Application of computer vision and laser interferometer to the inspection of line scale

Luo, P. F.; Pan, Sheau-Shi; Chu, Ting-Hao

doi:10.1016/j.optlaseng.2004.04.001

Cited by 20 publications

(7 citation statements)

References 16 publications

(17 reference statements)

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“…Medições por imagem possuem grande relevância em muitas aplicações. Luo et al (2004) combinam Visão Computacional, interferometria laser e uso de máquina de medição por coordenadas para desenvolver um sistema de inspeção. Eles notaram que este tipo de sistema aumenta a exatidão das MMC.…”

Section: Introductionunclassified

Visão Computacional Aplicacada À Metrologia Dimensional Automatizada: Considerações Sobre Sua Exatidão

Feliciano¹,

Souza²,

Leta³

2010

Engevista

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Resumo: O presente artigo tem por objetivo tratar de algumas técnicas de Visão Computacional, que podem ser úteis em aplicações de automação. Estas aplicações incluem: medição de peças, inspeção visual, análise de conformidade, etc. Sistemas de Visão Computacional em medições sem contato são especialmente úteis quando se têm objetos pequenos ou de geometria complexa, nos quais instrumentos convencionais não podem ser utilizados. Nestes tipos de situações, em alguns casos é possível utilizar Máquinas de Medição por Coordenadas (MMC). Além do valor de MMC ser elevado, nem sempre é simples transportar a peça para máquina. Nestes casos sistemas de inspeção e medição por imagem são boas alternativas. O sistema proposto tem como principais objetivos minimizar erros inerentes aos operadores e facilitar processos que requerem instrumentos/equipamentos mais complexos de medição. As seguintes premissas são feitas: (1) os objetos devem ter pequena espessura; e, (2) blocos padrão são usados para conversão de unidades. Neste artigo, apresentam-se os algoritmos desenvolvidos para realizar as medições de objetos retangulares com furos. Os resultados obtidos são comparados com aqueles obtidos por instrumentos convencionais. São destacadas as dificuldades existentes em sistemas automatizados de medição por imagem, a exatidão destes e a importância de compreender tais problemas ao usá-los para fins industriais. O artigo não pretende esgotar o assunto, mas apenas apresentar uma reflexão sobre medições em imagens.Palavras chave: Visão Computacional, Metrologia por imagem, Inspeção automatizada, Exatidão.Abstract: This paper uses some Computer Vision techniques to measure parts and discusses ordinary difficulties of automated inspection. The parts conformity analysis using a non-contact measurement system has been used specially to small objects, where accurate instruments are not so simple to be used. In these cases Coordinate Measuring Machine (CMM) can be used. However, in many times it is impossible to move the object to the CMM. In this case an image-automated inspection should be a good alternative. The proposed system consists in a CCD camera positioned in the upper viewer of the object. Some considerations must be pointed out: (1) the object should be thin, to reduce the height influence in the measurement; (2) standard gages must be used to convert pixels units to millimeters units. We present the algorithms developed to make dimensional measurements in industrial parts. A rectangle object with three holes is analyzed. The obtained results are compared with conventional instruments measurements. We highlight the difficulties concerned to image automated inspection, discussing accuracy and the relationships among images and measurements.

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Section: Introductionunclassified

Visão Computacional Aplicacada À Metrologia Dimensional Automatizada: Considerações Sobre Sua Exatidão

Feliciano¹,

Souza²,

Leta³

2010

Engevista

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“…Zaurin and Catbas [139] integrated the video images and sensor data from structural monitoring system to evaluate the safety condition of bridges. Luo et al [140] developed a vision inspection system combining machine vision, laser interferometer, and coordinate measuring machine. Waldbjørn et al [141] obtained the feedback signals (strain and displacement) by the fiber Bragg grating and digital image correlation when conducting the test control.…”

Section: Integration Technologymentioning

confidence: 99%

A Review of Machine Vision-Based Structural Health Monitoring: Methodologies and Applications

2016

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In the past two decades, a significant number of innovative sensing and monitoring systems based on the machine vision-based technology have been exploited in the field of structural health monitoring (SHM). This technology has some inherent distinctive advantages such as noncontact, nondestructive, long distance, high precision, immunity to electromagnetic interference, and large-range and multiple-target monitoring. A lot of machine vision-based structural dynamic measurement and structural state inspection methods have been proposed. Real-world applications are also carried out to measure the structural physical parameters such as the displacement, strain/stress, rotation, vibration, crack, and spalling. The purpose of this review article is devoted to presenting a summary of the basic theories and practical applications of the machine vision-based technology employed in structural monitoring as well as its systematic error sources and integration with other modern sensing techniques.

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“…Laser interferometer measurement system is a standard instrument for precise length measurements [3][4][5][6]. It consists of electronic devices and optical elements.…”

Section: Laser Interferometermentioning

confidence: 99%

Simulation of line scale contamination in calibration uncertainty model

Druzovec¹,

Ačko²,

Godina³

et al. 2008

Int. j. simul. model.

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Precise calibration of quartz line scales is very important for assuring traceability of microscopic measurements. Very significant influence in calibration uncertainty budget is represented by uncertainty of line centre detection. Line centre is usually detected through video signal processing using different types of algorithms. This paper is presenting calibration procedure that was developed in the Laboratory for Production Measurement at the Faculty of Mechanical Engineering in Maribor. It is focused in uncertainty analysis and especially in the influence of line scale contamination on determination of line centre position. Different types of line scale contamination like dirt spots, scratches, line edge incorrectness, and line intensity were simulated in order to test the ability of the line centre detection algorithm to eliminate such influences from the measurement results.

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Application of computer vision and laser interferometer to the inspection of line scale

Cited by 20 publications

References 16 publications

Visão Computacional Aplicacada À Metrologia Dimensional Automatizada: Considerações Sobre Sua Exatidão

Visão Computacional Aplicacada À Metrologia Dimensional Automatizada: Considerações Sobre Sua Exatidão

A Review of Machine Vision-Based Structural Health Monitoring: Methodologies and Applications

Simulation of line scale contamination in calibration uncertainty model

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