Investigação de novas ferramentas estatísticas e utilização de microcontrolador no monitoramento da queima na retificação plana tangencial
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Data
2006-06-26
Autores
Khenaifes, Maurício [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Na indústria moderna, a precisão e o custo são fundamentais para a qualidade do produto e competitividade no mercado. Desenvolver sistemas mais velozes, dinâmicos e autoajustáveis aplicando técnicas de controle é um objetivo dos pesquisadores de todas as áreas da engenharia. A retificação de materiais é um sistema complexo que possui muitas variáveis relacionadas, principalmente por possuir múltiplas arestas de corte associado a altas velocidades e potências de retificação. Para aumentar o domínio sobre o processo, sinais de emissão acústica e de potência de acionamento do rebolo têm sido monitorados em várias pesquisas. Nesse trabalho foram realizadas experiências utilizando a retificação plana tangencial com o aço ABNT 1020 e rebolo de óxido de alumínio, onde foi determinado a ocorrência e o início da queima através da variação da profundidade de corte, tendo-se o cuidado de manter os outros parâmetros constantes, inclusive a superfície de corte do rebolo através da operação de dressagem. Os sinais de emissão acústica e de potência elétrica foram adquiridos durante uma passada do rebolo sobre a peça, numa taxa de 2.5 milhões de amostras por segundo, e pro cessados através de um ferramental matemático, onde foram propostos outros parâmetros, para a análise da ocorrência da queima. Observou-se também a detecção do início da queima, onde o parâmetro proposto VARPO obteve bons resultados. Paralelamente foi realizado um estudo sobre os microcontroladores, onde foram inseridos os cálculos de detecção da queima do processo de retificação num PIC18F452, mostrando a viabilidade de um monitoramento.
In modern industry, the accuracy and cost are extremely important to the quality of product and market competition. The development of faster dynamic and robust systems by applying control techniques is the goal of researchers of all engineering areas. The grinding process is a complex system which contains many related variables mainly because its multiple cutting edges associated with high speed and power. In order to improve the knowledge on the process, acoustic emission and power signals have been monitored in several research investigations. In this work, surface grinding tests with ABNT 1020 steel and aluminum oxide grinding wheel were carried out in which the burning occurrence as well as the onset of it were studied. This was done by varying the depth of cut and maintaining the other grinding parameters constant, including the grinding wheel surface through the dressing operation. Acoustic emission and electrical power signals were acquired during a single grinding pass of the grinding wheel over the work-piece at 2.5 million of samples per second rate. The signals were digitally processed through many statistic algorithms among which new parameters for burn detection have been proposed. Also, the onset of burning occurrence was observed and remarkably detected for the proposed parameter dubbed VARPO. In addition, a study on microcontrollers was performed, and the implementation of the algorithms previously mentioned were carried out into the microcontroller PIC18F452, showing the monitoring feasibility.
In modern industry, the accuracy and cost are extremely important to the quality of product and market competition. The development of faster dynamic and robust systems by applying control techniques is the goal of researchers of all engineering areas. The grinding process is a complex system which contains many related variables mainly because its multiple cutting edges associated with high speed and power. In order to improve the knowledge on the process, acoustic emission and power signals have been monitored in several research investigations. In this work, surface grinding tests with ABNT 1020 steel and aluminum oxide grinding wheel were carried out in which the burning occurrence as well as the onset of it were studied. This was done by varying the depth of cut and maintaining the other grinding parameters constant, including the grinding wheel surface through the dressing operation. Acoustic emission and electrical power signals were acquired during a single grinding pass of the grinding wheel over the work-piece at 2.5 million of samples per second rate. The signals were digitally processed through many statistic algorithms among which new parameters for burn detection have been proposed. Also, the onset of burning occurrence was observed and remarkably detected for the proposed parameter dubbed VARPO. In addition, a study on microcontrollers was performed, and the implementation of the algorithms previously mentioned were carried out into the microcontroller PIC18F452, showing the monitoring feasibility.
Descrição
Palavras-chave
Emissão acústica, Engenharia industrial, Retificação, Detecção de queima, Monitoramento, Microcontrolador, Grinding, Burn detection, Monitoring, Microcontroller, Acoustic emission
Como citar
KHENAIFES, Maurício. Investigação de novas ferramentas estatísticas e utilização de microcontrolador no monitoramento da queima na retificação plana tangencial. 2006. 166 f. Dissertação (mestrado) - Universidade Estadual Paulista, Faculdade de Engenharia, 2006.