Robust pole-clustering of structured uncertain systems in union of disjointed circular regions

This paper presents a systematic procedure for depicting the robust pole-clustering of a system with structured uncertainties. Different from many previous researches on connected region, a union of disjointed circular regions on the complex plane containing either a single-nominal pole or multi-nominal poles is obtained utilizing matrix operation. In addition, a criterion for determining the allowable perturbation bounds of the structured uncertain system such that the pole clusters remain within certain pre-specified circular regions is also proposed. The validity of the proposed approach is confirmed by way of numerical examples.