Robustness with real parametric and structured complex uncertainty

Abstract

The problem of robust stability and performance in feedback control systems with n real (possibly related) uncertain parameters and structured unmodeled dynamics (the latter taking the form of m complex blocks dynamic uncertainties) is considered. A robustness margin r/sub m/ is defined with respect to such model uncertainty structure and an algorithm is developed to compute it. Robust stability and performance are characterized in terms of r/sub m/ or the structured singular value mu /sub m/. An iterative procedure using the above algorithm is given to compute tight bounds on k/sub m/ and mu /sub m/. These bounds are exact for the case m >