Continuously estimating persistent and intermittent failure probabilities


de Kleer, J.; Kuhn, L.; Liu, J. J.; Price, R.; Do, M. B.; Zhou, R. Continuously estimating persistent and intermittent failure probabilities. 7th IFAC Symposium on Fault Detection Supervision and Safety of Technical Processes (Safe Process 2009); 2009 June 30 – July 3; Barcelona, Spain.


Almost all previous work on model-based diagnosis has focused on persistent faults. However, some of the most difficult to diagnose faults are intermittent. It is very difficult to isolate intermittent faults which occur with low frequency but yet at high enough frequency to be unacceptable. For example, a printer which prints one blank page out of a 1000 or a computer that spontaneously reboots once per day is unacceptable. Accurate assessment of intermittent failure probabilities is critical to diagnosing and repairing equipment. This paper presents an overall framework for estimating component failure probabilities which includes both persistent and intermittent faults. These estimates are constantly updated while the equipment is running.

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