Robust unobservability for uncertain linear systems with structured uncertainty

This paper introduces a notion of robust unobservability for a class of uncertain linear systems with structured uncertainty described by averaged integral quadratic constraints. This notion relates to the question of when a state is unobservable for all possible values of the uncertainty. This question may arise which considering modelling and realization theory for uncertain systems. The paper presents an algorithm for finding the robust unobservability function and corresponding unobservable cone.