Research On Motion Control System Of Linear Motor XY Worktable

Vertical XY table is an important part of CNC machine,is widely used in processing and manufacturing industry,the performance of the XY table directly affects the performance of CNC machine.The research object of this paper is the linear motor driven XY worktable.The new XY table driven by the linear motor has a higher feed rate and machining accuracy than the conventional XY table driven by the rotating motor,so it has been more and more widely applied in the occasion of high speed and high precision.Contour accuracy is the most important index to measure the performance of XY worktable.The interpolation accuracy and the control precision of the servo control system are the key factors that affect the machining accuracy of the XY table.It is an important way to improve the machining precision of the XY table to establish the advanced interpolation algorithm and the servo control system,which can effectively suppress the interference factors in the operation of the linear XY table.Firstly the paper introduces the development status of linear motor and XY machine table technology all of the word,and expatiates the common control strategy of XY table contour control.Secondly the paper analyses the working principle of the linear motor and introduced the classification of the linear motor.And then using the coordinate transformation principle,establish the mathematical model of permanent magnet synchronous linear motor.Analysis of the cause of the contour error of XY worktable,and then establish the contour error model.Thirdly,this paper improved the traditional interpolation algorithm and then according to the design requirements and the main disturbance characteristics of linear motor,the paper designed a linear motor speed loop PDFF controller system and the position loop repetitive controller.Through the speed loop controller and the position loop controller design consists of the XY worktable single axis servo control system,to reduce the tracking error of the XY table.And then based on the XY table single axis servo control system,designed a biaxial cross-coupling servo control system.The X axis and the Y axis are compensated in real time by the real-time contour error estimation,so as to realize the real-time control of the contour error.Fourthly,by using the MATLAB/Simulink to simulate the designed XY servo control system.The simulation results show that the design of the single-axis servo control system which using the PDFF controller and the repetitive controller can effectively suppress the periodic disturbance caused by the linear motor itself and improve the tracking accuracy.Through the cross-coupling controller design of the two axes of the table,it can effectively solve the problem of dynamic parameter mismatch between the two axes of the table,thus further improving the contour accuracy of the XY table.Finally,this paper designs the hardware system of servo control system of linear motor XY table based on DSP chip.