A Simple Algorithm For Robust Stability Test. Under Structured And Unstructured Perturbations

摘要

In this paper we discuss the problem of robust stabil- ity of a class of multivariable systems with both struc- tured (parametric) and unstructrured norm bounded uncertainties. We first give a vertex-edge criterion of robust stability of the closed-loop system. Next we in- troduce the concept of the maximal defFerence of the phases of extreme points /spl theta//sub m/, by which the robust stability (or stability margin) of the multivariable system can be determined exactly. Finally, a simple algorithm for calculating /spl theta//sub m/ is presented.