Design of fuzzy gain-scheduled robust controllers using Kharitonov's extremal gain margin theorem

Article type: Research Article

Authors: Tzafestas, S.G. | Rigatos, G.G. | Vagelatos, G.A.

Affiliations: Intelligent Robotics and Automation Laboratory, Department of Electrical and Computer Engineering, National Technical University of Athens, Zografou 15773, Athens, Greece

Abstract: In this paper a novel fuzzy gain-scheduler is applied to linear plants the transfer functions of which consist of interval polynomials. The gain-scheduler performs an incremental tuning of the controller parameters employing a sliding-mode fuzzy control algorithm. The allowed ranges of variation of the controller gains are determined by using Kharitonov's Extremal Gain Margin Theorem. Sufficient conditions for the asymptotic stability of the closed-loop system are given. The validity of the method is verified via simulation tests.

Keywords: fuzzy gain scheduling, sliding-mode fuzzy logic control, Kharitonov's extremal gain theorem, interval polynomials, Lyapunov stability

Journal: Journal of Intelligent & Fuzzy Systems, vol. 10, no. 1, pp. 39-56, 2001