Perturbation bounds for structured robust stability

Structured robust stability involves large (but bounded) perturbations in certain loops of a multivariate system. That is, structured robust stability entails stability in the face of large, structured perturbations. The authors study the persistence under small, unstructured parametric perturbations of the robust stability (structured or unstructured) of a system. They derive parameter perturbation bounds which when repeated, ensure the robust stability of the perturbed models