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Optimal Passive Source Localization for Acoustic Emissions

Acoustic emission is a non-destructive testing method where sensors monitor an area of a structure to detect and localize passive sources of elastic waves such as expanding cracks. Passive source localization methods based on times of arrival (TOAs) use TOAs estimated from the noisy signals received...

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Autores principales: Prete, Carlos A., Nascimento, Vítor H., Lopes, Cássio G.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8699904/
https://www.ncbi.nlm.nih.gov/pubmed/34945893
http://dx.doi.org/10.3390/e23121585
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author Prete, Carlos A.
Nascimento, Vítor H.
Lopes, Cássio G.
author_facet Prete, Carlos A.
Nascimento, Vítor H.
Lopes, Cássio G.
author_sort Prete, Carlos A.
collection PubMed
description Acoustic emission is a non-destructive testing method where sensors monitor an area of a structure to detect and localize passive sources of elastic waves such as expanding cracks. Passive source localization methods based on times of arrival (TOAs) use TOAs estimated from the noisy signals received by the sensors to estimate the source position. In this work, we derive the probability distribution of TOAs assuming they were obtained by the fixed threshold technique—a popular low-complexity TOA estimation technique—and show that, if the sampling rate is high enough, TOAs can be approximated by a random variable distributed according to a mixture of Gaussian distributions, which reduces to a Gaussian in the low noise regime. The optimal source position estimator is derived assuming the parameters of the mixture are known, in which case its MSE matches the Cramér–Rao lower bound, and an algorithm to estimate the mixture parameters from noisy signals is presented. We also show that the fixed threshold technique produces biased time differences of arrival (TDOAs) and propose a modification of this method to remove the bias. The proposed source position estimator is validated in simulation using biased and unbiased TDOAs, performing better than other TOA-based passive source localization methods in most scenarios.
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spelling pubmed-86999042021-12-24 Optimal Passive Source Localization for Acoustic Emissions Prete, Carlos A. Nascimento, Vítor H. Lopes, Cássio G. Entropy (Basel) Article Acoustic emission is a non-destructive testing method where sensors monitor an area of a structure to detect and localize passive sources of elastic waves such as expanding cracks. Passive source localization methods based on times of arrival (TOAs) use TOAs estimated from the noisy signals received by the sensors to estimate the source position. In this work, we derive the probability distribution of TOAs assuming they were obtained by the fixed threshold technique—a popular low-complexity TOA estimation technique—and show that, if the sampling rate is high enough, TOAs can be approximated by a random variable distributed according to a mixture of Gaussian distributions, which reduces to a Gaussian in the low noise regime. The optimal source position estimator is derived assuming the parameters of the mixture are known, in which case its MSE matches the Cramér–Rao lower bound, and an algorithm to estimate the mixture parameters from noisy signals is presented. We also show that the fixed threshold technique produces biased time differences of arrival (TDOAs) and propose a modification of this method to remove the bias. The proposed source position estimator is validated in simulation using biased and unbiased TDOAs, performing better than other TOA-based passive source localization methods in most scenarios. MDPI 2021-11-27 /pmc/articles/PMC8699904/ /pubmed/34945893 http://dx.doi.org/10.3390/e23121585 Text en © 2021 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Prete, Carlos A.
Nascimento, Vítor H.
Lopes, Cássio G.
Optimal Passive Source Localization for Acoustic Emissions
title Optimal Passive Source Localization for Acoustic Emissions
title_full Optimal Passive Source Localization for Acoustic Emissions
title_fullStr Optimal Passive Source Localization for Acoustic Emissions
title_full_unstemmed Optimal Passive Source Localization for Acoustic Emissions
title_short Optimal Passive Source Localization for Acoustic Emissions
title_sort optimal passive source localization for acoustic emissions
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8699904/
https://www.ncbi.nlm.nih.gov/pubmed/34945893
http://dx.doi.org/10.3390/e23121585
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