Aircraft Wiring Integrity Verification using Pseudo-random Binary Sequence

Our approach to aircraft wiring inspection is to inject a special type of low level probe signal into the cable to be tested. The system response to this special input can be used to give the complete transfer function of the cable. Our hypothesis is that incipient failures in the cable will be detectable as subtle changes in that transfer function, including discontinuities which cause signal reflections and hence standing waves. Even very low probe signals can be used, and the test can be done on-line while the circuit is doing its normal function. The required electronics can be fabricated into a single chip which would be built into the system or even built into the connector. In this mode, the probe signal and test would be executing continuously. Alternatively, the approach can be used offline. Since very low level probe signals can be used, in many cases these signals can be induced into the cable without disconnecting the cable. To pick up the probe signal at the end of the cable, the cable would still need to be disconnected and plugged into a test box, or a special cable adaptor could be installed once, and then testing could be done without disconnecting the cable at either end.