Observer generalized representation for unstable delayed systems

Abstract

This paper proposes a method for representing a delayed input system through state variables. The main idea is to use a finite-dimensional approximation for the delay operator in order to find a state-space representation of an input-delay system. This representation is based on the canonical observer form, and a Luenberger-type observer has been proposed. The delay has a rational representation and it is obtained by means of a classical Pade approximation. A linear observer is used to estimate the delay-free output, which is used within a compensation scheme to stabilize the real process by means of a suitable controller. © 2011 Springer-Verlag.