Abstract

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 parameter is used to determine the extent of opening at the rear of a fully opened keyhole. We show that this parameter clearly interprets a hole in formation or a lack of penetration when welding is performed on workpieces with variable thicknesses at constant laser power.

© 2005 Optical Society of America

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  1. J. Beersiek, “New aspects of monitoring with a CMOS camera for laser materials processing,” in Proceedings of the International Congress on Applications of Lasers and Electro-Optics (Laser Institute of America, 2002).
  2. R. Guttler, “Sensor detects faults in keyhole,” Opt. & Laser Europe 10, 13–15 (1998).
  3. C. Bagger, F. O. Olsen, “Laser welding closed-loop power control,” J. Laser Appl. 15, 19–24 (2003).
    [CrossRef]
  4. J. Ortmann, E. W. Kreutz, C. Maier, T. Wehner, M. Kogel-Hollacher, S. Kaierle, R. Poprawe, “Online detection of defect classes for laser beam welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 2003).
  5. F. M. Haran, D. P. Hand, S. M. Ebrahim, C. Peters, J. D. C. Jones, “Optical signal oscillations in laser keyhole welding and potential application to lap welding,” Meas. Sci. Technol. 8, 627–633 (1997).
    [CrossRef]
  6. H. Gu, W. W. Duley, “Discrete signal components in optical emission during keyhole welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 1997), 83, Part 1, Sect. C, pp. 40–46.
  7. A. Sun, E. Kannatey-Asibu, M. Gartner, “Monitoring of laser weld penetration using sensor fusion,” J. Laser Appl. 14, 114–121 (2002).
    [CrossRef]
  8. P. Sanders, K. Leong, J. Keske, G. Kornecki, “Real-time monitoring of laser beam welding using infrared weld emission,” J. Laser Appl. 10, 205–211 (1998).
    [CrossRef]
  9. S. Postma, R. G. K. M. Aarts, A. J. F. M. Hesemans, “Penetration feedback control in overlap laser welding of sheet metal,” in Proceedings of WESIC (University of Twente, 2001), pp. 495–503.
  10. J. Beersiek, R. Poprawe, W. Schulz, H. Gu, R. E. Mueller, W. W. Duley, “On-line monitoring of penetration depth in laser beam welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 1997), Vol. 83, Part 1, Sect. C, pp. 30–39.
  11. S. Kaierle, P. Abels, G. Kapper, C. Kratzsch, J. Michel, W. Schulz, R. Poprawe, “State of the art and new advances in process control for laser materials processing,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 2001).
  12. C. Kratzsch, P. Abels, S. Kaierle, R. Poprawe, W. Schulz, “Coaxial process control during laser beam welding of tailored blanks,” in Proceedings AHPLA99, High-Power Lasers in Manufacturing, X. Chen, T. Fujioka, A. Matsunawa, eds., Proc. SPIE3888, 472–482 (2000).
    [CrossRef]
  13. J. Beersiek, “A CMOS camera as a tool for process analysis not only for laser beam welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 2001).
  14. J. Petereit, P. Abels, S. Kaierle, C. Kratzsch, E. W. Kreutz, “Failure recognition and online process control in laser beam welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 2002).
  15. F. M. Haran, D. P. Hand, C. Peters, J. D. C. Jones, “Focus control system for laser welding,” Appl. Opt. 36, 5246–5251 (1997).
    [CrossRef] [PubMed]
  16. A. Cobo, F. Bardin, P. Aubry, W. Knapp, O. Collin, J. D. C. Jones, D. P. Hand, J. M. López-Higuera, “Optical fibre-based focus control system for laser welding incorporating automatic setup,” in Proceedings of 16th International Conference on Optical Fiber Sensors, K. Hotate, H. Nagai, eds. (Institute of Electronics, Information and Communication Engineers, 2003), pp. 412–415.
  17. T. Klein, M. Vicanek, J. Kroos, I. Decker, G. Simon, “Oscillations of the keyhole in penetration laser beam welding,” J. Phys. D 27, 2023–2030 (1994).
    [CrossRef]
  18. F. Bardin, A. Cobo, J. M. Lopez-Higuera, O. Collin, P. Aubry, T. Dubois, M. Högström, P. Nylen, P. Jonsson, J. D. C. Jones, D. P. Hand, “Closed-loop power and focus control of laser welding for full penetration monitoring,” Appl. Opt. 44, 13–21 (2005).
    [CrossRef] [PubMed]

