四轮毂驱动电动汽车电机故障检测及容错控制策略

Research on motor fault detection and fault-tolerance control strategy for four wheel drive electric vehicle

针对四轮毂驱动电动汽车行驶过程中电机故障的危险工况,提出了一种基于模糊控制律的电机故障检测方法;为了保证车辆运行稳定性,设计了具有双层控制策略的四轮毂驱动电动汽车驱动容错控制系统,上层控制器中将汽车横摆角速度和质心侧偏角的实际值与理想值的差值作为滑模面,滑模控制的输出值为维持车辆稳定运行的附加横摆力矩;下层控制器采用了2种转矩分配策略,一是加入模糊控制器输出电机运行因子的二次规划转矩分配策略,二是以车辆期望转矩值与四倍低附着侧车轮最大转矩值为依据,执行基于模糊控制律的转矩分配策略。仿真和实验结果表明:本文所设计的驱动容错控制策略能够在某一个或两个电机突发故障时,仍能保持汽车按照预定的方向稳定行驶。

Aiming at the dangerous condition of motor fault in four wheel drive electric vehicle,a motor fault detection method based on fuzzy control law was proposed.At the same time,in order to ensure the stability of the vehicle,a fault-tolerant control system with double-layer control strategy was designed.The upper controller takes the difference between the actual value and the ideal value of the vehicle yaw rate and the mass center sideslip angle as the sliding surface,the output value of sliding mode control is the additional yaw moment to maintain the stable operation of the vehicle.Two torque distribution strategies were proposed in the lower controller.One is the quadratic programming torque distribution strategy with fuzzy controller output motor operation factor,and the other is the torque distribution strategy based on the fuzzy control law according to the expected torque value of the vehicle and the maximum torque value of four times of the wheel on the low attachment side.The simulation and experimental results show that the fault-tolerant control strategy can keep the vehicle running stably in the predetermined direction in case of sudden failure of one or two motors.