This invention relates generally to testing of equipment, and more specifically to, acoustic signature fault detection for and within electronic, electromechanical, and mechanical equipment.
Currently electronic, electromechanical, and mechanical equipment, for example, equipment for aircraft and for other vehicles including navigation, tactical and other systems, are tested using measurements of voltage, current, and temperature. More specifically, such systems, sometimes referred to in the testing environment as a unit under test (UUT), are typically tested using automated test equipment. In such automated test equipment (ATE) the UUTs are subjected to a set of stimuli (applied electrical signals or mechanical inputs) that are typically experienced under operating conditions. The ATE is configured to measure one or more output conditions, electrical or mechanical, that result due to the applied stimuli. Output conditions (measurements) that are different than expected output conditions are utilized to try to determine which portion, for example, a removable circuit card, is the source of the different than expected output conditions (e.g., the failed test or fault).
However, there is still sometimes ambiguity with such testing methods. Sometimes one or more circuit cards or other subassemblies have to be removed and replaced until the source of the failed test is isolated. Some components and combinations of components emit an audible sound when operating. Others emit a sound when not operating correctly. Still others emit a frequency when one or more components or subassemblies have failed that is different than a frequency emitted when all components are operating correctly. Such audible frequency emissions are sometimes collectively referred to as acoustic signatures.