迭代 4. 性能测试 为了测试多进制 LDPC 码的纠错性能, 基于代数学构造方法设计了 (00,00) (04,5) 两个码率为 / 的 8-LDPC 码, 并对这两种码型的性能进行了仿真 为了与信源速率和码率相同的 B-LDPC 码进行性能比较, 文中也仿真了两个对应比特码长码率相同的 (600,300) (307,536)B-LDPC 码性能 信道模拟为卫星通信的典型高斯噪声信道, 调制方式采用 BPSK, 最大迭代次数设置为 50 次 (00, 00)8-LDPC 码与 (600,300)B-LDPC 码的纠错性能, 及 (04,5)8-LDPC 码与 (307,536)B-LDPC 码的纠错性能分别参图 3 所示 0 - B-LDPC 8-LDPC 0 - bit error probability Eb/N0(dB) 图 (00,00)8-LDPC 码和 (600,300)B-LDPC 码纠错性能 Fig Error correcting performance of (00,00) 8-LDPC and (600,300) B-LDPC Codes B-LDPC 8-LDPC 0-3 bit error probability Eb/N0(dB) 图 3(04,5)8-LDPC 码和 (307,536)B-LDPC 码纠错性能 Fig 3 Error correcting performance of (04,5) 8-LDPC and (307,536) B-LDPC Codes 356

285 从图中可以看出, 在比特码长与码率都相同的条件下,8-LDPC 码的性能要明显好于 B-LDPC 码性能 在 / N 0 = 3 db 时,8-LDPC 码的误比特率比 B-LDPC 码低一到两个数量级 相比于 B-LDPC 码,8-LDPC E b 码的编码增益提高了约 0.6dB 5. 结论 本文研究了多进制 LDPC 码的图模型结构及通用编码算法, 介绍了置信度传递译码算法, 在此基础上分析了基于 FFT 的迭代译码算法 仿真结果表明, 多进制 LDPC 的性能较二进制 LDPC 有明显提高 随着卫星探测的深入, 对卫星通信在可靠性和带宽效率方面都提出了更高要求 在未来的工作中, 如何改善多进制 LCPC 码的环结构, 以及降低译码复杂度, 是进一步研究的方向 参考文献. R. G. Gallager. Low density parity chec codes[j], IRE Trans. Inform. Theory, 96, 8(): -8.. M. Davey, D. J. C. MacKay. Low density parity chec codes over GF(q)[J], IEEE Commun. Lett., 998, (6): Andrea Marinoni, Pietro Savazzi. Non-binary LDPC codes with good performance on channels affected by bursty noise, H. Song, J. R. Cruz. Reduced-complexity decoding of q-ary LDPC codes for magnetic recording[j], IEEE Trans. Magn., 003, 39(): Sung-Eun Par. Chiwoo Lim. A class of Structured LDPC Codes over GF(q) for Efficient Encoding. IEEE Transactions on communications.007.6(37): Lei Jing, Tang Chaojing, Wang Jianhui. An Effective Algorithm for Construction of LDPC Codes. Proceedings of 008 IEEE International Conference on Information and Automation, Zhangjiajie, China, 008, (6): Bo Zhou, Jingyu Kang, Shumei Song, Shu Lin, Construction of non-binary quasi-cyclic LDPC codes by arrays and array dispersions. IEEE Transactions on communications. 009, 57(6): Alfredo Braunstein. Farbod Kayhan. Riccardo Zecchina. Efficient LDPC Codes over GF(q) for Lossy Data Compression. IEEE Transactions on Information Theory, 009, 5(7): J.T. Zhang, M. Fossorier, D. Gu, and J. Zhang. Two-dimensional correction for min-sum decoding of irregular LDPC codes. IEEE Commun. Letters, 006, 3(0): G. Satoshi, O. Tomoai, K. Toshinobu. Modified Belief Propagation Decoding Algorithm for Low-Density Parity Chec Code Based on Oscillation. VTC 006-Spring IEEE 63rd, (3):

286 CODED MODULATE SUITABLE FOR COOPERATIVE COMMUNICATION GAO YONG, LEI JING, HUANG YING School of Electronic Science and Engineering, National University of Defence Technology, Changsha, Hunan, China Abstract: Iterative decoded bit-interleaved coded modulation (BICM_ID) could be seen as a good choice for coded cooperation (CC), but in cooperative communication it should be able to wor in bad channel states, try to reduce the calculation of cooperate partner, and we should improve the performance of BICM_ID. Through analyze and simulation I got improve arithmetic, constellation could be switched between DRO and gray automatically so as to reduce the calculation of partner, demodulation could be simplified by Constant_Log_APP, the length of frame could be chosen on condition of channel, and listed five methods to automatic control the number of iteration. Key Words: cooperative communication, BICM_ID, iteration, constellation 适应协作通信的编码调制 (CM) 方案 高勇雷菁黄英 国防科技大学电子科学与工程学院,, 湖南长沙中国 摘要 : 基于迭代译码的比特交织编码调制技术 (BICM_ID) 可以作为编码协作 (CC) 通信的可选编码方案, 但针对协作通信要求适应极差的信道环境, 尽量减少协作伙伴的计算量, 需要对 BICM_ID 做必要的改进以减少计算复杂度提高性能 通过分析及仿真得到改进算法, 星座映射采用 DRO 与 gray 自适应切换以减少协作伙伴的计算复杂度, 软解解调算法以 Constant_Log_APP 法进行简化, 帧长可根据信道情况进行选择, 并列举了迭代次数自适应控制的 5 种方法 关键词 : 协作通信 BICM_ 3 磅 ID 迭代 映射. 引言 在实际的蜂窝通信系统和无线自组织网络中, 移动终端由于受到体积 重量 成本等因素的限制, 无法实现利用多天线技术, 限制了多输入多输出 (MIMO) 技术的应用 协作分集技术是使具有单天线的移动设备按照一定方案共享彼此的天线, 产生一个虚拟 MIMO 系统从而获得分集增益 编码协作 (Coded Cooperation, CC ) 作为一种高效的方案越来越受到关注 编码调制则可以在不牺牲带宽和有效传输速率的条件下, 获得明显的编码增益 联合编码和调制的思想最早由 Masscy 在 974 年提出,Ungerboec 和 Imai 的研究表明, 调制和编码可以作为一个整体进行联合优化, 其核心思想就是在欧几里德空间优化码字, 利用简单的纠错编码就可以达到较理想编码增益 [] 目前, 主要的编码调制方案有 :Ungerboec 在 976 年提出的网格编码调制 (TCM), 以及 Imai H. 在 977 年提出的分组编码调制 (BCM) 也成为多级编码调制 (MLC) Zehavi 在 99 年提出的比特交织编码调制 (BICM) TCM BCM 在 AWGN 信道中都是最佳方案, 有着最佳的编码译码方法和最佳的映射规则 ; 但在衰落信道中结果不理想, 丧失了大量的编码增益 [] BICM 对于不同信道 (AWGN Rayleigh) 具有较强的稳健性 但含有比特交织器的编码调制系统本身存在 随机调制 性, 这造成了汉明距离和欧氏距离的非单调 358

287 关系, 使欧氏自由距离下降 研究表明, 可以通过使用判决反馈迭代译码来提高 BICM 在高斯信道中的性能, 即 BICM_ID 作者认为可以选择 BICM_ID 作为编码协作通信的备选编码方案 本文首先简要介绍 BICM_ID 和编码协作的基本原理,BICM_ID 应用于编码协作通信的基本条件, 并分别从解调算法的简化, 星座映射的优化设计, 帧长选择 迭代次数自适应控制方法进行讨论, 以适应编码协作通信系统的特殊要求. BICM_ID 系统在协作通信应用中的改进 BICM_ID 系统模型发送端信息序列 u 经过纠错编码和交织得到 b,b 通过标识映射得到星座符号序列 s 如图 所示 u b' b s π û D L ( b') a π M Le ( b) y L D e ( c ') L M a () c π 图 BICM_ID 系统模型 Fig the model of BICM_ID system 接收端迭代解调译码是通过内部软解调器和外部译码器互相交换软信息实现的 解调器根据接收的信 M 道符 y 和先验信息 La () c ( 初始化为 0) 来计算其输出给译码器的外信息 L M e ( b ), 解交织后作为译码器的 D 先验信息, 软输入软输出译码器根据其译码算法计算出各码元的外信息 Le ( c '), 交织后作为软解调器先验 M 信息 La () c 进行下一轮迭代译码 [3] 根据李晓东的研究表明 BICM_ID 将 m 进制的信号信道转化为 m 个并行子信道, 从而获得分集增益 通过合适的标识映射, 编码比特间大的二进制汉明距离可以间接转换为大的欧式距离 [4~5] 协作通信的基本系统模型, 如图 所示 : 图 协作通信系统模型 Fig Cooperative communication system model 359

288 在时刻 T= 用户源节点 S 发出信号, 协作伙伴 R 节点和目标节点 D 接收信号, 协作伙伴 R 节点将接收到的信号解码并重新编码, 在 T= 时刻发送出去, 此时, 只有目标节点 D 接收信号, 目标节点合并两个时刻接收到的信号, 进行解码, 这样就完成一帧信号的传输 协作通信中目标节点合并来自两条独立信道的信息, 从而可以获得分集增益 笔者认为编码协作通信对编码有如下要求 ) 用户与协作伙伴一般都是移动设备, 硬件设备受限, 同时协作伙伴既要接收信息, 解码信息, 又要发送信息, 故应当尽量降低协作伙伴的计算复杂度 然而 BICM_ID 涉及到软解调, 迭代译码等需要大量复杂的计算, 减少协作过程中计算复杂度成为需要研究的主要问题 ) 该编码方案要具有较好的纠错能力, 适应无线通信的信道极差的传输特性 BICM_ID 通过优化标识映射的方法, 在不增加系统复杂度情况下提高系统性能 3) 可以根据信道状况, 自适应的调整码率, 便于调节协作时分割和合并源节点与协作伙伴传播信息, 最大效率地利用带宽资源 BICM_ID 的编码器与映射器可以独立设计, 码率可以很方便地在编码器处调节 如卷积码,turbo 码可以用穿孔等方法进行调节. 星座图的设计选择 BICM_ID 中首轮渐进迭代性能限及渐进错误平层限为 [6~7] : dc ( ) E P Rd u + + const b log 0 b ( h( )) db 0 N0 db () 式中 : dc ( ) E b P Rd u + + const 0 N0 db log 0 b ( h( )) db m d h = dh( μ) = m m i= b= 0 i s s ˆ χb z m d h = d h( μ) = m m i= b= 0 i s s χb z () (3) (4) ẑ 为 s 最邻近点值, z 为 s 仅第 i 比特不同点值, dc ( ) 为码距,R 为码率 定义为调和中值, 公式 (.,.) 式是在信噪比较高的前提下推导的, 适用于信噪比较高系统的分 析限, 信噪比较低时可通过仿真观察 由公式易知 BICM_ID 的首轮渐进迭代性能限由 决定, 即 BICM 的性能由 d h 决定,BICM_ID 渐进错误平层限由 d h 决定 定义反馈增益为 : Gain = 0log( d / d ) (5) h h d h 360

289 常用各种标识映射方法的特征参数进行比较如表 所示, 并以 Gray SP MSP DRO 映射为例进行仿真 表. 常用 BICM_ID 星座映射参数 Table Common BICM_ID constellation mapping parameters 映射方法 d h d h Gain / db 映射 Gray ,,3,7,4,0,,6,,8,0,4,3,9,,5 SP ,3,,9,5,0,,4,4,,0,5,3,6,7, MSP ,,,5,,,5,6,4,7,0,3,3,4,9,0 MSEW ,,6,8,,,,5,9,7,0,4,4,0,3,3 Mixed ,3,,,,5,3,4,4,7,5,6,8,,9,0 EFD ,0,3,9,,6,5,5,,,8,,7,3,4,4 Random ,,6,5,0,9,3,5,7,4,4,8,3,,, DRO ,,4,4,7,,,8,0,,5,5,0,6,9,3 仿真条件 :/ 码率, 相关长度为 4 的卷积码 映射方式为 DRO, 迭代次数分别为,8 由仿真结果, 可以看出, 随着迭代次数的增加, 由于内部软解调器和外部译码器互相交换软信息, 误码率降低 当迭代次数为 时,gray 映射具有最佳的性能,DRO 性能最差, 结合表, 四种映射方式中,gray 映射 d h 最大, DRO 映射的 d h 最小, d h 决定 BICM_ID 的首轮迭代性能即 BICM 的性能, 同时, 随着迭代次数的增加, 4 DRO 映射性能有较大幅度提高, 而 gray 映射性能提高微乎其微, 迭代次数为 8 时, 在误码率 0,DRO 映射较 gray 映射有约 5dB 的增益 从表 中可以看出,DRO 映射具有最大的 d h 和反馈增益, 故迭代获得的增益最大 同时可以看到 DRO 映射 8 次迭代错误平层出现最晚且最低, 与公式 () 相符 仅改变标识映射, 系统的复杂度不变 因此在协作通信中, 一般协作伙伴与用户之间信道较好, 协作伙伴的计算能力有限, 目标节点一般为基站计算能力较强, 可选用双星座图切换的方法, 用户在 T= 时刻发送的信号可采用 gray 映射, 协作伙伴可以仅用一轮迭代就获得较好的性能, 而协作伙伴在 T= 时刻向基站发送的信号可采用 DRO 映射, 基站可通过多轮迭代获得较好最终结果 若协作通信采用帧延迟的方法, 即在 T=n 时刻源节点发送信号,T=n+ 时刻, 协作伙伴发送 T=n- 时刻信源信号的协作信号, 这样可以为迭代争取更多的处理时间, 可以直接采用 DRO 映射, 但系统时延增加. BICM_ID 中的软解调器的简化 对于某一比特 b 软解调器输出的计算公式如下 : L m pys ( i ) si X j= 0 M Pb ( = ; O) j e ( b) = log = log m Pb ( = 0; O) pys ( i ) si X0 j= 0 j e e M b La ( b) M b La ( b) (6) 36

290 这里 X b 表示符号 s i X b 的集合, 其中 s i 的第 位置的比特值是 b( b {0,}, = 0,, m ) M 解调器的输入是接收信号 y 和相应的先验对数似然比 (LLR) L ( b ) 引入 max* 函数 : x max*{ x } = ln{ e i }, 令 f( y s ) = ln p( y s ) + η,η 为常数, 则上式可化简为 i 作如下分解 : i i i i m m M M M Le ( b) = max* f( y si) + bj( si) La ( b ) j max* f( y si) + bj( si) La ( bj) si: b( si) = s : ( ) 0 i b s j i = = j= j j max*(, ) ln( x y ) max(, ) ln( x x y e e x y e y ) max( x, y) fc ( x y ) a (7) = + = + + = + (8) 迭代过程中要进行大量 max* 函数计算, 对它进行简化可以节省大量的计算, 根据对 f ( x y ) 进行 不同的近似可以得到以下四种算法 [8] :)Log_APP,)Linear_log_APP,3)Constant_Log_APP,4) Max_Log_APP / 码率, 相关长度为 4 的卷积码 映射方式为 DRO, 进行 8 次迭代的结果, 分别用以上四种软解调算法进行比较, 可以发现, 虽然以上四种算法计算复杂度相差很大, 但是除了 Max_Log_APP 性能略有下降以外, 其余算法相差不大 故可选除了 Max_Log_APP 外计算量最小的 Constant_Log_APP 作为解调算法 这一点对与协作通信中计算性能有限的协作伙伴软解调是非常有益的 本页解调器算法性能对比如图 3 图 4 c 图 3 软解调器算法性能对比 Fig 3 Soft modem algorithm performance comparison 36

291 .3 帧长的选择 图 4 软解调器算法性能对比 Fig 4 Soft modem algorithm performance comparison 相关信道衰落长会在深度衰落器导致突发错误, 理想交织器可以将信道衰落的相关性对编码纠错性能的不利影响消除 [9], 在 BICM_ID 中可以等效地将 m 进制调制看做 m 条并行不相关信道, 从而实际系统中不可能如理论分析那样采用无限长的理想交织器, 为此本文对帧长分别为 00,400,800,600 比特情况进行了仿真比较, 如图 5 图 6 所示 图 5 BICM_ID 不同帧长性能对比 Fig 5 BICM_ID at different frame long performance comparison 图 6 BICM_ID 不同迭代次数性能 Fig 6 BICM_ID performance of different iterations 图 5 是 BICM_ID 系统在瑞利信道下性能比较的结果, 相关参数为 / 码率, 相关长度为 4 的卷积码, 映射方式为 DRO, 进行 8 次迭代的 由图可得出以下规律, 帧长越长误码性能越好 ; 帧长越长, 交织越充分, 迭代时反馈回的信息独立性越好, 其抑制迭代中错误传播的能力就越强, 同等信道和编码条件下, 越能获得较好的性能 当交织长度达到一定数量时, 系统的性能会逐渐趋于定值即误码限 但帧长的增加, 会增大处理的时延, 增加对硬件的要求, 因此要根据协作通信中信道情况折衷选取帧长.4 迭代次数的自适应控制 363

292 图 6 比较了不同迭代次数下 BICM_ID 系统性能情况 仍为瑞利信道下,/ 码率, 相关长度为 4 的卷积码, 映射方式为 DRO, 迭代次数取为,,4,8,6 次 BICM_ID 中迭代次数决定了译码性能以及时延, 迭代次数越多性能越好, 但时延及计算量也就越大, 同时迭代次数增加到一定程度后性能改善幅度有限 固定迭代次数一方面可能无法纠正所有误码就停止迭代影响系统的误码性能, 另一方面协作伙伴与源节点信道可能很好, 浪费了计算量 协作伙伴节点计算资源有限, 自适应的调节迭代次数有重要意义, 在实际应用中可以根据一定的准则进行控制 ) 加入 CRC 校验, 符合校验则停止迭代, 但这样增加了冗余, 对于帧长较小的情况对系统效率造成影响 ) 根据两次迭代符号变化率, 两次迭代译码结果进行比较, 不同比特占总比特的比例小于一定门限可以认为达到编码纠错能力上限, 停止迭代 3) 根据码的结构判断迭代结束时刻 如 LDPC 码完全符合校验时停止迭代 4) 对当前帧信道进行估计, 根据统计结果决定本帧的迭代次数等 3. 结论 通过对 BICM_ID 和协作通信系统模型的分析, 通过对解调器 星座 迭代过程 帧长等进行了讨论, 认为可以通过简化算法来降低解调器的计算复杂度同时几乎不影响系统性能 优化星座图可以达到不增加系统复杂度条件下提高系统性能的效果, 双星座图切换方案大大降低了协作伙伴的计算复杂度, 帧延迟方案则可以为协作伙伴提供更多的处理时间 根据编码或信道的信息可以自适应地控制迭代次数从而减少计算量与延时, 适当调节帧长达到性能与系统复杂度的折衷 因此 BICM_ID 可以作为编码协作通信的一种有效编码方案 References ( 参考文献 ). Ungerboec G, Channel coding with multilevel/phase signals, IEEE Trans, on Information Theory, 98.. 袁东风, 张海霞, 编码调制技术原理及应用, 北京, 北京大学出版社. 3. 邹雪兰, 酆广增,SNR 估计误差对 BICM.ID 系统性能影响的研究, (5): 5~ Li X.D.,Ritcey J.A., Bit-interleaved coded modulation with iterative decoding and 8PSK signaling,ieee Trans. on Comm.,00, 50(8): Li X.D.,Ritcey J.A. Bit-interleaved coded modulation with iterative decoding, 999, (): ChindapolA, Ritcey J A. Design, Analysis, and Per formance evaluation forb ICMID with square QAM con stellations in rayleigh fading channels [ J ]. IEEE Jour nal on Selected Areas in Communications, 00, 9 (5) : Caire G, Taricco G, Biglieri E. Bit_interleaved coded modulation [ J ]. IEEE Trans on Information Theory, 998, 44 (5) : 吴湛击, 现代纠错编码与调制理论及应用, 北京, 人民邮电出版社, Jon W. Mar, Weihua Zhuang, 著, 李锵, 郭继昌, 译, 无线通信与网络, 北京, 电子工业出版社

