Development Of A Unified Control System For Electric Actuator

Electric actuator is a kind of important terminal equipment widely used in modern industry.It recieves remote or local control signal,and convert the signal to displace-ment in angular or linear form,thus the valve or other controlled devices are adjusted.With the development of industrial technology,higher requirements in performance and stability are requested.This paper analyzed and studied the research status and related technologies of electric actuator,then carried out the following research work:First of all,to lower costs and reduce inventory of spare parts,a unified electric actuator control system was proposed.It's feasibility is proved in theory,and a platform for experiments is built.Secondly,mathematical model of brushless DC motor(BLDCM)was built based on its working principle,and further an electric actuator control system was constructed on the basis of BLDCM.Then the swing characteristics of the system were analyzed.As the industrial monitoring system is more and more intelligent and networked,the CAN fieldbus is introduced.An implementation of CAN network on electric ac-tuator is carried out.The DMA mechanism in the process of sending and recieving messages is analyzed for the specified microcontroller.Then,this paper designed an electric actuator control system based on the analyses of electric actuator in domestic and foreign.Circuits were designed and softwares were programmed.This design uses the dsPIC33F family microcontroller as a core,and a three-phase inverter to drive BLDCM.It has the features of valve control through binary and analog signals,CAN communication,status feedback,fault protection and a convenient human machine interface.The electric circuits were showed in this paper;some key parameters were analyzed and calculated;program flow charts were given.This paper analyzed the program for mode control,interrupts,human machine interface and control of motor.To control the valve positon,the three closed-loop control strategy is applied.Finally,an electric actuator developing platform was constructed utilizing Mat-lab/GUI.This platform has the ability of sending valve control signals and setting pa-rameters to electric actuator,monitoring and recording operating status,and so on.It is proved to be greatly helpful in system developing and monitoring.