Robust H∞ control of linear neutral systems

This paper investigates the problems of robust stability and robust H-infinity control for a class of uncertain neutral systems. The class describes linear state models with norm-bounded uncertain system parameters and unknown constant state delay. First, we develop a sufficient condition for robust stability independent of delay. Then, we provide sufficient conditions for designing a memoryless state-feedback controller which stabilizes the uncertain neutral system under consideration and guarantees an H-infinity-norm bound constraint on the disturbance attenuation for all admissible uncertainties and unknown state delay. In both problems, the results are expressed in the form of linear matrix inequalities. It has been established that several earlier results are special cases of the developed theory. (C) 2000 Elsevier Science Ltd. All rights reserved.