elvishu@artc.org.tw Matlab/Siulink MSC/Carsi Siulation in the Design of Control Logic for Electric Power Steering Systes Abstract The electric power steering (EPS) syste has obvious advantages over the conventional hydraulic power steering (HPS) syste in ters of engine efficiency, space utilization, and environentally friendly issues. It substitutes an electric otor for a coplex hydraulic syste. The otor only operates when required. Therefore, this syste not only saves energy but also reduces cost and weight. On the other hand, the electric power steering syste can solve probles associated with the conventional one. The purpose of this research is to develop of an electric power steering control logic which is coposed of base-assist, daping, return, inertia, and ipact copensation logic. In addition, this research purposes a new ethod to iprove the copensation perforance. It eploys steering angle signal and vehicle speed signal into the control logic to tune the copensation gain iediately. As a result, it can increase the effect of copensation, optiize the steering response, and iprove the steering feel. For describing the vehicle dynaics and odeling the
steering feel accurately, this research integrates Matlab/Siulink with MSC/CarSi. Co-siulation technique is used to validate the proposed idea Keyword: electric power steering, base-assist logic, return copensation logic, daping copensation logic, inertia copensation logic, ipact copensation logic, and co-siulation. (Hydraulic Power Steering, HPS) (Electric Power Steering, EPS) Chen Chen[1] Newton s Second Law Parar Hung[2] Lagrange s Equations Liao Du[3] Matlab/Siulink Adas Choi[4] SiPowerSystes Matlab/Siulink Kurishige [5] Pang [6] [7~11] Matlab/Siulink MSC/CarSi
MSC/CarSi Matlab/Siulink (colun-type) (torque sensor) (electric otor) (reduction gear) (electronic control unit)
SteeringWheel, T, J, B, θ h Torque Sensor, K t Motor, T, J, B, θ Gearbox, n Steering Colun, J sc, B sc, θ sc Rack & Pinion, Fr, r, br, kr, xr, R (Newton s Second Law) (1) (2) (3) (4) (5) (6) (7) T h K ( θ θ ) B & θ = J & θ (1) t sc xr T ˆ + T f B & scθ sc + K t ( θ θ sc ) kr ( θ sc ) = J & scθ sc r (2) kr xr (θ sc ) Fr br x& r = && r xr (3) r r T ˆ = n (4) T T = I (5) k t E = & θ k IR IL & (6) b T B & θ = J & θ (7)
T h K t B J T f B sc J sc k r F r b r r r T k t E k b R L B J (Coulob friction odel) (8) F fric µ N v friction force sliding velocity F fric = µ N sign(v) (8) (base assist logic) (return copensation logic) (daping copensation logic) (inertia copensation logic) (ipact copensation logic)
torque wheel Steering Vehicle speed angle wheel Steering wheel Steering acceleration angular torque on Reaction shaft steering wheel Steering velocity angular logic Base aassist Return copensation logic Daping copensation logic Inertia copensation logic Ipact copensation logic controller Motor & otor Electric drive Motor
(overshoot) [9] (Reaction Torque on Steering Shaft, RTSS) (free yaw response) (flick)
[9] Matlab/Siulink MSC/CarSi Matlab/Siulink (integrated siulation) (on-center handling test) ISO 13674-1[12] 1k/hr.2Hz.2g
1 without assist with assist 5 Steering torque (N) -5-1 -2-15 -1-5 5 1 15 2 (on-center handling).2.15.1 Lateral acceleration (g).5 -.5 -.1 -.15 -.2-2 -15-1 -5 5 1 15 2 (on-center handling) 5k/hr 3
5 4 3 12degrees @5k/hr 1degrees @5k/hr 5degrees @5k/hr 2 Steering torque (N) 1-1 -2-3 -4-5 -1-5 5 1 5 4 3 1k/hr 8k/hr 6k/hr 2 Steering torque (N) 1-1 -2-3 -4-5 -5-4 -3-2 -1 1 2 3 4 5 15k/hr 3k/hr
12 1 without return @ 3k/hr with return @ 3k/hr without return @ 15k/hr with return @ 15k/hr 8 6 4 2.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Tie (sec) 5k/hr 8k/hr 8 6 without daping @ 5k/hr with daping @ 5k/hr without daping @ 8k/hr with daping @ 8k/hr 4 2-2 -4 1 2 3 4 5 Tie (sec)
6 4 3 without inertia @ 3k/hr with inertia @ 3k/hr 2 Steering torque (N) 1-1 -2-3 -4-6 -4-2 2 4 6.1 MSC/CarSi MSC CarSi
4 3 with ipact cop. without ipact cop. 2 1-1 -2-3.5 1 1.5 2 2.5 3 3.5 4 Tie (sec) Matlab/Siulink MSC/CarSi
[1] Xiang Chen and Xiaoqun Chen, Control-Oriented Model for Power Steering Syste, SAE TECHNICAL PAPER SERIES, 26-1-938. [2] Manu Parar and John Y. Hung, Modeling and Sensorless Optial Controller Design for an Electric Power Assist Steeing Syste, Industrial Electronics, Volue 3, Nov 22, pp.1784-1789. [3] Y. Gene Liao and H. Isaac Du, Modeling and analysis of electric power steering syste and its effect on vehicle dynaic behaviour, Int. J. of Vehicle Autonoous Systes, Volue 1, No. 2, 23. [4] Chinchul Choi, Wootaik Lee, Jung-Pyo Hong, SeongJoo Ki, JaeGoo Ki, JunGyu Song and JunNa Oh, Multi-doain odeling of Electric Power Steering with PMSM Drive Syste, Electric Machines & Drives Conference, Volue 2, May 27, pp.1355-136. [5] Masahiko Kurishige, Kouji Fukusui, Noriyuki Inoue, Takayuki Kiguku and Shigeki Otagaki, A New Electric Current Control Strategy for EPS Motors, SAE TECHNICAL PAPER SERIES, 21-1-484. [6] Du-Yeol Pang, Bong-Choon Jang and Seong-Cheol Lee, Steering Wheel Torque Control of Electric Power Steering by PD-Control, ICCAS25, Jun 25. [7] Masahiko Kurishige, Takayuki Kifuku, Noriyuki Inoue, Susuu Zeniya and Shigegi Otagaki, A Control Strategy to Reduce Steering Torque for Stationary Vehicles Equipped with EPS, SAE TECHNICAL PAPER SERIES, 1999-1-43. [8] Ji-Hoon Ki and Jae-Bok Song, Control logic for an electric power steering syste using assist otor, Mechatronics, Volue 12, Apr 22, pp. 447-459. [9] Masahiko Kurishige, Hideyuki Tanaka, Noriyuki Inoue, Kazuichi Tsutsui and Takayuki Kifuku, An EPS Control Strategy to Iprove Steering Maneuverability on Slippery Roads, SAE TECHNICAL PAPER SERIES, 22-1-618. [1],,,,,,, 95 12. [11] Yasuo Shiizu and Yashihiro Oniwa, Control for Moent of Motor Inertia on EPS, SAE TECHNICAL PAPER SERIES, 26-1-1179. [12] International Standard Organization, Road vehicle Test ethod for the quantification of on-centre handling Part 1: Weave test, ISO 13674-1:23