05_ARTS_FTtank_EHJDALMB.pdf (163.99 kB)
System fault diagnostics using fault tree analysis
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posted on 2008-09-19, 10:30 authored by Emma E. Hurdle, Lisa JacksonLisa Jackson, J.D. AndrewsOver the last 50 years advances in technology have led to an increase in the
complexity and sophistication of systems. More complex systems can be harder to
maintain and the root cause of a fault more difficult to isolate.
Down-time resulting from a system failure can be dangerous or expensive depending
on the type of system. In aircraft systems the ability to quickly diagnose the causes of
a fault can have a significant impact on the time taken to rectify the problem and
return the aircraft to service. In chemical process plants the need to diagnose causes of
a safety critical failure in a system can be vital and a diagnosis may be required within
minutes. Speed of fault isolation can save time, reduce costs and increase company
productivity and therefore profits. System fault diagnosis is the process of identifying
the cause of a malfunction by observing its effect at various test points.
Fault tree analysis (FTA) is a method that describes all possible causes of a specified
system state in terms of the state of the components within the system. A system
model is used to identify the states the system should be in at any point in time. This
paper presents a method for diagnosing faults in systems using FTA to explain the
deviations from normal operation observed in sensor outputs. The causes of a system's
failure modes will be described in terms of the component states. This will be
achieved with the use of coherent and non-coherent fault trees. A coherent fault tree is
constructed from AND and OR logic, therefore only considers component failed
states. The non-coherent method expands this allowing the use of NOT logic which
implies that the existence of component failed states and working states are both taken
into account. This paper illustrates the concepts of this method by applying the
technique to a simplified water tank level control system.
History
School
- Aeronautical, Automotive, Chemical and Materials Engineering
Department
- Aeronautical and Automotive Engineering
Citation
HURDLE, E.E., BARTLETT, L.M. and ANDREWS, J.D., 2005. System fault diagnostics using fault tree analysis. IN: Proceedings of the 16th Advances in Reliability Technology Symposium (ARTS) , Loughborough, UK, 2005, pp. 203-222.Publisher
© Loughborough UniversityPublication date
2005Notes
This is a conference paper.Language
- en