293 A NOVEL ITERATIVE RECEIVER BASED ON FREQUENCY DOMAIN SISO EQUALIZATION FOR MIMO-OFDM SYSTEM XIONG CHUN-LIN, LEI JING, WEI JI-BO School of Electronic Science and Engineering, National University of Defense Technology, Changsha, 40073, China Abstract:Based on variational Bayesian method, a novel iterative receiver with joint channel tracing, frequency domain soft input soft output (SISO) equalization and symbol decoding is proposed for MIMO-OFDM systems in time-varying multi-path channel. The proposed receiver exhibits some new features compared with the conventional one. Firstly, it estimates the channel frequency response (CFR) with the aid of soft signal information and previously predicted CFR. Moreover, the alman prediction algorithm is introduced for the CFR filter and prediction, which results in improved CFR tracing performance. Secondly, the frequency domain equalizer utilizes the symbol prior information obtained from SISO decoder and directly output the extrinsic information for the decoder. In addition, the receiver potentially increases channel utilization, as no pilots are required in data OFDM symbols. As can be seen from simulation results, in time-varying multi-path channel, compared with optimal MAP receiver, the proposed one greatly reduces the computational complexity at the cost of tolerable performance loss. Keywords:MIMO-OFDM system; iterative receiver; variational Bayes; soft input soft output equalization; alman prediction 一种新的基于频域 SISO 均衡的 MIMO-OFDM 迭代接收机 熊春林雷菁魏急波 国防科学技术大学电子科学与工程学院, 湖南长沙中国 摘要 : 针对时变多径信道下的 MIMO-OFDM 系统, 基于变分贝叶斯原理, 提出一种新的联合信道跟踪 频域软入软出 (SISO) 均衡和译码的迭代接收机 与传统接收机不同的是, 信道估计不仅利用信号软信息还利用信道的预测值 而且在信道跟踪过程中引入 alman 预测算法, 对信道估计值和预测值进行滤波, 并对后续信道进行预测, 因此提高了信道估计的精度 频域 SISO 均衡器以符号的软信息为输入并直接输出比特的外信息 此外, 该接收机在数据符号中不需内插导频, 从而提高了频谱利用率 仿真表明, 在时变多径信道下, 所提接收机与最优 MAP 接收机相比, 以稍许性能损失为代价换取复杂度的大大降低 关键词 :MIMO-OFDM 系统 ; 迭代接收机 ; 变分贝叶斯 ;SISO 均衡 ;alman 预测. 引言 MIMO 技术可以在不增加系统带宽和发射功率的条件下成倍提高信道容量,OFDM 技术则通过将频率选择性衰落转化为一系列平坦衰落子信道而降低了接收机的复杂度 MIMO-OFDM 技术充分利用两种技术的优点, 在实现高可靠信号传输的同时, 还可以增加系统容量, 提高系统的频谱效率, 因此是未来宽带无线通信的关键技术之一 [] 接收机的设计是 MIMO-OFDM 系统设计的重要环节之一 迭代技术可以提高接收机性能, 因此引起研究者的广泛关注 [~3] 365

294 近来, 变分贝叶斯理论逐渐被应用于机器学习 人工智能 统计推理和通信等多个领域中 [3~6] 该理论将多变量的联合分布近似为各变量的边际分布的乘积 从而, 可以方便地将多变量的联合优化转化为各变量的迭代优化 [7~9] 本文针对时变多径信道下的 MIMO-OFDM 系统, 基于变分贝叶斯理论, 推导出一种新的联合信道跟踪 SISO 均衡和译码的迭代接收机架构 在此架构下, 该接收机在每个子信道上进行迭代信道跟踪 均衡和译码 其中, 信道跟踪由信道估计 滤波和预测三部分组成 与传统迭代接收机类似, 所提接收机在进行信道估计时, 利用了检测器提供的符号软信息 而与传统接收机不同的是, 所提接收机在进行信道估计时, 还利用了信道的预测值, 而且在信道跟踪过程中引入 alman 预测算法, 对信道估计值进行滤波, 并对下一时刻信道进行预测, 从而有效改善了信道的跟踪性能 在进行信号检测时, 频域的 SISO 均衡器替代了传统的 SISO 检测器 此外, 所提接收机不需在数据符号中内插导频, 因此提高了信道利用率 仿真表明, 在时变多径信道下, 所提接收机与 MAP 迭代接收机相比, 以稍许性能损失为代价换取复杂度的大大降低 本文后续部分安排如下 : 第二节给出了 MIMO-OFDM 系统模型 第三节基于变分贝叶斯理论, 提出 MIMO-OFDM 系统的迭代接收机架构 第四节仿真所提接收机的性能 第五节对全文进行总结 本文符号说明 : 粗体表示矢量或矩阵, 如 H, 相应元素由斜体加下标表示, 如 H i, j 上标 T 和 H 分别表示矢量和矩阵的转置和共轭转置 E() i 或 E[] i 表示数学期望 为 Kronecher 积 vec() i 表示将矩阵按列顺序排成一个列矢量.MIMO-OFDM 系统模型 考虑 Nt 个发送天线和 Nr ( Nr Nt) 个接收天线的 MIMO-OFDM 系统, 每个 OFDM 符号包含 K 个子载波 在发送端, 设 n 时刻天线 t 的符号矢量为 X ( n) = [ X ( n,0), X ( n,),, X ( n, K )] T, 其中 X ( n, ) 为天线 t 的 t t t t 比特流经过编码 交织和 QAM 映射得到, 为 QAM 星座集合 ( 表示集合中元素的数目 ) X ( n) 经 过 OFDM 调制并加循环前缀 (CP) 后由天线 t 发出 假设第 (, tr ) rt rt rt rt t 天线对之间的信道时域响应为 h ( n) = [ h ( n,0), h ( n,),, h ( n, L )] T,L 为信多径长度且 L 小于 CP 长度, 且假定信道在一个 OFDM 符号间 隔内保持不变而在符号之间变化, 各天线对之间的信道相互独立且同分布 本文将信道近似为 阶 AR 模 [0] 型 h ( n) = Ah ( n ) + v ( n) () rt rt 式中 : A 为 AR 模型参数, v ( n) 为激励噪声, 其方差阵为 Q v 接收端已知信道统计特性 t 假设接收端具有精确的定时和频率同步, 接收信号去 CP 后变换到频域,n 时刻第 r 接收天线的 OFDM 符号 Y ( n) = [ Y ( n,0), Y ( n,),, Y ( n, K )] T 为 r r r r Nt Y ( n) = diag[ X ( n)] H ( n) + W ( n) () r t rt r t= 366

295 式中 : diag[ X ] 表示以矢量 X 为主对角线元素的对角阵, W ( n) = [ W ( n,0), W ( n,),, W ( n, K )] T 为 n 时刻 r r r r 接收天线 r 的频域叠加的高斯白噪声矢量, 其方差阵为 σ I, H ( n) 为第 (, tr ) 天线对之间的频域信道值, 可表示为 K rt H ( n) = F h ( n) rt L rt = [ H ( n,0), H ( n,),, H ( n, K )] rt rt rt T (3) 式中 : 矩阵 F L 的第 行 l 列元素为 F L( l, ) = exp( j π ( )( L )/ K ) 如果只考虑 OFDM 符号的第 个子载波, 则有 Y ( n) = H ( n) X ( n) + W ( n) (4) 式中 : Y ( n) = [ Y( n, ), Y( n, ),, Y ( n, )] T 为子载波 上的接收信号, Nr X n = X n X n XNt n 为对应的发送信号, = ( ) [ (, ), (, ),, (, )] T W ( n) [ W( n, ), W( n, ),, W ( n, )] T 为相应的噪 声矢量 H ( n ) 为所有收发天线对的子载波 上的频域信道响应, 具体可表示为 Nr H ( n) = ( F ( ) I ) h( n) L Nr H,( n, ) H,( n, ) H, Nt ( n, ) H,( n, ) H,( n, ) H, Nt ( n, ) = HNr, ( n, ) HNr, ( n, ) HNr, Nt ( n, ) (5) 这里 F L( ) 表示矩阵 F L 的第 行 令 H( n) = vec( H ( n)), ( c ) T X ( n) = X ( n) I ( c ) = + 为方便描述, 后面所有上标 都表示 vec() i 操作 Nr, 则式 () 可等价表示为 Y ( n) X ( n) H ( n) W ( n) (6) 3. 基于变分贝叶斯架构的迭代接收机 变分贝叶斯方法是一种变分优化的方法, 此方法将多变量的联合概率分布近似为各变量边际分布的乘 积, 从而对多变量的联合优化可以方便地转化为这些变量的迭代优化, 因此可以显著降低联合优化的计算 复杂度 [3~5] 各变量的最优近似边际分布通过最小化其与联合分布的 KL 距离得到 设有两随机变量 Z, Z, 其先验分布和联合分布分别为 p( Z), p( Z ) 和 p( Z, Z ), 近似边际分布为 qz ( ), qz ( ) 那么由变分贝叶斯方法 [3~5] 可得 ln qz ( ) = ln pz ( ) + E (ln pz ( Z )),( m=,) (7) m m q( Z ) / m m / m Z /m 表示除 Z m 外其它变量的集合 从而对两变量的联合优化转化为下式所示的迭代优化 367

296 式中 : 上标 () i 表示第 i 次迭代 () ln q i ( Z ) = ln p ( Z ) + E ( Z Z ) (8) ( i ) q ( Z ) () ln q i ( Z ) = ln p ( Z ) + E ( Z Z ) (9) ( i ) q ( Z ) 在 MIMO-OFDM 系统中, 将发送信号 X ( n ) 和信道频率响应 H ( n ) 作为待优化的未知参数 最优的接 收机使得 X ( n ) 和 H ( n ) 的联合概率最大化, 但是其复杂度非常高, 因此在实际系统中难以直接应用 基于 上述变分贝叶斯方法, 本文推导了一种新的联合信道跟踪 频域 SISO 均衡和译码的迭代接收机, 所得接 收机详细结构如图 所示 本接收机主要由信道跟踪模块 频域 SISO 均衡和译码模块组成 其中, 信道 跟踪模块由信道估计 alman 信道滤波和信道预测三部分组成, 如图 所示 : a L ( b Y ( n)) j Y μ, ω H ˆ ( ) n n L ( b Y ( n)) ext j H ˆ ( n ) H ˆ ( n n ) 图 MIMO-OFDM 系统基于频域 SISO 均衡的迭代接收机结构 Fig MIMO-OFOM system based on frequency-domain SISO equilibrium iterative receiver structure 且在信道跟踪过程中不需要任何导频信息 频域 SISO 均衡则利用 BCJR 译码器的先验信息和信道滤波值等获得发送信号的外信息 译码采用软入软出的 BCJR 译码算法 下面首先给出发送信号和信道的联合分布, 然后详细推导所提迭代接收机 根据 n 时刻及以前的接收信号 Y (: n), 发送信号和信道的联合概率分布为 p( X ( n), H ( n) Y (: n)) p( Y ( n) X ( n), H ( n)) p( X ( n), H ( n) Y (: n )) = p( Y ( n) X ( n), H ( n)) p( X ( n)) p( H ( n) Y (: n )) (0) 式中 :n 时刻发送信号 X ( n ) 与 n 时刻以前的接收信号 Y (: n ) 无关 ( 这很容易满足, 比如每个 OFDM 都单独进行编码交织等 ), 且 X ( n ) 与信道无关 368

297 不妨令 Z = X ( n), Z = H ( n), 接下来根据变分贝叶斯方法, 首先推导所提迭代接收机的频域 SISO 均 衡, 然后推导接收机的信道估计 alman 信道滤波和信道预测, 最后对接收机进行总结 为简化起见, 推 导中省略了迭代序号上标 () i 3. 频域 SISO 均衡 因为 X ( n ) 与信道无关, 从而由式 (0) 可得 p( X ( n), H ( n) Y (: n)) p( Y ( n) X ( n), H ( n)) p( X ( n)) () 基于变分贝叶斯方法, 根据上次迭代得到的信道边际分布 q( H ( n)), 利用式 (8) 和式 () 计算 X ( n ) 的对数边 际分布 ln q( X ( n)) ( ) = ln p( X ( n)) + E [ln p Y ( n) X ( n), H ( n) ] q( H ( n)) = ln p( X ( )) ( ) ˆ n Y ( ) ( ) n H n X n σ () 式中 : H ˆ ( n ) 为信道频域响应的估计, q( X ( n)) 为信号 X ( n ) 的边际分布且满足 Nt q( X ( n)) = q( X (, )) t t n (3) = p( X ( n)) 为 X ( n ) 的先验分布, 假设 X ( n ) 为服从高斯分布的随机矢量, 则有 p( X ( n)) = H x exp( ( X ( n) X ( n)) Λ ( X ( n) X ( n))/) (4) 式中 : X ( n ) 和 Λ x 分别为 X ( n ) 的均值和方差阵 假设各发送天线信号不相关, 则 Λ x 为对角阵 X ( n ) 中 第 t 个符号 Xt ( n, ) 的均值 Xt ( n, ) 和方差 λ x 分别为 t a Xt( n, ) = αp ( Xt( n, ) = α) (5) α λ = X ( n, ) α P ( X ( n, ) = α) (6) a xt t α t a 这里 λ 为矩阵 Λ x 的对角线上的第 t 个元素, P () i 为 BCJR 译码器提供的先验信息 xt 对式 () 求导令导数为 0 可得 Xˆ ( n) ˆ H ˆ ˆ H H ( n) H( n) H ( n) Y( n) = ( Λx + ) ( + Λ ( )) x X n σ σ ˆ H ˆ ˆ H = X ( n) + Λ H ( n)( H ( n) Λ H ( n) + σ I) x x ( Y ( n) Hˆ ( n) X ( n)) (7) 369

298 式中 : 利用了 X ( n ) 的先验信息, 这对提取外信息极为不利, 因此实际计算时, 令 Xt ( n, ) = 0, Λ x(,) tt =, [~] 则式 (7) 转化为 Xˆ ( n, ) = X ( n, ) + t t H ˆ H ˆ ˆ H ˆ t x + σ + λx t H ˆ H uu ˆ ˆ t t H Y H X HuX t u H ( n)[ H ( n) Λ H ( n) I ( ) H ( n) ( n)] ( ( n) ( n) + ( n)) σ σ x = t H H σ + ut H ( n) H( n) ut (8) (9) 这里 u t 表示第 t 个元素为 其它元素为 0 的 Nt 维列矢量, σ x 为估计误差的方差 根据 Xˆ t t ( n, ) 和 得 X ( n ) 的近似边际分布 σ x t 可 X ( n, ) Xˆ ( n, ) q( X ( n)) = exp( ) Nt t t t = πσ σ x xt t = Cexp( ( X ( n) Xˆ ( n)) Ξ ( X ( n) Xˆ ( n))/) H x (0) 上式中 C 为常数, Ξ = diag[ σ, σ,, σ ] 最终, 均衡器输出的外信息为 x x x x Nt L ( b Y ( n)) ext t,, j = ln α α j, + j, qx ( ( n, ) = α) p( b ) t m j t,, m qx ( ( n, ) = α) p( b ) t m j a a t,, m () 式中 : b t,, j 表示符号 Xt ( n, ) = α 的第 j 个比特, j, + ( 或 j, ) 表示 b t,, j= + ( 或 b t,, j= ) 的符号 集合 由此获得的外信息解交织后送到 BCJR 译码器进行译码 3. 信道估计 利用从 SISO 均衡器获得的分布 q( X ( n)), 下面详细推导频域信道估计算法, 推导中将采用式 (6) 所示的 等价信号模型 同样因为 X ( n ) 与信道无关, 从而由式 (0) 可得 p( X( n), H( n) Y(: n)) () p( Y ( n) X ( n), H ( n)) p( H ( n) Y (: n )) 基于变分贝叶斯方法, 利用式 (9) 和式 () 计算信道 H ( n ) 的边际分布 = q( X ( n)) ln q( H ( n)) E [ln p( X ( n), H ( n) Y (: n))] = ln p( H( n) Y(: n )) + E [ln p( ( n) ( n), ( n))] ( c) q( X ( n)) Y X H (3) 370

299 式中 : ln p( Y( n) X( n), H( n)) (4) ( ( ) ( ) ( )) H n n n ( ( n ) ( n ) = Y X H Y X H ( n )) σ 直接计算 p( H ( n) Y (: n )) 是非常困难的, 这里将其近似为高斯分布, 该分布的均值为预测值 ˆ H ( n n ), 方差为预测误差方差 R ( n n ) 从而式 (3) 可写为 H n ˆ H ˆ H H R H H ln q( ( )) = ( ( n) ( n n )) ( n n ) ( ( n) ( n n )) C () c H () c ( Y( n) X ( n) H( n)) ( Y( n) X ( n) H( n)) Pc σ c= (5) 将式 (5) 对 H ( n ) 求导令导数为 0 可得信道频率响应的估计 式中 : μ( X ( n)) 和 ω( X ( n)) 分别为 ˆ ( ) ( )[ ( ) ˆ H n = Ω n R n n H( n n ) (6) H + μ( X ( n)) Y ( n)] ( n) [ ( n n ) Ω = R + ω( X ( n))] (7) μ( X ( n)) = E [ X ( n)] = Xˆ ( n) I q( X ( n)) Nr ω( X ( )) [ X ( ) X ( )] Ξ I H n = Eq( X ( n)) n n = x Nr (8) (9) 当将 p( H ( n) Y (: n )) 近似为高斯函数后, q( H ( n)) 服从均值为 ˆ H ( n ) 和方差为 Ω ( n ) 的高斯分布 得 到 ˆ ( n H ) 和 q( H ( n)) 就等价于得到了 H ( n ) 和 q( H ( n)) 从式(6) 可知, 基于变分贝叶斯的信道估计算法利 用发送信号的软信息外, 还利用了信道的预测值 3.3 信道滤波和预测以信道估计值作为观测值, 根据式 (5) 可建立信道的观测方程 ˆ H ( n) = ( I F ( )) h ( n) + ξ ( n) (30) NrNt L 这里 ξ ( n ) 表示信道估计误差, 其方差阵为 Ω ( n ) 结合式 () 所示的状态方程, 则可以方便地引入 alman 预测算法 由 alman 滤波理论可知 [3],alman 预测算法可以分为滤波和预测两大步 令 F = I F ( ), 则对信道估计值的滤波为 NrNt L H H G( n) = Γ( n n ) F ( FΓ ( n n ) F + Ω ( n)) (3) hˆ ( n n) = hˆ ( n n ) + G ( n)( Hˆ ( n) F h ˆ ( n n )) (3) 37

