Control method of electronic differential of EV with four in-wheel motors

In order to realize the electronic differential system (EDS) in an electric vehicle (EV) with four-wheel drive, the project that based on four in-wheel brushless DC motors is proposed. According to the motor control theory and the traditional EDS, the whole design of the controller is given. Using the Ackermann-Jean-tand turning model and the four wheels steering system, the speed of four wheels is calculated independently during the turning with the EDS, the principle of torque distributing for four motors is discussed later. The control strategy for the consistency of the four wheels is designed. The different work conditions, including the condition of the vehicle with the uniform speed, accelerating and decelerating, are researched, and the control strategy of the EDS for the vehicle with four in-wheel motors is designed. By using four 700W 8 poles motors as example, the simulation and the no-load experiment are done. Simulation and experiment results validate the rationality of the controller, and show that the system has more favorable dynamic performance. The control strategy of the EDS fulfilled the request of the EV with four in-wheel motors.