Estudos da técnica de beamforming combinando arranjos de microfones e material poroso
Autor(a) principal: | |
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Data de Publicação: | 2017 |
Tipo de documento: | Dissertação |
Idioma: | por |
Título da fonte: | Manancial - Repositório Digital da UFSM |
Texto Completo: | http://repositorio.ufsm.br/handle/1/14128 |
Resumo: | In order to solve the problems caused by noise, it is essential that an adequate evaluation of the main sources of noise is carried out. This can be done using an acoustic imaging technique and one of them is the beamforming. Beamforming is a technique that consists of measuring the sound pressure of the source of interest by using a microphone array. After that the measured data goes to a post-processing generating an acoustic image of the source. Through that the main regions of sound radiation is shown. In this context usually outdoor measurements are taken. In this situation the microphones must be protected from the wind. For this purpose a layer of porous material may be used in front of the microphone array. Then its influence on the beamforming response is unknown. This work aims to evaluate the effect of the use of porous material on the microphone arrays at the beamforming response, using a free field directions vector hypothesis. For do this the porous material was first characterized according to its macroscopic parameters through impedance tube measurement. Then simulations were performed where it was possible to compare different materials and to test the influence of each macroscopic parameter on the array response. Measurements were also made in a semi-anechoic room where it was possible to evaluate the effect of distance between source and array, the deviation due to use different signals for evaluation, the three-dimensional beamforming preview and the recognitiopn of two sources by the array response. This methodology allowed to verify that the porous material cause a negatively affects on the array response through increasing the beamwidth. In other words, it increases the difficulty of the array to locate sources for certain frequencies. On the other hand the dynamic range increased with the use of the porous material representing a seeming improvement in the array response. However this increase is usually less than 2 [dB] what is not very representative. Moreover the sample thickness of the porous material was identified as the main characteristic that affects the array response. The thinner thicknesses have less influence on the array response thus having better results. |
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Estudos da técnica de beamforming combinando arranjos de microfones e material porosoBeamforming technique studies combining microphone arrays and porous materialBeamformingMaterial porosoLocalização de fontes sonorasFaixa dinâmicaLargura do lóbulo principalBeamformingPorous materialSound source localizationDynamic rangeBeamwidthCNPQ::ENGENHARIAS::ENGENHARIA DE PRODUCAOIn order to solve the problems caused by noise, it is essential that an adequate evaluation of the main sources of noise is carried out. This can be done using an acoustic imaging technique and one of them is the beamforming. Beamforming is a technique that consists of measuring the sound pressure of the source of interest by using a microphone array. After that the measured data goes to a post-processing generating an acoustic image of the source. Through that the main regions of sound radiation is shown. In this context usually outdoor measurements are taken. In this situation the microphones must be protected from the wind. For this purpose a layer of porous material may be used in front of the microphone array. Then its influence on the beamforming response is unknown. This work aims to evaluate the effect of the use of porous material on the microphone arrays at the beamforming response, using a free field directions vector hypothesis. For do this the porous material was first characterized according to its macroscopic parameters through impedance tube measurement. Then simulations were performed where it was possible to compare different materials and to test the influence of each macroscopic parameter on the array response. Measurements were also made in a semi-anechoic room where it was possible to evaluate the effect of distance between source and array, the deviation due to use different signals for evaluation, the three-dimensional beamforming preview and the recognitiopn of two sources by the array response. This methodology allowed to verify that the porous material cause a negatively affects on the array response through increasing the beamwidth. In other words, it increases the difficulty of the