2005 (1)

2003 (1)

C. Bagger, F. O. Olsen, “Laser welding closed-loop power control,” J. Laser Appl. 15, 19–24 (2003).
[CrossRef]

2002 (1)

A. Sun, E. Kannatey-Asibu, M. Gartner, “Monitoring of laser weld penetration using sensor fusion,” J. Laser Appl. 14, 114–121 (2002).
[CrossRef]

1998 (2)

P. Sanders, K. Leong, J. Keske, G. Kornecki, “Real-time monitoring of laser beam welding using infrared weld emission,” J. Laser Appl. 10, 205–211 (1998).
[CrossRef]

R. Guttler, “Sensor detects faults in keyhole,” Opt. & Laser Europe 10, 13–15 (1998).

1997 (2)

F. M. Haran, D. P. Hand, S. M. Ebrahim, C. Peters, J. D. C. Jones, “Optical signal oscillations in laser keyhole welding and potential application to lap welding,” Meas. Sci. Technol. 8, 627–633 (1997).
[CrossRef]

F. M. Haran, D. P. Hand, C. Peters, J. D. C. Jones, “Focus control system for laser welding,” Appl. Opt. 36, 5246–5251 (1997).
[CrossRef] [PubMed]

1994 (1)

T. Klein, M. Vicanek, J. Kroos, I. Decker, G. Simon, “Oscillations of the keyhole in penetration laser beam welding,” J. Phys. D 27, 2023–2030 (1994).
[CrossRef]

Aarts, R. G. K. M.

S. Postma, R. G. K. M. Aarts, A. J. F. M. Hesemans, “Penetration feedback control in overlap laser welding of sheet metal,” in Proceedings of WESIC (University of Twente, 2001), pp. 495–503.

Abels, P.

S. Kaierle, P. Abels, G. Kapper, C. Kratzsch, J. Michel, W. Schulz, R. Poprawe, “State of the art and new advances in process control for laser materials processing,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 2001).

C. Kratzsch, P. Abels, S. Kaierle, R. Poprawe, W. Schulz, “Coaxial process control during laser beam welding of tailored blanks,” in Proceedings AHPLA99, High-Power Lasers in Manufacturing, X. Chen, T. Fujioka, A. Matsunawa, eds., Proc. SPIE3888, 472–482 (2000).
[CrossRef]

J. Petereit, P. Abels, S. Kaierle, C. Kratzsch, E. W. Kreutz, “Failure recognition and online process control in laser beam welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 2002).

Aubry, P.

F. Bardin, A. Cobo, J. M. Lopez-Higuera, O. Collin, P. Aubry, T. Dubois, M. Högström, P. Nylen, P. Jonsson, J. D. C. Jones, D. P. Hand, “Closed-loop power and focus control of laser welding for full penetration monitoring,” Appl. Opt. 44, 13–21 (2005).
[CrossRef] [PubMed]

A. Cobo, F. Bardin, P. Aubry, W. Knapp, O. Collin, J. D. C. Jones, D. P. Hand, J. M. López-Higuera, “Optical fibre-based focus control system for laser welding incorporating automatic setup,” in Proceedings of 16th International Conference on Optical Fiber Sensors, K. Hotate, H. Nagai, eds. (Institute of Electronics, Information and Communication Engineers, 2003), pp. 412–415.

Bagger, C.

C. Bagger, F. O. Olsen, “Laser welding closed-loop power control,” J. Laser Appl. 15, 19–24 (2003).
[CrossRef]

Bardin, F.