300 Γ ( n n) = ( I G F ) Γ ( n n ) (33) ˆ ( ) ˆ H n n = F h ( n n) (34) H R ( n n) = F Γ ( n n) F (35) 式中 : Γ () i 表示时域信道滤波或预测误差的方差 而对下一个 OFDM 符号时的信道预测为 结合式 (3) 和式 (34) 易得 ˆ ( ) ˆ h n+ n = Φh ( n n) (36) H Γ ( n+ n) = ΦΓ ( n n) Φ + Q (37) v ˆ ( ) ˆ H n+ n = F h ( n+ n) (38) H R ( n+ n) = F Γ ( n+ n) F (39) ˆ ' ˆ ' ˆ H ( n n) = GH ( n) + ( I G ) H ( n n ) (40) 式中 : G ' = F G ( ), 因此对信道估计和预测的滤波其实就是估计值和预测值的加权平均 n 3.4 变分贝叶斯迭代接收机上面通过推导分别得到了迭代接收机的频域 SISO 均衡 信道估计 滤波和预测 在所提接收机中, 信道估计 频域 SISO 均衡和译码在每个子信道上迭代进行, 而且将 alman 预测拆分为滤波部分和预测部分, 其中滤波部分嵌入到迭代过程中, 而预测部分则在迭代完成后对下一个时刻信道进行预测 需要说明的是, 尽管在 SISO 均衡推导中利用的是信道估计值和相应方差, 实际中利用的是信道滤波值和相应方差 此外, 由上述推导可知, 该接收机在进行信道跟踪时完全不需要内插导频, 对信道的初始估计由发送帧的一个前导 OFDM 符号完成, 因此大大节省了导频的开销, 提高了系统的频谱利用率 所提迭代接收机在每个子信道上的处理流程总结如下 : 初始化 : Hˆ ( n n ) = Hˆ ( n n ), R ( n n ) = R ( n n ) 0 0 L ( B ( n ) Y ( n )) = 0 0 a 迭代 : i 从 到 M ( M 为迭代次数 ) 迭代. SISO 均衡和译码 : 根据译码器提供的先验信息利用式 (8) 和式 (9) 得到 i i X ˆ ( n ) 和 Ξ x, 并利用式 () (8) 和 (9) 计算比特外信息 μ ( X ( n )) 和 ω ( X ( n )), 然后对获得的外信息解交织后送到 BCJR 译码器译码 i i. 信道估计 : 根据 μ ( X ( n )), ω ( X ( n )) 和 Hˆ ( n n ), R ( n n ) 等利用 (6) 和 (7) 等得到频域信道估计 ˆ i i H ( n ) 和方差阵 Ω ( n ) 3. 信道滤波 : 根据 ˆ i i H ( n ), Ω ( n ) 和 hˆ ( n n ), Γ ( n n ) 等利用 (3)~(35) 对频域信道估计进行滤波, 得到 ˆ i i H ( n n ), R ( n n ) ( 每次迭代在这里结束 ) 信道预测 : 根据 ˆ M M h ( n n ), Γ ( n n ) 利用 (36)~(39) 得到 Hˆ ( n + n ), R ( n + n ) 37

301 4. 仿真结果 系统仿真参数为 : MIMO-OFDM 系统, 子载波数 K = 64,CP 长为 6, 调制方式为 QPSK 信道编 码为码率生成多项式为 (7,5) 8 的卷积码 信道为服从指数延迟功率分布的 3 径信道 [0] 归一化多普勒分 别为 f d = 0.0 和 f d = 0.00, 分别对应较快和较慢时变信道 每个发送帧由 个 OFDM 符号组成, 其中第 个符号为移相正交的导频符号用于完成信道的初始估计 [4] ; 后 0 个符号所有子载波传输数据 f = 0.0 和 f = 0.00 时, 所提接收机和 MAP 迭代接收机误比特率 (BER) 性能对比曲线分别如图 d 图 3 所示 d BER VB, Iter= VB, Iter= VB, Iter=3 VB, Iter= VB, Iter= VB, Iter=3 optimal, Iter= optimal, Iter= optimal, Iter= SNR(dB) f d =0.0 图 基于 SISO 均衡的迭代接收机 BER 性能 (f d =0.0) Fig the BER performance of iterative receiver based on SISO equilibrium (f d =0.0) BER VB, Iter= VB, Iter= VB, Iter=3 VB, Iter= VB, Iter= VB, Iter=3 optimal, Iter= optimal, Iter= optimal, Iter= SNR(dB) f d =0.00 图 3 基于 SISO 均衡的迭代接收机 BER 性能 (f d =0.00) Fig 3 the BER performance of iterativer receiver based on SISO equilibrium (f d =0.00) 373

302 其中 VB 表示由本文信道跟踪算法提供信道信息的 MAP 迭代接收机, 该接收机执行迭代 MAP 检测 和译码,optimal 表示完全已知信道信息的 MAP 迭代接收机,VB 表示本文所提接收机 从图 和图 3 可 以看出, 所提接收机 (VB) 从迭代中获得了非常可观的增益 图 显示, 在快时变环境下, 迭代次数相 3 同时, 与 VB 接收机性能相比, 所提接收机性能有所损失, 如在 BER=0 时, 性能损失约为 db 而在较 慢时变环境下, 迭代次数相同时, 所提接收机的性能损失明显减小 ( 见图 3), 如在 BER=0 3 时, 性能损 失减小为约 db 这种性能损失是因为 SISO 均衡器对外信息的计算不精确造成的, 具体来说,MAP 检测 利用所有 Nt 个可能的发送矢量计算外信息, 其外信息非常精确但计算量是指数级的, 而 SISO 均衡器分 开计算各天线发送符号的外信息, 其利用的发送矢量数为 ( 等效值 ), 从而计算复杂度大大降低 此 外, 迭代次数相同时, 与 optimal 所示接收机相比,VB 所示接收机性能也有损失 ( 见图 和图 3), 这是 由信道跟踪误差造成的 尽管外信息的不精确和信道信息不完全共同造成了所提接收机的性能损失, 但是 一方面实际的接收机都无法获得精确的外信息和信道信息, 另一方面这种性能损失是可接受的, 而且在相 对较慢时变信道下, 性能损失比较小 5. 结论基于变分贝叶斯原理, 本文针对 MIMO-OFDM 系统提出一种基于频域 SISO 均衡的迭代接收机架构 仿真表明, 在时变多径信道下, 所提接收机能较好跟踪信道的变化, 且与最优的 MAP 接收机相比, 该接收机以稍许性能损失为代价换取复杂度的大大降低 参考文献 :. Hongwei Yang. A Road to Future Broadband Wireless Acess: MIMO-OFDM Based Air Inrerface. IEEE Communication Magazine, 005, 43(): S.L. Ariyavisitaul, Turbo Space-Time Processing to Improve Wireless Channel Capacity. IEEE Transactions on Communications, 000, 48(8): B. Hu, I. Land, R. Piton, and B.H. Fleury. A Bayesian Framewor for Iterative Channel Estimation and Multiuser Decoding in Coded DS-CDMA. IEEE Global Telecommunications Conference, 007, (3): L.P.B. Christensen, J. Larsen. On Data and Parameter Estimation Using the Variational Bayesian EM-Algorithm for Bloc-Fading Frequency-Selective MIMO Channels. IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), 006, (4): D.D. Lin and T.J. Lim. The Variational Inference Approach to Joint Data Detection and Phase Noise Estimation in OFDM. IEEE Transactions on Signal Processing, 007, 55(): Stefanatos, K. Stelios, and K. Aggelos. Joint Data Detection and Channel Tracing for OFDM Systems Using the Variational Bayes Method. IEEE Worshop on Signal Processing Advances in Wireless Communications (SPAWC), 007, (): M. Jordan, Z. Ghahramani, T. Jaaola, and L. Saul. Introduction to Variational Methods for Graphical Models. Machine Learning, 999, (37):

303 8. David J.C. Macay. Information Theory, Inference, and Learning Algorithms, Cambridge University Press, M. Beal. Variational Algorithms For Approximate Bayesian Inference. Ph.D. thesis, Gatsby Computational Neuroscience Unit, London s Global University, UK, T.Y. Al-Naffouri. An EM Based Forward-Bacward Kalman Filter for the Estimation of Time Variant Channels in OFDM. IEEE Transactions on Signal Processing, 007, 55(7): M. Tuchler, A. Singer and R. Koetter. Minimum Mean Squared Error Equalization Using A-priori Information. IEEE Transaction Signal Processing, 00, 50(3): M. Nissila and S. Pasupathy. Soft-Input Soft-Output Equalizers for Turbo Receivers: A Statistical Physics Perspective. IEEE Transactions on Communications, 007, 55(7): V.K. Madisetti and D.B. Williams. Digital Signal Processing Handboo, CRC Press, H. Minn and N. Al-Dhahir. Optimal Training Signals for MIMO OFDM Channel Estimation. IEEE Transactions on Wireless Communicaitons, 006, 5(5):

304 BASED ON NIOS II TO THE FINGERPRINTING SYSTEM STUDY AND DESIGN WANG CHUAN Wuhan polytechnic, Wuhan, , china Abstract:For its uniqueness of fingerprints, and lifelong invariance become the most dependable creatures recognition technology subjects. Fingerprint identification system, in many applications have been widely used in the field. Nios II processors based on the embedded system of identifying implementation,the concrete expression of fingerprint identification system of the basic principle,the overall system structure and hardware design, and studied the fingerprints in the system recognizes the image preprocessing algorithm processes and implementation. In some basis for designing an embedded microprocessor Nios II to the fingerprinting hardware platforms. Keyword:Nios II processors; Fingerprint indentification Image processing; Embedded chips 基于 Nios II 的指纹识别系统研究与设计 王川 武汉职业技术学院电信工程学院, 湖北武汉中国 摘要 : 指纹因其唯一性和终生不变性成为目前最可靠的生物识别技术的研究对象 指纹识别系统, 在很多应用领域得到广泛应用 介绍了基于 Nios II 处理器的嵌入式纹识别系统的实现方法, 具体说明指纹识别系统的基本原理 系统总体结构 硬件结构设计, 以及深入的研究了指纹识别系统中的图像预处理算法流程和实现方法 在些基础上设计了一套基于 Nios II 微处理器的嵌入式指纹识别硬件和软件平台 关键词 :Nios II 处理器 ; 指纹识别 ; 图像处理 ; 嵌入式. 引言生物特征识别技术根据生理特征或行为特征对个人身份进行鉴别, 因此, 它具有更高的安全性和可靠性, 同时使用方式也更富于人性化 常见的生物特征包括指纹 掌纹 虹膜 脸像 声音 笔迹 DNA 等 综合考虑准确性 永久性 易用性和成本代价, 指纹识别技术是一种费效比和安全性都很高的方案, 因而在社会上有很广泛的应用 据统计, 国内市场上基于生物特征的身份认证系统中, 指纹识别产品占到 90% 以上. 指纹影像提取技术指纹其实是比较复杂的 多年来在各个研究机构产生了许多数字化的算法 但指纹识别算法最终都归结为在指纹图像上找到并比对指纹的特征 指纹的特征, 我们定义了指纹的两类特征来进行指纹的验证 : 总体特征和局部特征 总体特征是指那些用人眼直接就可以观察到的特征, 包括 : 基本纹路图案, 环型 (loop) 弓型(arch) 螺旋型(whorl) [], 其他的指纹图案都基于这三种基本图案 仅仅依靠图案类 376

305 型来分辨指纹是远远不够的, 这只是一个粗略的分类, 但通过分类使得在大数据库中搜寻指纹更为方便 其持续持续如图 所示 : 弓形指纹环形指纹螺旋形指纹 图 指纹形状 Fig Fingerprint shape ) 模式区 (Pattern Area): 模式区是指指纹上包括了总体特征的区域, 即从模式区就能够分辨出指纹是属于那一种类型的 有的指纹识别算法只使用模式区的数据 Aetex 的指纹识别算法使用了所取得的完整指纹而不仅仅是模式区进行分析和识别 ) 核心点 (Core Point): 核心点位于指纹纹路的渐进中心, 它用于读取指纹和比对指纹时的参考点 3) 三角点 (Delta): 三角点位于从核心点开始的第一个分叉点或者断点 或者两条纹路会聚处 孤立点 折转处, 或者指向这些奇异点 三角点提供了指纹纹路的计数和跟踪的开始之处 4) 式样线 (Type Lines): 式样线是在指包围模式区的纹路线开始平行的地方所出现的交叉纹路, 式样线通常很短就中断了, 但它的外侧线开始连续延伸 5) 纹数 (Ridge Count): 指模式区内指纹纹路的数量 在计算指纹的纹数时, 一般先在连接核心点和三角点, 这条连线与指纹纹路相交的数量即可认为是指纹的纹数 6) 节点 (Minutia Points): 指纹纹路并不是连续的, 平滑笔直的, 而是经常出现中断 分叉或打折 这些断点 分叉点和转折点就称为 节点 就是这些节点提供了指纹唯一性的确认信息 指纹上的节点有四种不同特性 : ) 类型 : 终结点 (Ending): 一条纹路在此终结 分叉点 (Bifurcation): 一条纹路在此分开成为两条或更多的纹路 3 分歧点 (Ridge Divergence): 两条平行的纹路在此分开 4 孤立点 (Dot or Island): 一条特别短的纹路, 以至于成为一点 5 环点 (Enclosure): 一条纹路分开成为两条之后, 立即有合并成为一条, 这样形成的一个小环称为环点 6 短纹 (Short Ridge): 一端较短但不至于成为一点的纹路 ) 方向 (Orientation): 节点可以朝着一定的方向 3) 曲率 (Curvature): 描述纹路方向改变的速度 4) 位置 (Position): 节点的位置通过 (x,y) 坐标来描述, 可以是绝对的, 也可以是相对于三角点或特征点的 一般认为, 指纹节点朝向确定, 用曲率描述纹路方向改变的速度, 节点位置通过直角坐标 ( 或绝对的或相对于三角点的坐标 ) 来描述 [] 对于指纹识别, 特别是对现场的模糊指纹进行认定的时候所使用的信息是细节特征点, 小桥 三角点 分叉点 端点和环如图 所示 根据纹路局部结构特征共定义了 50 多种细节特征 [3], 如果同时使用所有的这些特征, 将很难迅速自动地从指纹图像中提取并区分它们 377

306 图 指纹结构 Fig Fingerprints structure 指纹鉴定系统只使用其中 种主要的特征, 即分叉点和端点 其他细节特征都可以用它们的组合来表示 例如, 小桥是由 个端点组成, 而是由 个分叉点组成的 3. 指纹识别算法 指纹识别算法包括指纹图像预处理 指纹特征提取和指纹匹配 3 部分组成, 主要算法流程如图 3 所示 指纹图像预处理 指纹图像采集 归一化 Sobel 滤波 图像增强 图像二值化 图像细化 指纹特征提取 指纹匹配 图 3 指纹识别算法流程图 Fig3 Fingerprinting algorithm flowcharts 3. 归一化将指纹图像分成许多小块, 根据 Ratha 等提出的 沿着和横穿过指纹脊线流的灰度级方差大小有明显的不同 这一原理进行背景分离, 目的是避免在没有有效信息区域进行特征提取 加快 Nios II 处理速度 提高指纹特征提取和匹配精度等操作 指纹图像中脊线的变化较慢. 采用低通滤波器滤除方向中的噪声和错误 : 由式 () 归一化成 G(i,j); 把 G(i,j) 分成 (w w) 块, 根据 Sobel 算子对每块按式 () 分别计算每个像素点 (i,j) 的梯度 dx(i,j) 和 dy(i,j) 根据梯度值按式 (3) 计算每块的主方向, 再由式 (4) 得到像素 (i,j) 处的主方向 θ(i,j) G j) = Varo [ C ( i, j ) M ] Var Varo [ C ( i, j ) M ] Var M o +, C ( i, j) >M ( i, () M, C ( i, j) <M o 如果 M 0 V aro [ C( i, j) M ] <M, 则把灰度值为 M V ar 0 V aro [ C( i, j) M ] V ar 全部归为 0, 作为背景处理, 这 样可以有效地去除传感器表面残留纹印引入的噪声, 由于归一化中引入了门限值 M, 因此称为改进的归一化算法 式中 :M o V aro 是预先设定的指纹图像平均灰度和均方差 ;V ar 是指纹图像的平均灰度值 ; 是指纹图像的灰度矩阵 ;G(i,j) 是归一化图像, 目的是把不同源指纹图像的对比度和灰度调整一个固定的级别, 为后 378

307 379 续处理提供一个统一的图像规格 C(i,j)-M 为像素点的灰度幅值, 经比率调整后, 加到期望的均值上, 使得原来方差的点归一化后幅度更大, 方差小的更小 ; 灰度值大于或者小于均值的点, 归一化后继续大于或小于期望均值, 而且归一化为点操作, 不会改变指纹的纹理结构 3. Sobel 滤波算子索贝尔算子 [4] (Sobel operator) 是图像处理中的算子之一, 在众多的图像边缘检测算法中,Soble 算法具有计算简便 检测效果好等优点, 是一种被广泛应用的算法 Sobel 算法依据图像边缘的灰度值会产生突变的原理, 来对像素的灰度值进行处理 Sobel 算法具有方向选择性和频率选择性的带通滤波器, 通过滤波可以去除去噪音, 并不失真地保留指纹脊和谷的结构信息 利用 Sobel 算子计算出指纹的脊线方向并用低通滤波器平滑其方向图, 为图像滤波和匹配提供了良好的条件 其公式如下 : = = = ), ( ), ( ), ( u u x x v j u i G v u S j i d ; = = = ), ( ), ( ), ( u u y y v j u i G v u S j i d () 式中 :S x,s y 为 Sobel 算子,dx(i,j) 和 dy(i,j) 是像素点 (i,j) 的梯度 + = + = = ), ( ), ( ), ( w w w w i i u j j u y x x v u d v u d j i V + = + = = ), ( ), ( ), ( w w w w i i u j j u y x y v u d v u d j i V (3) = = = 0 ), ( ), ( ), ( arctan 0 ), ( ), ( j i V j i V j i V j i V x x y x j i,, π θ (4) 这样可计算出每块的主方向 (V x,v y ) 的值,θ(i,j) 代表是以像素点 (i,j) 为中心的方块的局部方向, 此方向将用于计算纹线的频率, 并且作为特征点的信息, 记为 θ 3.3 图像增强图像增强采用归一化 计算方向图 计算频率 计算区域掩码 滤波等改善图像的质量 恢复脊线原来的结构 计算频率的目的是在不含特征值的小区域中 ( 特别是中心点和三角点 ), 把这一小块指纹图像在垂直于脊线方向的灰度值看成一个正弦状波形图, 根据式 (5) 计算出波形的正弦函数的频率来表示脊线分布 ), ( )sin ( ), ( )cos ( j i j i d i u l w θ θ + + = ), ( )cos ( ), ( )sin ( j i j i d j u l w θ θ + = (5)

