Decentralised adaptive controllers for robust tracking and model following of uncertain large scale systems

The problem of decentralised robust tracking and model following is considered for a class of uncertain large scale interconnected systems. In this article, it is assumed that the upper bounds of the uncertainties and external disturbances are unknown. A modified adaptation law with σ-modification is introduced to estimate such unknown bounds, and on the basis of the updated values of these unknown bounds, a class of decentralised local state feedback controllers is constructed for robust tracking of dynamical signals. The proposed decentralised adaptive robust tracking controllers can guarantee that the tracking errors between each subsystem and the corresponding local reference model decrease uniformly asymptotically to zero. Finally, a numerical example is given to demonstrate the validity of the results.