A Distributed Fault-Detection and Diagnosis System Using On-Line Parameter Estimation

Abstract This paper describes a model-based fault-detection and diagnosis system based on a distributed system identification approach. The diagnostic system consists of a two level process including parallel hypothesis testing modules and a fault mode identification and estimation module. The proposed system is part of a distributed diagnostic system for use in an intelligent control system. The proposed approach utilizes a piecewise linear model to predict the system performance. The deviation between predicted and actual performance is used to identify the associated fault mode. Each hypothesis testing module is associated with a particular class of fault modes and can be viewed as a condition monitor in a distributed diagnostic system hierarchy. The results of the hypothesis modules are processed by the fault-detection and estimation module. Using the results of the on-line diagnosis, the intelligent control system will be able to accommodate the fault modes, reduce maintenance cost, and increase system availability.