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Analysis of Engine Sound by using Wavelet Transform

利用小波变换分析发动机声音

基本信息

批准号：
06805026
负责人：
OTA Hiroshi
金额：
$ 1.28万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06805026/
关键词：
Wavelet Transform Engine Sound Monitoring Diagnosis

项目摘要

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.

在本研究中，我们应用小波分析来监测四冲程发动机及其驱动系统。首先，我们在正常状态下空载驱动发动机，并测量发动机发出的声音和发动机缸体顶部的加速度。然后我们通过小波变换这些信号，并将它们与每个工作循环（进气、压缩、点火、膨胀、排气）相关联。接下来，我们将发动机设置为异常状态，即（i）失火，（ii）挺杆间隙过大，（iii）凸轮链熔化。在小波分析的计算中，我们发现正常的发动机信号与异常的发动机信号之间存在显着差异。最后，我们利用小波分析对发动机发出的声音和发动机的加速度进行分析，以检测发动机的工作状况和发动机发生的异常情况，最终得出以下结论。（1）通过小波分析计算声音和振动的各频率分量随时间的变化，并找到发动机的冲程（爆炸， (2) 基于上述(1)，我们可以通过寻找发生振动的幅度(峰值)和振动发生的时间来检测异常。