| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1995: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1994: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Research Abstract |
In this study, we applied Wavelet analysis to monitor a four-cycle engine and its driving system.
First, we drove an engine in normal condition with no load and measured sound emitted from engine and acceleration on the top of the engine block. Then we transformed these signals by Wavelet and related these to each operating cycle (intake, compression, gnition, expansion, exhaust).
Nex, we set up an engine in abnormal condition, i.e., (i) miss fire, (ii) larget tappet clearance, (iii) melt of cam chain. In the calculation of Wavelet analysis, we found a significant difference between normal engine signal and abnormal one.
Finally, we got following conclusions as a result that we analyzed sound emitted from an engine and acceleration of an engine by using Wavelet analysis to detect operating condition of engine and abnormality occurring to an engine.
(1) We calculate change of each frequency component of sound and vibration with time by Wavelet analysis and find a stroke of engine (explosion, closing motion of intake or exhaust valve) and a vibrating part.
(2) Based on above-mentioned (1), we can detect abnormalities by seek magnitudes of occurring vibration (peak magnitude) and the timing when vibrations occur.
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