A Based On The Voice Coil Motor Precision Positioning Control System

The voice coil motor is a kind of linear motor with high frequency response and high positioning accuracy.It is commonly used in the control system of precision instruments such as motors.It is widely used.The main purpose of this paper is to discuss the closed loop control system of linear voice coil motor.The goal of the design is to design a closed-loop control system.This system can solve the problem of position location on the basis of satisfying various indexes and improving precision.And through the use of advanced control algorithms,making the control system with adaptive.Precision positioning system consists of two parts:positioning the implementation of components and location detection components.Precision Positioning Actuators including stepper motor,voice coil motor,and microactuator(made with hysteresis,piezo material,and principle),it can be used to achieve accuracy levels based on the positioning scale.Voice coil motors are used in this application,position detection components can be used magnetic scale,capacitive scale,grating and differential transformer and other methods to complete,this paper uses a differential transformer.Specific research steps are following:First of all,determine the control system of the controlled object(voice coil motor),according to the controlled object to establish mathematical model.Then the executive unit of the control system(position sensor)is introduced,the mathematical model of the differential transformer is obtained,and then the working principle of the differential transformer position sensor is described.Secondly,the control strategies of voice coil motor are researched deeply,and the control methods of position loop,current loop and velocity loop are analyzed.And the corresponding control block diagram and transfer function are obtained.Then,the driving strategies of the voice coil motor are researched deeply,and the driving method of the PWM control mode is researched,and the processing circuit of the differential transformer of the executing unit is designed.Finally,the controlled objects,the controller and the execution units are combined with each other to form a complete closed-loop control system,and the system is designed and implemented in software and hardware.