4WID电动汽车转矩优化分配控制策略研究

Research on Optimal Distribution Control Strategy of 4WID Electric Vehicle Torque

为提高四轮独立驱动电动汽车(4WID)操稳性借助其具备各轮转矩独立可控的特征,可通过优化分配各车轮转矩的方式来提升其运行稳定性。针对此种控制形式提出分层控制方法,在上层控制器中将汽车横摆角速度的实际值与理想值的误差及误差变化率作为控制量输入,运用模糊PID控制输出维持车辆稳定运行的附加橫摆力矩,下层控制器是基于优化函数算法的转矩分配控制策略来优化各轮转矩。搭建Carsim/Simulink整车控制模型,并在低附着路面和不同的行驶车速条件下仿真验证。仿真结果显示,该转矩优化分配控制策略能够使各车轮转矩得到合理分配,并能使车辆质心侧偏角得到有效控制,进而使车辆的操纵稳定性得以改善。

In order to improve the stability of the four-wheel independent drive electric vehicle(4WID),with its independent and controllable characteristics of each wheel torque,the running stability can be improved by optimizing the torque distribution of each wheel.A hierarchical control method is proposed for this type of control.In the upper controller,the error between the actual value of the vehicle yaw rate and the ideal value and the error rate of change are used as the control quantity input,and the fuzzy PID control output is used to maintain the additional horizontal operation of the vehicle.The pendulum torque,the lower layer controller is based on the torque distribution control strategy of the optimization function algorithm to optimize the torque of each wheel.The Carsim/Simulink vehicle control model was built and simulated under low adhesion road conditions and different driving speeds.The simulation results show that the torque optimal distribution control strategy can reasonably distribute the torque of each wheel and effectively control the vehicle’s centroid angle,thus improving the steering stability of the vehicle.