Research On High-precision 3D Contouring Control Based On Task Cartesian Coordinate Frame

With the demands on higher precision and efficiency in high-ending manufacturing,improving the trajectory tracking performance in multi-axis servo systems has become a research hotspot.Contouring error is an important physical quantity to measure the accuracy of trajectory tracking in multi-axis servo systems.In order to improve the versatility of the contouring error control architecture under different contouring error estimation methods,simplify the controller design,reduce the task amount of parameter tuning,and compensate the dynamic performance of the system,and improve the contouring accuracy.This paper builds 3D contouring error control framework based on the Task Cartesian coordinate frame(TCCF).Due to the uncertainty of the dynamic parameters and external disturbances in the actual multi-axis servo system,these disturbances and uncertainties will reduce the accuracy of contouring error control.In order to improve the accuracy of contouring error control and reduce the complexity of adaptive controller design,this paper develops the adaptive robust controller to TCCF for three-dimensional contouring error control.The stability of controller is proved and simplified.In the aspect of contouring error estimation,the advantages and disadvantages of the existing methods are analyzed from the real-time and accuracy of calculation.Since the tangent approximation,the osculating circular approximation and the standard expansion approximation can only refer to the fixed position of the trajectory in each control period.The dynamic performance is poor.The Newton method is used to calculate the contouring error dynamically,and the initial value and the iteration step size are analyzed.The existing Newton iterative method is proposed to improve the contouring error and ensure its ability to quickly converge to a local minimum.Since the nonlinear dynamics of the parallel robotic contouring control compared with the XYZ machine tool.On the basis of compensating the dynamic characteristics of the robot,the solution of the dynamic model under TCCF is used.The general contouring error design method based on the Lagrangian dynamic model of the robot in TCCF is proposed.And the proof of controller stability is given.