Contour Control Technology Research Based On Multi-Axis Motion Control System

In order to meet the increasing demands of the current manufacturing industry for product quality,performance,appearance,and comprehensive cost performance,the multi-axis contour motion control platform is widely used in contour processing equipment due to its simple structure,high degree of freedom,and stable performance.in.To obtain high-precision and high-quality processing results,it is necessary to improve the contour motion control performance of the multi-axis control system.Among them,the contour error is an important index to measure the performance of the contour control system,and if you want to obtain high-precision contour control performance,you must know the accurate contour error value,but the contour error is difficult to be directly measured by the position measuring device.This dissertation introduces the current research status of multi-axis contour control problems at home and abroad around two aspects of contour control strategy and contour error estimation,analyzes the advantages and disadvantages of various methods,and points out the current research deficiencies and urgent needs,which provides the direction for the research of this dissertation.This dissertation first clarifies the difference between contour error and tracking error.Contour error is different from tracking error,which is difficult to measure directly.This dissertation analyzes the contour error estimation performance of the existing geometric approximation method,parameter contour analysis method and iterative search method to get the problems of these methods.Aiming at these problems,this dissertation proposes an online contour error estimation method based on the idea of iterative search—Newton iterative contour error estimation method,and on this basis,proposes an accelerated Newton iterative contour error estimation method with fourth-order convergence speed.In industrial production and processing,contour processing tasks are often repetitive contour trajectories.Therefore,this dissertation proposes a set of contour error control strategies of "CEE+NTSMC+ILC" to achieve high-precision contour motion control of multi-axis systems.Among them,CEE(Contouring Error Estimation)uses the accelerated Newton iteration method proposed in this dissertation to estimate the contour error,and NTSMC(Non-singular terminal sliding mode control)uses a non-singular terminal sliding mode controller as a single-axis controller to ensure the stability of the each single-axis control system.ILC(Iterative Learning Control)designs an iterative learning controller based on contour error as the contour controller of a multi-axis contour control system.Its output acts on the desired trajectory input in the form of precompensation to obtain a corrected reference contour input and suppress periodic disturbance and noise,thereby eliminating contour errors.This dissertation uses rigorous mathematical derivation to prove the convergence and stability of the proposed contour error estimation method and contour error control strategy,and uses simulation to verify it.At the same time,this dissertation uses the XY axis linear motor motion platform as the experimental platform,and the correctness of the method proposed in this dissertation is further verified through experiments.