Remote measurement of distance and thickness using a deflected laser beam

Various methods of detecting surface defects are being used in automated industrial manufacturing environments. This work presents the design and development of a laser charged couple device (CCD) displacement scanning system. The surface defect detection method using a laser CCD displacement sensor is derived from an idea in which surface defects such as cracks, inclusions and holes of three-dimensional morphology characteristics are compared to normal surface especially in continuous casting slabs. Some novel research methods have been applied to develop the surface defect detection system used: first, getting a one-dimensional distance matrix along transverse direction and a two-dimensional matrix combining with a certain moving speed through the laser CCD displacement sensor; second, obtaining the slab surface profile and mapping to a greyscale image and finally, obtaining the surface defect regions by an image processing and searching algorithm and quantitatively detecting slab surface defect shape and depth. The research results in the lab trials have shown that the methodology proposed is effective to detect two-dimensional defect size and reconstruct a three-dimensional surface defect shape. At the same time, it is also able to accurately locate and identify surface defects and realise automatic surface defect non-destructive detection online, and provides a theoretical base and technology idea for further studying surface defects online inspection for hot continuous casting slab.

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“…2 Laser range finder and inspection systems have found many applications, including manufacturing and automated control systems.…”

Section: Introductionmentioning

confidence: 99%

“…Online surface quality inspection of the product is becoming a key factor for continuous casting-direct rolling and cost minimisation in any industry. 2 Laser range finder and inspection systems have found many applications, including manufacturing and automated control systems.…”

Section: Introductionmentioning

confidence: 99%

Experimental study of surface defects in continuous casting using developed laser scanning system

Ouyang

Zhao

et al. 2011

Ironmaking & Steelmaking

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“…These systems are essential tools for the implementation of modern statistical process control procedures. Non-contact methods of measuring thickness and distance with laser sensors have already been widely reported in the literature [6][7][8][9]. Very high orders of accuracy in the measurement of lengths at close ranges of up to several meters are achieved by interferometric methods [10,11].…”

Section: Introductionmentioning

confidence: 99%

Multi-beam fibre-optic laser scanning system for surface defect recognition

Abuazza¹,

Brabazon²,

El-Baradie³

2004

Journal of Materials Processing Technology

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Multi-beam scanning systems are being used in automated industrial manufacturing environments to determine surface defects. Recent methods of surface defect detection involve the use of fibre-optic light emitting and detection assemblies. This paper deals with the design and development of a new high-speed photo-electronic system. A line of five emitting diodes and five receiving photodiodes were used as light sources and detectors respectively. These arrays of emitting diodes and photodetectors were positioned opposite each other. Data capture was controlled and analysed by PC using LabView software. A newly developed technique of using an angled array of fibres allows an adjustable resolution to be obtained with the system, with a maximum system resolution of approximately 100 m (the diameter of the collecting fibre core). This system was successfully used to measure various materials surface profile, surface roughness, thickness, and reflectivity. The advantages of this new system may be seen as lower cost, less bulky, greater resolution and flexibility.

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“…Utilizando-se no lugar do espelho m6vel, urn defletor acustico-6ptico, altas precisoes sao alcan9adas, em distancias de ate dezenas de metros. KOEBNER (1984), BODLAJ e KLEMENT (1976). E importante notar que a precisao de medida de todos os modelos de MDTs aqui descritos, depende fundamentalmente do tamanho do feixe visualizado sobre 0 alvo e da qualidade da sua imagem formada sobre 0 sensor.…”

Section: Sensor De Posi~io De Imagemunclassified

Medidores de distância por triangulação a laser.

Stefani¹

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Introdu~ao Como e possivel medir a espessura de um material mole, deformavel, estando este em movimento, sem que 0 processo de medida altere 0 seu valor? Como e possivel, por exemplo, verificar as dimensoes de uma peya em movimento, ao mesmo tempo em que esta sendo trabalhada? Como verificar se um conjunto foi posicionado corretamente em relayao a outro, estando ambos em movimento? AMm destas situayoes, poderia-se enumerar uma serie de casos em que as tecnicas de mediyao ja estabelecidas nao se aplicam com a eficiencia desejavel. Por outro lado, ja saD de conhecimento, dito cientifico, uma serie de tecnicas que poderiam ser aplicadas, mas que, por diversas razoes, ainda nao 0 foram.

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Remote measurement of distance and thickness using a deflected laser beam

Cited by 18 publications

References 2 publications

Experimental study of surface defects in continuous casting using developed laser scanning system

Experimental study of surface defects in continuous casting using developed laser scanning system

Multi-beam fibre-optic laser scanning system for surface defect recognition

Medidores de distância por triangulação a laser.

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