Anti-windup design: an overview of some recent advances and open problems

Abstract

This paper deals with the anti-windup technique which can be used to tackle the problems of stability and performance degradation for linear systems with saturated inputs. The anti-windup techniques which can be found in the literature today have evolved from many sources and, even now, are diverse and somewhat disconnected from one another. In this survey, an overview of many recent anti-windup techniques are provided and their connections to one another are stated. The anti-windup technique is also explained within the context of its historical emergence and the likely future directions of the field are speculated. The focus of this paper is on the so-called "modern" anti-windup techniques which began to emerge during the end of the 20th century and which allow a priori guarantees on stability to be made. The survey attempts to provide constructive LMI conditions for the synthesis of anti-windup compensators in both global and local contexts. Finally, some interesting extensions and open problems are discussed, such as nested saturations, the presence of time delays in the state or the input, and anti-windup for nonlinear systems.

A non-square sector condition and its application in deferred-action anti-windup compensator design

“…Then only Λ [1] is ever active and activation occurs when "physical" saturation occurs i.e. we have the standard ("immediate" [32]) AW case [9,29,6] considered in most of the literature. (2) Deferred action/Delayed AW.…”

“…Normally, the AW compensator is activated upon the occurrence of saturation. The subject of AW is now fairly mature and the reader is referred to the surveys [29,6], the edited volume [28] and the monographs [7,11,36]. In addition, two earlier papers [16,3] describe and connect some of the early work on AW.…”

Virtual actuator-based FTC for LPV systems with saturating actuators and FDI delays

“…Control systems are affected by saturations, which means that the control action that can be delivered by the actuators is limited in magnitude [1]. It is important to take into account the presence of saturations during the design of a control system, otherwise its real performance could exhibit strong performance degradation and, in some cases, instability could occur as well.…”

Steady-State Integral Proportional Integral Controller for PI Motor Speed Controllers

“…The current command generated by the controller exceeds this maximum prescribed input limit when the motor is subjected to sudden input or loading changes. Moreover, the motor exhibits large overshoot, long settling time, and even instability if the PID controller pushes the system into a non-linear region and experiences windup [7]. Based on the reviews in Ref.…”