Torque Vectoring Control for Handling Improvement of 4WD EV

Abstract

Exploiting the structural merit that electric motors can be controlled precisely in speed und torque, this paper investigates the use of Torque Vectoring Control (TVC) for improving handling of electric vehicles. The strategy consists of two control levels. The upper level controller layer achieves reference yaw rate tracking, by using the 2-DOF planar bicycle model with a linear tire model to calculate the desired yaw rate. Then with sliding mode control law the desired yaw moment is determined. The lower control level determines control inputs for four driving motors by means of optimum traction distribution. Simulations are carried out by using the co-simulation of vehicle dynamics software CarSim and Simulink to verify the effectiveness of this control system and the effects of parameter variations (friction coefficient and throttle).