308 将 (5) 式代入 X[ ] = w w d = 0 g( u, v) 中计算特征值, 其中,=0,,,l-,l,w X[] 中所有极大值的平均 距离 T(i,j) 称为原图像的频率图, 则波形频率为 F(i,j)=/T(i,j) 计算区域掩码的目的是为了防止在指纹灰度图中部分质量较差的区域出现大量的伪特征 对前面得到的 (w w) 块按 (6) 式计算脊线方向灰度方差来进行分割 V ( i, j) = ar 7 = [ C( i, j) C( i m, j m )] w w var = V ( 0 +, 0 + ) ar i i j j w i = 0 j = 0 K (6) 式中 :m 表示已得到的该块的方向数,c(i m,j m ) 表示像素 (i,j) 沿 m 方向上的第 点灰度 R( i, j) =, if [ K var ( i, j) >Th] { 0, else 得出块方向灰度方差掩码,Th 是预先设定的分割阈值, 大于然后再进行 Gobel 滤波,G(i,j) 与滤波函 数卷积得到增强图像 E(i,j) 如公式 (7) 输出 E i, j) = 55 ( wg / u= wg / v= wg / wg / h[ u, v, θ ( i, j), F ( i, j) G( i u, j v) (7) 滤波针对 R(i,j)= 区域,wg 为高斯滤波器窗口的大小 3.4 图像的二值化找出像素点极大点和极小点位置及时对应的值, 对极大值和极小值求平均, 将些平均值作为该像素点二值化的门限, 称其为动态阀值 X th ; 将当前像素点对应的平均灰度值 ( 即 X[(w-)/] 与 X th 比较, 若小于 X th, 同时, 当前像素点在波形图极小点一个有限的邻域内, 则当前像素点为脊线点, 否则为谷线点, 即 0,( X [( w ] ) (, ) { ) / X th f x y = 55, otherwise (8) 式中 : f ( x, y) 表示二值化影像中该像素处的值,55 为二值化影像中背景影像和纹线的灰阶值,0 为二值影像中脊线的灰阶值 380

309 3.5 图像细化对指纹传感器采集图像的特性, 采用 3x3 的模板从得到可靠的细化二值图像中根据公式 8 C = R( + ) R( ) (9) N = 式中 :R(i) 分别对应模板 M 检测点的相邻 8 个点 C N = 时 M 为末梢点,C N =6 时 M 为分支点 ) 将末梢点和分支点提取出来 4. Nios 指纹识别系统设计 4. 系统架构指纹登记包括指纹采集 指纹图像预处理 特征点提取 特征模板存储和输出显示 ; 指纹比对在特征点提取后, 是将生成的特征模板与存储在指纹特征模板库中的特征模板进行特征匹配, 最后输出显示匹配结果 指纹识别系统框图如图 4 所示 存入指纹库 指纹采集 指纹图像预处理 特征点提取 特征点匹配 输出显示 图 4 指纹识别系统框图 Fig 4 Fingerprint identification system bloc diagram 系统在结构上分为三层 : 系统硬件平台 操作系统和指纹识别算法 4. 硬件系统设计 Nios II 软核处理器是 ALTERA 公司于 004 年推出的通用 3 位 RISC CPU, 它能满足任何应用 3 位嵌入式微处理器的需要 [5]. 用户可以获得超过 00 DMIPS 的性能 Nios II 软核处理器具有 3 位处理器的基本结构单元 (3 位指令大小,3 位数据和地址路径,3 位通用寄存器和 3 个外部中断源 ), 设计者可以根据系统需求的变化来调整嵌入式系统的特性, 以选择满足性能和成本的最佳方案 Nios II 系列可支持用户自定义指令, 而 Nios II ALU 则直接与用户自定义的指令逻辑相连 由于设计者能为系统中使用的每个 Nios II 处理器创建多达 56 个专用指令 [6], 因此, 设计者能够调整系统硬件以增强对实时软件算法的处理能力 ALTERA 公司同时还推出了 Nios II 集成开发环境 (IDE) 和一些常用的免费 IP 核, 以方便设计者的软件开发 另外, 设计者使用 Altera 公司 Quartus II 开发软件中的 SOPC Builder 系统开发工具还能够很容易地创建专用的处理器系统, 并能够根据系统的需求添加 Nios II 处理器核的数量 38

310 指纹识别系统主要由指纹采集模块 系统核心模块 数据存储模块和输出显示模块等几部分组成 本系统硬件结构框图如图 5 所示 图 5 系统硬件结构框图 Fig 5 System hardware structure chart 本系统的核心模块是在 ALTERA 公司的 Cy-clone II C35 上实现的, 相应的软件开发套件包括 Quartus II 5.0 和 Nios II 5.0 集成开发环境 (IDE) Cyclone II 系列 FPGA 是 ALTERA 公司最新推出的低成本 高性价比的通刚 FPGA [7],CycloneII C35 具有 3,6 个 LE 单元 05 个 M4K RAM 块 35 个嵌入式乘法器, 完全可以满足系统的性能要求 通过 QuartusII 中的软件工具 SOPC Builder 可实现 Nios II 处理器的创建和各种 IP 模块的管理和配置, 以构建系统的核心模块 图 5 中, 根据系统的实际要求由 SOPC Builder 配置的处理器核心包括 Nios II 处理器 指纹卡 PIO 协处理器 PIO Avalon Tri-Atate Bridge UART 模块和 LCD PIO 等模块 配置好这些模块后, 便可进行系统生成 SOPC Builder 在系统生成过程中可生成 HDL 源文件和 BDF 文件 SOPC Builder 为定制的 Nios II 核心模块创建的一个符号 (Symbol) 就存放在 BDF 文件中, 用户可以在 Quartus 软件中使用该符号 本系统核心模块是使用 Quartus 的符号表文件编译生成的 4.3 软件系统设计系统软件可利用 C 语言在 Nios II 集成开发境下开发 Nios II 集成开发环境 (IDE) 是 Nios II 软核处理器的主要开发工具, 包括编辑 编译和程序调试 Nios II IDE 为软件开发提供了一个集成的设计开发环境 它有一个包括工程管理 源代码开发和基于 JTAG 调试功能的图形界面 (GUI), 故可大大简化复杂的 Nios II 处理器设计 系统软件设计流程图如图 6 所示 5. 结论设计的基于 Nios II 的嵌入式指纹识别系统, 使用 Nios 的定制指令, 采用硬件替代软件实现部分指纹图像的处理 大大缩短了指纹图像的处理时间和匹配时间 使以 Nios II 处理器为核心的系统能够快速地完成大量数据处理 极大地提高了系统的运行速度 38

311 使用 Altera 的 Cyclone FPGA 实现, 具有开发周期短 设计灵活 可把若干外部模块综合设计到一片高密度 FPGA 中等优点, 同时设计更小巧 成本更低 更便于系统升级 开始 Nios II 初始化 采集指纹 指纹图像预处理 特征提取 特征匹配 特征存储 显示 Fig 6 System software design flow chart 图 6 系统软件设计流程图 References ( 参考文献 ). Vizcaya P,Gerhardt L. A nonlinear orientation model for global description of fingerprints. Pattern Recognition, v. 009, (7): 3-7. Niepeng Gen wenbo.fingerprinting techniques shallow about [j]; computer nowledge and technical (academic exchange 007, (7): 聂鹏, 耿文波. 指纹识别技术浅谈 [J]; 电脑知识与技术 ( 学术交流 ), 007, (7): Altera.Triple Speed Ethernet User Guide.Version, 009,(9): Niao aiyang, Zhang xuedong, Zhang mingzhu. A new algorithm delineate those images, computer engineering and application, 008, 44 (5): 廖开阳, 张学东, 章明珠. 一种新的指纹图像快速细化算法 [J]. 计算机工程与应用, 008, 44(5): Peng shenlian zhoubo Qiou weidong chen yan Zhou xuegong. soc challenge based on design and the practice of nios sopc. beijing : tsinghua university press, 004 彭澄廉周博邱卫东陈燕周学功. 挑战 SOC 基于 NIOS 的 SOPC 设计与实践. 北京 : 清华大学出版社, Fran vahid, etc. embedded system design and interpretation. Luoli. beijing::beijing aerospace university press, Fran Vahid 等. 嵌入式系统设计. 骆丽等译. 北京 : 北京航空航天大学出版社, Nios II Custom Instruction User Guide

312 DESIGN OF PHASE-LOCKING HIGH-RESOLUTION FREQUENCY SYNTHESIZER GAN GUANG-MING Deparment of physics,xiaogan University, Xiaogan Hubei, 4300, China Abstract: Frequency synthesizer is designed by trinuclear mathod in the article, it can send out the frequency of MHz with 0 Hz resolution.the main configuration of which is the chip MC4555 that adopted by delivering number of serial.in this way,the whole frequency synthesizer which is simple structure,little lining of microcomputer small capacity easy debugging and stabilize and reliability of performance. Key words:discriminator; frequency synthesizer; phase-loc ring 高分辨率锁相频率合成器的设计 甘光明 孝感学院物理与电子工程学院, 湖北孝感中国 4300 摘要 : 本文采用了三环的方法来设计的频率合成器, 其输出频率为 76.08~ MHz, 频率间隔为 0Hz 该频率合成器采用了串行送数式的 MC4555 芯片构成环路, 使整个合成器结构简单, 微机连线少, 体积小, 调试方便, 而且性能稳定可靠 关键字 : 鉴相器 ; 频率合成器 ; 锁相环. 引言频率合成器的应用日益广泛 其应用于军 民用电台 高保真接收机及其他通信 测试设备中, 使得从许多频率中选择某一工作频率变得极为简单而又精确, 其应用相当广泛 但由于通信频谱日益拥挤, 以及计算机和微处理机的应用与日俱增 使得频率拥挤要求有高精度的发射频率, 从而便于波道的密集分布 ; 同时又要求选择十分容易, 只有这样, 才能有效地使用现有地波道 ; 当计算机或微处理器进行控制地时候, 还要求能根据数字指令来选择频率 频率合成器正好能满足这些要求 [] 但随着现代通信和仪器地发展, 对频率源提出了越来越高地要求 即要求合成器的输出频段不断扩展, 频率间隔越来越小, 而对相位抖动和频谱纯度的要求越来越高, 这样就使鉴相频谱比较低的单环频率合成器无法满足要求, 从而相继地出现了双环, 多环频率合成器 双环 多环频率合成器的出现解决了单环频率合成器无法解决的问题, 即频率间隔与鉴相频率之间的矛盾 高分辨高频环的相位稳定性问题等 []. 频率合成器方案设计频率合成器原理框图如图 所示 : 384

313 图 频率合成器原理图 Fig The schematic of Frequency synthesizer 它是一种典型的三环方案 图中环 I, 环 II 为数字锁相环, 环 III 为频率相加环 从图中可见 : 各环输 出频率 f 03 f 0 f 0 有如下关系 : f M 03 3 M f 0 = f r 3 = f M 0 () M M f = + () 3 03 M 3 f 0 f 0 M f = N f (3) 0 r f r f = N (4) 将 (3) (4) 式代入 () 式可得 f M M 3 6 = M 3N f r + ( 75 0 N f ) (5) M 03 r 图中, 要求环 I 和环 II 对输出频率 f 03 的频率步进分别为 0Hz 和 00Hz, 则由 () 式有 : 00Hz M = (6) 3 M M M f r Hz = (7) 3 0 f r 385

314 取环路的比相频率分别为 f = r 500Hz, f = Hz r 0, 则得 M 5 3 = M M M 3 = 50 并将其分 别代入 (5) 式可得 : f 5 N = 0 0 N + ( N)=( 5+N ) 0 0 (8) 而 f = ~ (8) 式的 5 + N 应取 76~06 则 N =747~046 并将其代入 (8) 式中 : 将 N,N 分别代入 (3) (4) 得 : f 03 = ~ N 0N = ( ~ ) ( ~ ), N = 000~00 频率相加环 III 鉴相器频率 f r 可由如下关系求得 : f 0 = 69 ~ MHz f 0 = 4.94 ~ 0. 9MHz f r f 03 3 = ( f M M 3 0 ) 可得 : f 又由于环 III 为输出环, 为了提高环路锁定速度和输出频谱质量, 应尽可能提高 r 3, 并令 M=0, 则 f 03 f r 3 = ( f 0 ) = 7.6 ~ Hz 0 5 M = 50M M 3 = 500 由此可见 : 采用三环频率合成器, 三个环的鉴相频率 f r f r f r3 都可取得比较高, 环路分频比 N N N 3 = M M 3 = 50 也都不是很大, 而合成器输出频率 f 03 的分辨率可以达到 0Hz 频率间隔 386

315 然而, 由于三环频率合成器由于环路多, 因此带来了电路结构复杂, 体积大, 可靠性差, 成本高等缺点 近年来由于锁相环路大规模集成电路, 单片锁相环频率合成器电路和集成压控振荡器的出现, 使单个锁相环路成为一 二片集成电路器件而已, 从而完美地解决了多环频率合成器电路结构复杂 可靠性差, 成本高等缺点 在本文的三环频率合成器中, 我们采用 MC4555 组成数字环 I [3] 3. 三环频率合成器的电路 (I 环 ) MC4555- 是 0 脚陶瓷或塑料封装型, 可进行 4 位串行输入数据编程, 含有参考振荡器, 可选择 8 种分频比的参考分频器, 数字鉴相器, 程序分频器 ( 分频比为 3~6383), 以及接收串行输入数据的移位寄存器和锁存器 它适合配用单模前置分频组成环路 是引脚和方框图 [4], 分别如图 和图 3 所示 图 MC4555- 引脚图 Fig the Pin of MC4555- osc o osc in REFout RA0 RA RA VDD 8 5 8ROM 参考译码器 位 R 计数器 8 6 LD PDout F IN ENABLE 9 V SS 7 4位 N 计数器 锁存器 OR OV SW SW DATA 4 位移位寄存器 CLOCK 0 图 3 MC4555- 内部电路图 Fig 3 Internal circuit diagram of MC

316 为了改善振荡器频率和偏置电压之间的非线性关系, 采用两只变容二极管串接 ) 单管连接法如图 4 所示 V K 5μ 0.μ L C μ 3 f V (MHz) f V V ( V ) 图 4 单管连接电路图 Fig 4 Single tube connection circuit ) 双管连接法如图.5 所示 5μ 5K 0.μ L μ fv (MHz) f V V ( V ) 图 5 双管连接电路图 Fig 5 Double tube connection circuit 混频电路采用 74s74 集成 D 触发器组成 S 型芯片具有比 LS 更高的转换速度,74S74 的最小转换速度 为 75Hz 能满足本文要求的混频输入和输出 [5] 74S74 的引出脚及内部电路原理图如图 6 所示 V CC 4 CLR 3 D CK PR 0 Q Q 9 8 PRENT CLEAR Q CLK CLOCK Q CLR D CK PR Q Q GND D 图 6 74S74 的引出脚及内部电路原理图 Fig 6 The diagram of pin and internal circuit of 74S74 388

317 由其逻辑原理图可知,prent 为低电平时,Q 保持 clear 为低电平时,Q 保持 0, 所以要使 74S74 正 常工作, 则 PRENT,CLEAR 都保持高电平 [6] 74S74 的混频电路如图 7 所示 : VCO 输入 OSC 输入 + 5V 混频输出 图 7 74S74 的混频电路图 Fig 7 the Frequency mixing circuit diagram of 74S74 VCO 从 D 触发器 D 端输入,OSC 从 CLOCK 端输入, 两者在 74S74 内部混频, 最后 Q 端输出 其输出波形图如图 8 所示 : f = f VCO f, OSC D CL Q 图 8 74S74 的混频电路图输出波形图 Fig 8 the output waveform of the Frequency mixing circuit of 74S74 但是, 在 VCO 输出的压控振荡频率通常只有十几 ~ 几十毫伏, 不能触发 74S74 的 D 触发器进行混频, 所以在 VCO 输出级之后必须加入一级放大电路, 使 VCO 输出的微弱信号放大到能触发 74S74 的振幅 放大器电路, 由于本文 VCO 为高达 00MHz 的输出信号, 所以放大电路采用 VHF 的宽带高频前置放大晶体管 SC3358 为使 VCO 输出与 SC3358 阻抗匹配, 在信号输入 SC3358 之前先加一级缓冲级 射极跟随器 [7] 4. 结论多环频率合成器是当今频率合成技术的标志, 在多波段接收机中, 有时使用多达 4~5 个环的频率合成器, 以实现整个宽带范围内的具有最小噪声的快速频率转换 本文所介绍的频率合成器由于采用了串行送数式的 MC4555 芯片构成环路, 使整个合成器结构简单, 微机连线少, 体积小, 调试方便, 而且性能稳 389

318 定可靠, 因此, 单片大规模锁相环频率合成器电路的出现给多环频率合成器的设计带来了福音, 也给设计 高分辨率 高性能频率合成器提供了可取方案 References ( 参考文献 ) Zhang Guan-bai. Loc phase frequency synthesis technology[m].beijing, Electronic Industry Press, 995. 张冠百. 锁相与频率合成技术 [M]. 北京 : 电子工业出版社, 995. zhang jue-sheng, zheng ji-yu. Phase-loced technology[m]. xian: Xi'an University of Electronic Science and Technology press 张厥盛, 郑继禹. 锁相技术 [M]. 西安 : 西安电子科技大学出版社 Qiu wen-rong. PLL Digital Frequency Synthesizer Application[J]. Application of Electronic Technique, 996, (6): 裘文荣. 数字频率合成器锁相环的应用 [J]. 电子技术应用, 996, (6): Chen de-huang. design double PLL frequency synthesizer with LMX370[J]. Application of Electronic Technique, 00, (): 陈德煌. 应用 LMX370 设计双锁相环频率合成器 [J]. 电子技术应用, 00, (): Yu hui, et al. The design of high resolution and Broadband frequency synthesizer [J]. Journal of Chengdu University of Information Technology, 007, (4): 俞晖等宽带高分辨率频率合成器设计 [J]. 成都信息工程学院学报 007, (4): Wang shu-e. PLL frequency synthesizer [J]. Journal of Telemetry;Tracing and Command, 988, (06) 王树柯. 锁相环式频率合成器 [J]. 遥测遥控, 988, (6): Roland E.Best.the application, design and simulation of PLL[M].beijing:tsinghua University press,003. Roland E.Best. 锁相环设计 仿真与应用 [M]. 北京 : 清华大学出版社, Motorola, Inc.MC07 Datasheet[M].U.S.A:Motorola, Inc,999, (3): Si long,xiong yuan-xin. A PLL Frequency Synthesizer with High Multiple-Frequency[J]. Microelectronics, 005, (4): 司龙, 熊元新. 一种多倍频选择的高倍频锁相环频率合成器 [J]. 微电子学, 005, (4):