array to locate sources for certain frequencies. On the other hand the dynamic range increased with the use of the porous material representing a seeming improvement in the array response. However this increase is usually less than 2 [dB] what is not very representative. Moreover the sample thickness of the porous material was identified as the main characteristic that affects the array response. The thinner thicknesses have less influence on the array response thus having better results.Em busca de resolver os problemas causados pelo ruído é fundamental que seja realizada uma avaliação adequada das principais fontes geradoras de ruído. Para isso, pode-se utilizar alguma técnica de imageamento acústico. Uma das formas de se fazer isso é por meio do beamforming, uma técncia que consiste na medição da pressão sonora da fonte de interesse, por um arranjo de microfones. Após isso, os dados medidos passam por um pós-processamento gerando uma imagem acústica da fonte, mostrando as principais regiões de radiação sonora. Neste contexto, geralmente são feitas medições ao ar livre onde os microfones devem ser protegidos da incidência do vento. Para isso, pode ser utilizada uma camada de material poroso em frente ao arranjo de microfones, cuja influência na resposta do beamforming é desconhecida. Este trabalho tem por objetivo avaliar o efeito do uso de material poroso sobre o arranjo de microfones na resposta do beamforming, utilizando uma hipótese de vetor de direções de campo livre. Para isso, primeiramente o material poroso foi caracterizado de acordo com seus parâmetros macroscópicos por meio de medição em tubo de impedância. Depois, foram realizadas simulações em que foi possível comparar diferentes materiais e testar a influência de cada parâmetro macroscópico na resposta do arranjo. Também foram realizadas medições em uma câmara semianecoica que permitiram avaliar os efeitos da distância entre fonte e arranjo, o uso de sinais diferentes para avaliação, medições em dois planos simultaneamente e com duas fontes. Essa metodologia permitiu verificar que, em geral, o material poroso afeta negativamente a resposta do arranjo aumentando a largura do lóbulo principal. Em outras palavras, aumenta a dificuldade do arranjo de localizar fontes para determinadas frequências. Por outro lado a faixa dinâmica aumentou com o uso do material poroso, representando uma aparente melhora na resposta do arranjo. Entretanto, esse aumento é, geralmente, menor que 2 [dB], sendo assim pouco representativo. Ademais, identificou-se a espessura da amostra do material poroso como sendo a principal característica que afeta a resposta do arranjo, concluindo que espessuras mais finas imprimem menor influência sobre a resposta do arranjo, tendo assim melhores resultados.Universidade Federal de Santa MariaBrasilEngenharia de ProduçãoUFSMPrograma de Pós-Graduação em Engenharia de ProduçãoCentro de TecnologiaCarneiro, Eric Brandãohttp://lattes.cnpq.br/2876372207029481Fonseca, William D'Andreahttp://lattes.cnpq.br/1677987461176747Paixão, Dinara Xavier dahttp://lattes.cnpq.br/3967266929672774Gomes, Marcio Henrique de Avelarhttp://lattes.cnpq.br/6090334823327910Pozzer, Talita2018-08-29T21:56:28Z2018-08-29T21:56:28Z2017-08-11info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfhttp://repositorio.ufsm.br/handle/1/14128porAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/info:eu-repo/semantics/openAccessreponame:Manancial - Repositório Digital da UFSMinstname:Universidade Federal de Santa Maria (UFSM)instacron:UFSM2021-06-21T17:11:34Zoai:repositorio.ufsm.br:1/14128Biblioteca Digital de Teses e Dissertaçõeshttps://repositorio.ufsm.br/ONGhttps://repositorio.ufsm.br/oai/requestatendimento.sib@ufsm.br||tedebc@gmail.comopendoar:2021-06-21T17:11:34Manancial - Repositório Digital da UFSM - Universidade Federal de Santa Maria (UFSM)false |
dc.title.none.fl_str_mv |
Estudos da técnica de beamforming combinando arranjos de microfones e material poroso Beamforming technique studies combining microphone arrays and porous material |
title |
Estudos da técnica de beamforming combinando arranjos de microfones e material poroso |
spellingShingle |
Estudos da técnica de beamforming combinando arranjos de microfones e material poroso Pozzer, Talita Beamforming Material poroso Localização de fontes sonoras Faixa dinâmica Largura do lóbulo principal Beamforming Porous material Sound source localization Dynamic range Beamwidth CNPQ::ENGENHARIAS::ENGENHARIA DE PRODUCAO |
title_short |
Estudos da técnica de beamforming combinando arranjos de microfones e material poroso |
title_full |
Estudos da técnica de beamforming combinando arranjos de microfones e material poroso |
title_fullStr |
Estudos da técnica de beamforming combinando arranjos de microfones e material poroso |
