电动助力转向系统建模与控制策略研究

Research on Modeling of Electric Power Steering System and Control Strategy

概述了电动助力转向系统的优点,建立了电动助力转向的数学模型。在此基础上对比分析了比例控制策略和比例微分控制策略的不同控制效果。仿真结果表明,在助力增益较大时,比例控制会引起转向盘振动,同时来自路面的高频干扰也容易传递到转向盘,使手感变差。比例微分控制引入微分环节,增加了系统的阻尼,通过调节微分系数,可以调节系统带宽,因而较好解决了转向轻便性、转向盘振动和抑制路面高频干扰之间的矛盾。

The advantages of Electric Power Steering System were summarized and the model of EPS was developed. On the basis of the model, the different control effects of proportion control and proportion-plus-derivative control were compared. The simulation results show that the proportion control with higher gain will cause the vibration of the steering wheel, at the same time, will allow high frequency disturbance to transmit easily to the steering wheel and create harsh steering feel. Proportion-plus-derivative control introduces the derivative function and increases the damping of EPS system. The system bandwidth can be adjusted by changing the derivative coefficient, so the contradiction among the steering agility, the vibration of the steering wheel and restraining the high frequency disturbance from road can be solved successfully.