H_∞Control with Exact Linearization and its Application to Magnetic Levitation Systems

Abstract

This paper is concerned with robust controller design for a class of nonlinear systems. First, taking account of the nonlinearity of the systems, we propose a controller design method which consists of H_∞ robust control and exact linearization via nonlinear state feedback. The latter one is designed to yield the linear system which is exactly equal to the linear approximation model of the plant around an equilibrium point. Second, applying the proposed method to a simple magnetic levitation system, we illustrate the validity of our method by experiments.