319 DESIGN FOR A NEW DISPLACEMENT ELECTRIC EDDY CURRENT SENSOR SONG SHU-XIANG, WAN LI, HUANG SHOU-LIN, XIE HONG-GUO College of Electronic Engineering, Guangxi Normal University, Guilin 54004, China songshuxiang@mailbox.gxnu.edu.cn Abstract: Electric eddy current sensor has the characteristic of no scent for the medium, and can test the conductor without contact and itelligent oi-drectional, so it iswidely app lied to the mental distance test. The principle,the circuit design and the experimental method is emphasized,and the preliminary test of the sensor has been done. The result of experiment shows that the diameter of the probe is 50 mm, the ranging of the eddy current sensor is in good linearity between mm and 9.5 mm, and its ranging is in nonlinear between mm and 9.5 mm and between 9.5mm and 35 mm. Keywords: electric eddy currentsensor; probe; measuring circuit 新型位移电涡流传感器设计 宋树祥万里黄守麟解鸿国广西师范大学电子工程学院, 广西桂林 摘要 : 电涡流传感器具有对介质不敏感 非接触 全方位智能测量等特点, 广泛应用于对金属的距离检测中 本文设计了一种非接触电涡流传感器, 重点阐述其测量工作原理 电路设计和实验方法, 并对传感器进行了测试, 实验结果表明在探头直径为 50mm 时, 电涡流传感器在 ~9.5 mm 之间线性度较好, 在 0~mm 和 9.5~35 mm 之间存在非线性 关键词 : 电涡流传感器 ; 探头 ; 测量电路. 电涡流传感器测距原理 根据麦克斯韦方程, 一个随时间变化的电流产生一个磁场 ; 而一个随时间变化的磁场也在它的周围产生一个封闭的 涡旋 电场 如图 所示 : [] 线圈 金属导体 图 电涡流测距原理 Fig.Principle of eddy current ranging 39

320 当接通传感器系统电源时, 在前置器内会产生一个高频电流信号, 该信号通过电缆送到探头的头部, 在头部周围产生交变磁场 H 如果在磁场 H 的范围内没有金属导体材料接近, 则发射到这一范围内的能量都会全部释放 ; 反之, 如果有金属导体材料接近探头头部, 则交变磁场 H 将在导体的表面产生电涡流场, 该电涡流场也会产生一个方向与 H 相反的交变磁场 H 由于 H 的反作用, 就会改变探头头部线圈高频电流的幅度和相位, 即改变了线圈的有效阻抗 这种变化既与电涡流效应有关, 又与静磁学效应有关, 即与金属导体的电导率 磁导率 几何形状 线圈几何参数 激励电流频率以及线圈到金属导体的距离等参数有关 假定金属导体是均质的, 其性能是线性和各向同性的, 则线圈 金属导体系统的物理性质通常可由金属导体的磁导率 μ 电导率 σ 尺寸因子 r, 线圈与金属导体距离 d, 线圈激励电流强度 I 和频率 ω 等 [~5] 参数来描述 因此线圈的阻抗可用函数 Z = F( μ, σ, r, d, I, ω) 来表示 如果控制 μ, σ, r, I, ω 恒定不变, 那么阻抗 Z 就成为距离 d 的单值函数, 由麦克斯韦尔公式, 可以求得此函数为一非线性函数, 其曲线为 S 形曲线, 在一定范围内可以近似为一线性函数 在实际应用中, 通常是将线圈密封在探头中, 线圈阻抗的变化通过封装在前置器中的电子线路的处理转换成电压或电流输出 这个电子线路并不是直接测量线圈的阻抗, 而是采用并联谐振法, 如图 所示, 图 传感器原理框图 Fig.Diagram of sensor principle 即在前置器中将一个固定电容 C C 和探头线圈 L 并联与晶体管 T 一起构成一个振荡器, 振荡器的振荡幅度 Ux 与线圈阻抗成比例, 因此振荡器的振荡幅度 Ux 会随探头与被测间距 d 改变 Ux 经检波滤波, 放大, 非线性修正后输出电压 Uo,Uo 与 d 的关系曲线如图 3 所示, 图 3 传感器输出特性曲线 Fig 3. Output characteristic curve of the sensor 39

321 可以看出该曲线呈 S 形, 即在线性区中点 δ0 处 ( 对应输出电压 U0) 线性最好, 其斜率 ( 即灵敏度 ) 较大, 在线性区两端, 斜率 ( 灵敏度 ) 逐渐下降, 线性变差. 电涡流传感器设计. 探头的设计探头垂直面对被测体表面, 它能精确地探测出被测体表面相对于探头端面间隙的变化 通常探头由线圈 头部 壳体 高频电缆 高频接头组成, 其典型结构见图 4 所示 图 4 探头结构 Fig 4 Construction of the probe 线圈是探头的核心, 它是整个传感器系统的敏感元件, 线圈的物理尺寸和电气参数决定传感器系统的线性量程以及探头的电气参数稳定性 探头头部可采用耐高低温的 PPS 工程塑料, 通过 二次注塑 工艺将线圈密封其中 这样可以增强探头头部的强度和密封性, 在恶劣环境中可以保护头部线圈能可靠工作 头部直径取决于其内部线圈直径, 由于线圈直径决定传感器系统的基本性能 线性量程, 一般情况传感器系统的线性量程大致是探头头部直径的 /~/4 探头壳体用于支撑探头头部, 并作为探头安装时的装夹结构, 壳体采用不锈钢制成 传感器的主要元件是固定于框架上的扁平线圈 线圈尺寸和形状关系到传感器的灵敏度和测量范围 传统的传感器设计需要对线圈反复绕制, 从而求得最佳的线圈尺寸参数, 现在, [6] 可借助计算机利用 Matlab 软件将探头参数输入, 对传感器的输出电压随位移变化的改变量进行仿真计算. 振荡 整流滤波 放大和电压 / 电流转换器电路设计本文所设计的电涡流传感器振荡 整流滤波和放大电路如图 5(a) 所示 晶体管 T 电容 C C3 探头线圈和运放 AA 组成正反馈振荡电路, 其谐振频率为 / πlc 本文采用调幅法, 当探头线圈远离被测导体时 LC 并联谐振回路的谐振频率为标准的 / πlc, 当测头线圈接近被测导体时, 线圈的等效电感发生变化, 致使回路失谐而偏离激励频率, 呈现的阻抗相应减小, 使输出电压也减小, 所以, 输出电压与测量距离建立起函数关系, 即 U o = f (d) 为了获得线性输出, 可对测量范围进行控制 图 5(a) 中, 二极管 D 和电容 C4 R7 C5 构成整流滤波电路 整流滤波的作用是将高频载波电压信号转换成直流电压信号 运算放大器 AB 完成对前级输出的直流电压信号的放大和调零作用, 调零电路使输出电压信号调零, 从而保证测量为零时, 输出电压为零 该电路需要 6.8V 的直流基准电源电路, 如图 5(b) 所示 393

322 (a) 振荡 整流滤波 放大电路图 (a) Oscillations, rectifying filter and amplification circuit diagram (b) 6.8V 直流基准电源产生电路 (b) 6.8 V dc benchmar power generator 图 5 电涡流传感器电路原理图 Fig 5. Circuit schematic diagram of electric eddy current sensor 由运算放大器构成的电压 / 电流转换器如图所示 : 图 6 V/I 转换器 Fig 6. V/I converter 394

323 通过简单计算可得输出电流和输入电压之间的关系 : I out = ( Vo /00) (0 / 300), 这样就实现了传感器的电流输出 3. 实验结果 在 +4Vdc 电源供电下, 负载为 0Ω, 被测试件材料为 40CrMo, 环境温度 0 的测试条件下, 对所设计探头直径为 5mm 和 50mm 的电涡流传感器进行测量, 所测结果如表 所示 4. 讨论 表 电涡流传感器的实验结果 Table. Experiment results of electric eddy current sensor 探头直径线性量程 (mm) 线性范围 (mm) 线性中点 (mm) 非线性误差最小被测面 (mm) φ ~ ±.5% φ 50 φ ~ ±.8% φ 被测体尺寸与材料的对测量的影响 在测量过程中, 被测金属导体的磁导率 μ 电导率 σ 尺寸因子 r 介对测量也有影响, 因此除了探头 延伸电缆 前置器决定传感器系统的性能外, 严格地讲被测体也是传感器系统的一部分, 即被测体的性能参数也会影响整个传感器系统的性能 被测体尺寸的影响探头线圈产生的磁场范围是一定的, 在被测体表面形成的涡流场也是一定的, 通常认为, 当被测面为平面时, 以正对探头中心线的点为中心, 被测面直径应当大于探头头部直径.5 倍以上 ; 当被测体为圆轴而且探头中心线与轴心线正交时, 一般要求被测轴直径为探头头部直径的 3 倍以上, 否则灵敏度就会下降, 一般当被测面大小与探头头部直径相同时, 灵敏度会下降至 70% 左右 被测体的厚度也会影响测量结果 因此如果被测体太薄, 将会造成电涡流作用不够, 使传感器灵敏度下降, 一般厚度大于 0.mm 以上的钢等导磁材料及厚度大于 0.6mm 以上的铜 铝等弱导磁材料, 则灵敏度不会受其厚度的影响 4. 被测体表面加工状况的影响 不规则的被测体表面, 会给实际的测量值造成附加误差, 特别是对于振动测量, 这个附加误差信号与实际的振动信号叠加一起, 在电气上很难进行分离, 因此被测表面应该光洁, 不应该存在刻痕 洞眼 凸台 凹槽等缺陷 ( 对于特意为键相器 转速测量设置的凸台或凹槽除外 ) 通常, 对于振动测量被测面表面粗糙度 Ra 要求在 0.4μm~0.8μm 之间 (API670 标准推荐值 ), 一般需要对被测面进行衍磨或抛光 ; 对于位移测量, 由于指示仪表的滤波效应或平均效应, 可稍放宽 ( 一般表面粗糙度 Ra 不超过 0.8μm~.6μm) [7~8] 5. 结论 实验结果可以看出 : 所设计的电涡流位移传感器, 测量位移线性范围宽 在探头直径为 50mm 时, 电涡流传感器在 ~9.5 mm 之间线性度较好, 在 0~mm 和 9.5~35 mm 之间存在非线性, 如果要提高传感器的线性度还需进一步在非线性段进行线性校正 References ( 参考文献 ). Wang Peng; SI Shu-jia; Ding Tian-huai; Fu Zhi-bin. Thermal Effect of the Eddy Current Sensor Probe for Measuring the Gaps Between Curved Surfaces [J]. Acta Armamentarii,009,30(8):

324 王鹏, 司书甲, 丁天怀, 傅志斌. 曲面间隙测量电涡流传感器探头的热效应研究 [J]. 兵工学报, 009, 30(8): Liu Yi-zhu; Guo Su-na. Design of coin recognition system based on electricity turbulent flow sensor [J]. Journal of Henan Polytechnic University(Natural Science),00,9():9-3. 刘艺柱 ; 郭素娜 ; 基于电涡流传感器的硬币识别系统的设计 [J]. 河南理工大学学报, 00, 9(): Sun Ying ; WANG Pingjiang; LI Jiajia; TANG Xiaoqi. A Full-closed Loop CNC System of Saw Grinding Based on Eddy Current Sensor[J]. Manufacturing Technology & Machine Tool,00,8(): 孙莹, 王平江, 李佳佳, 唐小琦. 基于电涡流传感器的全闭环锯片磨床数控系统开发 [J]. 制造技术与机床, 00, 8(): Yang Li-jian; Liu Jia-xin; Gao Song-wei; Wang Jun-feng; Xie Ling. Design for Large Range Electric Eddy Current Sensor[J]. Instrument Technique and Sensor,009,33():-5. 杨理践, 刘佳欣, 高松巍, 王峻峰, 谢玲. 大位移电涡流传感器的设计 [J]. 仪表技术与传感器, 009,33(): Tang Yi-ping; He Wu-jie; Zhu Yi-hua. Design of Intelligent Omni-Directional Vibration Sensor. Chinese Journal of Sensors and Actuators,008,0(8): 汤一平, 贺武杰, 朱艺华. 智能全方位振动传感器的设计研究 [J]. 传感技术学报,008, 0(8): Xu Jian; Localization Design of 8mm Electric Eddy Displacement / Vibration Sensing Probe[J]. Process Automation Instrumentation,006, 7(): 徐健. 8mm 电涡流位移 / 振动传感器探头的国产化设计. 自动化仪表,006, 7(): Li Zhong-xiu; Wu Jun; Li Lu; Zhou Wen-wu. Frequency Modulated Eddy Current Displacement Sensor Based on FPGA[J]. Instrument Technique and Sensor,007, (7) : 7-9. 李中秀, 吴俊, 李璐, 等. 基于 FPGA 的调频式电涡流位移传感器 [J], 仪表技术与传感器, 007, (7): Wang Jun-ping. Research on the Widerange Eddy Current Sensor : [A dissertation submitted for the master s degree ].Northwestern Poyteehnca Unversity,Xi an,00. 王军平. 大量程电涡流传感器的研制 : [ 学位论文 ]. 西安 : 西北工业大学,

325 THE METHOD OF NEURON ACTION POTENTIAL SORTING BASED ON WAVELET TRANSFORM AND FUZZY C-MEANS CLUSTERING SHI LI, WANG YAN School of Electrical Engineering, Zhengzhou University Zhengzhou 45000, China Abstract:The precise sorting of neuron action potential is the premise to explore the coding and decoding discipline of neurons in depth. A new method combining wavelet transform with fuzzy C-means clustering is proposed to classify neuron action potential. First, the discrete wavelet transform is used to extract the features of every action potential detected, then those wavelet coefficients of higher contribution ratio are selected as the characteristics of each action potential, and finally, fuzzy C-means clustering algorithm is applied to cluster these features in order to achieve action potential classification. The experimental results show that the proposed sorting algorithm can effectively classify the neuron action potential obtained from the primary visual cortex of rats. The sorting result is of higher correct classification rate and more robust by using the new algorithm proposed this paper compared with the traditional method. Keywords: neuron action potential; sorting; wavelet transform; Fuzzy C-Means cluster 基于小波变换和模糊 C- 均值聚类的神经元动作电位分类算法 师黎 王岩 郑州大学电气工程学院, 河南郑州中国 摘要 : 神经元动作电位的精确分类是深入探究神经细胞进行信息编码解码规律的前提 本文采用小波变换和模糊 C- 均值聚类 (FCM,Fuzzy c-mean) 相结合的方法实现神经元动作电位 (action potential) 的分类 首先, 对提取的每个神经元动作电位进行离散序列小波变换, 然后挑选出对各个动作电位贡献率较大的小波系数作为其特征点, 最后, 运用模糊 C- 均值聚类算法对这些特征进行聚类, 从而实现动作电位的分类 实验结果表明, 本文所提方法能够很好的实现大鼠初级视觉皮层 (V 区 ) 神经元动作电位的分类 与传统分类方法相比, 本文提出的分类算法实现分类的正确率更高, 鲁棒性更强 关键词 : 神经元动作电位 ; 分类 ; 小波变换 ; 模糊 C- 均值聚类. 引言大脑的神经元通过发放动作电位进行信息的传递 交流和处理 [] 在静息电位的基础上, 细胞受到一个适当的刺激, 其膜电位所发生的迅速 一过性的极性倒转和复原, 这种膜电位的波动称为动作电位 [] 动作电位一般只有几十微伏, 用来在神经系统中传播和对信息进行编码 [3], 其研究结果对建立有效的人工神经网络模型以解决实际问题有重要的推动作用 目前, 神经元动作电位主要通过微电极阵列记录得到 [4~5], 但是阵列中每根电极记录到的信号往往是电极临近区域多个神经元信号的叠加, 而且还包含大量的背景噪声 因此, 准确 高效的分离出每个神经元动作电位显得尤为重要 近年来, 国内外许多学者致力于神经元动作电位信号的分类研究 动作电位的分类方法主要归为特征聚类法和模板匹配法两大类 特征聚类法通常分为两步, 首先对动作电位的波形特征进行提取, 然后运用 397

326 聚类算法进行分类 常用的特征提取方法主要有主元分析法 [6] 独立成分分析法(ICA) [7~8] 小波变换方 [9~0] 法等, 常用的聚类方法主要有基于贝叶斯混合模型的聚类方法 [~] K-means 聚类法 [3] 模糊 C 均值 [4] 聚类等 其中, 主元分析法将变量进行组合变换, 产生新的隐式变量, 用最少的变量 ( 主成分 ) 大致反映出所研究的波形特征 该方法能够节省计算资源, 易于实现, 并且比一般的特征分类方法的精度要高 但是, 当变量相关性突出时, 主成分或不能反映真实的数据信息 基于独立成分分析的分类方法是选择一组相邻的电极, 当不同电极间采集到相同的动作电位时, 把这些动作电位当作独立成分分量, 用独立成分分析分解这组信号, 达到盲信号分离, 实现动作电位信号的分类 但是, 由于多电极之间距离很大, 很多动作电位信号都衰减得很厉害, 同一个神经元动作电位信号很难被多个电极同时测到, 而且神经元的个数远远大于多电极个数 因此, 将 ICA 用于动作电位的分类比较困难 利用离散小波变换对动作电位进行分类, 是一种特征分析和滤波相结合的分类方法, 通过在时域和频域对动作电位信号的刻画, 找到合适的特征进行分类 该方法能更有效地分离波形和幅值非常类似的信号 基于贝叶斯混合模型的聚类方法把每一类别认为是混合模型中的一个具有独立统计分布的模型, 然后通过极值化概率函数获得最优的类别参数, 从而实现动作电位信号的分类 该方法虽然能提高分类精度并通过贝叶斯判据估计类别数目, 但由于在记录过程中噪声的复杂性, 数据的统计特性并不明了, 需要进一步研究 K-means 算法是从被分析数据中随机选择若干个对象作为初始聚类中心, 这样产生的聚类结果具有很大不确定性, 如何选择初始聚类中心点是影响聚类结果的重要因素, 且 K-means 算法给出的是局部最优解, 而不是全局最优解 模糊聚类方法是用隶属度确定每个数据点属于某个聚类的程度的一种聚类方法, 由给定的任意初始聚类中心经过多次迭代使价值函数的变化小于某个设定的阈值, 这种方法在一定程度上可以解决动作电位信号的叠加问题, 提高分类的精度, 但是聚类数目需要预先给定, 并通过一定方法去验证类别的有效性 在模板匹配法中, 一般首先确定典型动作电位的波形, 然后以这些波形为模板, 根据信号与模板之间的匹配程度对信号进行分类 在对多个动作电位叠加形成的信号进行分离时, 模板匹配法则有明显的优势 但在实际的研究工作中, 由于大批量数据需要处理, 由人工确定动作电位的模板是费时费力 综合以上算法的特点, 本文提出一种基于离散序列小波变换和模糊 C- 均值聚类相结合的动作电位分类算法 首先, 对提取的每个神经元动作电位进行离散序列小波变换, 然后按照一定标准, 挑选出对各个动作电位贡献率较大的小波系数作为其特征点, 最后利用模糊 C- 均值方法对经小波变换后的特征集合进行自动分类 采用本文所述算法处理实验室采集的大鼠初级视皮层 V 区神经元动作电位信号时, 分类效果良好 与传统分类方法相比, 此算法实现分类的正确率更高, 鲁棒性更强. 基于离散小波变换的动作电位特征提取 小波变换是一种时间和频率两域相结合的时频分析方法, 在时频域都具有表征信号局部特征的能力, 因此适用于分析时变信号 在实际应用中, 计算机能够处理的信号都是经过采样后的离散序列, 因此离散小波变换的工程应用领域最广 利用小波变换实现动作电位特征的提取, 可视作一个特征降维同时去噪的过程, 可以直接以部分小波系数作为特征, 也可以小波系数的统计特信息作为特征 考虑到小波变换所得到的系数非常多, 如果都作为特征, 势必严重降低分类器的性能, 因此本文选取对动作电位信息量较大方差贡献率对应的小波系数组成特征向量, 作为分类器的输入 利用离散小波变换对动作电位特征进行提取的步骤如下所述 : 398

