基于轮胎合力计算与分配的车辆横向稳定性控制研究

摘要

In view of that the calculation and allocation algorithm of tire resultant force is only suitable for the vehicles with four-wheel independent braking and steering, and the achievable range of longitudinal resultant force and yaw moment of tire is limited by road adhesion coefficient, a control strategy for vehicle lateral stability with real-time calculation, adjustment and dynamic allocation of tire’s longitudinal resultant force and yaw moment is proposed. Taking into account the calculation error of linear feedback, offline numerical optimization and nonlinear programming are adopted to determine the achievable range of tire’s longitudinal resultant force and yaw moment, the resultant forces and moments calculated are adjusted into the achievable range and dynamically allocated. The controller for slip ratio and front wheel sideslip angle is designed to make tire friction force track each component force without estimating the side force of rear wheel while ensuring accuracy. Finally a simulation is conducted and verified by a driver-in-the-loop test based on LabVIEW PXI and veDYNA. The results show that the lateral stability control of vehicle based on resultant force calculation and allocation can effectively enhance the track maintenance capability of vehicle, improve vehicle stability on low adhesion road, with a control effect better than that of sliding mode variable structure control.%鉴于轮胎合力计算与分配算法只适用于四轮独立制动/驱动和四轮独立转向车辆，以及路面附着系数对轮胎纵向合力和横摆力矩可实现范围的限制，提出一种对轮胎纵向合力和横摆力矩进行实时计算调整和动态分配的车辆横向稳定性控制策略。针对线性反馈计算的误差，采用离线数值优化和非线性规划方法实时确定轮胎纵向合力和横摆力矩的可实现范围，将计算的合力和力矩调整至可实现范围内并进行动态分配。设计滑移率和前轮侧偏角控制器使轮胎摩擦力跟踪各分力，在保证精度的同时避免对车辆后轮侧向力的估计。最后进行了仿真分析与基于LabVIEW PXI和veDYNA的驾驶员在环试验验证。结果表明，基于合力计算与分配的车辆横向稳定性控制可有效地提高车辆轨迹保持能力，改善低附着路面上车辆的稳定性，控制效果优于滑模变结构控制。