Robust guaranteed cost control for a nonlinear neutral system with infinite delay

The paper presents new results for the robust guaranteed cost control problem for a nonlinear neutral system having infinite delay with a given quadratic cost function. A delay dependent stability criterion, based on a model transformation technique, is proposed. A state feedback control law is then designed using the Razumikhin stability approach and the Lyapunov matrix equation to ensure not only the closed-loop systems robust stability but guarantee that the closed-loop cost function value remains within a specified bound. The problem of designing the optimal guaranteed cost controller is also given in terms of inequalities. An example illustrates the theoretical results.