Robust Sensor Fault Reconstruction Using A Reduced Order Linear Observer

Abstract

This paper presents an observer based robust sensor fault reconstruction scheme. A popular observer based robust fault detection method is eigenstructure assignment; where the observer has certain eigenvectors, resulting in the fault detection scheme being decoupled from disturbances. This paper firstly investigates the existence conditions for the right eigenvector assignment method. Then an alternative scheme using reduced order observers is presented, with existence conditions that are less restrictive than that of right eigenvector assignment, whilst still being decoupled from disturbances. Following that, it proposes a design method for the observer using Linear Matrix Inequalities. A design example validates the work in this paper; where the fault reconstruction scheme is totally decoupled from any disturbances.