Trajectory Path Planning And Control For Direct Drive XY CNC Table Base On Velocity Field Theory

For the problem that nonlinearity, uncoordinated, external disturbance and parameterperturbation have a serious impact on the contour accuracy of the system of the direct driveXY table, a dynamic inverse contour control based on velocity field theory and an autodisturbance rejection contour control based on velocity field theory were proposed.Firstly, on the basis of reading many foreign and domestic references, it summarizesthe development and status of the direct drive XY table system. It introduces the controlmethods of the single axis permanent magnet synchronous linear motor and the contourcontrol methods of the XY table.Secondly, the structure characteristics and the working principle of the direct driveXY table are introduced. The mathematical model of the direct drive XY table isestablished. The factors to impact the contour accuracy of the direct drive XY table areanalyzed and the methods to improve the contour accuracy are summed. On this basis,according to the velocity field theory, it plans the given trajectory using the velocity fieldand biaxial coordination control is transformed to single-axis speed control. Thensingle-axis velocity controller is designed to reduce the velocity error and improve thecontour precision.Then, for the problem that nonlinearity, uncoordinated, external disturbance andparameter perturbation have a serious impact on the contour accuracy of the system, twocontour controllers are designed using the dynamic inverse control method and the autodisturbance rejection control method. The single-axis velocity controller which is designedusing the dynamic inverse control method can weaken the nonlinear effects of the systemand make the velocity error approach to zero. The single-axis velocity controller which isdesigned using the auto disturbance rejection control method can weaken the effects ofexternal disturbances and parameter perturbation to the system and make the velocity errorapproach to zero, and reduce the contour error. Lastly, LM22-26series direct drive XY table is considered as the controlled object,and it is necessary to simulate and analyze using MATLAB/Simulink. The two designedcontrollers and the classic control strategies are used in direct drive XY table respectively.The simulation results are given and the control performances of the different controlmethods are analyzed and compared. Compared with the classical control strategies, thedynamic inverse controller which is designed based on the velocity field theory caneffectively weaken the nonlinear effects of the system and the auto disturbance rejectioncontroller which is designed based on the velocity field theory can effectively weaken theeffects of external disturbances and parameter perturbation to the system. Both of them canreduce the velocity error and improve the control precision.