Fundamental Theroy and Experimental Research

Time delay estimation and acoustic emission source location of rock based on phase difference

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  • 1. College of Information Engineering, Hebei United University, Tangshan, Hebei 063009, China; 2. College of Mining Engineering, Hebei United University, Tangshan, Hebei 063009, China

Received date: 2014-05-12

  Online published: 2018-06-13

Abstract

Lots of uncertain factors affect the time delay estimation precision of time-difference location method in rock acoustic estimation(AE) experiments. Aiming at this problem, the all phase phase-difference time delay estimation method is proposed. Time delay of AE signal is deduced through the phase-difference obtained by combining wavelet decomposition and all phase frequency analysis. AE sub-band signals with the same dominant frequency from different sensors are found with wavelet decomposition. Then the phases of middle sample of every sub-band signal are obtained with all phase frequency analysis method for those chosen sub-band signals, and the time-differences of AE signals’ reaching different sensors are computed according to the relationship between phase-difference and time-difference. Finally, the AE source is located by the method of time-difference location. Experiments are conducted on a 50 mm×100 mm×50 mm granite stone, and AE source is generated by broken lead at ten different points. Under the lab environment, the results from the proposed AE location method indicate that using phase-difference based on wavelet transform and all phase frequency analysis can effectively improve the accuracy of location of AE source. Compared to the results obtained by the PCI-2 acoustic emission instrument, the absolute error reduces by about 3 mm, so as to provide an effective way for AE source inversion.

Cite this article

HUANG Xiao-hong , ZHANG Yan-bo , TIAN Bao-zhu , LIU Xiang-xin, . Time delay estimation and acoustic emission source location of rock based on phase difference[J]. Rock and Soil Mechanics, 2015 , 36(2) : 381 -386 . DOI: 10.16285/j.rsm.2015.02.012

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