State Estimation Techniques for FDI

Contents

The main objective of this chapter is to present three different observer structures that can be used for non-linear discrete-time systems with unknown inputs. As was pointed out in Chapter 2, there are two general tasks that have to be fulfilled while developing novel observer structures. The first one concerns the development of linearisation-based techniques and its main objective is to improve the convergence of such schemes. In order to solve this challenging problem, Section 4.1 introduces the concept of the so-called Extended Unknown Input Observer (EUIO) [96, 187]. This section presents a comprehensive convergence analysis of the EUIO with the Lyapunov method. Based on the achieved results, a complete design procedure is proposed and carefully described. Section 4.2 portrays further development of the EUIO. In particular, it exposes less restrictive convergence conditions than those proposed in Section 4.1. The achieved results are then used for the development of a new EUIO design procedure.