Hierarchical Control Algorithm for Stability Enhancement of 4WD Electric Vehicle with In-Wheel Motors

Abstract

According to the characteristic that each wheel torque of 4WD electric vehicle is independent controllable, the control allocation method with hierarchical structure to optimize the distribution of motor torque can improve the handling stability of the vehicle. The controller is composed of an upper controller and a lower distributor, of which the upper controller can calculate the generalized force of longitudinal force and yaw moment that the vehicle needed based on the vehicle state, and the lower controller is used to figure out the torque allocated to each wheel. The whole vehicle and steering system models are established for simulation and demonstration through the application of Matlab and Simulink. The simulation results show that the control allocation method with hierarchical structure can effectively improve the handling stability of the vehicle.