Decentralized control of large-scale nonlinear systems in generalized output-feedback canonical form

Abstract

A global decentralized adaptive output-feedback dynamic compensator is proposed for stabilization and tracking of a class of large-scale systems that are globally diffeomorphic into systems which are interconnections of subsystems in generalized output-feedback canonical form. This form includes as special cases the standard output-feedback canonical form and various other forms considered previously in the literature. Output-dependent nonlinearities are allowed to enter both additively and multiplicatively. The system is allowed to contain unknown parameters multiplying output-dependent nonlinearities, and, also, unknown nonlinearities satisfying certain bounds. Under the assumption that a constant matrix can be found to achieve a certain property, it is shown that reduced-order observers and backstepping controllers can be designed to achieve practical stabilization of the tracking error in each subsystem. Sufficient conditions under which asymptotic tracking and stabilization can be achieved are also obtained. This represents the first decentralized adaptive output-feedback tracking results for this class of systems.