ROBUST-CONTROL OF MULTIVARIABLE CRITICAL SYSTEMS

Based on the method of inequalities and H-infinity-optimization method, this paper develops an approach to robust control design of multivariable critical systems with external and internal uncertainties. In this approach the formulation of the robust control design of these systems is expressed by a set of inequalities which includes output performance criteria in the time domain and a robust performance criterion in the frequency domain of the system, Some relationships between an input space, a modelling error space, a controller, output performance and robust performance are established by inequalities for SISO and MIMO critical systems so that the robust control design problem of these systems is largely simplified.