Disturbance decoupled functional observers for fault estimation in nonlinear systems

TL;DR

This paper develops disturbance decoupled functional observers for nonlinear systems to improve fault estimation, providing necessary and sufficient conditions and demonstrating their application in a chemical reactor case study.

Contribution

It introduces a novel methodology for designing lower order disturbance decoupled observers with linear dynamics for nonlinear systems.

Findings

Derived necessary and sufficient conditions for observer existence.

Proposed a fault-estimation scheme based on the observers.

Validated results through a chemical reactor case study.

Abstract

This work deals with the problem of designing disturbance decupled observers for the estimation of a function of the states in nonlinear systems. Necessary and sufficient conditions for the existence of lower order disturbance decoupled functional observers with linear dynamics and linear output map are derived. Based on this methodology, a fault-estimation scheme based on disturbance decoupled observers will be presented. Throughout the paper, the application of the results will be illustrated through a chemical reactor case study