IEEE Aerospace Conference, Big Sky, MT, March 7-14, 2009.

An Innovative Approach for Isolating
Faulty Parameters

Sachin Kumar, Eli Dolev, and Michael Pecht
Prognostics Health Management Group
Center for Advanced Life Cycle Engineering (CALCE)
University of Maryland, College Park, MD 20742


This paper presents an innovative diagnostic approach that includes detection and fault isolation using the Mahalanobis distance (MD). The fault isolation approach is based on the analysis of residual MD values corresponding to performance parameters. The residual value is calculated by taking the differences between MD values estimated in two different scenarios: first, when a performance parameter is present, and second, when that performance parameter is absent. The residual of MD values for each parameter is obtained by using training data under several experiments planned by design-of-experiment concept, to analyze impact of each parameter. The distribution of residual MD values for each parameter is analyzed and a 95% probabilistic range is established. This range represents the expected contribution by parameters towards healthy systems MDs, and it is used to identify parameters that are responsible for the anomalous behaviour of a system. Parameters that fall beyond the threshold limit are considered responsible for the anomalous behaviour, and the parameter that has lowest residual value is isolated as
the faulty parameter. A case study on notebook computers is presented to demonstrate and test the suggested new approach’s ability to isolate faulty parameters.

Complete article is available to CALCE Consortium Members.

© IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.

[Home Page] [Articles Page]
Copyright � 2008 by CALCE and the University of Maryland, All Rights Reserved