摘要 |
<p>A method and apparatus for detecting faults in a single-point impact sensing system having electrically conductive self-test plates within the sensor to electrostatically deflect the sense element during self-test sequence. The deflection of the sense element is identical to deflection which would occur during an actual activation worthy impact event. The response time from the deflection of the sense element to the change in state of an activation flag is recorded and compared with an expected response time stored in non-volatile memory. Differences between the test time and the expected time is indicative of either a hard fault such as malfunction or reduced function of sensing system components or soft faults such as loss of calibration. Diagnostic self-test in this manner not only checks the electrical continuity of the impact sensing system, but also the mechanical integrity and the calibration of the sensing system.</p> |