Many-Valued Logic and Qualitative Modelling of Electrical Circuit s
Mark H. Le · 2004
Several authors have reported previous work on qualitative modelling of electrical systems by assumin g steady-state conditions and reducing circuits to networks of resistive elements . This has been very successful in certain applications, particularly for Failure Mode Effects Analysis in automotive electrical systems . In support of this work we have concentrated on simple, minimal models that maintain structural isomorphism with the real system; the motivation being t o provide an accessible conceptual structure for ease o f use by engineering staff . However, a number of difficulties remain and solutions to these would increase th e applicability of the method . In this paper we introduce further developments that address several of the remaining important issues and provide solutions to some recent obstacles . After describing a series of problems, we draw on the field o f many-valued logic for inspiration and investigate som e qualitative analogies. The results of a new labelling scheme show the advantages of a 5 valued quantity space for resistance . This is shown to resolve previousl y ambiguous cases and opens up considerably more mod elling possibilities . The interpretation of the labelling scheme can be tailored to the application domain, giving powerful modelling options.