327 ) 对检测到的每个动作电位取同样长度的采样点数 M, 构成一个离散序列 s 对于某段待分析信号, 假设检测到 L 个动作电位, 这样就得到 L 个离散序列 ; ) 选择合适的基函数对 L 个离散序列分别进行小波变换 如果最大分解次数取 J, 则经小波变换之后, 每个离散序列对应将得到一个由低频概貌向量 r J 和经每一次分解得到的高频细节向量 d -J+ ( =,,,J ) 构成的向量, 称系数样本,L 个离散序列对应得到 L 个系数样本, 每个系数样本的长度与所选择的基函数类型有关, 以 Matlab 小波工具箱中的小波基函 db4 为例, 小波分解扩展模式选取 periodization, 则每个小波变换系数样本的长度与被分析序列的长度相等, 因此最终得到一个 N*M 维系数矩阵 : [ q, q, ] T Q =, () q L 式中 :q j 表示为 q j = { rj, J, d j, J, d j, J,..., d j, }, j =,,..., L () 3) 通过公式 (3) 计算矩阵中每个列向量各个元素的方差, 共得到 M 个方差, 它们彼此互不相关, 这些方差可理解为对每个动作电位的非相似性测度的贡献 ; L L St = ( a jt a jt ), t =,,...,M (3) L L 式中 :a jt 表示系数矩阵第 j 行第 t 列元素 j= j= 4) 根据公式 (4) 求出动作电位波形非相似性测度的贡献率 r j : St rt =, t =,,..., M M S t = t 5) 将贡献率 r t 从大到小排列, 选出贡献率之和大于 85% 的前 n(n<m) 个方差对应的小波系数构成向量 x j = { x j,x j,,x jn}, j =,,..., L, 代表第 j 个动作电位序列的特征, 构成一个 L*n 的特征矩阵 X [ x,x, ] T =, 为下一步的聚类做准备,xL (4) 3. 模糊 C- 均值聚类动作电位分类算法小波系数代表了神经元动作电位的特征, 将其进行聚类实现神经元的分离 本文采用目前理论最完善应用最广泛的基于目标函数的模糊 C 均值算法 (FCM,Fuzzy c-mean) 模糊 C- 均值算法如下所述 : 阵 U 欲将这 L 个 n 维特征矢量 x { x, x, j j j, x jn}, j =,,..., L = { u ij } 表示, 式中阵元 c L u ij 表示对象 x j 属于目标类 i 它的阵元 u ij 需满足如下条件 : ) [ 0,] u ; ij N = 分为 c 类, 动作电位分类结果用模糊分类矩 w 的程度或资格, 因此 U 也称为隶属度矩阵, ) 0 < uij < N, i, 即任一类都不是确定的空集, 总是有一些模式以不同的程度隶属于它, 同时他 j = 也不是确定的全集 X ; c 3) u =, j, 即 X 中的每一个模式 x j 属于各类的程度总和为 ij i= 399

328 FCM 算法在迭代寻优过程中, 不断更新各类的中心及隶属度矩阵各元素的值, 直到逼近下列准则函数的最小值 式中 : V { v, v,, } = v c, v i 为类别 T 其平方定义为 d ( x v ) A( x v ) d ij j i ij J N c m m( U, V ) uij dij j = i i = (5) w 的中心矢量 ; 模糊度 [, ] = j i j i ; A 为某一个正定矩阵, 当 A = I, ij c m ; d ij 表示 x j 到 v i 的距离, d 表示欧式距离, 即 = x v, 约束条件为 u =, j, 运用拉格朗日乘数法, 可得无约束的则函数 : 上式取极小值的必要条件是 i= ij F u F = ij N c j = i= = mu F = ( λ j j = m ij c i= N m u d λ ( u ) (6) u m ij ij ij ij j = j c i= ij λ = 0 (7) j ) = 0 通过变换可得隶属度矩阵元属及聚类中心公式如下 : uij = (9) c m dij = dj N m uij x j j = vi = N (0) u 假设提取的每个动作电位特征向量由 n 个值构成, 用 FCM 算法对 N 个动作电位进行聚类的步骤如下所述 : ) 确定类数 c( c N) 参数 m A = I 和一个适当的小的数 > 0 ) 初始化模糊分类矩阵 3) 根据公式 (0) 计算分类矩阵 (0) U, 即令 = 0 s ; ( s+) 4) 按以下方法更新 U 对于 = N ; a) 计算 I j 和 I j (s) U 中每个类别的中心矢量 { } (s) i j ~ { i d = 0} {,, c} I j j = ij b) 计算 action potential 特征值 x j 的新隶属度 : v ; ε ; 通常取 < m 5 I () I j =, () (8) 400

329 3) 步 如果 I j Φ, 则根据公式 (9) 计算 u ij ; 否则, u ij = 0, i I j, 并取 uij = (s) ( s +) ( ) ( s+ ) 5) 以一个适当的矩阵范数比较 U, U, 若 U s U < ε 则停止 ; 否则 s = s +, 返回到第 4. 实验及结果分析 4. 实验 本研究选取年龄 -6 个月, 体重 克的 Long Evans 大鼠作为实验对象 ( 由郑州大学动物中心提供 ) 采用微电极技术记录大鼠初级视觉皮层的神经信号, 按体重 4ml/g 腹腔注射 0% 水合氯醛或按体重 5ml/g 腹腔注射 % 戊巴比妥钠对大鼠进行麻醉, 麻醉深度以用指掐大鼠后肢无敏感反应为度 将其头部固定于大鼠脑立体定位仪上, 用刀剃掉头皮上的毛发, 切开头部皮肤, 暴露颅骨, 用手术刀刮去颅骨附着脑膜, 并用过氧化氢 (3%) 去除颅骨上多余物质 然后将多通道微电极阵列 ( 4 4 钨丝微电极 ) 植入大鼠初级视觉皮层 V 区 ( 以前囟为原点, 向后 7.3mm, 向外 3.0mm 定出初级视皮层在水平面上的位置 ) 将硬脑膜挑破, 微电极穿过软脑膜, 下到适当深度后开始记录自发放电信号 本研究所选用的信号采集设备为 8 通道的神经信号处理系统 Cerebus system(blacroc Microsystem 公司生产 ) 根据每个通道所记录电信号的信噪比情况, 设定合适的阈值, 实现动作电位的自动检测, 其中动作电位采样点数设为 48, 采样频率选为 30000Hz 4. 结果分析首先, 读取通过实验采集的大鼠 V 区神经元动作电位信号 ( 含有 8 个动作电位 ), 如图 所示 c i I j 50 实 x 0-3 图 Cerebus system 采集的大鼠 V 区神经元动作电位信号 Fig. Action potential of neuron in rats V acquired by Cerebus system 然后, 选择 Matlab 小波工具箱中的 db4 作为小波基函数, 对读取的动作电位数据进行两层分解, 小波分解的扩展模式设定为 periodization, 这样保证每个小波变换系数的长度与原波形长度保持一致 对动作电位数据进行小波分解后, 可得到一个 8*48 的小波系数组成的矩阵 最后, 提取小波系数中对动作电位信息量累计贡献率大于 85% 的系数作为每个动作电位的特征向量, 图 给出了前三维的特征散点图 如图 所示 : 40

330 图 小波特征分布散点图 Fig scatter of wavelet features 从图 可以明显看出, 在前三维小波系数特征组成的特征空间中, 动作电位特征基本聚为 簇 由此推知, 此通道记录到的动作电位主要来源于两个神经元, 可以分为两类动作电位信号 基于以上小波变换提取的动作电位特征, 按照文中第 3 部分给出的模糊 c 均值聚类的步骤进行聚类, 聚类数目设为, 则动作电位分类结果如图 3 所示 : x 0-3 图 3 实测神经元动作电位的分类结果 Fig 3. the sorting result of actual neuron action potential 从图 3 可以看出, 该通道的动作电位信号分为两类时 (A 类,B 类 ), 同类动作电位的相似性极高, 不同类之间动作电位的相似性极低 这进一步说明, 此通道记录的动作电位数据由两个神经元发放 另外, 对其它共 8 个通道的数据进行同样的分析, 得到同样类似结果 为了衡量该算法抗噪性能, 本文在实测神经元动作电位信号中加入不同信噪比的高斯白噪声, 然后对其进行分类 在不同信噪比情况下的动作电位分类结果如表 所示 ( 以不加噪声时的分类正确率为基准 ) 通过表 可以看出, 在信噪比大于 -5dB 时, 实现正确分类的比率能达到 99% 以上 ; 当信噪比低于 -30dB 时, 分类正确率迅速下降到 93% 以下 三种不同的方法实现动作电位分类的结果以及误分类率 如表 所示 40

331 表 不同信噪比情况下的分类结果比较 Table. The sorting result of signal with different SNR 信噪比 (db) A 类 ( 个 ) B 类 ( 个 ) 正确率 (%) 表 不同方法实现分类的结果比较 Table.The sorting result of signal with different SNR by using different method 信噪比 小波变换 + 模糊 C 均值 小波变换 +K 均值 模板匹配算法 (db) A,B 类中动作电位 ( 个 ) 错误率 (%) A,B 类中动作电位 ( 个 ) 错误率 (%) A,B 类中动作电位 ( 个 ) 错误率 (%) / / / / / / / / / / / / / / / / / / / / / 由表 可以看出 : 随着信号信噪比的降低, 三种算法的分类结果都出现了不同程度的错误率, 其中模板匹配算法的分类结果在信噪比为 -5dB 时就出现错误率, 小波变换和 K 均值方法在信噪比为 -5dB 时出现错误率, 而本文提出算法的分类在信噪比为 -5dB 时才出现错误率, 表现出较强的抗干扰能力 另外, 由于模板匹配法在计算过程中需要按照某种原则从数据中选择模板, 然后根据匹配程度来进行分类, 而模板的选择随机性比较大, 且易受噪声的干扰 5. 结论本文提出了一种基于离散小波变换与模糊 C 均值聚类相结合的神经元动作电位分类算法 此方法综合了小波变换的多尺度特征和模糊 C 均值聚类抗干扰能力强的优点, 所以, 利用本文算法进行神经元动作电位分类能够获得更高的分类正确率 并且, 在动作电位信号信噪比较低时 (SNR=-5dB), 采用本文算法仍然能够得到较准确的分类结果 ( 平均错误率仅约 0.45%) 下一步的工作是在算法的个别参数设置上进行相应的优化 403

332 References ( 参考文献 ). Ding Weidong, Yuan Jingqi,Liang Peiji. Study on the detection and sorting of multi-electrode neural spies [J]. Chinese Journal of Scientific Instrument,006,7(): Riee f,warland D,Stevenc D R V,et al.spie: Exploring the neural code[m].cambridge,the MIT Press, Bruno B. Averbec,Daeyeol Lee.Coding and transmission of information by neural ensembles[j].trends in Neuroscience,004,7(4): Brown EN, Kass RE, Mitra PP. Multiple neural spie train data analysis: stateof- the-art and future challenges[j]. Nat Neurosci, 004, (7): Carmena JM, Lebedev MA, Henriquez CS, Nicolelis MA. Stable ensemble performance with single-neuron variability during reaching movements in primates[j]. J Neurosci,005, (5): Dimitrios A. Adamos, Efstratios K. Kosmidis, George Theophilidis. Performance evaluation of PCA-based spie sorting algorithms[j]. Computer methods and programs in biomedicine, 008,9(3): Dorian Aur, Mandar S. Jog. Building spie representation in tetrodes[j]. Journal of Neuroscience Methods, 006, 57(): S. Taahashi, Y. Saural. Real-time and automatic sorting of multi-neuronal activity for sub-millisecond interactions in vivo[j]. Neuroscience. 005, 34(): Taahashi Tetsuya,Katayama Norihiro, Kiuchi osamu, et al. Wavelet Transform-based Neuronal Spie Sorting Method for Multi-channel Multi-unit Recording Data[J]. IEIC Technical Report, 006, 06(370): R. Quian Quiroga, Z. Nadasdy, Y. Ben-Shaul. Unsupervised Spie Detection and Sorting with Wavelets and Superparamagnetic Clustering[J]. Neural Computation,004,6(8): Aharon Bar-Hillel, Adam Spiro, Eran Star. Spie sorting: Bayesian clustering of non-stationary data[j]. Journal of Neuroscience Methods,006,57(): Fran Wood Sharon, Fran Wood, Sharon Goldwater, Michael J. Blac. A Non-Parametric Bayesian Approach to Spie Sorting. 8th Annual International Conference of the IEEE, New Yor, 006: Milan Djilas, Christine Azevedo-Coste, David Guiraud, et al. Spie Sorting of Muscle Spindle Afferent Nerve Activity Recorded with Thin-Film Intrafascicular Electrodes[J]. Computational Intelligence and Neuroscience,00, 00: Z. Hilal Inana, Mehmet Kuntalpb, Astudy on fuzzy C-means clustering-based systems in automatic spie detection[j]. Computers in Biology and Medicine, 007,37(8):

333 THE DESIGN OF HF SURFACE WAVE RADAR ECHO SIMULATOR BASED ON DIGITAL RADIO FREQUENCY MEMORY KANG YONG,, YANG ZHI-JIE, ZHONG ZHI-FENG 3, ZHANG SHU-JIE ) School of Electronic Information, Wuhan University, Wuhan ,China; ) Air Defense Forces Command Academy,Zhengzhou 45005,China; 3) Hubei University, Wuhan ,China; 978y@63.com Abstract:Aimed at the echo s characteristics of LMF radar, HF surface wave radar s echo simulator based on digital radio frequency memory is presented. The system uses digital down-conversion technology and digital up-conversion technology. The digital memory and controller of DRFM is designed on a FPGA chip. Compared with the traditional simulator based on analog delay line, the parameters of simulant echo can be controlled conveniently and independently. The simulator s principle and its design for HF chirp radar are discussed in detail. Through theoretical analysis and simulation results, the validity of this method to simulate radar echo is proved. 基于 DRFM 的高频地波雷达回波模拟器设计, 康勇 杨子杰 3 钟志峰 张树杰 ) 武汉大学电子信息学院, 湖北武汉中国 ) 防空兵指挥学院, 河南郑州中国 ) 湖北大学, 湖北武汉中国 引言 摘要 : 针对高频地波雷达目标回波的特点, 提出了一种基于 DRFM 技术的高频地波雷达回波模拟器实现方案 系统采用了数字上 下变频技术, 利用 FPGA 构建 DRFM 的核心单元 : 存储器和控制器, 由 PC 机通过 VXI 总线实现模拟目标参数的独立控制, 即解决了延时线模拟器回波参数固定的问题, 又扩展了回波模拟器的应用范围 文中重点讨论了高频地波雷达回波模拟的设计原理, 给出了系统的实现方案, 通过理论分析和仿真结果验证了方案的可行性 关键词 : 高频地波雷达, 机内自测试, 线性调频, 回波模拟, 数字射频存储, 现场可编程门阵列 在雷达系统的研制过程中, 对雷达性能指标的检测是一个重要环节, 完全采用外场测试即不方便又费 力耗时 雷达回波模拟器是检测雷达性能指标的有力工具 [~4], 不仅为设计者节省了研制费用, 而且可以为 雷达分系统的研制 测试工作的并行展开提供保证 [5], 提高工作效率 缩短研制周期 传统的雷达回波模 拟器通常采用模拟延时线的方法模拟目标距离对回波的影响 [6], 存在着参数调整受限且不便的问题 数字 射频存储 (DRFM) 技术以高速采样和数字存储作为技术基础, 具有对射频和微波信号的存储和再现能力, 广 泛应用于军用雷达和电子战领域, 通过对敌方雷达信号的接收 存储 处理 再现, 产生虚假雷达回波信 405

334 号, 进行电子对抗 如果输入为雷达自身的发射信号, 对其进行相应的处理之后重构信号, 再反馈给雷达系统, 就可以模拟各种目标回波信号 [7~8] 本文介绍了一种基于 DRFM 技术的高频地波雷达回波模拟器设计方案, 该模拟器不仅可以灵活地模拟目标的距离信息 速度信息, 而且可以实现多重目标信号的模拟 该模拟器的回波模拟过程不依赖于雷达的具体工作体制, 因此可以作为一种通用的雷达回波模拟硬件平台 本文针对武汉大学研制的 OSMAR (Ocean State Monitor and Analysis Radar) 系列雷达, 主要讨论线性调频体制高频地波雷达回波信号的模拟. 回波模拟器设计原理. 高频地波雷达回波模拟的意义与应用回波模拟器的应用贯穿于雷达研制 试验 使用的各个阶段 雷达研制过程中模拟器可以用作研究雷达数据处理方法的实验设备, 保证雷达各分系统的研制工作能够并行展开, 提高工作效率 ; 雷达试验阶段可利用模拟回波信号, 对样机的性能指标进行测试和评定 ; 雷达使用时回波模拟器可作为雷达机内自测试 (BIT) 系统的关键部分 [9], 用于雷达系统的自检和故障诊断 ; 另外目标回波的模拟过程也是对目标特征理论研究的验证过程, 可以用于验证和评价目标模型 因此, 雷达回波模拟器的设计具有重要的理论和现实意义 本文中的雷达回波模拟器主要应用于 OSMAR 系列的高频地波雷达, 模拟器与雷达其它分系统的关系如图 所示 ( 虚线表示回波模拟器及其信号连接 ) 图 回波模拟器在高频地波雷达中的应用 Fig HF ground wave radar echo simulator application 当接通回波模拟通路之后, 发射机输出的射频信号经衰减器送入回波模拟器, 在回波模拟器调制目标 信息, 模拟出目标的回波信号经衰减器送入雷达接收机, 用于接收通道软 / 硬件的调试 测评和雷达系统的 故障诊断 406

335 . DRFM 技术原理数字射频存储 (DRFM) 的概念最早由英国 EMI 电子公司的 Chris Haynes 于 974 年提出 [0], 该技术已广泛应用于军用雷达电子对抗领域 [], 主要用于产生虚假雷达目标信号去欺骗敌方雷达 DRFM 的基本组成如图 所示, 图 DRFM 原理框图 Fig Bloc diagram of a typical DRFM 输入射频信号经下变频变换为中频信号, 经 A/D 采样 量化后将数据记录到存储器中, 处理器对存储数据的变换处理生成所需的数据, 再经 D/A 转换 上变频实现射频信号的再生, 存储器应采用高速双端口存储器以确保信号记录和再生过程同时进行 利用 DRFM 技术实现高频地波雷达回波模拟器设计的关键在于如何对存储数据进行处理, 给再生信号添加目标信息, 实现目标回波信号的模拟.3 高频地波雷达回波模拟原理 雷达发射信号本身不包含任何目标信息, 当发射信号遇到目标时, 目标对发射信号进行调制使之携带 目标信息后, 反射成为回波信号, 这就为回波模拟提供了理论基础 [] 对于雷达目标回波信号的模拟主要 包括 : 距离信息的模拟和速度信息的模拟 根据雷达探测原理, 目标距离可用式 () 表示 : R= c Δ t/ () 式中 :c 为光速, Δ t 为延迟时间 雷达探测时只需要知道目标回波的延迟时间 Δ t, 就可以计算出目 标距离雷达的距离 R 因此通过将发射信号延迟一个固定的时间, 就可以模拟目标距离信息 根据多普勒 原理, 被测目标的径向运动速度可用式 () 表示 : ( ) ( ) V =± c Δ f / f =± c Δ ω / ω () 0 0 式中 : c 为光速, f0( ω 0) 为探测信号频率, Δf ( Δ ω) 为多普勒频移 由于不同体制雷达的回波特性也不同 [], 因此回波模拟器应根据雷达体制输出相应特性的模拟回波 OSMAR 系列高频地波雷达采用线性调频信号发射体制 [3], 发射具有一定重复周期的线性调频正弦信号, 一个扫频周期内雷达发射信号表达式为 : 407

