Fuzzy Disturbance Compensation And Contour Control Of Direct Drive XY Platform

Linear motor XY platform is an important part of CNC machine tools and CNC machinetools has been widely used. Contour accuracy is an important indicator of XY platform motioncontrol system, permanent magnet linear synchronous motor driven XY stage during periodiccontouring process is affected by many factors related to the actual displacement and otherperiodic load disturbance and will produce periodic contour error associated with theprocessing cycle.First, the thesis discusses the development and prospects of the direct drive linear motorXY platform contour control at home and abroad in recent years, then introducing structure ofpermanent magnet linear synchronous motor, the mathematical model and the XY platformworks for high-precision contour machining tasks; XY platform contour error model isestablished and put forward the corresponding solutions on the basis of analyzing the causes ofthe contour error.Second, the subject of the linear motor XY platform suffered disturbances were analyzed,in order to weaken the influence of external disturbances contour accuracy and enabling high-precision contour control XY platform. This thesis designs improved PI disturbancecompensator that using the idea of the state observer,describes the principles state observerand design methods PI disturbance compensator based on status observer (VPDC), usingtransfer function method to analyze the relationship between the disturbance torque estimatedvalue and the actual value of the disturbance torque and the use of the angular accelerationsignal disturbance compensator is constructed on the external disturbance compensationcontrol, and analyzes the impact of the control system after joining the disturbancecompensation. Meanwhile the PI compensator disturbance and improved cross-coupledcontroller are combined, and simulation model and simulation experiments are conducted.Simulation results show that the control system has a strong anti-interference and high contouraccuracy.Finally, when XY platform was driven by the permanent magnet linear synchronousmotor, in order to weaken the contour error model which is relatively complex and system disturbances which are unknown, parameter uncertainty on contouring accuracy, then XYplatform controlled by high-precision contour is achieved. This thesis designs a fuzzydisturbance compensation based LuGre friction model.In the full analysis on the basis of thefuzzy control theory and LuGre friction model, using fuzzy systems with arbitrary precisionnonlinear function approximation and LuGre friction model ability to compensate for friction.Meanwhile the Fuzzy compensator disturbance based LuGre model and improved cross-coupled controller are combined, and simulation model and simulation experiments areconducted. The simulation results show that the control system has nice immunity and highcontour accuracy.