Systematic Anti-Windup Compensator Design for Multivariable Systems

The aim of anti-windup compensation is to modify the dynamics of a control loop when control signals saturate, so that a good transient behaviour is attained after desaturation, while avoiding nonlinear oscillations and repeated saturations. Model-based anti-windup compensation is here considered for multiple-input multiple-output (MIMO) systems. A modified controller structure is proposed, which leaves the nominal closed-loop dynamics unchanged, as long as none of the control signals saturate. The proposed approach is applicable to continuous-time as well as discrete-time systems. Although it is developed for systems in input-output form, it can be used for systems in state-space form as well. 1 Introduction The problem of finding controllers which have desired properties during or after saturation events has, over the years, resulted in a number of different anti-windup strategies. Many of the proposed methods focus on adjusting the states of the controller during a saturation event..