Modelling issue in fault diagnosis

Abstract

When introducing fault diagnosis as a scientific discipline, it is worth providing some basic definitions. These definitions, suggested by the IFAC Technical Committee SAFEPROCESS, have been introduced in order to unify the terminology in the area. Fault is an unpermitted deviation of at least one characteristic property or variable of the system from acceptable/usual/standard behaviour. Failure is a permanent interruption of the system ability to perform a required function under specified operating conditions. Fault detection is a determination of faults present in the system and the time of detection. Fault isolation is a determination of the kind, location, and time of detection of a fault. Follows fault detection. Fault identification is a determination of the size and time-variant behaviour of a fault. Follows fault isolation. Fault diagnosis is a determination of the kind, size, location and time of detection of a fault. Follows fault detection. Includes both fault isolation and fault identification. In the literature, there exist also other definitions of fault diagnosis. A very popular definition of fault diagnosis includes also fault detection [60]. Such a definition of fault diagnosis is used in this monograph. © 2008 Springer-Verlag Berlin Heidelberg.