A new method of diagnostic row reasoning based on trivalent residuals

Abstract

The genesis of the proposed fault isolation approach was the belief that the added value may be achieved through the synthesis of various approaches. In this paper, we propose a new method of fault isolation, which promises the achievement of a favorable effect of synergy. Principally, the proposed approach merges a fault isolation system (FIS) with a modified hitting set tree (HS) inferring algorithm. As a result, a new hybrid approach based on three-valued residuals is presented. It manifests two highly desirable features of diagnostic systems, namely efficient isolability of multiple faults which is inherent for the hitting set tree approach, and a high distinguishability of faults provided by the fault isolation system. The beneficial synergy effect was indicated and confirmed in the example of the diagnosis of a two-tank system. The performed comparative study shows a significant increase in the fault distinguishability obtained with the proposed approach compared with others. The advantageous features of the proposed approach in terms of fault isolability, flexibility of applied models, and the usage of expert knowledge predestinate it for industrial implementations.