An evaluation of the dependability of observer based fault detection and isolation scheme : a structural approach

The aim of this paper is to study the dependability of a fault detection and isolation scheme and the impact of sensor's failure probability on such scheme during the mission duration of a system. The proposed method is based on a graph-theoretic approach and assumes only the knowledge of the system's structure. For a linear structured system, we first recall the fault diagnosis conditions when using an observer based scheme. Then we deduce the sets of sensors that ensure the validity of such conditions. Next, we proceed with a dependability analysis to compute the reliability of this kind of diagnosability property based on the sensors’ reliability. The approach proposed in this paper is original because it allows combining dependability and structural analysis for studying system's properties.