针对分布式驱动电动汽车各车轮电机力矩和液压制动力矩可独立控制的特点,以操纵稳定性为目标,设计电机与液压制动复合分配的控制策略.控制策略采用分层控制的结构,上层运动控制器根据驾驶员输入和车辆状态的反馈求取广义力,下层控制分配器在执行器约束及速度约束下,考虑轮胎纵侧耦合特性对横摆转矩的影响,采用二次规划法进行转矩分配,实现车辆的稳定性控制效果.最后利用CARSIM和MATLAB软件对电液复合算法进行了联合仿真,并进行了实车试验来验证算法,最终的仿真和试验结果表明复合分配控制策略的控制效果相对仅用电机控制时要好,提高了车辆的稳定性控制效果.
Based on the characteristic of distributed drive electric vehicles that the torque of motors and hydraulic brake system can be controlled, an algorithm combing motors and hydraulic system was proposed with the aim of stability control. The algorithm used a hierarchical control structure. The upper layer calculates the generalized force based on the driver input and vehicle state. Under the constraint of actuators and speed and the influence of tire coupling characteristic, the lower layer takes quadratic programming method to optimize torque allocation. Finally the algorithm was simulated on CARSIM and MATLAB platform and verified by vehicle tests. The results of simulations and tests show that the algorithm can improve the stability. And the control result of the algorithm of motors and hydraulic brake system is better than that of motors.