Robust stabilization of nonlinearly perturbed large-scale systems by decentralized observer-controller compensators

This paper is concerned with the problem of robust stabilization for nonlinearly perturbed large-scale systems via decentralized observer-controller compensators. The large-scale system is composed of several interconnected perturbed subsystems, each containing a nonlinearly perturbed plant and an observer-controller compensator. Here a robust stability criterion for the perturbed large-scale system is introduced, and a simple but useful inequality is derived for synthesizing the decentralized observer-controller compensators. The main features of this paper are as follows: (i) the nominal plant of each subsystem is not constrained to be stable and/or minimum phase; (ii) the perturbations of the plants and/or interconnections are considered; and (iii) a two degree observer-controller compensating scheme is employed to treat the perturbed large-scale systems.