Design of Torque Distribution Strategy for Four-Wheel-Independent-Drive Electric Vehicle

Abstract

In order to further improve the handling stability of four-wheel-independent-drive electric vehicle, the control strategy designed in this paper adopts the hierarchical structure. The upper controller uses the vehicle dynamics principle and relevant expert control experience to formulate the corresponding fuzzy control rules to build the fuzzy controller. The linear two-degree-of-freedom reference model is built to obtain the desired driving state information of the vehicle, and the corresponding deviations are obtained by comparing with the actual vehicle state information, which are the input of the designed fuzzy controller to obtain the additional yaw moment required for stable driving of the vehicle. The lower controller obtains the generation mechanism of additional yaw moment through the 7-degree-of-freedom vehicle model and the characteristics of tire friction ellipse. Based on this, the regular distribution strategy is designed to obtain the driving torque on each driving motor. Through Carsim/Simulink joint simulation and hardware-in-the-loop experiments based on MicroAutoBox, the effectiveness and real-time performance of the designed control strategy are fully verified, and accelerate the development process of vehicle controller.