Vibration-based fault detection of accelerometers in helicopters

Victor Girondin (1) , Mehena Loudahi (1) , Hervé Morel (2) , Komi Midzodzi Pekpe (3) , Jean Philippe Cassar (3)

1 LAGIS - Laboratoire d'Automatique, Génie Informatique et Signal
2 Eurocopter France
3 STF - Systèmes Tolérants aux Fautes

Vibration-based monitoring is an approach for health analysis of helicopters. However, accelerometers and other sub-elements that convert and transmit vibrations to the recording system must not corrupt the signal. These elements are prone to defects because of external injuries during flights or maintenance. This paper will deal with a method to tackle problems of loosening and mechanical shocks. The objective is to perform a passive detection of accelerometer failures from the vibrations without knowledge of previous recordings. Experiments of mechanical failures have been carried out on a shaker to reproduce in flight vibrations, and it appears that the loosening and mechanical shocks introduce asymmetry and random peaks in the temporal vibrations. Loosening was successfully detected but mechanical shocks were much harder to detect as a result of strong dependences in the vibratory environment. Loosening data sets from flights confirm experimental observations and the proposed detection method allows for the detection of the fault with better performance than standard indicators.

Mots clés: accelerometers; vibration; helicopter; monitoring; skewness; HUMS

Domaines: Vibrations [physics.class-ph]; Vibrations [physics.class-ph]

Victor Girondin, Mehena Loudahi, Hervé Morel, Komi Midzodzi Pekpe, Jean Philippe Cassar. Vibration-based fault detection of accelerometers in helicopters. SAFEPROCESS - 8th IFAC Symposium on Fault Detection, Supervision and Safety of Technical Processes, Aug 2012, Mexico City, Mexico. pp.720-725, ⟨10.3182/20120829-3-MX-2028.00049⟩. ⟨hal-00747788v2⟩