四轮驱动电动汽车车速估计与DYC控制研究

Research on Vehicle Speed Estimation and DYC Control of Four Wheel Drive Electric Vehicle

四轮驱动电动汽车因每个车轮独立可控,在对车辆进行直接横摆力矩控制(Direct Yaw-moment Control,DYC)时需要根据车轮滑移率选择干预车轮而施加合适的控制转矩,而滑移率的获取有赖于精确的车速信息。设计了基于扩展卡尔曼滤波的车速估计算法,依据车轮滑移状态及车辆状态参数提出了直接横摆力矩控制策略及期望转矩与期望横摆力矩的计算方法。在CarSim与Simulink联合仿真环境下对所提出的车速估计算法及直接横摆力矩控制策略进行了离线仿真。仿真结果表明,车速估计算法能准确估计车速信息,绝对误差较小;直接横摆力矩控制策略能够根据横摆角速度的偏差,正确地选择干预车轮,及时地控制车轮转矩,从而保持车辆的横向稳定性。

Four wheel drive electric vehicle for each wheel can be controlled independently,the Direct Yaw-moment Control of vehicle need based on wheel slip ratio of wheels to select the Intervening wheel to apply appropriate control torque,The acquisition of slip rate depends on the precise speed information.The vehicle speed estimation algorithm based on Extended Kalman Filter is designed,and the direct yaw moment control strategy is presented based on the wheel slip state and the vehicle state parameters. In the Car Sim and Simulink simulation environment speed estimation algorithm and direct cross yaw moment control strategy are used in the off-line simulation of the proposed. The simulation results show that the speed estimation algorithm can accurately estimate the speed information,absolute error is small;the direct yaw moment control strategy can according to the deviation of the yaw angular velocity and correctly choose intervention wheel,in a timely manner to control wheel torque,so as to keep the vehicle lateral stability.