四轮毂电机电动车的电子差速控制方法

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

为了实现四轮独立驱动电动车电子差速系统,通过对电机驱动理论及传统电子差速方法进行分析,提出了基于4台无刷直流轮毂电机的控制方案,给出了控制器总体设计思路。采用全轮转向方式,利用Ackermann-Jeantand转向模型,计算了电子差速过程中随着转向角度变化的各个车轮的车速,同时分析了转向时转向轮之间的转矩分配问题。给出了电动车行驶时的四轮速度一致性协调方案,研究了车辆匀速运行和加减速运行时的工作状态,并确定了四轮驱动电动车转向时的电子差速控制策略。通过4台700W的8对极电机进行了仿真和空载实验,实验结果表明,电动车控制器设计合理,系统具有良好的动态性能;电子差速系统控制策略正确,能够满足四轮独立驱动电动车的行驶要求。

In order to realize the electronic differential system （EDS） in an electric vehicle （EV） with fourwheel 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-Jeanrand 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.