F. Bardin, A. Cobo, J. M. Lopez-Higuera, O. Collin, P. Aubry, T. Dubois, M. Högström, P. Nylen, P. Jonsson, J. D. C. Jones, D. P. Hand, “Closed-loop power and focus control of laser welding for full penetration monitoring,” Appl. Opt. 44, 13–21 (2005).
[CrossRef] [PubMed]

A. Cobo, F. Bardin, P. Aubry, W. Knapp, O. Collin, J. D. C. Jones, D. P. Hand, J. M. López-Higuera, “Optical fibre-based focus control system for laser welding incorporating automatic setup,” in Proceedings of 16th International Conference on Optical Fiber Sensors, K. Hotate, H. Nagai, eds. (Institute of Electronics, Information and Communication Engineers, 2003), pp. 412–415.

Beersiek, J.

J. Beersiek, “A CMOS camera as a tool for process analysis not only for laser beam welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 2001).

J. Beersiek, “New aspects of monitoring with a CMOS camera for laser materials processing,” in Proceedings of the International Congress on Applications of Lasers and Electro-Optics (Laser Institute of America, 2002).

J. Beersiek, R. Poprawe, W. Schulz, H. Gu, R. E. Mueller, W. W. Duley, “On-line monitoring of penetration depth in laser beam welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 1997), Vol. 83, Part 1, Sect. C, pp. 30–39.

Cobo, A.

F. Bardin, A. Cobo, J. M. Lopez-Higuera, O. Collin, P. Aubry, T. Dubois, M. Högström, P. Nylen, P. Jonsson, J. D. C. Jones, D. P. Hand, “Closed-loop power and focus control of laser welding for full penetration monitoring,” Appl. Opt. 44, 13–21 (2005).
[CrossRef] [PubMed]

A. Cobo, F. Bardin, P. Aubry, W. Knapp, O. Collin, J. D. C. Jones, D. P. Hand, J. M. López-Higuera, “Optical fibre-based focus control system for laser welding incorporating automatic setup,” in Proceedings of 16th International Conference on Optical Fiber Sensors, K. Hotate, H. Nagai, eds. (Institute of Electronics, Information and Communication Engineers, 2003), pp. 412–415.

Collin, O.

F. Bardin, A. Cobo, J. M. Lopez-Higuera, O. Collin, P. Aubry, T. Dubois, M. Högström, P. Nylen, P. Jonsson, J. D. C. Jones, D. P. Hand, “Closed-loop power and focus control of laser welding for full penetration monitoring,” Appl. Opt. 44, 13–21 (2005).
[CrossRef] [PubMed]

A. Cobo, F. Bardin, P. Aubry, W. Knapp, O. Collin, J. D. C. Jones, D. P. Hand, J. M. López-Higuera, “Optical fibre-based focus control system for laser welding incorporating automatic setup,” in Proceedings of 16th International Conference on Optical Fiber Sensors, K. Hotate, H. Nagai, eds. (Institute of Electronics, Information and Communication Engineers, 2003), pp. 412–415.

Decker, I.

T. Klein, M. Vicanek, J. Kroos, I. Decker, G. Simon, “Oscillations of the keyhole in penetration laser beam welding,” J. Phys. D 27, 2023–2030 (1994).
[CrossRef]

Dubois, T.

Duley, W. W.

J. Beersiek, R. Poprawe, W. Schulz, H. Gu, R. E. Mueller, W. W. Duley, “On-line monitoring of penetration depth in laser beam welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 1997), Vol. 83, Part 1, Sect. C, pp. 30–39.

H. Gu, W. W. Duley, “Discrete signal components in optical emission during keyhole welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 1997), 83, Part 1, Sect. C, pp. 40–46.

Ebrahim, S. M.

F. M. Haran, D. P. Hand, S. M. Ebrahim, C. Peters, J. D. C. Jones, “Optical signal oscillations in laser keyhole welding and potential application to lap welding,” Meas. Sci. Technol. 8, 627–633 (1997).
[CrossRef]

Gartner, M.

A. Sun, E. Kannatey-Asibu, M. Gartner, “Monitoring of laser weld penetration using sensor fusion,” J. Laser Appl. 14, 114–121 (2002).
[CrossRef]

Gu, H.

H. Gu, W. W. Duley, “Discrete signal components in optical emission during keyhole welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 1997), 83, Part 1, Sect. C, pp. 40–46.

