The control strategy of electronic differential for EV with four in-wheel motors

Abstract

A prototype of Electric Vehicle (EV) with four-wheel-drive is presented, which, instead of a complex mechanical transmission system, is equipped with an adequate controller known as Electronic Differential System (EDS). This EDS distributes torque and power to each in-wheel motor according to the requirements, adapts the speed of each motor to the driving conditions and simulates the behavior of a differential. Using the Ackermann-Jeantand turning model and the four wheels steering system, the speed of four wheels is calculated independently during the turning with the EDS. The control strategy for the consistency of the four wheels is designed. The different work conditions including the condition of the vehicle with the constant speed, accelerating and decelerating are researched, and the control strategy of the EDS for the vehicle with four in-wheel motors is designed. For verifying this strategy, the paper used the in-wheel motor as example. The simulation with Matlab/Simulink and the relevant experiment are made. Simulation and experiment results verified the rationality of the controller, and show that the system has more favorable dynamic performance. Results also indicate that this strategy can be successfully implemented into the traction drive of EV.