Controllers with variable gain for uncertain systems with saturating actuators and time-delays

Controllers are studied to achieve closed-loop robust stability and satisfactory transient behavior for a class of uncertain state-delayed systems with saturating actuators. The controllers are based on a nominal controller, which is then augmented with a time-varying gain to reduce the effect of uncertainties on the transient behavior. The methodology is based on providing delay-dependent conditions given as LMIs, derived from Lyapunov-Krasovskii (L-K) functionals. The results are illustrated on a simulated uncertain state-delayed system with a saturating actuator.