R. Rennert, C. Pritzkow

In the last years vibro-acoustic diagnostic has been taken into account for health and usage monitoring more and more also in civil aviation. To guarantee safe aircraft operation, condition monitoring on aircraft engines and drive systems by vibration measurement and analysis is a widely accepted subsidiary method. In an research project IMA GmbH Dresden and partners developed the embedding of a vibro-acoustic diagnosis system into an existing aircraft engine control unit. The investigation deals with the problem of aircraft engine vibrations from the diagnosticians point of view, especiaiiy with some aspects of dealing with memory shortage. Calculation time and memory in aircrafts is strictly limited and high priced. We could show, how it wiii be possible to perform the extensive diagnosis calculation in a strictly limited aircraft engine control unit. Ail described concepts and methods were putted into practise. Test results show vibration monitoring periods on aircraft engines during test rigs runs. The diagnosis data are coiiected in intensity plots, this means diagrams with the time history of frequency spectra, from special operation conditions of aircraft engines. The characteristic vibration patterns of the surveyed aircraft engine occur clearly. At the request of air carriers a new algorithm for online unbalance identification was developed. Using a non-linear curve fit method it aiiows permanent unbalance identification also under highly variable speeds. The unbalance detection algorithm works like a narrow band filter for one special frequency, in our case the turbine shaft frequencies. We proved the filter characteristics of the new algorithm as weii as the effect of influence values like noise level, speed change etc. on the resulting unbalance values. The unbalance detection algorithm was also tested on real aircraft engines. Result of all investigations is an aircraft engine control unit with the additional functionality of a vibro-acoustic diagnosis system. That could be reached without any hardware extension by complete use of existing vibration sensors, measurement equipment, calculation resources and data transfer paths. So we can provide an economic solution to increase safety on aircraft engines. Due to low costs and flexible implementation that diagnosis extension is especiaiiy designed for small and mid-size aircrafts.

23rd ICAF Symposium of the international Committee on Aeronautical Fatique, 2005, Hamburg

Conference Poster

englisch

A5, 10 Seiten

DGLR-Bericht, 2005, 2005-03, 23rd ICAF Symposium of the international Committee on Aeronautical Fatique - Proceedings; S.541-550; 2005; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn

NA

diagnostics, health monitoring

Bestellbar

2005