ROBUST CONTROL AND FILTERING OF DISCRETE–TIME UNCERTAIN DYNAMICAL SYSTEMS

Abstract

This paper is concerned with the problems of robust control and robust filtering of a class of discrete–time nonlinear systems with parameter uncertainty. The parameter uncertainty we consider is real time–varying norm–bounded and appears in both the state and output equations. Interest is focused on the design of linear dynamic output feedback controllers and linear filters for the uncertain system and three problems are addressed. The first one is the robust stability analysis and stabilization whereas the other two problems are the design of controllers and filters to achieve both robust stability and robust performance in an H∞ sense. A technique is proposed for the above analysis and synthesis problems by converting them into ‘scaled’ H∞ analysis and control problems which do not involve parameter uncertainty and nonlinearities.