Research Of Electric Power Steering System's Electronic Control Unit And Control Survey

EPS(electric power steering) system is one of important parts of vehicles,it relates with vehicle handling stability,active safety,and travelling comfort.EPS is a newer power steering system,it can control the feeling of steering,and meanwhile, it's good for environment.At present,EPS is becoming the focus of the steering system because it meets the demand of vehicle's electrification and intellectualization.The fundamental component of the EPS system was introduced.With in-depth study,the related mathematical model of EPS was established,analysis EPS's dynamic characteristics,steering response and the stability of motor quantificationally.The main parts of EPS's ECU include the modules of motor control circuit, over-current protection circuit,relay control circuit,input signal interface circuit, electromagnetic clutch control circuit,fault diagnosis circuit,etc.The PCB has been designed and the related debug which must be done in development phrase of the PCB.Meanwhile,the related measures and methods which are used to decrease hardware interference were considered.EPS's data acquire system was developed.The PLC's hardware has been designed,the software used in PC was also programmed by visual programming language(VB),and the serial port control was called.The way of communication between PLC and PC is serial communication.Meanwhile,CAN interface circuit also was designed in order to communicate with other electronic control systems.In according to the design of hardware,the EPS system must be stable,reliable and on time,so the control algorithm named PID was used in programmer.Finally, Reference to "vehicle electric power steering device technology and bench test method(draft)",the system's function tests,load characteristics test,power current characteristics of test,back to performance test were involved.We can find that the experimental results which can show the EPS system control method are correct.And the results are fit to a vehicle's working condition.