Less conservative delay-dependent robust stability criteria for linear time-delay systems
This note concerns with the robust stability of linear uncertain systemswith state-delay. The uncertainty is assumed to be of polytopic type. A less conservative delay-dependent linearmatrix inequality (LMI)method is presented based on a new Lyapunov–Krasovskii functional. The present method incorporates a relaxed parameter-dependent technique combined with a recently proposed idea of introducing free-weightingmatrices.When confined to delay-free case, the present result is also less conservative than existing stability tests using parameter-dependent methods. Numerical examples are given to show the less conservativeness of the results.