Simulation And Analysis Of Control Strategy Of Column Type Electric Power Steering

In recent years, the automotive industry is in surging development and the demand of the vehicle's quality is convincingly strengthened. More and more vehicles have a kind of electric power steering (EPS) system because EPS resolve the problem of the hydraulic steering system, improve the characteristic of steering control, reduce the fuel consume and make for the environment. That indicate EPS has a tremendous development direction.This thesis aims to the research of EPS modeling, the characteristic of assist curves, control of EPS and the general rules relevant to vehicle handling dynamics, for the purpose of providing theoretical basis to the design of EPS, reducing the gap between our country and the developed countries and promoting the research level of EPS for the domestic car makers. The primary content is as follows.Firstly the research of EPS domestic and aboard is introduced. The structure is analyzed to get the acknowledge of the system working principles. Secondly the simulation model of the vehicle is built based on the simulation software MSC.ADAMS( a multi-body dynamics software) and the key components and parts are chose. This is mainly including sub-systems such as steering system, front and rear suspension system, and front and rear tire model. The road frequency spectrum map is also included. Based on the basis of the theory of the characteristic curve and control strategy, the suitable value for the current vehicle model is found. With the help of Matlab/Simulink, the model of electromotor is built and is simulated with the simulation model of the vehicle using co-simulation method. Finally the vehicle model equipped with EPS is analyzed, and compared with the National Standard. The result shows the chosen curve and control strategy take great effect in improving the steering handling and self-return performance.