0465805 - ÚPT 2017 RIV US eng C - Conference Paper (international conference)
Horník, Petr - Mrňa, Libor - Pavelka, Jan
Possibilities in optical monitoring of laser welding process.
Optics and Measurement International Conference 2016 (Proceedings of SPIE 10151). Bellingham: SPIE, 2016, 1015110:1-6. ISSN 0277-786X.
[Optics and Measurement International Conference 2016. Liberec (CZ), 11.09.2016-14.09.2016]
R&D Projects: GA MŠMT ED0017/01/01; GA MŠMT(CZ) LO1212; GA TA ČR TA04020456
Institutional support: RVO:68081731
Keywords : laser welding * process monitoring * autocorellation function
Subject RIV: BH - Optics, Masers, Lasers
DOI: https://doi.org/10.1117/12.2257234

Laser welding is a modern, widely used but still not really common method of welding. With increasing demands on the quality of the welds, it is usual to apply automated machine welding and with on-line monitoring of the welding process. The resulting quality of the weld is largely affected by the behavior of keyhole. However, its direct observation during the welding process is practically impossible and it is necessary to use indirect methods. At ISI we have developed optical methods of monitoring the process. Most advanced is an analysis of radiation of laser-induced plasma plume forming in the keyhole where changes in the frequency of the plasma bursts are monitored and evaluated using Fourier and autocorrelation analysis. Another solution, robust and suitable for industry, is based on the observation of the keyhole inlet opening through a coaxial camera mounted in the welding head and the subsequent image processing by computer vision methods. A high-speed camera is used to understand the dynamics of the plasma plume. Through optical spectroscopy of the plume, we can study the excitation of elements in a material. It is also beneficial to monitor the gas flow of shielding gas using schlieren method.
Permanent Link: http://hdl.handle.net/11104/0264258