Optical techniques for real-time penetration monitoring for laser welding.

@article{Bardin2005OpticalTF,
  title={Optical techniques for real-time penetration monitoring for laser welding.},
  author={Fabrice Bardin and Adolfo Cobo and Jos{\'e} Miguel L{\'o}pez-Higuera and Olivier Collin and P. Aubry and Thierry Dubois and Mats H{\"o}gstr{\"o}m and Per Nyl{\'e}n and Peter Jonsson and Julian David Clayton Jones and Duncan P. Hand},
  journal={Applied optics},
  year={2005},
  volume={44 19},
  pages={
          3869-76
        }
}
Optical techniques for real-time full-penetration monitoring for Nd:YAG laser welding have been investigated. Coaxial light emission from the keyhole is imaged onto three photodiodes and a camera. We describe the spectral and statistical analyses from photodiode signals, which indicate the presence of a full penetration. Two image processing techniques based on the keyhole shape recognition and the keyhole image intensity profile along the welding path are presented. An intensity ratio… 
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51 Citations

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References

SHOWING 1-10 OF 21 REFERENCES
On-line monitoring of penetration depth in laser beam welding
The penetration depth is one of the fundamental process parameters in laser beam welding. On-line monitoring and control of the penetration depth is a significant contribution to meet todays quality…
Optical signal oscillations in laser keyhole welding and potential application to lap welding
We describe an optical sensor for process monitoring of Nd:YAG laser welding. This sensor detects the broadband radiation produced by the welding process, dividing it into broad spectral bands…
Real-time monitoring of laser beam welding using infrared weld emissions
A nonintrusive, solid-state device has been developed to monitor in real time the infrared emissions during laser welding. The weld monitor output is an analog signal (100–1000 mV) that depends on…
Monitoring of laser weld penetration using sensor fusion
Depth of penetration is a critical parameter in laser welding. In many applications, full penetration is desired, but difficult to detect in real time. A sensor fusion system using infrared,…
Closed-loop power and focus control of laser welding for full-penetration monitoring.
TLDR
A closed-loop control system ensuring full penetration in welding by controlling the focus position and power of a 4-kW Nd:YAG laser is described and performance in bead-on-plate welding of Inconel 718 and titanium is demonstrated.
A CMOS camera as a tool for process analysis not only for laser beam welding
A new system for process monitoring of laser beam welding based on a CMOS-camera was presented in former presentations [1,2,3]. The system observes the welding process online and coaxial to the laser…
Coaxial process control during laser beam welding of tailored blanks
Production of laser beam welded tailored blanks requires both, high quality processing as well as a quality assurance by reliable monitoring systems for each welded part. Actual quality monitoring…
New aspects of monitoring with a CMOS camera for laser materials processing
A new system for process monitoring of laser beam welding based on a CMOS-camera was presented in former presentations [1,2]. The system observes the welding process online and coaxial to the laser…
Focus control system for laser welding.
TLDR
A focus control system for Nd:YAG laser welding based on an optical sensor incorporated into the fiber delivery system to detect light generated by the process, which works for both pulsed and continuous laser radiation.
Penetration feedback control in overlap laser welding of sheet metal
This paper deals with a method to control the penetration depth in overlap laser welding, using feedback control. Some applications demand that an overlap weld is joined sufficiently, while it is not…
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