ROBUST STABILITY ANALYSIS VIA QUADRATIC DIFFERENTIAL FORMS

This paper is concerned with the application of quadratic differential forms (QDF's) to robust stability analysis of a linear system with parametric uncertainty. The QDF plays an important role in the Lyapunov stability theory in the behavioral framework. By using QDF's, we derive an LMI condition for robust stability of a linear uncertain system described by a high-order differential-algebraic equation. This condition guarantees the existence of a parameter-dependent Lyapunov function which allows less conservative analysis. We also show that, when applied to a state-space model, the present condition recovers some existing robust stability conditions.