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On-line estimation of laser-drilled hole depth using a machine vision method.

Ho CC, He JJ, Liao TY - Sensors (Basel) (2012)

Bottom Line: Therefore, a low cost on-line inspection system is developed to increase productivity.A correlation between the cumulative size of the laser-induced plasma region and the depth of the hole is presented.The result indicates that the estimated depths of the laser-drilled holes were a linear function of the cumulative plasma size, with a high degree of confidence.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical Engineering, National Yunlin University of Science and Technology, Douliou, Yunlin 64002, Taiwan. HoChao@yuntech.edu.tw

ABSTRACT
The paper presents a novel method for monitoring and estimating the depth of a laser-drilled hole using machine vision. Through on-line image acquisition and analysis in laser machining processes, we could simultaneously obtain correlations between the machining processes and analyzed images. Based on the machine vision method, the depths of laser-machined holes could be estimated in real time. Therefore, a low cost on-line inspection system is developed to increase productivity. All of the processing work was performed in air under standard atmospheric conditions and gas assist was used. A correlation between the cumulative size of the laser-induced plasma region and the depth of the hole is presented. The result indicates that the estimated depths of the laser-drilled holes were a linear function of the cumulative plasma size, with a high degree of confidence. This research provides a novel machine vision-based method for estimating the depths of laser-drilled holes in real time.

No MeSH data available.


Related in: MedlinePlus

Experimental setup.
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f1-sensors-12-10148: Experimental setup.

Mentions: In this paper, we present a novel measuring method for the on-line monitoring of laser-drilled holes based on machine vision analysis. Therefore, on-line optical inspection system with low cost is developed to increase productivity. The monitoring of pulsed laser-induced plasma is used as the basis for on-line inspection control system for the hole drilling. Our measuring setup includes image acquisition units, laser machining equipment, and a computer analysis unit, as shown in Figure 1. First, we use the CMOS camera of the image acquisition unit for the on-line acquisition of an image of the laser machining zone of the workpiece's surface. The high laser energy will cause melting and vaporization of the metal material during laser machining, and cause the air and metallic vapor to ionize simultaneously. This ionization phenomenon will involve plasma and light, and it is captured by the CMOS camera. The images consist of both plasma and light information. Finally, the image data are sent to the computer analysis unit for an on-line analysis of the correlation between the geometrical forms of the machining zone, including the depth of a blind hole, and the image information. This experimental setup achieves the advantages of a lower cost, on-line monitoring, and good performance.


On-line estimation of laser-drilled hole depth using a machine vision method.

Ho CC, He JJ, Liao TY - Sensors (Basel) (2012)

Experimental setup.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3472821&req=5

f1-sensors-12-10148: Experimental setup.
Mentions: In this paper, we present a novel measuring method for the on-line monitoring of laser-drilled holes based on machine vision analysis. Therefore, on-line optical inspection system with low cost is developed to increase productivity. The monitoring of pulsed laser-induced plasma is used as the basis for on-line inspection control system for the hole drilling. Our measuring setup includes image acquisition units, laser machining equipment, and a computer analysis unit, as shown in Figure 1. First, we use the CMOS camera of the image acquisition unit for the on-line acquisition of an image of the laser machining zone of the workpiece's surface. The high laser energy will cause melting and vaporization of the metal material during laser machining, and cause the air and metallic vapor to ionize simultaneously. This ionization phenomenon will involve plasma and light, and it is captured by the CMOS camera. The images consist of both plasma and light information. Finally, the image data are sent to the computer analysis unit for an on-line analysis of the correlation between the geometrical forms of the machining zone, including the depth of a blind hole, and the image information. This experimental setup achieves the advantages of a lower cost, on-line monitoring, and good performance.

Bottom Line: Therefore, a low cost on-line inspection system is developed to increase productivity.A correlation between the cumulative size of the laser-induced plasma region and the depth of the hole is presented.The result indicates that the estimated depths of the laser-drilled holes were a linear function of the cumulative plasma size, with a high degree of confidence.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical Engineering, National Yunlin University of Science and Technology, Douliou, Yunlin 64002, Taiwan. HoChao@yuntech.edu.tw

ABSTRACT
The paper presents a novel method for monitoring and estimating the depth of a laser-drilled hole using machine vision. Through on-line image acquisition and analysis in laser machining processes, we could simultaneously obtain correlations between the machining processes and analyzed images. Based on the machine vision method, the depths of laser-machined holes could be estimated in real time. Therefore, a low cost on-line inspection system is developed to increase productivity. All of the processing work was performed in air under standard atmospheric conditions and gas assist was used. A correlation between the cumulative size of the laser-induced plasma region and the depth of the hole is presented. The result indicates that the estimated depths of the laser-drilled holes were a linear function of the cumulative plasma size, with a high degree of confidence. This research provides a novel machine vision-based method for estimating the depths of laser-drilled holes in real time.

No MeSH data available.


Related in: MedlinePlus