Regional eigenvalue-clustering robustness of linear output feedback systems with both time-varying structured and unstructured uncertainties as well as nonlinear actuators

Abstract

This paper investigates the regional eigenvalue‐clustering robustness of linear output feedback systems with both time‐varying structured (elemental) and unstructured (norm‐bounded) parameter uncertainties as well as nonlinear actuators. A sufficient condition is proposed for ensuring that all the eigenvalues of output feedback systems with both time‐varying structured and unstructured parameter uncertainties as well as nonlinear actuators remain inside the specified region. No restriction is imposed on the shapes of the specified region. The proposed method is applicable to both the continuous‐time case and the discrete‐time case. When all the eigenvalues are just required to locate in the stable region, the proposed criterion will become the stability robustness criterion. Two numerical examples are given to illustrate the application of the proposed sufficient condition.