循环球电动助力转向系统控制及补偿策略

考虑循环球式转向系统内多因素的影响,设计循环球式电动助力系统的控制及补偿策略,建立循环球式电动助力转向系统模型,设计电流助力曲线,采用模糊PID控制方法,实现电机的实时控制;为了获得更好的助力力矩,补偿系统内损失,基于LuGre摩擦模型,通过观测到的系统参数,建立摩擦状态观测器,得到摩擦补偿叠加电流。使用Matlab/Simulink与CarSim的联合仿真验证控制系统;通过对增加摩擦补偿策略前后的对比分析,可知所设计的电动助力转向电流控制系统能综合车辆行驶时的摩擦、车速和转向盘转角等信息,由助力执行电机产生适当的助力,更准确地实现驾驶员的驾驶意图,使得回正过程更加平稳。

A control and compensation strategy of the electric power recirculating ball steering system

Considering the influence of multiple factors in the recirculating ball steering system,a control and compensation strategy of the electric power recirculating ball steering system is designed.The model of the electric power recirculating ball steering system is established,the current assist curve is designed,and the fuzzy PID control method is adopted,so as to realize the real-time control of the motor.In order to obtain better boosting torque and compensate for the loss in the system,based on the LuGre friction model,the observed system parameters are used to establish the friction state observer,in order to obtain the friction compensation superimposed current.Through the joint simulation verification control system of Matlab/Simulink and CarSim,the comparative analysis before and after adding the friction compensation strategy shows that the designed electric power steering current control system can comprehensively consider the friction,speed and steering wheel angle of the vehicle while it is dri-ving and use the motor to generate appropriate power so as to achieve the driver’s driving intention more accurately and make the return process more stable.