Research On Optimal Control Method Of Automobile Electronic Power Steering System

As one of the most important systems of automobile components,the automobile steering system is a device used by the driver to adjust or restore the original driving direction when the road condition information changes,which is the bridge between driver,car and road.With the substantial improvement of the level of science and technology and the increasingly fierce competition in the automobile industry,electric power steering system has become the mainstream of the market with a series of advantages such as its simple structure,energy saving and environmental protection,and on-demand assistance.The quality of the electric power steering system is directly related to the portability and stability of the vehicle steering.In order to relieve the driver’s maneuverability and improve the car’s steering performance,a new robust control strategy is proposed in this paper.The main contents are as follows:(1)Firstly,the common steering shaft assisted EPS is selected as the research object of this article by introducing the type,basic structure and working principle of the EPS system.Each main component of the system is simplified and the force analysis is carried out to establish the mathematical model of the system.(2)The relevant parameters are determined by the characteristics of the assist characteristic curve,and the design of the linear assist characteristic curve is completed.(3)According to the selected performance index,the LQR control research of the system is completed firstly.And on this basis,combined with sliding mode control,the optimal integral sliding mode optimal control strategy proposed in this paper is designed.(4)The vehicle model is established in CarSim,and the effectiveness of the control method is proved by the co-simulation test of running CarSim and Simulink.Judging from the simulation test results,the optimal control method proposed in this topic for the automotive electric power steering system can appropriately improve the performance of the steering system to a certain extent,and at the same time,it also provides feasible innovative ideas for the optimization control research of EPS system.