Generalized cross-coupled control for contour error reduction

Abstract

Cross-coupled control (CCC) improves contouring accuracy in contouring CNC systems by directly reducing contour errors rather than indirectly through reducing the axial following errors. This paper described a generalized crosscoupled control (GCCC) approach which is based on the same principles as the variable-gain CCC, itself an improvement of conventional CCC. Unlike the normal CCC approaches, GCCC can be applied for any free-form contour, including those defined only by a series of (x, y) coordinates as found in the position reference inputs in CNC systems. Simulation experiments show that GCCC is as effective as CCC in improving contouring accuracies but removes some of the latter's limitations.