Direct Drive X-Y Table Adaptive Zero Phase Error Tracking Control

Taking the direct-drive X-Y table servo control system as research object, according tothe X-Y table in the process because of uncertainty and nonlinear disturbance and other factorswhich influence the system dynamic the processing precision, tracking controller by using theadaptive zero phase error tracking controller (adaptive ZPETC) and disturbance observer(DOB), to reduce the parameter variations and load disturbances and other uncertain factors inthe system, so as to improve the servo system of X-Y CNC table of the single axis trackingaccuracy and robustness. On this basis, the contour error compensation method based on timeseries prediction technology, which can dynamically control the interpolation process, so as toeffectively reduce the contour error. The main contents are as follows:Firstly, analyzing mathematical model and contour error of the direct-drive X-Y table.By reading and analyzing a large number of domestic and related information, the existingcontrol methods of the X-Y table contour precision and the permanent magnet linearsynchronous motor tracking precision are summarized. At the same time, the causes of thecontour error are analysed, a control method combined with adaptive ZPETC, DOB and thecontour error compensation method based on time series prediction technology is come outaccording to the causes of contour error.Secondly, in order to meet the direct drive high precision positioning of single axis servosystem and anti-interference capability requirements, proposed an adaptive robust trackingcontrol strategy of zero phase error tracking controller and disturbance observer combined.The adaptive zero phase error tracking controller can make ZPETC with self adjustmentability, and the disturbance observer is used to improve the system stability and robustness.The design for ZPETC to the variation of the parameters with self adjustment ability, a stateobserver is designed, and the minimum variance estimation methods for the parameterestimation, in order to obtain the minimum variance adaptive zero phase error trackingcontroller estimates. The method has the characteristics of simple calculation process of selfadjustment ability. In order to enhance the stability and the robustness of the system, using theDOB robust feedback controller based on parameter changes to compensation and the effecton the system load disturbance. DOB is equivalent to the front passage introducesa compensation. Once again, in order to reduce the contour error, between the two to improve themachining accuracy, the index weighted smoothing model to the contour error compensationmethod in the following error prediction. The contour error compensation method based ontime series prediction technology, can dynamically control the interpolation process, so as toeffectively reduce the contour error. Through the contour error model of arbitrary curve, drawthe contour error distribution formula, and determining the single axis contour errorcompensation size.Finally, in order to verify the validity of the adopted method, take the direct-drive X-Ytable as the control object, the adaptive zero phase error tracking controller, a disturbanceobserver and a contour error compensation method for time series prediction technology basedon the direct-drive X-Y table is simulated, and the simulation is carried out in PID+CCCconditions. The simulation results and analysis, which proves the validity of the method.