Guaranteed LQR-properties control of uncertain linear systems with time-delay of neutral type

A feedback design method for linear neutral delay differential systems is proposed. The feature of this method is that, even when the plant has uncertain parameters, the resulting closed loop system is assured to be always a linear quadratic regulator (LQR). The weighting matrix in the cost functional contains some uncertainty, nevertheless, the good robustness properties are retained like ordinary LQRs. The degree of exponential stability of the closed loop system can be pre-assigned. The design procedure is demonstrated with a numerical example.