Research Of Multi-axis Contour Error Pre-compensation Based On PMAC

One of the important indexes of CNC system is control precision. The control precision is one of the important indexes of the CNC system. With the development of modern industrial products, the requirements of the control precision are much more higher. Scholars at domestic and abroad have conducted in-depth research on how to improve the control precision of CNC system. Among them, to improve the control precision from the contour error compensation is one of the important research directions.Firstly, in this thesis, based on the PC+PMAC, the multi-axis motion control platform was built. On the basis of the overall framework, the hardware and software of the system were developed. A friendly user software interface on PC was developed by using VC++. The platform realized the basic function, meanwhile, achieved the custom control algorithm. It provides a good platform to verify the contour error compensation method.Then, in this thesis, the drive system of the multi-axis motion control platform was modeled. Two kinds of contour error model, the contour error model and the generalized contour error model, were put forward in this paper. Combined with multi-axis contour error model, the contour error pre-compensation technique was studied. The actual position was achieved by the transfer identification function, pre-compensation contour error was achieved, and improved the control precision of multi axis system. In view of how to identify the transfer function of the drive system, The common system identification methods were studied in this paper. Through inputting the M sequence and acquiring the output signals, the identification of transfer function was gotten in the Matlab system identification toolbox. The reliability of the identification result was verified by the curve.Finally, the simulation platform was built by the transfer function of the drive system in the software MTALAB. The reliability of the system was verified by the multi-axis contour error model. By using the simulation software, the cross coupling compensation method and pre-compensation method were analyzed. Meanwhile, experiments were conducted on the multi-axis motion control platform by using multiple curves. The good results indicted the pre-compensation method is feasible.