J. Beersiek, R. Poprawe, W. Schulz, H. Gu, R. E. Mueller, W. W. Duley, “On-line monitoring of penetration depth in laser beam welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 1997), Vol. 83, Part 1, Sect. C, pp. 30–39.

Guttler, R.

R. Guttler, “Sensor detects faults in keyhole,” Opt. & Laser Europe 10, 13–15 (1998).

Hand, D. P.

F. Bardin, A. Cobo, J. M. Lopez-Higuera, O. Collin, P. Aubry, T. Dubois, M. Högström, P. Nylen, P. Jonsson, J. D. C. Jones, D. P. Hand, “Closed-loop power and focus control of laser welding for full penetration monitoring,” Appl. Opt. 44, 13–21 (2005).
[CrossRef] [PubMed]

F. M. Haran, D. P. Hand, S. M. Ebrahim, C. Peters, J. D. C. Jones, “Optical signal oscillations in laser keyhole welding and potential application to lap welding,” Meas. Sci. Technol. 8, 627–633 (1997).
[CrossRef]

F. M. Haran, D. P. Hand, C. Peters, J. D. C. Jones, “Focus control system for laser welding,” Appl. Opt. 36, 5246–5251 (1997).
[CrossRef] [PubMed]

A. Cobo, F. Bardin, P. Aubry, W. Knapp, O. Collin, J. D. C. Jones, D. P. Hand, J. M. López-Higuera, “Optical fibre-based focus control system for laser welding incorporating automatic setup,” in Proceedings of 16th International Conference on Optical Fiber Sensors, K. Hotate, H. Nagai, eds. (Institute of Electronics, Information and Communication Engineers, 2003), pp. 412–415.

Haran, F. M.

F. M. Haran, D. P. Hand, C. Peters, J. D. C. Jones, “Focus control system for laser welding,” Appl. Opt. 36, 5246–5251 (1997).
[CrossRef] [PubMed]

F. M. Haran, D. P. Hand, S. M. Ebrahim, C. Peters, J. D. C. Jones, “Optical signal oscillations in laser keyhole welding and potential application to lap welding,” Meas. Sci. Technol. 8, 627–633 (1997).
[CrossRef]

Hesemans, A. J. F. M.

S. Postma, R. G. K. M. Aarts, A. J. F. M. Hesemans, “Penetration feedback control in overlap laser welding of sheet metal,” in Proceedings of WESIC (University of Twente, 2001), pp. 495–503.

Högström, M.

Jones, J. D. C.

F. Bardin, A. Cobo, J. M. Lopez-Higuera, O. Collin, P. Aubry, T. Dubois, M. Högström, P. Nylen, P. Jonsson, J. D. C. Jones, D. P. Hand, “Closed-loop power and focus control of laser welding for full penetration monitoring,” Appl. Opt. 44, 13–21 (2005).
[CrossRef] [PubMed]

F. M. Haran, D. P. Hand, S. M. Ebrahim, C. Peters, J. D. C. Jones, “Optical signal oscillations in laser keyhole welding and potential application to lap welding,” Meas. Sci. Technol. 8, 627–633 (1997).
[CrossRef]

F. M. Haran, D. P. Hand, C. Peters, J. D. C. Jones, “Focus control system for laser welding,” Appl. Opt. 36, 5246–5251 (1997).
[CrossRef] [PubMed]

A. Cobo, F. Bardin, P. Aubry, W. Knapp, O. Collin, J. D. C. Jones, D. P. Hand, J. M. López-Higuera, “Optical fibre-based focus control system for laser welding incorporating automatic setup,” in Proceedings of 16th International Conference on Optical Fiber Sensors, K. Hotate, H. Nagai, eds. (Institute of Electronics, Information and Communication Engineers, 2003), pp. 412–415.

Jonsson, P.

Kaierle, S.

J. Petereit, P. Abels, S. Kaierle, C. Kratzsch, E. W. Kreutz, “Failure recognition and online process control in laser beam welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 2002).

S. Kaierle, P. Abels, G. Kapper, C. Kratzsch, J. Michel, W. Schulz, R. Poprawe, “State of the art and new advances in process control for laser materials processing,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 2001).

