On Delay-independent Stability Criteria for Linear Time-delay Systems

Several LMI representations for delay-independence stability are proposed by applying Projection Lemma and the so- calledSmall Scalar Method.These criteria realize the elimination of the products coupling the system matrices and Lyapunov matrices by introducing some additional matrices.When they are applied to robust stability analysis for polytopic uncertain systems, the vertex-dependent Lyapunov functions are allowed,so less conservative results can be obtained.A numerical example is employed to illustrate the effect of these proposed criteria.