SYSTEM-ANALYSIS VIA INTEGRAL QUADRATIC CONSTRAINTS

This paper introduces a unified approach to robustness analysis with r espect to nonlinearities, time variations, and uncertain parameters, F rom an original idea by Yakubovich, the approach has been developed un der a combination of influences from the Western and Russian tradition s of control theory. It is shown how a complex system can be described , using integral quadratic constraints (IQC's) for its elementary comp onents, A stability theorem for systems described by IQC's is presente d that covers classical passivity/dissipativity arguments but simplifi es the use of multipliers and the treatment of causality, A systematic computational approach is described, and relations to other methods o f stability analysis are discussed, Last, but not least, the paper con tains a summarizing list of IQC's for important types of system compon ents.