Advanced Techniques for Electrical Wire Fault

Wiring integrity has become a very important issue in the safety of both military and civilian aircraft. As existing aircraft are being used past their designed lifetime and newer aircraft begin to rely more on fly-by-wire technology and avionics to control critical onboard systems, wire system safety is more important than ever. Coupled with rising costs at all maintenance levels and high profile commercial crashes such as TWA 800 and Swiss Air 111, advanced diagnostic and prognostic technologies are needed. Current reflectometry inspection methods are unable to effectively detect latent faults such as chafed and cracked insulation. However, this does not need to be the case. We propose here an advanced signal processing algorithm that combines wavelet analysis of recorded time domain reflectometry (TDR) signals with a new way of viewing the wavelet coefficients over time and scale that creates a fingerprint-like image of the inspected cable. Small latent flaws hidden in the raw TDR signal will show up in these new fingerprint-like images as discernable patterns, and thus can be detected and located either manually or automatically through intelligent user-friendly software.