PERFORMANCE EVALUATION OF INTEGRATED CONTROL OF DIRECT YAW MOMENT AND SLIP RATIO CONTROL FOR ELECTRIC VEHICLE WITH REAR IN-WHEEL MOTORS ON SPLIT-MU ROAD

Abstract

Three different torque control algorithms are compared and evaluated for rear wheel drive electric vehicle (EV COMS) with in-wheel motors on split-mu road. The performance of direct yaw moment control, slip ratio control and integral control of both direct yaw moment and slip ratio control are studied by applying these control algorithms to electric vehicle for a straight motion on a split-mu road. The split-mu road disturbs the straight motion and vehicle will deviate from straight path with some error. In simulation, driver model is applied and driver effort of steering wheel angle eliminates this error in all the three cases. The simulation results show that the integral torque control schemes exhibit better performance as compared to direct yaw moment control and slip ratio control as it needs very little driver effort for vehicle straight motion. The three torque control schemes are also compared experimentally on a split-mu road using EV COMS. The desired yaw rate is set to zero in the software and the vehicle trajectory with reference to the desired straight path is recorded and compared. The integral control showed little deviation of test vehicle yaw rate from the desired zero yaw rate as compared to the other two control algorithms.