Position Domain Contour Tracking with Cross-Coupled Control

A common problem with modern manufacturing processes that utilize high speed machining is the ability to accurately track the contour of a product. Various control methods have been developed to improve axial tracking performances for time domain controllers. This paper discusses a new control method developed in position domain with cross-coupled control to apply to a 3-axis CNC machine for contour tracking improvement. The contour tracking performance of a position domain controller with cross-coupled control is improved when compared to an equivalent time domain controller since the tracking error of a reference axis in position domain does not contribute to the overall contouring error. Simulation of the position domain controller and time domain controller yielded positive results for the position domain controller with improved contour tracking for both linear and circular contours. Position domain controller with cross-couple control provides improved contour tracking performance over both position domain controller without cross-coupled control and the equivalent time domain controller.