title_full_unstemmed |
Estudos da técnica de beamforming combinando arranjos de microfones e material poroso |
title_sort |
Estudos da técnica de beamforming combinando arranjos de microfones e material poroso |
author |
Pozzer, Talita |
author_facet |
Pozzer, Talita |
author_role |
author |
dc.contributor.none.fl_str_mv |
Carneiro, Eric Brandão http://lattes.cnpq.br/2876372207029481 Fonseca, William D'Andrea http://lattes.cnpq.br/1677987461176747 Paixão, Dinara Xavier da http://lattes.cnpq.br/3967266929672774 Gomes, Marcio Henrique de Avelar http://lattes.cnpq.br/6090334823327910 |
dc.contributor.author.fl_str_mv |
Pozzer, Talita |
dc.subject.por.fl_str_mv |
Beamforming Material poroso Localização de fontes sonoras Faixa dinâmica Largura do lóbulo principal Beamforming Porous material Sound source localization Dynamic range Beamwidth CNPQ::ENGENHARIAS::ENGENHARIA DE PRODUCAO |
topic |
Beamforming Material poroso Localização de fontes sonoras Faixa dinâmica Largura do lóbulo principal Beamforming Porous material Sound source localization Dynamic range Beamwidth CNPQ::ENGENHARIAS::ENGENHARIA DE PRODUCAO |
description |
In order to solve the problems caused by noise, it is essential that an adequate evaluation of the main sources of noise is carried out. This can be done using an acoustic imaging technique and one of them is the beamforming. Beamforming is a technique that consists of measuring the sound pressure of the source of interest by using a microphone array. After that the measured data goes to a post-processing generating an acoustic image of the source. Through that the main regions of sound radiation is shown. In this context usually outdoor measurements are taken. In this situation the microphones must be protected from the wind. For this purpose a layer of porous material may be used in front of the microphone array. Then its influence on the beamforming response is unknown. This work aims to evaluate the effect of the use of porous material on the microphone arrays at the beamforming response, using a free field directions vector hypothesis. For do this the porous material was first characterized according to its macroscopic parameters through impedance tube measurement. Then simulations were performed where it was possible to compare different materials and to test the influence of each macroscopic parameter on the array response. Measurements were also made in a semi-anechoic room where it was possible to evaluate the effect of distance between source and array, the deviation due to use different signals for evaluation, the three-dimensional beamforming preview and the recognitiopn of two sources by the array response. This methodology allowed to verify that the porous material cause a negatively affects on the array response through increasing the beamwidth. In other words, it increases the difficulty of the array to locate sources for certain frequencies. On the other hand the dynamic range increased with the use of the porous material representing a seeming improvement in the array response. However this increase is usually less than 2 [dB] what is not very representative. Moreover the sample thickness of the porous material was identified as the main characteristic that affects the array response. The thinner thicknesses have less influence on the array response thus having better results. |
publishDate |
2017 |
dc.date.none.fl_str_mv |
2017-08-11 2018-08-29T21:56:28Z 2018-08-29T21:56:28Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://repositorio.ufsm.br/handle/1/14128 |
url |
http://repositorio.ufsm.br/handle/1/14128 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.rights.driver.fl_str_mv |
Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ info:eu-repo/semantics/openAccess |
rights_invalid_str_mv |
Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Universidade Federal de Santa Maria Brasil Engenharia de Produção UFSM Programa de Pós-Graduação em Engenharia de Produção Centro de Tecnologia |
publisher.none.fl_str_mv |
Universidade Federal de Santa Maria Brasil Engenharia de Produção UFSM Programa de Pós-Graduação em Engenharia de Produção Centro de Tecnologia |
dc.source.none.fl_str_mv |
reponame:Manancial - Repositório Digital da UFSM instname:Universidade Federal de Santa Maria (UFSM) instacron:UFSM |
instname_str |
Universidade Federal de Santa Maria (UFSM) |
instacron_str |
UFSM |
institution |
UFSM |
reponame_str |
Manancial - Repositório Digital da UFSM |
collection |
Manancial - Repositório Digital da UFSM |
repository.name.fl_str_mv |
Manancial - Repositório Digital da UFSM - Universidade Federal de Santa Maria (UFSM) |
repository.mail.fl_str_mv |
atendimento.sib@ufsm.br||tedebc@gmail.com |
_version_ |
1805922036377190400 |