Test and diagnosis of analog circuits: When fuzziness can lead to accuracy

Abstract

Editor: B. Kaminska Abstract.Testing and diagnosing analog circuits is a very challenging problem. The inaccuracy of measurement and the infinite domain of possible values are the principal difficulties. AI approaches were the base of many systems which tried to overcome these problems. The first part of this paper is a state of the art of this research area. We present two fundamental approaches, model-based reasoning and qualitative reasoning, and the systems implementing them; a discussion and an evaluation of these systems are given. In the second part, we present and propose a novel approach based on fuzzy logic in order to go further in dealing with analog circuits testing and diagnosis. Tolerance is treated by means of fuzzy intervals which are more general, more efficient and of higher fidelity to represent the imprecision in its different forms than other approaches. Fuzzy intervals are also able to be semi-qualitative which is more suitable to the simulation of analog systems. We use this idea to develop a best test point finding strategy based on fuzzy probabilities and fuzzy decision-making methodology. Finally, a complete expert system which implements this approach is presented.

Fault diagnosis of electronic systems using intelligent techniques: a review

“…It uses fuzzy logic, in its front end to deal with the uncertainty of measurements, and internally to generate membership degrees for faults, predicted by the outcomes of multiple tests. In [8], [53], and [54], and extensions to the model-based ATMS architecture, employing fuzzy logic is described. Essentially, fuzzy logic is used to improve the accuracy of component modeling and measurements.…”

“…Fuzzy logic has been combined with model-based reasoning, particularly in the domain of analog circuit diagnosis. Circuit measurements are represented using fuzzy values, and inferences are propagated using fuzzy techniques [6], [8], [53], [54].…”

“…Applications, which apply fuzzy logic to the diagnosis of electronic systems are also reported. FLAMES is a program for troubleshooting analog circuits [53], [54]. It is a GDE-like program employing ATMS.…”