Introduction

Abstract

A fault can generally be defined as an unexpected deviation of at least one characteristic property, called the feature of the system, from the normal condition which tends to degrade the overall performance of a system and leads to undesirable but still tolerable behavior of the system Gertler JJ, Fault detection and diagnosis in engineering systems, 1998, [1]. The increased productivity requirements and stringent performance specifications have led to more demanding operating conditions in many modern engineering systems such as aircraft, automotive vehicles, high-speed railways, and power systems. Such conditions increase the possibility of faults which will result in off-specification production, increased operating costs, detrimental environmental impacts and even catastrophic disasters that claim both property and human life Venkatasubramanian V et al., Comput Chem Eng, 27: 293-311, 2003, [2], Chen W, Model based fault diagnosis in complex control systems-robust and adaptive approaches. PhD thesis, Simon Fraser University, 2007, [3].