C. Kratzsch, P. Abels, S. Kaierle, R. Poprawe, W. Schulz, “Coaxial process control during laser beam welding of tailored blanks,” in Proceedings AHPLA99, High-Power Lasers in Manufacturing, X. Chen, T. Fujioka, A. Matsunawa, eds., Proc. SPIE3888, 472–482 (2000).
[CrossRef]

J. Ortmann, E. W. Kreutz, C. Maier, T. Wehner, M. Kogel-Hollacher, S. Kaierle, R. Poprawe, “Online detection of defect classes for laser beam welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 2003).

Kannatey-Asibu, E.

A. Sun, E. Kannatey-Asibu, M. Gartner, “Monitoring of laser weld penetration using sensor fusion,” J. Laser Appl. 14, 114–121 (2002).
[CrossRef]

Kapper, G.

S. Kaierle, P. Abels, G. Kapper, C. Kratzsch, J. Michel, W. Schulz, R. Poprawe, “State of the art and new advances in process control for laser materials processing,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 2001).

Keske, J.

P. Sanders, K. Leong, J. Keske, G. Kornecki, “Real-time monitoring of laser beam welding using infrared weld emission,” J. Laser Appl. 10, 205–211 (1998).
[CrossRef]

Klein, T.

T. Klein, M. Vicanek, J. Kroos, I. Decker, G. Simon, “Oscillations of the keyhole in penetration laser beam welding,” J. Phys. D 27, 2023–2030 (1994).
[CrossRef]

Knapp, W.

A. Cobo, F. Bardin, P. Aubry, W. Knapp, O. Collin, J. D. C. Jones, D. P. Hand, J. M. López-Higuera, “Optical fibre-based focus control system for laser welding incorporating automatic setup,” in Proceedings of 16th International Conference on Optical Fiber Sensors, K. Hotate, H. Nagai, eds. (Institute of Electronics, Information and Communication Engineers, 2003), pp. 412–415.

Kogel-Hollacher, M.

J. Ortmann, E. W. Kreutz, C. Maier, T. Wehner, M. Kogel-Hollacher, S. Kaierle, R. Poprawe, “Online detection of defect classes for laser beam welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 2003).

Kornecki, G.

P. Sanders, K. Leong, J. Keske, G. Kornecki, “Real-time monitoring of laser beam welding using infrared weld emission,” J. Laser Appl. 10, 205–211 (1998).
[CrossRef]

Kratzsch, C.

S. Kaierle, P. Abels, G. Kapper, C. Kratzsch, J. Michel, W. Schulz, R. Poprawe, “State of the art and new advances in process control for laser materials processing,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 2001).

J. Petereit, P. Abels, S. Kaierle, C. Kratzsch, E. W. Kreutz, “Failure recognition and online process control in laser beam welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 2002).

C. Kratzsch, P. Abels, S. Kaierle, R. Poprawe, W. Schulz, “Coaxial process control during laser beam welding of tailored blanks,” in Proceedings AHPLA99, High-Power Lasers in Manufacturing, X. Chen, T. Fujioka, A. Matsunawa, eds., Proc. SPIE3888, 472–482 (2000).
[CrossRef]

Kreutz, E. W.

J. Petereit, P. Abels, S. Kaierle, C. Kratzsch, E. W. Kreutz, “Failure recognition and online process control in laser beam welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 2002).

J. Ortmann, E. W. Kreutz, C. Maier, T. Wehner, M. Kogel-Hollacher, S. Kaierle, R. Poprawe, “Online detection of defect classes for laser beam welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 2003).

Kroos, J.

T. Klein, M. Vicanek, J. Kroos, I. Decker, G. Simon, “Oscillations of the keyhole in penetration laser beam welding,” J. Phys. D 27, 2023–2030 (1994).
[CrossRef]

Leong, K.

P. Sanders, K. Leong, J. Keske, G. Kornecki, “Real-time monitoring of laser beam welding using infrared weld emission,” J. Laser Appl. 10, 205–211 (1998).
[CrossRef]

Lopez-Higuera, J. M.

López-Higuera, J. M.

