SUFFICIENT CONDITIONS FOR ROBUST STABILITY OF LARGE-SCALE DYNAMICAL-SYSTEMS INCLUDING DELAYED STATES AND PARAMETER PERTURBATIONS IN INTERCONNECTIONS

The problem of the robust stability of large-scale dynamical systems i ncluding delayed states and parameter perturbations in interconnection s is considered. By using algebraic Riccati equations and some analyti cal methods, some sufficient conditions on linear decentralized state feedback controllers are derived so that the systems remain stable in the presence of delayed states and parameter perturbations. Such condi tions give some bounds on the perturbations of interconnections with d elayed states and uncertain parameters, and result in a quantitative m easures of robustness for large-scale dynamical systems including dela yed states and uncertain parameters in interconnections. The results o btained in this paper are applicable not only to large-scale systems w ith multiple time-varying delays, but also to large-scale systems with out exact knowledge of the delays, i.e., large-scale systems with unce rtain delays.