Abstract
<p class="Abstract">This paper discusses the origin and problem of the fault compensation effect. The fault compensation effect is an underrated common side effect of the fault isolation approaches developed within the Fault Detection and Isolation (FDI) community. In part, this is justified due to the relatively low probability of such an effect. On the other hand, there is a common belief that the inability to isolate faults due to this effect is the evident drawback of model-based diagnostics. This paper shows how, and under which conditions, the fault compensation effect can be identified. In this connection, the necessary and sufficient conditions for the fault compensation effect are formulated and exemplified by diagnosing a single buffer tank system in open and closed-loop arrangements. In this regard, we also show the drawbacks of a bi-valued residual evaluation for fault isolation. In contrast, we outline the advantages of a three-valued residual evaluation. This paper also brings a series of conclusions allowing for a better understanding of the fault compensation effect. In addition, we show the difference between fault compensation and fault-masking effects.</p>
Highlights
The model-based diagnostics of industrial processes intensively makes use of residuals [1], [2], [3]
The design of the diagnostic systems in which residuals are sensitive exclusively to single faults is strongly recommended for fault detection and isolation approach (FDI) because it avoids fault compensation effects
The incidence matrix reflects the relation between faults and diagnostic signals
Summary
The model-based diagnostics of industrial processes intensively makes use of residuals [1], [2], [3]. This paper deals mainly with the problem of the fault compensation effect and intends to expose some weaknesses of the FDI model-based diagnosing. The FDI approaches to isolating multiple faults should be criticized as they may lead to misdiagnosis in a case of a fault compensation effect. The paper contributes both to the theory and practice. The defined conditions contribute to the FDI theory and practice by proposing a method for seeking potential fault compensation effects by design or analyzing a diagnostic system.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
