汽车ABS与AFS集成控制算法

摘要

提出一种制动防抱死系统(ABS)与主动前轮转向(AFS)系统的集成控制算法.ABS采用逻辑门限值控制算法,以车轮的角加速度为主要门限、滑移率为辅助门限.AFS采用基于二自由度车辆模型建立的横摆力矩补偿前馈控制和滑模反馈控制相结合的复合控制算法.采用8自由度车辆模型验证所提出的控制算法,该模型包含“Magic Formula”轮胎模型和基于单点预瞄的驾驶员模型.在Matlab/Simulink中通过对开路面的直线制动工况和定圆弯道制动工况下的仿真来评价集成控制算法.仿真结果表明:在对开路面上ABS与AFS的集成控制能够有效地缩短制动距离,提高车辆制动过程的方向稳定性.%An integrated control algorithm of antilock braking system ( ABS) and active front steering (AFS) system was proposed. A logic threshold control algorithm was used for ABS with the wheel angular acceleration as main threshold and the slip rate as auxiliary threshold. Based on a two degrees of freedom vehicle model, a combined control algorithm of sliding mode feedback control and yaw compensation feedforward control was used for AFS. The integrated control algorithm was evaluated by an 8 degrees of freedom vehicle model with 'Magic Formula' tire model and driver single-point preview model. The braking maneuver simulations of μ-split roads characterized by straight sections and bend sections with fixed curvature were performed with Matlab/Simulink to evaluate the algorithm validity. The simulation results show that the integrated control algorithm can significantly shorten the braking distance and enhance the vehicle steering stability in braking process.