STABILIZING UNCERTAIN DISCRETE-TIME-SYSTEMS BY OBSERVER-BASED CONTROL

The problem of stabilizing uncertain discrete-time systems by observer -based control is considered. The uncertainties permitted in the syste ms are assumed to be structured and bounded but otherwise arbitrary. T he design criterion is based on the quadratic stability of the overall closed-loop systems. By formulating the uncertainties in terms of qua dratic bound matrices, a set of coupled generalized Riccati and Lyapun ov equations (CGRLE) are derived. A less conservative design criterion can be obtained by recursively solving the CGRLE with the stability o f the closed-loop system checked at each step. Examples are provided t o illustrate the advantages of this method.