Method of and apparatus for automatic fault diagnosis of electrical circuits employing on-line simulation of faults in such circuits during diagnosis
AssigneeGenRad, Inc.
InventorsLutz Henckels, Rene Haas, Ralph Anderson
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Abstract
This disclosure is concerned with the use of on-line simulation of circuit faults during diagnosis to generate a small part of a complete fault dictionary needed for diagnosis of the circuit, being adapted for use of a mini-computer-based automated test system having only a small amount of secondary storage; and being adapted for an exact match diagnosis with modeled failures, and a heuristic approach for a partial match of faulty behaviour that leads to a highly probable diagnosis.
Claims9
A method of automatic fault diagnosis of an electrical circuit under test comprising applying a set of tests to the circuit under test;
- comparing the responses of the circuit under test with the responses of a good circuit to detect variations which are indicative of faults;
- selecting from a stored partial fault dictionary of modeled circuit faults a list of possible circuit faults which are capable of producing at least one of said variations;
- simulating on-line circuits having at least one of the faults from said list;
- generating the responses of the simulated circuits to the set of tests;
- and comparing the responses of the simulated circuits with the responses of the circuit under test to effect fault diagnosis.
Electrical circuit fault diagnosis apparatus for a circuit under test comprising means for applying a set of tests to the circuit under test;
- means for comparing the responses of the circuit under test with the responses of a good circuit to detect variations which are indicative of faults;
- means for selecting from a stored partial fault dictionary of modeled circuit faults a list of possible circuit faults which are capable of producing at least one of said variations;
- means for simulating on-line circuits having at least one of the faults from said list;
- means for generating the responses of the simulated circuits to said set of tests;
- and means for comparing the responses of the simulated circuits with the responses of the circuit under test to effect fault diagnosis.
Dependencies are inferred from the claim text.