A. Cobo, F. Bardin, P. Aubry, W. Knapp, O. Collin, J. D. C. Jones, D. P. Hand, J. M. López-Higuera, “Optical fibre-based focus control system for laser welding incorporating automatic setup,” in Proceedings of 16th International Conference on Optical Fiber Sensors, K. Hotate, H. Nagai, eds. (Institute of Electronics, Information and Communication Engineers, 2003), pp. 412–415.

Maier, C.

J. Ortmann, E. W. Kreutz, C. Maier, T. Wehner, M. Kogel-Hollacher, S. Kaierle, R. Poprawe, “Online detection of defect classes for laser beam welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 2003).

Michel, J.

S. Kaierle, P. Abels, G. Kapper, C. Kratzsch, J. Michel, W. Schulz, R. Poprawe, “State of the art and new advances in process control for laser materials processing,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 2001).

Mueller, R. E.

J. Beersiek, R. Poprawe, W. Schulz, H. Gu, R. E. Mueller, W. W. Duley, “On-line monitoring of penetration depth in laser beam welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 1997), Vol. 83, Part 1, Sect. C, pp. 30–39.

Nylen, P.

Olsen, F. O.

C. Bagger, F. O. Olsen, “Laser welding closed-loop power control,” J. Laser Appl. 15, 19–24 (2003).
[CrossRef]

Ortmann, J.

J. Ortmann, E. W. Kreutz, C. Maier, T. Wehner, M. Kogel-Hollacher, S. Kaierle, R. Poprawe, “Online detection of defect classes for laser beam welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 2003).

Petereit, J.

J. Petereit, P. Abels, S. Kaierle, C. Kratzsch, E. W. Kreutz, “Failure recognition and online process control in laser beam welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 2002).

Peters, C.

F. M. Haran, D. P. Hand, C. Peters, J. D. C. Jones, “Focus control system for laser welding,” Appl. Opt. 36, 5246–5251 (1997).
[CrossRef] [PubMed]

F. M. Haran, D. P. Hand, S. M. Ebrahim, C. Peters, J. D. C. Jones, “Optical signal oscillations in laser keyhole welding and potential application to lap welding,” Meas. Sci. Technol. 8, 627–633 (1997).
[CrossRef]

Poprawe, R.

J. Ortmann, E. W. Kreutz, C. Maier, T. Wehner, M. Kogel-Hollacher, S. Kaierle, R. Poprawe, “Online detection of defect classes for laser beam welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 2003).

J. Beersiek, R. Poprawe, W. Schulz, H. Gu, R. E. Mueller, W. W. Duley, “On-line monitoring of penetration depth in laser beam welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 1997), Vol. 83, Part 1, Sect. C, pp. 30–39.

S. Kaierle, P. Abels, G. Kapper, C. Kratzsch, J. Michel, W. Schulz, R. Poprawe, “State of the art and new advances in process control for laser materials processing,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 2001).

C. Kratzsch, P. Abels, S. Kaierle, R. Poprawe, W. Schulz, “Coaxial process control during laser beam welding of tailored blanks,” in Proceedings AHPLA99, High-Power Lasers in Manufacturing, X. Chen, T. Fujioka, A. Matsunawa, eds., Proc. SPIE3888, 472–482 (2000).
[CrossRef]

Postma, S.

S. Postma, R. G. K. M. Aarts, A. J. F. M. Hesemans, “Penetration feedback control in overlap laser welding of sheet metal,” in Proceedings of WESIC (University of Twente, 2001), pp. 495–503.

Sanders, P.

P. Sanders, K. Leong, J. Keske, G. Kornecki, “Real-time monitoring of laser beam welding using infrared weld emission,” J. Laser Appl. 10, 205–211 (1998).
[CrossRef]

Schulz, W.

J. Beersiek, R. Poprawe, W. Schulz, H. Gu, R. E. Mueller, W. W. Duley, “On-line monitoring of penetration depth in laser beam welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 1997), Vol. 83, Part 1, Sect. C, pp. 30–39.

S. Kaierle, P. Abels, G. Kapper, C. Kratzsch, J. Michel, W. Schulz, R. Poprawe, “State of the art and new advances in process control for laser materials processing,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 2001).

