Research On High Precision Numerical Electric Actuator Based On Fieldbus CAN

Electric actuator is a necessary part of the process control system and has large application in electric power, metallurgy,oil and chemical industry of automatic control field .Study of intelligent actuator is vacant until 1990s in our country, especially for intelligent actuator of the high precision conformed to the field bus. So the study and design of high precision intelligent actuator based on fieldbus has great meaning.This paper study and design a new ,applied and numerical intelligent actuator of high precision by enough using technique of computer and fieldbus communication and does some research on adjust rate and CANbus communication.This electric actuator with the core of microcontroller PIC18F458 possesses the CANbus communication, the control of valve, the real-time display of valve location, the diagnosis of fault and the failure protection and the soft manual operation.Firsterly,this paper introduces the application and investigation actuality and development tendency of electric actuator, CANbus and control principle ,points that the development tendency is miniaturization, Electrco-mechanical integrative system,numerical control, intelligentization,field bus and network.Secondly, the paper presents the circuit diagram of the system hardware, the software flow chart and some programme codes including system makeup, choosing of element, hardware of CANbus interface,design scheme of software,A/D subprogram and control arithmetic subprogram and CANbus communication subprogram.In the end, it introduces the test and debugs of the designed supervise system by emluator most including test of CANbus communication and PWM pulse controling rate .The result indicates that the whole design is feasible and reliable and the presumed function has been realized.