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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Classifica??o automatizada de falhas tribol?gicas de sistemas alternativos com o uso de redes neurais artificiais n?o supervisionadas

Cabral, Marco Antonio Leandro 17 January 2017 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-03-28T19:32:54Z No. of bitstreams: 1 MarcoAntonioLeandroCabral_TESE.pdf: 13589109 bytes, checksum: dcecde654045d4bb434b8363031ec773 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-03-29T19:12:55Z (GMT) No. of bitstreams: 1 MarcoAntonioLeandroCabral_TESE.pdf: 13589109 bytes, checksum: dcecde654045d4bb434b8363031ec773 (MD5) / Made available in DSpace on 2017-03-29T19:12:55Z (GMT). No. of bitstreams: 1 MarcoAntonioLeandroCabral_TESE.pdf: 13589109 bytes, checksum: dcecde654045d4bb434b8363031ec773 (MD5) Previous issue date: 2017-01-17 / Prevenir, antever, evitar falhas em sistemas eletromec?nicos s?o demandas que desafiam pesquisadores e profissionais de engenharia a d?cadas. Sistemas eletromec?nicos apresentam processos tribol?gicos que resultam em fadiga de materiais e consequente perda de efici?ncia ou mesmo de utilidade de m?quinas e equipamentos. Diversas t?cnicas s?o utilizadas na tentativa de, atrav?s da an?lise de sinais oriundos dos equipamentos estudados, que seja poss?vel a minimiza??o das perdas inerentes ?queles sistemas e as consequ?ncias desses desgastes em momentos n?o esperados, como uma aeronave em voo ou uma perfuratriz em um po?o de petr?leo. Dentre elas podemos citar a an?lise de vibra??o, medi??o da press?o ac?stica, monitoramento de temperatura, an?lise de part?culas de ?leo lubrificante etc. Entretanto sistemas eletromec?nicos s?o complexos e podem apresentar comportamentos inesperados. A manuten??o centrada na confiabilidade necessita de recursos tecnol?gicos cada vez mais r?pidos, eficientes e robustos para garantir sua efici?ncia e efic?cia. T?cnicas de an?lise de efeitos e modos de falha (FMEA ? Failure Mode Effect Analysis) em equipamentos s?o utilizadas para aumentar a confiabilidade dos sistemas de manuten??o preventiva e preditiva. As redes neurais artificiais (RNA) s?o ferramentas computacionais que encontram aplicabilidade em diversos segmentos da pesquisa e an?lise de sinais, onde h? necessidade do manuseio de grandes quantidades de dados, associando estat?stica e computa??o na otimiza??o de processos din?micos e um alto grau de confiabilidade. S?o sistemas de intelig?ncia artificial que t?m capacidade de aprender, s?o robustas a falhas e podem apresentar resultados em tempo real. Este trabalho tem como objetivo a utiliza??o de redes neurais artificiais para tratar sinais provenientes da monitora??o de par?metros tribol?gicos atrav?s do uso de uma bancada de testes para simular falhas de contato em um compressor de ar, a fim de criar um sistema de detec??o e classifica??o de falhas automatizado, n?o supervisionado, com o uso de mapas auto-organiz?veis, ou redes SOM (self organizaed maps), aplicado ? manuten??o preventiva e preditiva de processos eletromec?nicos. / Preventing, anticipating, avoiding failures in electromechanical systems are demands that have challenged researchers and engineering professionals for decades. Electromechanical systems present tribological processes that result in fatigue of materials and consequent loss of efficiency or even usefulness of machines and equipment. Several techniques are used in an attempt to minimize the inherent losses of these systems through the analysis of signals from the equipment studied and the consequences of these wastes at unexpected moments, such as an aircraft in flight or a drilling rig in an oil well. Among them we can mention vibration analysis, acoustic pressure measurement, temperature monitoring, particle analysis of lubricating oil etc. However, electromechanical systems are complex and may exhibit unexpected behavior. Reliability-centric maintenance requires ever faster, more efficient and robust technological resources to ensure its efficiency and effectiveness. Failure Mode Effect Analysis (FMEA) techniques in equipment are used to increase the reliability of preventive and predictive maintenance system. Artificial neural networks (ANNs) are computational tools that find applicability in several segments of the research and signal analysis, where it is necessary to handle large amounts of data, associating statistics and computation in the optimization of dynamic processes and a high degree of reliability. They are artificial intelligence systems that have the ability to learn, are robust to failures, and can deliver realtime results. This work aims at the use of artificial neural networks to treat signals from the monitoring of tribological parameters through the use of a test bench to simulate contact failures in an air compressor in order to create an automated fault detection and classification system, unsupervised, with the use of self-organized maps, or SOM, applied to the preventive and predictive maintenance of electromechanical processes.

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