Research On Position Estimation And Control Technology Of Permanent Magnet Linear Synchronous Motor Based On Linear Hall

Compared with rotating motors,permanent magnet synchronous linear motors have a series of advantages,such as simple structure,no need for ball screw and other transmission mechanisms,good dynamic response,high positioning accuracy,unlimited travel range and so on.So they are very suitable for modern computer numerical control machine,lithography machine,electromagnetic launch,etc.With the expansion of the application field,the cost has become a core problem restricting its development and application,in which the position sensor occupies a large part of the cost.Using linear Hall as a position sensor has the advantages of small size,light weight,low cost,and good environmental adaptability.But it also has the disadvantage of relatively low accuracy.This paper aims to study the drive and control system of permanent magnet synchronous linear motor based on linear Hall sensor.First of all,due to the motor operation and the error of the Hall sensor,the output signal of the Hall sensor may contain complex harmonics.Based on this problem,this paper designs a harmonic elimination method to eliminate the harmonics of the Hall signal and reduce the error.Then it is combined with the phase-locked loop to achieve position detection.Aiming at the shortcomings of the traditional phase-locked loops,which are sensitive to harmonics and unable to track the signals with linearly varying frequency without error,separate designs are carried out.The harmonic elimination algorithm is used to solve the harmonic problems,and the type III phase-locked loop was used to achieve the tracking of the signals with linear varying frequency without error.In addition,a position detection system based on harmonic elimination algorithm and type III phase-locked loop is designed.Secondly,since the output signals of the linear Hall sensor are the sine and cosine value of the magnetic field signal,it is considered to directly use the Hall signal to achieve coordinate transformation and current closed loop control.The system aims to achieve coordinate transformation and current closed loop control without using sine and cosine calculations to reduce the calculation burden of the current controller.But the Hall signal axis must be corrected to ensure the maximum thrust at the same current.According to the actual system parameters and requirements,the second-order S curve and PI plus advanced correction position controller are designed to ensure that the system has goodstatic and dynamic performance.Finally,based on the experimental platform,the simulation model of this system is build to verify the effectiveness of the designed position detection system,current closedloop control system and position control system.And the permanent magnet synchronous linear motor drive and control system based on linear Hall sensor is designed,including hardware design of controller and driver based on the DSP(TMS320F28379D)and software design of motor control.