L2 PERFORMANCE IMPROVEMENT THROUGH ANTI-WINDUP DESIGN FOR TIME DELAY SYSTEMS IN THE PRESENCE OF SATURATING INPUTS

This paper deals with the synthesis of static anti-windup compensators for linear systems presenting both state time-varying delays and saturating inputs. Considering that the system is subject to the action of L2 bounded disturbances, a method for computing the anti-windup compensator in order to guarantee both that the trajectories of the system are bounded and a certain L2 performance level is achieved by the regulated outputs, is proposed. Based on Lyapunov-Krazovskii functionals, a descriptor approach and the use of a modified sector-based relation, conditions to solve the problem are derived. From these conditions, LMI-based optimization problems are proposed in order to minimize the L2 gain, as well as in order to maximize the bound on the admissible disturbances and/or on the delay.