| 摘要: |
| 柴油机的振动信号中含有大量噪声，在进行故障特征提取之前必须加以消除。首先对傅里叶滤波降噪、小波 降噪和小波包降噪的效果进行了对比，然后将奇异值分解技术用于信号降噪，最后提出了一种将小波包和奇异值分 解相结合的降噪方法。该方法将输人信号进行一次小波包分解，利用奇异值分解方法对分解后的幅值量化系数进 行降噪。实例表明，小波包和奇异值分解相结合的方法降噪效果最好。与其他方法相比,用新的方法对柴油机缸盖 振动信号进行降噪处理的信噪比最高,且能明显识别出燃烧爆发、气门落座等各个阶段的振动信号，大大提高了特 征提取的准确率。 |
| 关键词: 柴油机 振动信号 降噪 小波包分解法 奇异值分解法 |
| DOI： |
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| 基金项目:国家自然科学基金资助项目(50105015);北京市新星计划基金资助项目(2003B33);北京市教育委员会共建项目 (XK114140478) |
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| De-noising of diesel vibration signal using wavelet packet and singular value decomposition |
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DU AN Li-xiang, ZHANG Lai-bin, WANG Zhao-hui, ZHANG Dong-liang
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(Faculty of Mechanical and Electronic Engineering in China University of Petroleum，Beijing 102249, China )
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| Abstract: |
| The vibration signals of diesel include much noise that must be eliminated before characteristic parameters extraction. Firstly, the effects of vibration-signal de-noising among Fourier transform, wavelet decomposition and wavelet packet decomposition were compared. Secondly, the singular value decomposition was applied to de-noise vibration signals. Finally, a new de-noising method integrated with wavelet packet and singular value was put forward. In this method, vibration signals are decomposed by wavelet packet，and the wavelet packet coefficient is de-noised by singular value decomposition again. The results indicate that the new de-noising method is the best. The signal-to noise ratio of the vibration signals of diesel cylinder lid is the highest. The diesel vibration wave-form of combustion and valve gets clearly and the extracted characteristic parameters become more precise. |
| Key words: diesel vibration signal de-noising wavelet packet decomposition singular value decomposition |
