Analysis of Multivariable Control Systems in the Presence of StructuredUncertainties

摘要

An analysis of the stability properties of uncertain multivariable controlsystems in the frequency domain is presented. Necessary and sufficient stability criteria are reviewed along with singular value scaling techniques for characterizing permissible uncertainties. Such scaling methods have become widely accepted tools for the analysis of control systems in the presence of structured uncertainties. Included in this study are the general block similarity scaling techniques advanced by Doyle and the nonsimilarity scaling approach of Kouvaritakis and Latchman. For element-by-element structured uncertainties, both scaling methods reliably compute Doyle's structured singular value, micron, which provides an indication of system stability. However, the similarity scaling formulation has the disadvantage of expanding an n x n system matrix to an n