Research And Realization Of Initiative-Return-to-Center Control For Electric Power Steering System

Electric power steering system (EPS) is a rapid development in recent years and the emergence of power steering systems. EPS system is the latest sensor technology, EPS growth in foreign countries is already very mature, many models have put him as the standard configuration, and achieved good economic and market efficiency. In the domestic production of large quantities of EPS is not much in terms of product reliability and stability there are many shortcomings. In many domestic cars EPS system, most of them just have the power to control, with the initiative back to the positive control function is still relatively small. Many domestic universities and research institutions to the EPS control strategy a lot of research, because the control strategy will have a direct impact on the steering performance and safety of the car, but the car back to study the positive control and active damping control strategy is still relatively less. With the rapid development of modern automotive technology, automotive and special conditions in the high-speed requirements are also increasing, the car back to the positive control and active damping control has also become the focus of our study can not be ignored.Based on the structure and working principle of the EPS system, first introduced the structure and principles of the key components of the EPS system. And against a car company for a MPV models, the entire system was assembled EPS design. And the model for the foundation, through the various moving parts of the EPS system and simplified kinetic analysis to establish EPS system dynamics model, and then integrated various factors, EPS system established three degrees of freedom model of vehicle, with a transverse roll and yaw three degrees of freedom model cars. Subsequently introduced EPS power control, power characteristics of the system of research and analysis, to design a suitable power characteristic curve EPS system. And focus on the initiative back to the EPS control system being studied, based on proposed closed-loop PID steering wheel angle back to being active damping control strategies and control strategies. On the basis of EPS system dynamics model and three degrees of freedom model of vehicle use MATLAB/Simulink simulation software to create an EPS control system back positive control and damping control simulation model, control strategy and simulation analysis prior to the establishment of observation car Back under different input torque are different speed control. EPS controller design hardware and software systems for a variety of chip and system selection switch tube and build each H-bridge driver circuit and sensor signal processing circuit; according to the system to achieve the function and design of the hardware circuit has completed various software Design module. Finally, the real vehicle for steering the car back to the positive test, the system is designed to verify the actual observed real vehicle test curve, to discuss the effect of the actual control of the control system.