Frequency-domain grouping robust fault diagnosis for analog circuits with uncertainties

1 SUMMARY A new frequency-domain grouping robust fault diagnosis (GRFD) scheme, based on the design for both grouping-robust estimation/evaluation of component variation rate and Boolean-based decision process, is proposed for solving fault diagnosis of large-scale analog circuits with uncertainties, including both component tolerances and measurement errors. In this scheme, first, grouping-robust estimators for one partitioning of all component groups, designed by using grouping full-column rank output measurement technique, are employed to estimate the component variation rate. Secondly, grouping-robust evaluators, in which a judge policy for faulty possibility of components is suggested, are employed for the careful evaluation of component variation rate in order to reduce the effect of both component tolerances and measurement errors to the diagnostic test result for one group partitioning. Next, expanding the one-partitioning GRFD scheme, an overall GRFD scheme is proposed by combining Boolean-based decision process for analog fault diagnosis. Finally, a fault diagnosis example of a large-scale analog circuit is illustrated. The results indicate that, without any a priori information about the type of component failure, precise diagnosis for a large-scale circuit with component tolerances and measurement errors is accomplished at the lowest measurement cost.