DocumentCode :
2845991
Title :
Microphone Arrays for Acoustic Detection during Laser Welding of Cold-Rolled Steel Strip
Author :
Sansan, Ao ; Zhen, Luo ; Nan, Zhao ; Xianzheng, Bu ; Yang, Li
Author_Institution :
Sch. of Mater. Sci. & Eng., Tianjin Univ., Tianjin, China
Volume :
1
fYear :
2010
fDate :
13-14 Oct. 2010
Firstpage :
935
Lastpage :
939
Abstract :
In order to achieve the quality control for the cold-rolled steel strip, it was required to monitor the laser welding processing. Acoustic signal detecting based on microphone is wildly applied in the welding processing. However, traditionally single microphone was limited by hostile background noise in the realistic industry environment. In this paper, a microphone array consisting of 7 microphones was employed to sample the acoustic signal generated by the laser welding. In order to reduce the background noise and extract the clean welding acoustic signal, the Constant Modulus Algorithm was used to the array beam former. Meanwhile, power spectrum density estimation and wavelet packet transform methods were applied to analyze the original acoustic signal and the beam former output signal. By comparing the two signals, it was obviously shown that the beam former output signal could effectively reduce the power spectrum density of the background noise at lower frequency bands. And the energy contribution was concentrated in the 15 kHz frequency range. Meanwhile, the frequency characteristic of the acoustic signal during the penetration welding processing by the modulated laser beam was explained.
Keywords :
acoustic signal detection; laser beam welding; microphone arrays; wavelet transforms; acoustic detection; acoustic signal detection; array beam former; background noise; cold-rolled steel strip; constant modulus algorithm; laser welding processing; microphone arrays; modulated laser beam; penetration welding processing; power spectrum density estimation; quality control; wavelet packet transform; welding acoustic signal; Acoustics; Laser beams; Laser noise; Microphone arrays; Noise measurement; Welding; acoustic signal; constant modulus algorithm; laser welding; microphone array; power spectrum density;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Intelligent System Design and Engineering Application (ISDEA), 2010 International Conference on
Conference_Location :
Changsha
Print_ISBN :
978-1-4244-8333-4
Type :
conf
DOI :
10.1109/ISDEA.2010.147
Filename :
5743330
Link To Document :
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