An observer-based anti-windup scheme for non-linear systems with input constraints

This article addresses the problem of anti-windup design for feedback linea rizable non-linear systems with input constraints, subject to dynamic contr ollers with linear dynamics and non-linear gains. A method for designing th e controller gains and a non-linear 'observer-based' anti-windup modificati on is proposed, which allows reducing the behaviour of the closed-loop syst em under the dynamic feedback controller to that under a given static feedb ack linearizing controller, arbitrarily fast. The proposed anti-windup meth od allows, thus, to attenuate the effect of windup arbitrarily fast and gua rantee that the region of closed-loop asymptotic stability under the dynami c controller is limited only by the corresponding region under the static f eedback linearizing controller. The application and advantages of the metho d are illustrated through a simulation study on a methyl-methacrylate polym erization reactor.