Research On Structure Optimization And Control Method Of Linear Motor For Maglev Positioning Stage

Drive of permanent magnet synchronous linear motor of Maglev precision positioning stage due to the advantages of simple structure,good sealing performance,low friction,no wear,fast response etc.,has broad application prospects in modern precision machining equipment,industrial automation,ultra precision measurement and other areas etc..But at the same time,due to the strong coupling,nonlinear,load disturbance and other factors of the permanent magnet synchronous linear motor drive system,it brings some difficulties to the high precision motion control of linear motor.Therefore,it is of great economic value and practical significance to study the structure optimization and control technology of permanent magnet synchronous linear motor with maglev precision positioning stage.This thesis takes the maglev two-dimensional positioning stage as the research object,a series of research work on the structure and control system of permanent magnet synchronous linear motor is carried out,the purpose is to achieve high system control precision and high response speed,the main work contents are as follows:Firstly,in order to suppress the harmonic components in the electromagnetic force of permanent magnet synchronous linear motor and reduce the thrust fluctuation in linear motor operation,based on the HALBACH type permanent magnet synchronous linear motor as the research object,this thesis proposes an improved linear motor structure.The three-dimensional finite element model of linear motor is established by the finite element numerical analysis software.The air-gap magnetic field and the electromagnetic force were simulated and analyzed.The analysis results show that the optimization of the motor structure can reduce the electromagnetic force fluctuation of the linear motor,which is beneficial to improve the control precision of the maglev stage.Secondly,in view of the characteristics of strong coupling and nonlinearity of the dynamic model of the maglev stage,a control method of differential geometry soft variable structure is applied to the control system.Based on the theory of differential geometry feedback linearization,the state feedback linearization of the dynamic model of the maglev stage is studied,and the precise linearization and decoupling control of the suspension and horizontal subsystems of the maglev stage are realized.Then,a variable saturation soft variable structure controller is designed according to the linearized subsystem model,the purpose is to achieve high speed adjustment and control precision.The simulation results show that the controller can achieve better control performance than traditional PID control and sliding mode variable structure control.Finally,based on the relevant theoretical research,two experimental prototypes are developed and manufactured,and the back electromotive force experiment is carried out.The analysis results verify the superiority of the optimized structure motor.