Introduction to Monitors, Detectors, and Diagnosticians

Abstract

A “fault” is to be understood as an unexpected change of system function although it may not represent physical failure or breakdown. Such a fault or malfunction hampers or disturbs the normal operation of an automatic system, thus causing an unacceptable deterioration of the performance of the system or even leading to dangerous situations. We use the term “fault” rather than “failure” to denote a malfunction rather than a catastrophe. The term failure suggests complete breakdown of a system component or function, whilst the term fault may be used to indicate that a malfunction may be tolerable at its present stage. A fault must be diagnosed as early as possible even it is tolerable at its early stage to prevent any serious consequences.