336 式中 : 0 T 为扫频周期 为 [4] : ( ) S t = cos( ω t+ αt + ϕ ), 0 t T (3) T 0 0 ω 为发射信号起始频率, α = π B / T 为线性调频斜率, ϕ 0 为初相位, B 为线性调频带宽, 假设距离 R 0 处有一目标以径向速度 v 远离雷达方向匀速运动, 则目标回波信号相对于发射瞬间的时延 该目标回波信号为 : τ v R v c c c 0 = τ0 + t = + t (4) () S t = cos[ ω ( t τ) + α( t τ) + ϕ ], 0 t T R 0 0 R0 R0 R0 v v v v = cos{ ω0( t ) + α( t ) + ( α ω0) t+ [ α( ) α ω0] t + ϕ0} c c c c c c c (5) 高频地波雷达将接收的回波信号与本振信号混频并经过低通滤波产生差频信号, 通过对差频信号的频 率分析获得目标的距离信息和速度信息 差频信号表达式为 : ( ) = ( ) ( ) S t lowpass{ S t S t } Δ T R R0 v R0 v v v v = cos[(α + ω0 α ) t+ ( α α ) t + ϕ0] c c c c c c c = cos[ ϕ ( t)], 0 t T Δ (6) 差频信号的频率表达式为 : f () t Δ = dϕδ () t π dt α R0 v α v α R0 v α v v = + f0 + t t π c c π c π c c π c c (7) 由于高频地波雷达探测的目标均为低速目标, v c, 因此 (7) 式中后两项可以忽略 ; 第一项为目标距离 R 0 引起的频率差, 代表距离信息 ; 第二项为目标径向运动引起的多普勒频移, 代表速度信息 ; 第三项为 观测时间内目标以速度 v 运动走过的距离所引起的频率变化, 又因为高频地波雷达设计时要求在相干积累 时间内目标运动不超过一个距离元, 所以第三项也可以忽略 高频地波雷达回波模拟器的任务就是利用 (3) 式所表示的输入信号, 产生模拟目标回波信号满足 (5) 式的 要求 即模拟回波信号表达式为 : 408

337 ( ) ( ) S t = S t,0 t T MR R R0 R0 v R0 v v v = cos{ ω0( t ) + α( t ) ω0t+ α t+ α( ) t α ω0t + ϕ0} c c c c c c c (8) 与雷达处理回波信号过程中忽略后三项的道理相同, 利用回波模拟器按照 (8) 式模拟目标回波时已可以忽略 R0 v α t c c v v α ( ) t α ω0t 这三项, 因此模拟回波信号表达式简化为 : c c R0 R0 v SMR () t = cos[ ω0( t ) + α( t ) ω0t+ ϕ0], 0 t T (9) c c c 现代线性调频体制雷达数字化处理回波信号时, 一般使用二次傅立叶变换求回波多普勒谱 [5] 第一次傅立叶变换针对每一次线性扫频周期内的中频采样信号, 目的是提取目标的距离信息 ; 将不同扫频周期内第一次傅立叶变换后的同一频率 ( 意味着同一距离元 ) 结果, 按时间顺序先后排列, 进行第二次傅立叶变换, 得到该距离元上目标的多普勒谱 能够这样进行处理的前提是 : 目标速度引起的多普勒频移 Δω Δ ω 远小于单位距离元造成的频移 [6] 这意味着在同一扫频周期之内, Δ ωt 可认为是一个常量, 而目标速度对回波信号相位的影响主要表现为 : 相邻线性调频周期回波信号的相位, 相差一个固定的相位值 Δ ωt 同理, 模拟回波信号时表达式 (9) 中的 v 0t c ω v 也可以作为常量处理, 用 0nT c ω 来代替, n 代表第 n 个扫频周期, 模拟回波信号表达式变化为 : R0 R0 v SMR () t = cos[ ω0( t ) + α( t ) ω0nt + ϕ0], 0 t T (0) c c c 对比 (0) 式和 (3) 式可知, 利用高频地波雷达回波模拟器记录雷达发射信号 生成单个目标回波信号的模 R0 拟过程, 只需要通过两步完成 : 第一 对输入信号延时 c, 即可模拟出目标的距离信息 ; 第二 依据扫 频周期的顺序 n, 给该扫频周期信号的相位增加一个固定的相位值 v 0nT c ω, 即可模拟出目标的速度信息 通过改变延迟时间 扫频周期间的相位增加值, 可以灵活的模拟不同距离 不同速度的目标回波 ; 采用多 通道技术, 将不同通道信号的叠加, 可以方便的模拟多目标回波 409

338 3. 回波模拟器的结构与设计 3. 总体结构基于 DRFM 的高频地波雷达回波模拟器设计, 存在上 下变频的过程 如果采用模拟混频的方式, 存在有本振泄漏 镜像干扰 交叉调制等寄生信号噪声的影响 [7~8] 因此, 本设计采用数字上 下变频方案, 既可以充分抑制上述噪声, 同时有利于保证 I/Q 两支路的幅相一致性 回波模拟器总体结构如图 3 所示 : 图 3 回波模拟器总体结构 Fig 3 The overall structure of echo simulator 图中主要包括 A/D 转换器 数字下变频器 现场可编程门阵列 数字上变频器 A/D 转换器选用 ADI 公司的高速 bita/d 芯片 AD935, 最高采样速率可达 65MSPS 数字下变频器(DDC) 选用 ADI 公司的 AD660 的芯片, 其内部包含 : 频率变换单元 二阶固定系数梳状抽取滤波器 五阶固定系数梳状抽取滤波器和一个系数可编程的抽取滤波器单元, 输入数率高达 67MSPS, 具有 3bit 可编程的数控本振, 可编程抽取率在 至 6384 之间 本设计选用现场可编程门阵列 (FPGA) 作为存储 处理 参数配置和通讯平台 [9], 芯片选用 ALTERA 公司的 CYCLONE 系列产品 EPC6, 内含 5980 个逻辑单元, 包含有 0 个 8x36bit 的 M4K 模块, 总 RAM 空间达到 960bit 数字上变频器(DUC) 选用 ADI 公司的 AD9857 芯片, 该芯片将 DDS 核 数字上变频器 时钟倍频电路 数字插值与滤波器以及高速的 4bitDAC 等功能集成在一起, 具有完善的正交数字上变频能力和高质量的模拟信号输出 3. FPGA 设计 回波模拟器设计的核心在于 FPGA 的设计, 如图 4 所示 : 40

339 图 4 FPGA 内部结构图 Fig 4 FPGA design FPGA 内部主要分为三个模块 : 数据存储与处理模块 参数配置与控制模块 VXI 通信模块 VXI 通信模块完成回波模拟器与 PC 机之间的 VXI 总线传输 ; 参数控制与配置模块完成对整个系统的 配置, 同时通过对数据存储与处理模块的控制给数据添加模拟目标的距离 / 速度信息 ( 延时 / 多普勒频移 ); 数据存储与处理模块由数据存储器 乘法器 加法器组成 数据存储器是由 FPGA 内设计的 FIFO 来构造, 参数控制器根据 PC 机送来的目标距离信息 R 0, 利用 计数器对 FIFO 的输出使能端进行控制, 使 FIFO 输出相对于输入延时 R0 c, 使 FIFO 输出数据携带模拟目 标的距离信息 ; 根据前文介绍的回波模拟原理, 目标速度 v 的模拟是按扫频周期的顺序 n 给每个扫频周期 的数据增加一个相位增量 v 0nT c ω, 这一处理是在同步控制信号的控制下利用乘法器对 FIFO 输出数据乘以 v exp( j 0nT ) c ω 来完成的 由于需要对 I/Q 两支路信号进行分别进行处理, 根据公式 () 在 FPGA 内具体实现时, 需要构造 4 个乘法器和 个加法器来给输出数据添加目标的速度信息 需要指出的是图 4 所示的数 据存储与处理模块仅能模拟单目标回波, 当需要模拟多目标回波时, 可将该模块作为一个目标模拟通道, 将输入的 I in /Q in 两路数据分别送入多个模拟通道, 再将多个通道 I out /Q out 输出分别求和后送入数字上变频器 v siout + jsqout = ( siin + jsqin )exp( j ω0nt) c v v v v = [ siin cos( ω0nt ) sqin sin( ω0nt)] + j[ siin sin( ω0nt ) + sqin cos( ω0nt )] c c c c () 4

340 4. 结果与分析 4. 方法验证 运用 MATLAB 对该回波模拟方法进行仿真验证, 产生位于 0 距离元 (0 速度元 ) 和 40 距离元 (50 速度元 ) 的两个目标回波, 按高频地波雷达信号处理过程经过 次 FFT 变换分别得到 距离元的多普勒功率谱, 如图 5 所示 : 在 0 和 40 距离元多普勒谱图上, 两个目标在相应的速度元上得到准确的呈现, 说明该模拟方法有效 4. FPGA 仿真结果运用 Quartus II 对于在 FPGA 中给输入数据叠加模拟目标距离和速度信息的处理过程进行仿真, 其结果如图 6 所示 : 图 5 个目标的模拟回波在不同距离元的多普勒谱 Fig 5 Simulated echo doppler spectrum 图 6 FPGA 中叠加目标距离与速度信息仿真结果 Fig 6 FPGA Simulation results 4

341 图中 datai dataq 为输入的 I in /Q in 两支路信号,dataVI datavq 为加载的多普勒频移参数,delay_para 为给定的延迟时间参数,resI,resQ 为输出 I out /Q out 两支路信号,cl 为全局工作时钟 从图中可以看出输出信号 resi,resq 相对输入信号 datai dataq 有了延时并加入多普勒频移信息, 说明按图 4 设计 FPGA 实现高频地波雷达回波模拟方法可行 5. 结论本文介绍了一种基于 DRFM 技术的高频地波雷达回波模拟器设计方案, 通过改变延迟时间 按扫频周期线性叠加相位和采用多通道技术可以完成多目标回波的模拟 ; 利用数字上 下变频技术, 由可编程器件完成回波模拟的控制, 该模拟器可以灵活的进行参数设置, 并且可以作为不同体制雷达的通用回波模拟平台 ; 受 DRFM 技术特点的限制, 该模拟器需要雷达发射信号的输入, 但作为雷达机内自测试 (BIT) 设备, 用于雷达的检测和故障诊断更具有实际意义 References. Mitchell R L. Radar Signal Simulation [M]. London:Artech House Inc., Yang Jun-ling, SU Ling-hua, Wan Jian-wei. Design and realization of radar IF echo simulator based on DDS [J]. Systems Engineering and Electronics,006,8(9): 杨俊岭, 苏令华, 万建伟. 基于 DDS 的雷达中频回波模拟器的设计与实现 [J]. 系统工程与电子技术,006,8(9): Liu Chao-jun,Wang Wei,Qiu Zhao-un. Research on the simulation of the characteristic signal of the wide band radar target based on DDS [J]. Systems Engineering and Electronics,005,7(9): 刘朝军, 王伟, 邱兆坤, 陈曾平. 基于 DDS 的宽带雷达回波信号模拟技术研究 [J]. 系统工程与电子技术, 005, 7(9): Zhang Xin-xun,Zhang Bing,Li Guang-qiang. Design of IF Radar Echo Simulator Based on PCI Bus and DDS Technique [J]. Fire Control Radar Technology, 008,37():87-9. 张新勋, 张兵, 李广强. 基于 PCI 总线和 DDS 技术的雷达中频回波模拟器的设计 [J]. 火控雷达技术, 008, 37(): Cao Ru-jie. Research of Radar Test Technology Based on drfm[j]. m icroelectronics & computer, 008,5(8): 曹汝杰. 基于数字储频技术的雷达检测方法研究 [J]. 微电子学与计算机, 008,5(8): Yang Shao-quan, ZHAO Guo-qin. Echo simulator of an FMCW altimeter[j]. Journal of xidian university, 999,6(6): 杨绍全, 赵国庆. 调频连续波雷达回波模拟 [J]. 西安电子科技大学学报, 999, 6(6): Xiao Han-b. Digital Radio Frequency Memory and Its Application to Radar Echo Simulato [J]. Guidance & fuz,00,3(3):5-9 肖汉波. 数字射频存储器及其在雷达信号模拟中的应用 [J]. 程与电制导与引信, 00, 3(3): Wang Chao, Li Yi, Yuan Nai-chan. Design of high resolution radar echo simulato [J]. Systems Engineering and Electronics, 007,9(8): 王超, 李毅, 袁乃昌. 高分辨雷达目标回波模拟器设计 [J]. 系统工程与电子技术, 007,9(8): Alamouti S M. A Simple Transmit Diversity Technique for Wireless Communications[J]. ieee. journal on select areas in communications, 998,6(8):

342 0. Roome S J. Digital radio frequency memory [J]. Electronics and Communication Engineering Journal,990,(8): Wang Zhenglin, Liu J ian. Reconnaissance and jamming integration processing technique against coherent radar [J]. J. Wuhan Univ.(Nat. Sci. Ed.), 009,5():9-44. 王正林, 刘建. 抗相参雷达的侦察干扰一体化处理技术 [J]. 航天电子对抗, 009, 5(): Jerry L Eaves, Edward K Reedy. Principles of Modern Radar [M]. New Yor:Van Nostrand Reinhold Company, Yang Zi-jie,KE Heng-yu, Wen Bi-yan. Waveform Parameters Design for Sea State Detecting HF Ground- Wave Radar [J]. J. Wuhan Univ.(Nat. Sci. Ed.), 00,47(5): 杨子杰, 柯亨玉, 文必洋等. 高频地波雷达波形参数设计 [J]. 武汉大学学报 ( 理学版 ), 00, 47(5): Yang Zi-jie,Tian Jian-sheng. Design of HF Ground Wave Radar Receiver[J]. J. Wuhan Univ.(Nat. Sci. Ed.), 00,47(5): 杨子杰, 田建生, 高火涛等. 高频地波雷达接收机研制 [J]. 武汉大学学报 ( 理学版 ), 00,47(5): Khan R H,Mitchell D K. Waveform Analysis for High Frequency FMICW Radar [J]. IEE Proceedings-F,99,38(5): WEN Bi-yang,CHEN Lin-song, YANG Zi-jie. The Design of HF Radar Echo Simulator with DDS Chip [J]. J. Wuhan Univ.(Nat. Sci. Ed.), 00,47(5): 文必洋, 陈林松, 杨子杰等. 利用 DDS 器件设计高频雷达回波模拟器 [J]. 武汉大学学报 ( 理学版 ), 00,47(5): Webber G, Culp J. DRFM Requirements Demand Innovative Technology [J]. Microwave Journal,986,9(): Merrill I Solni. Introduction to Radar Systems [M]. BEIJING, Pubilishing House of Electronics Industry,00. 雷达系统导论 [M]. 北京 : 电子工业出版社, Xiang Dao-pu, Li Xiang-yang, MENG Xian-hai. Design and Implementation of a General Digital Radar Echo Simullator [J].Modern Rada, 007,9(7): 向道朴, 丽向阳, 孟宪海. 一种通用雷达回波模拟器的设计与实现 [J]. 现代雷达, 007, 9(7):

343 DYNAMIC MODELING OF QUADRATIC BUCK CONVERTER BASED ON STATE-SPACE AVERAGE METHOD GAO XUE-JUN, WU JIA, YE WEI The College of Electrical Engineering & Renewable Energy, Three Gorges University, Yichang, 44300, China Abstract:Space state average model and small signal AC model of Quadratic Buc converter based on state space average method is set up, the transfer function is obtained, which method can be used to analyze the stability of these witching power supplies. Finally, the validity of this model is confirmed by the simulin in Matlab. Key words:state Space Average Method; Quadratic Buc converter; transfer function; stability 基于状态空间平均法的平方型 Buc 变换器的动态建模 高学军伍佳叶炜 三峡大学电气与新能源学院, 湖北宜昌中国 摘要 : 采用状态空间平均法建立了平方型 Buc 变换器的状态平均模型和小信号交流模型, 推导出平方型 Buc 变换器的传递函数, 此方法可用于类似开关电源的稳定性分析 最后通过 Matlab 仿真, 验证了该模型的正确性 关键词 : 状态空间平均法 ; 平方型 Buc 变换器 ; 传递函数 ; 稳定性. 引言 电力电子系统的静态和动态性能的好坏与反馈控制设计密切相关 要进行反馈控制设计, 首先要建立被控对象的动态模型 电力电子系统框图如图 所示 : 电源电力电子变换器负载 驱动电路 控制器 PWM 调制器 图 电力电子系统结构 Fig. Bloc diagram of Power electronics System 在进行反馈控制设计前, 首先要建立电力电子变换器和 PWM 调制器的动态模型 在经典自动控制理论中, 一旦建立电力电子变换器和 PWM 调制器的传递函数, 就可以用频率特性法 根轨迹图法等来设计反馈控制网络的设计 [] 45

344 一般 DC/DC 变换器的建模方法分为两大类 : 一类为数字仿真法, 另一类为解析建模法 状态空间平均法 (State-Space Averaging Method) 是解析建模法中的一种, 它是目前应用最广泛 最基本的方法, 其优点是简单, 物理概念清楚, 可以利用线性电路理论对变换器系统进行稳态和动态分析, 对变换器的设计有重要的指导意义 []. 平方型 Buc 变换器原理 DC/DC 电源转换装置中, 通常需要适应宽范围的输入电压或是满足宽范围的输出电压 对于输出电压较低的情况, 传统的 Buc 变换器必须工作在相当低的占空比下才能满足要求 由于开关功率元器件导通时间短, 因而承受正向阻断电压应力时间长, 电压应力较大, 减少了开关功率元器件的使用寿命 同时由于受开关管最小开通时间的限制, 使变换器只能工作在较低的工作频率, 降低了变换器的效率 一种新型可实现高降压比的变换器如图 所示 : L S L + S C U S C R V0 S 图 平方型 Buc 变换器主电路 Fig. The main Circuit of Quadratic Buc Converter 该变换器是由两个基本 Buc 变换器串联而成, 其中包含两个 LC 滤波器, 一个开关管, 和三个二极管, 其电压转换比 M 是占空比 D 的平方, 故称为平方型 Buc 变换器 [5] -. 电流连续模式 (CCM) 在电流连续模式下, 二极管 s 与开关管 s 同步, 即 s 导通时, s 也导通, s 截止时, s 也截止 其等效电流如图 3 所示 : L S L + L S L + S Vc C S Vc C U S C R V0 U S C R V0 S S 图 3(a)s 导通状态等效电路 Figu3(a). The equivalent circuit when S is on - 图 3(b) s 截止状态等效电路 Fig 3(b). The equivalent circuit when S is off - 46

