The use of knowledge-based systems to aid in the diagnosis of faults in physical
devices has grown considerably since their introduction during the 1970s. The
majority of the early knowledge-based systems incorporated shallow knowledge,
which sought to define simple cause and effect relationships between a symptom and
a fault, that could be encoded as a set of rules. Though such systems enjoyed much
success, it was recognised that they suffered from a number of inherent limitations
such as inflexibility, inadequate explanation, and difficulties of knowledge elicitation.
Many of these limitations can be overcome by developing knowledge-based systems
which contain deeper knowledge about the device being diagnosed. Such systems,
now generally referred to as model-based systems, have shown much promise, but
there has been little evidence to suggest that they have successfully made the
transition from the research centre to the workplace.
This thesis argues that knowledge-based systems are an appropriate tool for the
diagnosis of faults in complex devices, and that both deep and shallow knowledge
have their part to play in this process. More specifically this thesis demonstrates how
a wide-ranging knowledge-based system for quality assurance, based upon shallow
knowledge, can be developed, and implemented. The resultant system, named
DIPLOMA, not only diagnoses faults, but additionally provides advice and guidance
on the assembly, disassembly, testing, inspection and repair of a highly complex
hydro-mechanical device. Additionally it is shown that a highly innovative modelbased
system, named MIDAS, can be used to contribute to the provision of
diagnostic, explanatory and training facilities for the same hydro-mechanical device.
The methods of designing, coding, implementing and evaluating both systems are
explored in detail.
The successful implementation and evaluation of the DIPLOMA and MIDAS
systems has shown that knowledge-based systems are an appropriate tool for the
diagnosis of faults in complex hydro-mechanical devices, and that they make a
beneficial contribution to the business performance of the host organisation.
Furthermore, it has been demonstrated that the most effective and comprehensive
knowledge-based approach to fault diagnosis is one which incorporates both deep and
shallow knowledge, so that the distinctive advantages of each can be realised in a
single application. Finally, the research has provided evidence that the model-based
approach to diagnosis is highly flexible, and may, therefore, be an appropriate
technique for a wide range of industrial applications. / Science and Engineering Research Council, and Alvey Directorate
| Identifer | oai:union.ndltd.org:BRADFORD/oai:bradscholars.brad.ac.uk:10454/4374 |
| Date | January 1992 |
| Creators | Doherty, Neil F. |
| Contributors | Kochhar, A.K. |
| Publisher | University of Bradford, Department of Mechanical & Manufacturing Engineering |
| Source Sets | Bradford Scholars |
| Language | English |
| Detected Language | English |
| Type | Thesis, doctoral, PhD |
| Rights | <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/"><img alt="Creative Commons License" style="border-width:0" src="http://i.creativecommons.org/l/by-nc-nd/3.0/88x31.png" /></a><br />The University of Bradford theses are licenced under a <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/">Creative Commons Licence</a>. |
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