Stabilization of a class of uncertain nonlinear time-delay systems subject to input delays

This paper considers a class of uncertain time-delay control systems of the retarded type in which the uncertainty is an additive perturbation of a known (nominal) nonlinear model and there is a time-delay in the input. The perturbation may be time-, state-, delayed state-, and/ or input-dependent. Using a state- and input-dependent transformation and a descriptor system approach, a class of memoryless feedback controllers is designed to stabilize the class of systems. Sufficient conditions, which include a delay-dependent matrix inequality and a delay-dependent stability criterion, involving some bounding parameters for the uncertainty in the system and the input delay, are presented.