Robust H∞ performance for linear delay-differential systems with time-varying uncertainties

The present paper concerns robust H infinity performance for linear delay-differential systems which involve an uncertain time delay and time-varying norm-bounded parameter uncertainties, Based on the Lyapunov functional, a simple criterion is proposed which assures the pseudo-quadratic stability as well as an H infinity-norm bound, The criterion is given in the form of a linear matrix inequality which is affine or convex in additional scalar parameters. A simple criterion is presented to evaluate the extent of the performance robustness.