Design and experimental validation of robust controllers for machine tool drives with linear motor

Abstract

This paper discusses the design and experimental validation of two controllers for a prototype machine tool axis, actuated by a linear motor: an H ∞ controller and a discrete-time sliding mode controller. Robustness of the tracking performance with respect to load changes up to 300% is considered. Experiments show that the discrete-time sliding mode controller is robustly performant in this load range. The H ∞ controller based on standard weighing functions is not robustly performant for the considered range of load changes. This paper proposes an alternative performance weighing function, inspired by the sliding mode controller, which yields an H ∞ controller with improved robust performance, comparable to that of the sliding mode controller.