Robust LQR design of neutral systems with time-varying delay and polytopic uncertainty

In designs of a state feedback controller, the resulting system is desired to be robust stable, even when the plant has a time-delay and an uncertainty which have possible to not only reduce the controller performance, but to also destabilize the system. In this paper, we propose a design method to construct a robust linear quadratic regulator (robust LQR) for a neutral system with a time-varying delay and polytopic uncertainties. The regulator is guaranteed to have a good robustness properties as same as the ordinary finite dimensional LQR.