345 令 t = 0 时, s s 导通, s s ) 因反向电压而截止, 等效电路如图 3(a) 所示 s 导通期间, 电感 L L 为蓄能状态, 通过它们的电流线性增加, 电感电流斜率分别为 : dil U VC = () dt L di dt L 当 t = 时, i L i L 均达到最大值 Ton VC VO = () L 当 t Ton 时, s s 截止, 等效电路见图 3(b) s 截止期间, 由于楞次定律, 电感形成电流源对电容充电, s s 因正向电压而导通 电感 L 与输出滤波电容 C 上的储能通过二极管 s 形成回路而传 递能量给负载 通过 L L 的电流线性减小, 电感电流斜率分别为 : di dt L di dt L VC = (3) L VO = (4) L 当 t = T 时, i L i L 均达到最小值 当 t T 时, s 又导通, 进入下一个开关周期. 电流断续模式 (DCM) 在电流断续模式下, 二极管 s 与开关管 s 不同步, 即 s 导通时, s 已经截止, 此时, il i 在不 L 同步工作模式中, 电压转换率不仅与占空比 D 有关, 还与负载 R 有关, 且不同步工作模式下的电压转换率要大于同步工作模式下的转换率 对于降压转换器, 与其衍生型的转换器而言, 系统工作在连续电流模式下能得到较佳的输出特性 为了得到宽范围输出电压及其良好的输出特性, 一般通过选择合适的参数使系统工作在连续电流模式 [3] 对于平方型变换器, 可选择合适的参数使其工作在电流连续模式 3. 平方型 Buc 变换器的建模 电力电子电路由于存在开关器件, 随着开关状态的切换, 电路的拓扑相应地发生变化, 总体来说是一个时变非线性电路 但在相邻两次开关状态切换中间, 电路又可看作线性电路, 因此在开关状态保持期间, 可用线性定常数状态方程表示 [] 为了设计 Buc 电路的控制算法, 首先要建立电路的数学模型, 采用的方法有状态空间方法 滑模等多种方法 [6~9] 本文采用状态空间方法分析建立电路的模型, 为分析方便, 假设电路中开关管和二极管均为理想器件, 平方型 Buc 变换器工作在 CCM 方式 在开关管导通期间 ( 0 t dts ), 由图 3(a) 可得 : 47

346 48 ) ( t u L v v i i RC C C C L L L v v i i C C L L C C L L = + (5) 在开关管截止期间 ( S S T t dt ), 由图 3(b) 可得 : ) ( t u v v i i RC C C L L v v i i C C L L C C L L = + (6) 将式 (5) 和 (6) 合并平均, 得到 CCM 方式下平方型 Buc 变换器的状态空间平均模型 : ) ( t u L d v v i i RC C C d C L L d L v v i i C C L L C C L L = + (7) 上述的状态空间平均方程为非线性方程, 仍需要用扰动法求解小信号线性动态模型 现在对基本状态方程组施加扰动, 使其产生直流项和小信号项, 并忽略二阶交流小项, 得到平方型 Buc 变换器的小信号交流模型为 : = u d C i L V L D L U v v i i RC C C D C L L D L v v i i L C C C L L C C L L (8) 对式 (8) 进行 Laplace 变换, 可求得平方型 Buc 变换器的传递函数 输入到输出的传递函数为 : ) ( ) ( ) ( a s a s a s a s K s u s v s G o vu = = (9) 控制到输出的传递函数为 : ) ( ) ( ) ( a s a s a s a s b s b s b s d s v s G o vd = = (0) 式中 : 0 C L L C a =, R L C C R C L C D a + =, C L L C L C D a + + =

347 a 3 = C R D K =, L C L C DU b 0 =, b L C L C 3 D U =, C L C R DU b = L C 4 simulin 仿真及结果分析 假设平方型 Buc 变换器的参数为 : 输入电压 U = 4V, 输出电压 V O = V, 输出负载 R = 5Ω 为使其 工作在 CCM 方式下, 选择电路参数如下 : L = 400μH, C = 33μF, L = 350μH, C = 00μF, 开关频率 f = 50KHz 如图 4 所示 : V ref (s) 参考信号 误差信号 (s) E V O (s) G C (s) G m (s) (s) B (s) 反馈信号 H (s) G vd 图 4 平方型 Buc 变换器闭环系统框图 Fig 4. The closed-loop system of Quadratic Buc Converter 为平方型 Buc 变换器闭环控制系统, 式中 (s) G vd 为平方型 Buc 变换器的控制 d (s) 到输出 v o (s) 的 传递函数, G m (s) 为 PWM 脉宽调制器的传递函数, H (s) 为反馈分压网络的传递函数, GC (s) 为补偿网络 的传递函数 其占空比 D = VO U = 4 V V = 将以上各参数代入式(0), 得到平方型 Buc 变换器控制 到输出的传递函数为 : s s G vd ( s) = () s + 0 s s s 设参考电压 V ref = 5V, 锯齿波幅值 V m = 3V, 则反馈分压网络传递函数和 PWM 脉宽调制器的传递 函数分别为 : Vref 5V H ( s) = = = 0.4 () V V O G m ( s) = = (3) V 3 平方型 Buc 变换器系统原始回路增益函数为 : m G ( s) = G O m ( s) G vd ( s) H( s) = s 原始回路增益函数的零极点分布图和波特图如图 5 和图 6 所示 s s s s s (4) 49

348 图 5 零极点分布图 Fig 5. The Distribution of Zero-Pole Points 图 6 控制到输出传递函数波特图 Fig 6. The Bode Plot of Control-to-output Transfer Function 幅频图中可以看到在 0.7Hz 和.66Hz 处有振荡, 主要受两对复极点的影响 在.66Hz 处有最大增益 7.4dB, 系统的穿越频率为.8Hz, 相位裕量为 -38, 增益裕量为 -.db 显然系统是不稳定的, 系统稳态精度不能满足要求 MATLAB 中的控制系统工具箱提供了 SISO 设计工具 (SISO Design Tool),SISO 设计工具为线性系统的补偿器的设计和分析提供了一个交互式环境 [4] 导入系统的模型后, 如图 7 所示 : 5. 结论补偿后的开环波特图如图 8 所示 : 图 7 SISO tool 界面 Fig 7. SISO design Tas 40

349 图 8 补偿后的波特图 Fig 8. The Bode Plot after Compensation 穿越频率为 88Hz, 相位裕量为 97, 增益裕量为 7.dB, 满足系统动态和静态特性的指标 通过对平方型 Buc 变换器的反馈控制器的设计, 可以建立平方型 Buc 变换器闭环控制 siminlin 仿真模型, 仿真波形如图 9 所示 : 图 9 (a) 输入电压 4V, 给定参考电压 V Fig 9 (a). Input Voltage 4V & the Reference Voltage is V 图 9(b) 输入电压 4V, 给定参考电压 0V Fig 9 (b). Input Voltage 4V & the Reference Voltage is 0V 对于不同的给定参考电压, 输出电压均能较好地跟踪追随, 且调节时间短, 输出电压纹波小 本文利用状态空间平均法建立了平方型 Buc 变换器的数学模型, 并由数学模型得出了闭环系统传递函数 依此采用 PI 补偿控制器对系统的输出电压加以闭环校正, 并利用 MATALB 仿真分析了 PI 补偿控制器对平方型 Buc 变换器系统性能的改善 实验结果表明了基于状态空间平均法所建立的平方型 Buc 变换器动态模型的正确性 4

350 References( 参考文献 ). Xu Dehong. Modeling and Control of Power Electronic Systems [M]. Beijing: Machinery Industry Press,005 徐德鸿. 电力电子系统建模及控制 [M]. 北京 : 机械工业出版社,005.. Zhang Zhansong. Principle and Design of Switching Power Supply[M]. Beijing: Electronic Industry Press,004 张占松. 开关电源的原理与设计 [M]. 北京 : 电子工业出版社, D.Masimovic and S.Cu, Switching converters with wide DC conversion range, IEEE Trans. on Power Electronics,99, 6(): Zheng Jingtao, Ma Guang, Xu Youli. The SISOTOOL Applications in Corrector Design of the Automatic Control System, Microcomputer Information, 007. (4): 甄景涛, 马光, 许友丽.SISOTOOL 在自动控制系统校正中的应用 [J]. 微计算机信息,007, (4): GAO Xue-jun,Ye Wei, Study of Quadratic Converter with Wide Output Voltage Range, Proceedings of 9th Conference on Technology and Application of Electronic Information, July 8-3,009, China. 6. Wen Yafeng, Application of State Space Averaging Method for Switch Circuit Modeling, Electro-technical Application, 008, (8): 文亚凤. 状态空间平均法在开关电源动态建模中的应用 [J], 电气应用,008, (8): NI Yu, XU Jian-ping, Design of Sliding Mode Control Buc Converter With Bounded Input, Proceedings of the CSEE,00, (8): 倪雨, 许建平. 控制受限滑模控制 Buc 变换器设计 [J], 中国电机工程学报, 00, (8): FU Guang-jie; CAO Xue, Improvement and Application of a Small Signal Model for Boost Converter, Power Electronics, 009, (): 付光杰, 曹雪. 改进的 Boost 变换器小信号模型及其应用 [J], 电力电子技术, 009, (): JING Zhongzhao, HUANG Xi, Two-phase synchronous Buc DC/DC converter, Electric Power Automation Equipment, 00, (): 景中炤, 黄熙. 一种双相结构的同步 Buc DC/DC 变换器 [J], 电力自动化设备,00, ():

351 VOLTAGE LOW HARMONIC ANALYSIS OF SVPWM INVERTER YU SHI-QIU College of Electronic Information,Yangtze University, Jingzhou, Hubei, 43403, China Abstract: The basic principle of Voltage Space Vector PWM is introduced The modulation signal function and waveform of SVPWM are acquired. The control method of five-phase type SVPWM was implemented and the driving signal waveform was acquired based on TMS30F8.Carrier ratio impact on the inverter output phase voltage and line voltage low harmonic,and dead time impact on inverter output fundamental line voltage RMS was analyzed, and the research results was of referential significance for practice. Keywords: Space vector PWM;Inverter;Harmonic SVPWM 逆变器低次电压谐波分析 余仕求长江大学电子信息学院, 湖北荆州中国 摘要 : 介绍电压空间矢量脉宽调制 (SVPWM) 的基本原理, 得到五段式 SVPWM 调制信号函数及波形 以 TMS30F8 为基础, 实现五段式 SVPWM 控制算法, 得到驱动波形 分析载波比对逆变器输出相电压和线电压低次谐波的影响以及死区时间对线电压基波有效值的影响 研究结果对实际应用具有重要的参考意义 关键词 : 空间矢量 PWM; 逆变器 ; 谐波. 引言电压空间矢量脉宽调制 (SVPWM) 控制是异步电动机变频调速控制方法之一 与正弦波脉宽调制 (SPWM) 方法相比, 其谐波电流和转矩脉动都更小, 直流电压利用率更高 [] 从电压空间矢量组合方式来说, 有七段式和五段式 [] 五段式的开关损耗小, 但谐波要大些 关于五段式 SVPWM 逆变器输出电压高次谐波的分析论文比较多, 而基于实测的五段式 SVPWM 逆变器输出电压低次谐波的分析论文很少见 正因如此, 本文从分析五段式 SVPWM 驱动信号出发, 利用 TMS30F8 实现了五段式 SVPWM 驱动输出, 得到了驱动信号波形, 进行了驱动信号的谐波分析 当忽略开关管的开关过程时, 驱动信号与逆变器输出电压具有相似性 测试结果说明了载波比 N 和死区时间对逆变器输出电压低次谐波的影响. SVPWM 基本原理 三相电压逆变器主电路如图 所示 43

352 P U d T T 3 BU BV BW T 5 O U d U V W BX BY BZ T 4 T 6 T O N 图 三相电压逆变器主电路 Fig Three-phase voltage inverter main circuit 若用上桥开关状态表示三相逆变器开关状态, 表示开关导通, 0 表示开关断开 共有 8 种开 关状态 : , 对应产生 8 个基本电压空间矢量, 分别用 U 0,..., U 7 表示 其中 U,, U 6 为 6 个非零基本电压空间矢量, U,U 0 7 为 个零基本电压空间矢量 6 个非零基本电压空间矢量大小相等, 空间上互差 60º, 并将整个平面等分为 6 个区间, 分别用 0 至 5 表示, 每个区间占 60 合成电压空间矢量 U r 总是处在其中一个区间内, 并由该区间相邻的 个基本电压空间矢量合成, 如图 所示 U 4 (0) U 3 (00) 3 U 5 (00) +j b U θ au 0 4 U (0) 5 U r + U (00) U 6 (0) SVPWM 通过控制 PWM 占空比来改变合成电压空间矢量 U r 的大小和方向 以 0 区间为例, 设 PWM 周期为 T, U 作用时间为 at, U 作用时间为 bt, 零矢量 U, U 0 7 作用时间为 (-a-b)t, 其结果即是合成电压空间矢量 U U U U 合成为 : r r 由 和 U r 图 基本电压空间矢量合成 Fig Synthesis of the basic voltage space vector = au + b () U 设 n 表示区间号, 在 0~5 区间内, 合成电压空间矢量 U 一般表达式为 : r 44

353 = + U r au n+ bu n+ () 式中 :a b 均为小于 的正数, 且 a+b 改变系数 a b 的值, 可以控制使合成空间电压矢量 U r 的位置和大小 设 U r 与 U 的电夹角为 θ, 当 U r 长度和 θ 一定, 由图 及正弦定理可得 : Ur a U b U = = (3) sin( π / 3) sin( π / 3 θ) sinθ 由图 知, U = U = U d, 代入上式得 0 区间 a b 为 : U r sin( π /3 θ) a = = M sin( π / 3 θ ) 3U d (4) U r sinθ b = = M sinθ 3U d 由上式很容易得到各区间 a b 计算式 : an ( ) = Msin[ π /3 ( ωt nπ /3)] (5) bn ( ) = Msin( ωt nπ /3) 在进行数字处理时, 须将 θ 离散化为 θ = ωt, 为 PWM 周期 T 的计数值,ω 为 U r 旋转的电角频率 由于在 6 个区间里 a b 的计算方法是一样的, 因此将 0 区间 a b 计算式推广到 6 个区间, 得到 a b 的一般离散化公式 : a( n, ) = M sin[ π / 3 ( ωt nπ / 3)] (6) b( n, ) = M sin( ωt nπ / 3) 随着 的增加, 当 T 大于 π/3 时,n 加 当 n 大于 5 时,n 和 均回零, 周而复始 3. 五段式 SVPWM ω 3. 五段式 SVPWM 驱动模式 SVPWM 有五段式和七段式两种驱动模式 五段式驱动模式开关损耗小, 但谐波大一些 0 区间五段式驱动模式如图 3 所示 BU BV BW T 0 a T bt a T T 0 图 3 0 区间 5 段式驱动模式 Fig3 5-stage drive mode in 0 range 45

354 由 等 5 个开关状态组成, 零矢量 U 0 作用时间为 T0 = ( a b) T, 两侧对称 分布 ; 矢量 U (00) 作用时间为 at, 两侧对称分布 ; 零矢量 U (0) 作用时间为 bt, 中心对称分布 在一个 PWM 周期内开关次数为 4, 其中有一组桥的开关不动作, 所以开关损耗小 由 () 式得到在各区间每相上桥开关导通时间, 如表 所示 Table 表 各区间上桥开关导通时间表 The up bridge switch conduction interval schedule in each region 区间号 BU(U 相 ) BV(V 相 ) BW(W 相 ) 0 (a+b)t bt 0 at (a+b)t 0 0 (a+b)t bt 3 0 at (a+b)t 4 bt 0 (a+b)t 5 (a+b)t 0 at 3. 五段式 SVPWM 开关控制函数开关控制函数用来决定 PWM 的占空比 以 U 相为例, 设 U 相开关控制函数为 KU( ω t) 将式(5) 中 a b 代入表, 以 0 区间起点作为坐标原点,0~ 等 3 个区间放在坐标原点右侧,3~5 等 3 个区间移到坐标原点左侧, 得到 U 相连续的开关控制函数 KU( ω t) 的表达式 : 0; π ωt < π / 3 [3 区间 ] KU ( ω t) = MT sin( ωt + π / 3); π / 3 ωt < 0 [4, 5 区间 ] MT sin( ωt + π /3); 0 ωt < π /3 [0, 区间 ] (7) 0; π / 3 ωt < π [ 区间 ] KU( ω t) 波形如图 4 所示 KU -π -π /3 0 π /3 π ω 图 4 KU(ωt) 波形图 Fig4 Waveform of KU(ωt) 利用三相对称原理, 不难得出另两相上桥开关控制函数 KV( ωt), KW( ω t) 表达式 KU( ω t) 只是一模拟量 在数字控制里, 须先将 KU( ω t) 离散化 用三角波作为载波, 以 KU( ω t) 作调制波 采用规则采样法产生 PWM, 开关控制函数 KU( ω t) 的离散公式为 : 0; π jωt < π / 3 [3 区间 ] MT sin[( j + ) ωt + π / 3]; π / 3 jωt < 0 [4,5 区间 ] KU ( jωt ) = (8) MT sin[( j + ) ωt + π /3]; 0 jωt < π /3 [0, 区间 ] 0; π / 3 jωt < π [ 区间 ] j 为 PWM 周期序列号, 范围为 [ π π, ] ωt ωt 46

355 开关管的驱动信号为逻辑量, 用 BU ( ω t) 表示 在 KU( ω t) 为零的 3 区间内, BU ( ω t) = 0, 而在 KU( ωt) 为非零的 区间内, BU ( ω t) 为 PWM 调制波 在某一个 PWM 周期内驱动信号 BU ( ω t) 离散表达式为 : 0; π ωt < π / 3 [3 区间 ] 0; jωt ωt < ( j+ ) ωt ωku( jωt) [0,,4, 5 区间 ] BU ( ωt) = ; ( j + ) ωt ωku ( jωt ) ωt < ( j + ) ωt + ωku ( jωt ) [0,,4,5 区间 ] (9) 0; ( j+ ) ωt + ωku( jωt) ωt < ( j+ ) ωt [0,, 4,5 区间 ] 0; π /3 ωt < π [ 区间 ] 4. 实验波形结果与分析 TMS30F8 具有实现 SVPWM 驱动功能 [3] 利用上述结果, 在 TMS30F8 上编程实现该算法, 得到 SVPWM 输出波形 示波器测得 U 相上桥驱动波形如图 5(a) 所示,RC 低通滤波器后的驱动波形如图 5(b) 所示, 该波形与开关控制函数 KU( ω t) 波形基本一致 将示波器两输入端分别与两上桥驱动端连接, 得到两驱动之间信号波形, 如图 (a) 所示 ; 图 (b) 为经 RC 低通滤波器后得到的波形, 该波形近似正弦波 a) ms V b) ms V 图 5 上桥驱动信号波形 ( 载频 5KH Z, 载波比 N=30, 调制度 M=) Fig5 waveform of the up bridge drive signal(carrier frequency: 5KH Z,N=30,M=) (a) ms V (b) ms V 图 6 两驱动之间信号电压波形 ( 载频 5KH Z, 载波比 N=30, 调制度 M=) Fig6 voltage waveform Between the two drive signal(carrier frequency: 5KH Z,N=30,M=) 47