KEYWORDS analog circuit – fault diagnosis – test vector –tolerance –test node – multifrequency-modified nodal analysis ABSTRACT A method to identify and select test points for analog circuit testing and to detect multiple soft faults in linear analog circuits using multiple frequency measurements is proposed in this paper. Modified nodal analysis (MNA) method is used to simulate the circuit und...

Classical single stuck-at faults are analyzed as surrogates for any non-classical fault that may have caused an observed failure. Although multiple stuck-at faults are used as an illustrative example of non-classical faults, proposed algorithms are applicable to any other type of fault. Our effect-cause analysis is less complex than existing methods. The diagnostic procedure adds or removes fau...

This paper explores a class of multiple-model-based fault detection and identification (FDI) methods for bias-type faults in actuators and sensors. These methods employ banks of Kalman-Bucy filters to detect the faults, determine the fault pattern, and estimate the fault values, wherein each Kalman-Bucy filter is tuned to a different failure pattern. Necessary and sufficient conditions are pres...

Multiple fault diagnosis is a challenging problem because the number of candidates grows exponentially in the number of faults. In addition, multiple faults in dynamic systems may be hard to detect, because they can mask or compensate each other’s effects. The multiple fault problem is important, since the single fault assumption can lead to incorrect or failed diagnoses when multiple faults oc...

A new approach to fault analysis is presented. We consider multiple stuck-at-0/1 faults at the gate level. First, a fault collapsing phase is applied to the network, so that equivalent faults are eliminated. During the analysis we consider frontier faults where there is at least a normal path from each faulty line to a primary output. It is shown that the set of frontier faults is equivalent to...