基于转矩矢量控制分布式电驱动客车操纵性改善方法

Handling Improvement for Distributed Drive Electric Bus Based on Torque Vectoring Control Method

摘要:

基于分布式电驱动系统，设计转矩矢量控制提高分布式驱动电动客车操纵性能。针对大客车转向时的载荷变化大，以及轮胎、悬架、转向系耦合特性强的特点，采用多项式描述前后轴等效侧向力和回正力矩与侧偏角关系，并设计质量估计算法在车轮垂向载荷变化时对侧偏刚度进行修正。考虑车辆非线性特性，定义车辆理想转向特性，并设计不同转角与车速下的直接横摆力矩控制前馈项。为提高控制器鲁棒性，采用抗积分饱和的滑模变结构控制算法设计直接横摆力矩控制反馈项。仿真和试验结果表明，施加操纵性改善控制后，车辆更接近中性转向，蛇行试验峰值转角平均值降低21%以上，操纵性能显著提升。

Abstract:

Based on the distributed electric drive system， a handling improvement method was designed for a distributed drive electric coach using torque vectoring control. In view of the large load transfer， the strong coupling characteristics of tire， the suspension， and the steering system during coach corning， the relationship among equivalent lateral force， aligning torque， and the tire sideslip angle were described respectively by using polynomials. A mass estimation algorithm was designed to modify the lateral stiffness when the vertical load of the wheel changed. The vehicle reference steering characteristics was defined considering vehicle nonlinear characteristics， and the feedforward term of torque vectoring control at different steering angles and speeds was designed. In order to improve the robustness of the controller， an anti-integral saturation sliding mode variable structure control law was used as the feedback item of the torque vectoring control. The simulation and experiment results show that by using the proposed controller the vehicle steering characteristic is closer to neutral steering， and the mean value of peak steering angle in slalom test is reduced by more than 21%， which means the handling performance is significantly improved.