Model-free approach for regulation of multi-link flexible robots

Abstract

This paper presents a class of non-model-based position controllers for a planar multi-link flexible robot. With the controllers, one can achieve not only the closed-loop stability of the original distributed parameter system, but also the asymptotic stability of the undamped truncated system, which is obtained through representing the deflection of each link by an arbitrary finite number of flexible modes. The system dynamics (which is very complicated in the case of a multi-link flexible robot) is not explicitly involved in the controller design and stability proof. Instead, only a very basic system energy relationship and the dynamic equations of a single-link flexible robot are utilized. The controllers possess several remarkable advantages over the traditional model-based ones. Numerical simulations are carried out on a two-link flexible robot and satisfactory results are obtained.