Fuzzy based Output Feedback H_∞ Control for Uncertain Nonlinear Systems An LMI Approach

Abstract

This paper presents the problem of robustly stabilizing a class of nonlinear systems by using an H _∞ fuzzy output feedback controller. Sufficient condition is derived to ensure the robust stability of the fuzzy observer based controller with guaranteed H _∞ disturbance attenuation level. The observer and controller design problem is cast in the form of bilinear matrix inequalities (BMIs). Using two-step procedure, these BMIs are reduced to two sets of LMIs which can be solved very efficiently using convex optimization techniques. The design procedure proposed in this paper extends previous results in the literature by considering both the premise uncertainty and the consequent uncertainty simultaneously. Furthermore, a modified two-step procedure is suggested for the plants with linear output equation. Finally, a simulation example illustrates the validity and applicability of the given approach