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International Standard Serial Number:
ISSN 1001-4551
Sponsor:
Zhejiang University;
Zhejiang Machinery and Electrical Group
Edited by:
Editorial of Journal of Mechanical & Electrical Engineering
Chief Editor:
ZHAO Qun
Vice Chief Editor:
TANG ren-zhong,
LUO Xiang-yang
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86-571-87041360,87239525
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No.9 Gaoguannong,Daxue Road,Hangzhou,China
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meem_contribute@163.com
Abstract: In order to solve the problem that the sound signal of belt conveyor is seriously disturbed by reverberation and background noise in the acoustic diagnosis, the reasons of reverberation and the composition of sound signal were analyzed,an acoustic signal enhancement method based on super directional beamforming (SBF) and improved singular value decomposition (ISVD) was proposed. Firstly, the optimal frequency band was selected based on the maximum energy variation to determine the frequency band with more fault information. Then, SBF was used to remove the interference of reverberation on the sound signal, ISVD method was used to reduce the noise of the signal after reverberation, and the envelope spectrum of the signal was analyzed. The fault characteristic frequency measured in practice was compared with the theoretical fault characteristic frequency, and the fault characteristics of the belt conveyor were extracted. Finally, the test was designed, the data were collected, and the data collected from the coal mine site were analyzed and verified by using this method. The method was compared with the weighted prediction error algorithm (WPE), the linear constrained minimum variance (LCMV) and the recursive least square method (RLS).The research results show that: comparing with the original signal, the amplitude at the inner circle fault characteristic frequency of 153.1 Hz and the frequency doubling of 312.5 Hz in the envelope spectrum of test data processed by SBFISVD method is significantly improved, and the signal-to-noise ratio is significantly increased from -31.39 dB to -25.4 dB. The sound signal enhancement method based on SBF-ISVD has remarkable effect on removing reverberation and reducing noise, and the bearing fault feature extraction effect is good, which can realize the sound signal enhancement of belt conveyor under complex ambient noise.
Key words: belt conveyor; bearing fault diagnosis; acoustic diagnosis; reverberation cancellation; noise reduction; frequency band; super directivity beamforming(SBF); improve singular value decomposition(ISVD)