电动轮汽车电液复合ESP的协调控制研究

Research on coordinated control of electro-hydraulic compound ESP for electric wheel

传统车辆的车身电子稳定系统(Electronic Stability Program,简称ESP)通常采用液压系统进行控制,液压控制虽有承载能力大的优点,但其在动态响应性能上存在局限性。针对纯液压ESP在动态控制上的不足,鉴于轮毂电机具有优秀的动态控制性能,从提升车辆ESP性能这角度出发,在电动轮汽车上开展电液复合ESP的协调控制方法研究。应用Matlab/Simulink和Car Sim两软件分别建立了电动轮汽车的理想二自由度参考模型、Car Sim整车模型、轮毂电机模型、失稳状态判断模型、双层控制器模型,在双移线行驶工况下,分别对无ESP、纯液压ESP、电液复合ESP这三类情况进行联合仿真。仿真结果对比后表明:在电动轮汽车上,电液复合ESP比无ESP及纯液压ESP具有更佳控制效果,如横摆角速度响应精度提升15%以上,响应速度缩短27%,车轮滑移率保持在比较合理的范围内(低于20%),防滑性与行驶安全性更好。此项研究将为电动轮汽车电液复合ESP的协调控制进一步研究提供理论依据。

The traditional Electronic Stability Program（ ESP） is usually controlled by hydraulic system. Although hydraulic system has an advantage of large carrying capacity,it has a limitation on the dynamic response performance. Aiming at the deficiency of the pure hydraulic ESP on dynamic control and in view of the excellent dynamic performance of in-wheel motor,the coordinated control method of electro-hydraulic compound ESP on in-wheel motor driven vehicle is studied to improve the dynamic response performance of ESP. The ideal in-wheel motor driven vehicle model of twodegrees,Car Sim vehicle model,vehicle in-wheel motor model,the instability state judgment model,double-layer control model is built by applying Matlab/Simulink and Car Sim,respectively. Under the double line driving condition,the co-simulation on in-wheel motor driven vehicle without ESP,with pure hydraulic ESP and with electro-hydraulic compound ESP were conducted. Comparing the simulation results,it indicates that in-wheel motor driven vehicle with electro-hydraulic compound ESP has a better control effect than without ESP and with pure hydraulic ESP,its response accuracy of yaw rate is increased more than 15%,the response speed is decreased 27%,the wheel slip ratio is kept in a reasonable range（ less than 20%）,and the skid resistance and driving safety are improved. The study will provide the theory basis for further research on the coordinated control of electro-hydraulic compound ESP on in-wheel motor driven vehicle.