Some of the most widely-investigated control charting techniques for autocorrelated data are based on time series residuals. If the mean shift in the autocorrelated process is a sudden step shift, the resulting mean shift in the residuals is time varying and has been referred to as the fault signature. Traditional residual based charts, such as a Shewhart, CUSUM, or EWMA on the residuals, do no...

In this paper, a novel design and development of a fuzzy logic controller using static synchronous series compensators (SSSC) to damp out the swinging oscillations in a FACTS based integrated multi-machine power system when a three-phase line to line ground fault takes place at one of the generators in the power system is proposed. The multi-machine power system considered consists of three gen...

A new evaluation method is presented that employs cut sequence set (CSS) to analyze fault trees. A cut sequence is a set of basic events that fail in a specific order that can induce top event. CSS is the aggregate of all the cut sequences in a fault tree. The paper continues its former researches on CSS and uses CSS, composed of sequential failure expressions (SFE), to represent the occurrence...

Multiple fault diagnosis is a difficult problem for dynamic systems. Due to fault masking, compensation, and relative time of fault occurrence, multiple faults can manifest in many different ways as observable fault signature sequences. This decreases diagnosability of multiple faults, and therefore leads to a loss in effectiveness of the fault isolation step. We develop a qualitative, event-ba...

Abstract: This paper describes a fault detection and isolation (FDI) scheme performed on the benchmark problem of a ship propulsion system. The model used for the ship propulsion system is nonlinear, for which two types of additive sensor faults, an additive incipient fault, and a multiplicative parametric fault are simulated. The estimation of the fault severity is accomplished by using an ada...

Most existing techniques which employ DWT (discrete wavelet transform) to detect servomechanism fault events are based on the analysis of measured motor current signals. However, the outcomes of these techniques tend to be unreliable when the motor suddenly accelerates or generates a very high output torque. Accordingly, to reduce the occurrence of false alarms, this paper develops a fault dete...

In 1995, the Hyogoken-Nanbu earthquake (M 7.3) ruptured the Nojima fault, Awaji Island, central Japan. To investigate the recovery process of a fault zone after a large earthquake, repeated water injection experiments have been conducted every few years in an 1800-m-long borehole near the Nojima fault since 1997. In addition, the groundwater discharge rate and pressure have been observed in an ...

ÐThis paper presents a class of count-and-threshold mechanisms, collectively named -count, which are able to discriminate between transient faults and intermittent faults in computing systems. For many years, commercial systems have been using transient fault discrimination via threshold-based techniques. We aim to contribute to the utility of count-and-threshold schemes, by exploring their eff...