A new approach to the pre-compensation of contour errorsfor three-axis machine tools using an adaptive cross-coupled controller

Abstract

Pre-compensation of contour errors is an effective method for predicting and compensating contour errors to position command; however, some challenges remain, such as modeling and precise control strategies specifically for contour errors. This paper presents an improved method for pre-compensation of contour error through a novel adaptive cross-coupled prediction compensation controller (ACPCC), in order to enhance robustness and the capacity to resist disturbance. Its central structure is constituted by a fuzzy PID controller, in which the bottom width of membership functions is optimized by improved particle swarm optimization. Estimation of tracking error and contour error is based on the servo system parameters and error-modeling, respectively, and contour error is regulated by the ACPCC and decoupled to each axis to modify reference commands ahead of sending them to the machine tool. Simulations and experiments are performed on a three-axis machine tool to validate effectiveness. The results demonstrate that the proposed method can significantly reduce tracking error and contour error compared with other control schemes.