电动助力转向系统的鲁棒H∞控制研究

Research on Robust H∞ Control of Electric Power Steering System

电动助力转向系统(Electric Power Steering,EPS)中,机械摩擦、传感器噪声和路面干扰等不确定因素将降低EPS的助力跟踪性能、转向轻便性和鲁棒稳定性。针对该问题,以电动助力转向的助力跟踪性能、转向路感和车辆操纵稳定性为控制目标,基于电压补偿控制,设计了鲁棒H∞控制器。利用MATLAB/SIMULINK搭建了EPS控制模型、二自由度整车模型、轮胎模型,在单位阶跃操纵力矩作用下,仿真对比了电压补偿控制和基于电压补偿的鲁棒H∞控制的仿真响应情况,结果表明基于电压补偿的鲁棒H∞控制具有更好的助力跟踪性能、转向路感和鲁棒稳定性。

In Electric power steering(EPS)systems,mechanical friction,sensor noise and road disturbance will reduce the power tracking performance,steering portability and robust stability of EPS.Aiming at this problem,a robust H∞controller was designed based on voltage compensation control,with the power tracking performance,steering road sense and vehicle handling stability as the control objectives.Using MATLAB/SIMULINK to build the EPS control model,two degrees of freedom vehicle model,tire model,under the effect of unit step control torque,the simulation compared the compensation control of voltage and voltage compensation based simulation response of robust H∞control.The results show that the robust H∞control based on voltage compensation has better power tracking performance,steering feeling and robust stability.