C. Kratzsch, P. Abels, S. Kaierle, R. Poprawe, W. Schulz, “Coaxial process control during laser beam welding of tailored blanks,” in Proceedings AHPLA99, High-Power Lasers in Manufacturing, X. Chen, T. Fujioka, A. Matsunawa, eds., Proc. SPIE3888, 472–482 (2000).
[CrossRef]

Simon, G.

T. Klein, M. Vicanek, J. Kroos, I. Decker, G. Simon, “Oscillations of the keyhole in penetration laser beam welding,” J. Phys. D 27, 2023–2030 (1994).
[CrossRef]

Sun, A.

A. Sun, E. Kannatey-Asibu, M. Gartner, “Monitoring of laser weld penetration using sensor fusion,” J. Laser Appl. 14, 114–121 (2002).
[CrossRef]

Vicanek, M.

T. Klein, M. Vicanek, J. Kroos, I. Decker, G. Simon, “Oscillations of the keyhole in penetration laser beam welding,” J. Phys. D 27, 2023–2030 (1994).
[CrossRef]

Wehner, T.

J. Ortmann, E. W. Kreutz, C. Maier, T. Wehner, M. Kogel-Hollacher, S. Kaierle, R. Poprawe, “Online detection of defect classes for laser beam welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 2003).

Appl. Opt. (2)

J. Laser Appl. (3)

C. Bagger, F. O. Olsen, “Laser welding closed-loop power control,” J. Laser Appl. 15, 19–24 (2003).
[CrossRef]

A. Sun, E. Kannatey-Asibu, M. Gartner, “Monitoring of laser weld penetration using sensor fusion,” J. Laser Appl. 14, 114–121 (2002).
[CrossRef]

P. Sanders, K. Leong, J. Keske, G. Kornecki, “Real-time monitoring of laser beam welding using infrared weld emission,” J. Laser Appl. 10, 205–211 (1998).
[CrossRef]

J. Phys. D (1)

T. Klein, M. Vicanek, J. Kroos, I. Decker, G. Simon, “Oscillations of the keyhole in penetration laser beam welding,” J. Phys. D 27, 2023–2030 (1994).
[CrossRef]

Meas. Sci. Technol. (1)

F. M. Haran, D. P. Hand, S. M. Ebrahim, C. Peters, J. D. C. Jones, “Optical signal oscillations in laser keyhole welding and potential application to lap welding,” Meas. Sci. Technol. 8, 627–633 (1997).
[CrossRef]

Opt. & Laser Europe (1)

R. Guttler, “Sensor detects faults in keyhole,” Opt. & Laser Europe 10, 13–15 (1998).

Other (10)

J. Beersiek, “New aspects of monitoring with a CMOS camera for laser materials processing,” in Proceedings of the International Congress on Applications of Lasers and Electro-Optics (Laser Institute of America, 2002).

J. Ortmann, E. W. Kreutz, C. Maier, T. Wehner, M. Kogel-Hollacher, S. Kaierle, R. Poprawe, “Online detection of defect classes for laser beam welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 2003).

H. Gu, W. W. Duley, “Discrete signal components in optical emission during keyhole welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 1997), 83, Part 1, Sect. C, pp. 40–46.

A. Cobo, F. Bardin, P. Aubry, W. Knapp, O. Collin, J. D. C. Jones, D. P. Hand, J. M. López-Higuera, “Optical fibre-based focus control system for laser welding incorporating automatic setup,” in Proceedings of 16th International Conference on Optical Fiber Sensors, K. Hotate, H. Nagai, eds. (Institute of Electronics, Information and Communication Engineers, 2003), pp. 412–415.

S. Postma, R. G. K. M. Aarts, A. J. F. M. Hesemans, “Penetration feedback control in overlap laser welding of sheet metal,” in Proceedings of WESIC (University of Twente, 2001), pp. 495–503.

J. Beersiek, R. Poprawe, W. Schulz, H. Gu, R. E. Mueller, W. W. Duley, “On-line monitoring of penetration depth in laser beam welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 1997), Vol. 83, Part 1, Sect. C, pp. 30–39.

S. Kaierle, P. Abels, G. Kapper, C. Kratzsch, J. Michel, W. Schulz, R. Poprawe, “State of the art and new advances in process control for laser materials processing,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 2001).

