Contouring control of multi-axis machine tools with iterative learning control

The accuracy of machine tools can be improved through using the learning control algorithm which can provide a better input command toward the closed-loop system. Due to the complexity of actual contour error model, the equivalent contour error is introduced. In this study, the target of the learning control is to reduce the equivalent contour error which the actual contour error will also be reduced. The iterative learning control algorithms were verified through the experiments which were done on x-y axis system of five-axis milling machine and controlled by PC-based controller. The results from the experiments show that the actual contour error can be reduced by 80% within five times of learning.