基于状态反馈的四轮转向汽车最优控制研究

Research on Optimal Control of Four-Wheel Steering Vehicle Based on State Feedback

针对四轮转向汽车传统模糊PID控制算法控制效果及稳定性差等缺点,在四轮转向二自由度模型基础上考虑车身的侧倾及轮胎的非线性特性,建立三自由度非线性模型。在此基础上,利用最优控制理论设计了基于车辆状态反馈的最优控制器,并在阶跃、脉冲和蛇形等典型试验工况下,与传统的前轮转向汽车和模糊PID控制下的四轮转向汽车进行操纵稳定性仿真对比分析。仿真结果表明:最优控制器能很好地跟踪理想模型,提高汽车的操纵稳定性和行驶安全性。

Aiming at the disadvantages of poor control effect and stability of traditional fuzzyPID control algorithm for fourwheel steering vehicle,a 3-DOF non-linear model is established based on the 2-DOF model of four-wheel steering considering the non-linear characteristics of body roll and tire.On this basis,the optimal controller based on vehicle state feedback is designed by using the optimal control theory.Under typical test conditions such as step,pulse and serpentine,the control stability of four-wheel steering vehicle controlled by traditional front wheel steering vehicle and fuzzy PID control is simulated and compared.The simulation results show that the optimal controller can track the ideal model well and improve the vehicle handling stability and driving safety.