Research Control Strategy Of Electric Power Steering System

EPS system is one of the research hotspots and top technology of the current development of vehicle technology. EPS has the following advantanges, including energy saving, environmental protection, and better handling characteristics and so on.In this paper, aiming at the problems of EPS which can not provide reasonable assist torque in the full speed range, because the blind spot of dynamical characteristic curve; In the process of return-to-center, EPS system has the insufficient and overshooting problem. Firstly, this paper introduces the composition and theory of the EPS. Secondly, this paper analyses the relationship among the steering resistance torque, assistant torque and manipulation torque. Basis on the test data, this paper also analyses the advantages and disadvantages of corresponding dynamical characteristics curve. In order to solve the above problem, this paper research on control strategy and the way of judgment, and then create the simulation model.Main research content are as follow:(1)Introduces the development situation of EPS. Analysed the composition and the functions of EPS system, creating mathematical model of EPS system.(2)Through the analysis to the steering resistance torque, assistant torque and manipulation torque in the process of steering, and then analyze the dynamical characteristics curve, determine the characteristic curve of the EPS system in this paper.(3)Analysed the work principle of EPS system, and determined the EPS return control mode, assist control mode, etc.(4)Analysing the conventional motor control method, constructing the motor control strategy based on PMW driving technology and the adaptive fuzzy PID algorithm.(5)Under Matlab/Simulink environment, constructing the simulation model of EPS system, verifying the validity of this paper’s design about the dynamical characteristics and control strategy.