The cumulated lengths of electrical cables always increase in aircrafts: up to 20 km in a helicopter, 40 km in a fighter and 500 km cables of all types in a modern civil transport aircraft such as A380. Electrical wiring is a critical part in the nominal operation of a system: its reliability influences widely the flights safety. The importance of the wired network has thus grown to the same level as the systems it is connected to. The sensitivity of the network to the defects evolves because of the design complexity and integration of new technologies: various inconveniences can emerge at system level due to electrical cables. The diagnosis of the network is then essential to detect and locate these defects, and so to reduce the maintenance cost. Reflectometry based methods, such as D-MCTDR (Distributed Multi Carrier Time Domain Reflectometry), are prototyped and tested on real harnesses to validate their use in real aircraft conditions. To increase the reliability of wired networks or to ease their maintenance, reflectometry is the most promising method. This method provides information for the detection, localization and characterization of electrical defects (or mechanics defects having electrical consequences) in wired network. The application to avionics is currently under study in the Harness BITE project, gathering a consortium of large industries such as Airbus, Dassault Aviation, Eurocopter, Labinal, Latelec, Crouzet and Delphi, with upstream research from CEA LIST. The project has followed an incremental testing strategy, going from simple unconnected wires to ramified wires connected to various voltage values and loads. So far, we have proven the efficiency of the MCTDR method, implemented on dedicated electronic boards with FPGA, with more than 1 GHz equivalent oversampling frequency [8]. The embedded diagnosis strategy enables to detect and localize hard defects for quite long wire lengths, and also resistive and shielding defects thanks to the opportunity of using a reference diagnosis measurement. A distributed version of the diagnosis, namely D-MCTDR, is currently under test on supplied cables connected to various loads. This method allows an unambiguous localization of a defect on a ramified network topology. The next tests will evaluate the ability of diagnosing intermittent defects and will improve the post-processing of the distributed diagnosis.
Aircraft power supply wiring monitoring system
Überwachungssystem für die Energieverteilung von Flugzeugen
2011
7 Seiten, 7 Bilder, 8 Quellen
Conference paper
Storage medium
English
Engineering Index Backfile | 1944
|Engineering Index Backfile | 1945
|