Anti-Windup Design for MIMO Plants Having General Infinite and Unstable Zero Structure

Abstract

In this paper an anti-windup scheme for multi-input, multi-output (MIMO) plants is presented. While the proposed anti-windup scheme has general applicability, attention in this paper is focused on issues concerned with the infinite and unstable (or non-minimum phase) plant zeros, as represented in the factorization of rational transfer function matrices provided by the generalized interactor matrix. This factorization can be used directly to obtain controllers providing triangular decoupling of the closed-loop system. It is argued that design for triangular decoupling of non-minimum phase plants is one way of designing linear controllers whose performance degrades gracefully in the presence of input saturations. In particular, by forgoing the requirement that the closed-loop system be diagonally decoupled, it is possible to obtain controllers capable of limiting peak control amplitudes without necessarily compromising controller bandwidth.