Multiple catastrophic fault diagnosis of analog circuits considering the component tolerances

This paper deals with the diagnosis of multiple catastrophic faults, being cuts (open‐circuits) of some connecting paths and/or short‐circuits of some pairs of points in analog circuits. A method enabling us to detect and identify the faults, taking into account the deviations of the circuit parameters within their tolerance ranges, is developed. The method exploits an appropriate fault dictionary. The fault dictionary is used only for preliminary identification of the faults, because it is based on the analysis of the circuits with nominal parameters. The crucial point of the method is a verification procedure, proposed in this paper, based on the linear programming approach. It leads to the results considering the component variations within their tolerance ranges. In addition, a procedure for selecting appropriate test points, employing some evolutionary techniques, is developed. Although the approach presented in this paper is described in detail for linear circuits, it can be directly generalized to nonlinear circuits. Three numerical examples, including two linear and one nonlinear circuits, illustrate the proposed method and show its efficiency. Copyright © 2011 John Wiley & Sons, Ltd.