An Adaptive Control Approach for Discrete-Time Systems with Unknown Backlash at the Input

Abstract

In this paper, we focus on the development of an adaptive control scheme for systems with unknown backlash. More specifically, we propose a discrete timeadaptive backlash inverse based controller for plants that have a known line arpart and an unknown backlash at its input. We also demonstrate that the harmful effects of backlash can be cancelled by adding two control blocks. These blocks are the following: an adaptive backlash inverse structure and an adaptive linear filter controller. The latter block provides a new adaptive law for the updating of the backlash parameters. We show by simulations that our adaptive control approach improves the system performance once the difference between the backlash output and the adaptive backlash inverse input, converges to a very small value. The simulations involve a third order system that highlights the efficiency of the proposed adaptive control approach.