Lateral Stability Control System Based on Cooperative Torque Distribution for a Four In-Wheel Motor Drive Electric Vehicle

In this study, nonlinear and actuator redundancy problems are proposed in the vehicle lateral stability control system for a four in-wheel motor drive electric vehicle. The solution of tire nonlinear problem uses nonlinear model predictive control method to obtain the target direct yaw moment. The torque distribution algorithm is designed to use the constrained optimal control theory based on Lagrange multiplier method. Motor torque often cannot meet the demand of torque because of the limitation of torque provided by the motor; this paper proposes the control strategy based on cooperative in-wheel motor and hydraulic brake during braking. A CARSIM/MATLAB co-simulation is conducted for algorithm verification. It is found from the simulation results that the proposed control scheme which is effective to trace the desired yaw rate and side-ship angle simultaneously as well as guaranteed the vehicle lateral stability.