Optimisation du système de surveillance des hélicoptères pour l'amélioration du diagnostic et de la maintenance

摘要

A Health and usage Monitoring System (HUMS) anticipates discrepancies in the rotorcraft drive-train, giving the operator an opportunity to perform corrective maintenance before any damage becomes critical. In addition to usage spectrum analysis, a HUMS deploys vibration monitoring as a means to detect propagating faults. This method consists in comparing in-flight vibration recordings to a normal state baseline. A recurrent problem with this approach is that this baseline is aircraft specific and subject to change between major overhauls, forcing the operator to relearn the baseline on regular bases. This study presents methods for evaluating the time-progression of the drive-train vibration signature. By studying fluctuation in vibration signature over time, it is possible to detect events such as maintenance actions and fault propagations without any aircraft specific baseline. Several progression analysis methods are tested, both parametric models and filter-banks. Finally, progression analysis is used as a basis for fault detection, and is shown to produce better results than traditional methods.