C. Kratzsch, P. Abels, S. Kaierle, R. Poprawe, W. Schulz, “Coaxial process control during laser beam welding of tailored blanks,” in Proceedings AHPLA99, High-Power Lasers in Manufacturing, X. Chen, T. Fujioka, A. Matsunawa, eds., Proc. SPIE3888, 472–482 (2000).
[CrossRef]

J. Beersiek, “A CMOS camera as a tool for process analysis not only for laser beam welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 2001).

J. Petereit, P. Abels, S. Kaierle, C. Kratzsch, E. W. Kreutz, “Failure recognition and online process control in laser beam welding,” in Proceedings of the International Congress of Applications of Lasers and Electro-Optics (Laser Institute of America, 2002).

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Figures (10)

Fig. 1
Fig. 1

Schematic of experimental arrangement.

Fig. 2
Fig. 2

(a) Photograph of top and bottom surface of weld produced in 2 mm thick Inconel at a speed of 1.2 m/min, (b) UV/visible signal detected by the detection box during welding. (c) Spectrogram calculated from the UV/visible signal.

Fig. 3
Fig. 3

(a) UV/visible and (b) IR signals detected by the detection box during welding for an increase of the laser power while the laser beam is moving at a speed of 1.2 m/min (2 mm thick Inconel). (c) Amplitude spectrum component and negative spike content calculated from the UV/visible and IR signals (threshold level T = 1.8).

Fig. 4
Fig. 4

(a) Keyhole images recorded when 2-mm-thick bead-on-plate titanium was welded at a speed of 1.8 m/min. (b) IR signal detected by the detection box. (c) Compactness coefficient calculated from the keyhole images. The bold curve is a running average of the compactness coefficient. The zero value corresponds to an entire black image. The weld has been produced by increasing the laser power with a constant speed.

Fig. 5
Fig. 5

Images of the keyhole and their corresponding intensity profile. The intensity profile represents the average profile along the three lines.

Fig. 6
Fig. 6

(a) Keyhole images recorded when 2-mm-thick bead-on-plate titanium was welded at a speed of 1.8 m/min. (b) Sketches of their intensity profiles. (c) IR signal detected by the detection box. (d) Depth coefficient H calculated from the keyhole image intensity profile. The weld has been produced by increasing the laser power with a constant speed (same weld as presented in Fig. 4).

Fig. 7
Fig. 7

(a) Photographs of top and bottom surface when 1.6-mm-thick bead-on-plate Inconel was welding for three laser powers (1.4, 1.9, and 2.4 kW) at a speed of 0.6 m/min. (b) IR signal recorded by the detection box. (c) Amplitude of the spikes calculated in real time from the IR signal. (d) Amplitude of the spectrum component in the frequency range between 1600 and 2400 Hz calculated in real time from the IR signal. (e) Keyhole opening depth coefficient calculated in real time from the images.

Fig. 8
Fig. 8

(a) Longitudinal cross section of the Inconel stepped workpiece; (b) Photographs of top and bottom surface when bead-on-plate Inconel was welded at constant laser power and at a speed of 0.6 m/min; (c) UV/visible and (d) IR signals recorded by the detection box; (e) Amplitude of the spectral component in the frequency range between 1600 and 2400 Hz calculated in real time from the UV/visible and IR signals.

Fig. 9
Fig. 9

(a) Longitudinal cross section of the Inconel stepped workpiece. (b) Photographs of top and bottom surface when welding bead-on-plate Inconel at constant laser power and at a speed of 0.9 m/min. (c) Keyhole images recorded at 30 Hz. (d) Keyhole opening depth coefficient H. The region around the highlighted images is shown in more details in Fig. 10.

Fig. 10
Fig. 10

(a) Sequence of keyhole images at the 1.8–1.4-mm-thick interface. (b) Keyhole opening depth coefficient H calculated in real time for each frame (30 Hz).

Equations (3)

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Spike = [ ( y min ( y ) ) T ( max ( y ) y ) ] ,
Compactness = ( Perimeter ) 2 Area × 4 π .
H = 100 ( I max I min ) / ( I max ) ,

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