Past Issues

Studies in Informatics and Control
Vol. 16, No. 2, 2007

Scheduling of Local Robust Control Laws for Nonlinear Systems

Pedro Teppa, Jacques Bernussou, Germain García, Hael Khansah
Abstract

This paper presents a systematic approach for nonlinear control design by using the gain scheduling technique to insure the transition of a nonlinear dynamical process from an actual operating condition to a desired one. The nonlinear system is represented in neighborhoods of equilibrium points by a family of polytopic uncertain linear systems. The nonlinear equations of the system are imbedded in the interior of an inclusion polyhedron. A robust control law is built so as to insure asymptotic stability to a given equilibrium within a maximal ellipsoidal region contained in the interior of the polyhedron. Given a pre-specified equilibrium curve connecting the initial and final points, it is shown how to fix a sequence of equilibrium points together with the local associated ellipsoids covering the curve and enabling a convergent control sequence. State feedback and output feedback for the local robust control synthesis are considered, together with local performance criteria. A simple numerical experiment is provided to illustrate both the effectiveness of the synthesis and the performance achieved.

Keywords

Gain Scheduling, Transition Control, Polytopic Uncertainty, Quadratic Stability, Linear Matrix Inequalities (LMI).

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