Switching supervisory control in fusion laser cutting with vision-based process state detection

Switching supervisory control in fusion laser cutting with vision-based process state detection

CAPRIO Leonardo, GUERRA Sofia, PACHER Matteo, GANDOLFI Davide, SAVARESI Sergio Matteo, TANELLI Mara, PREVITALI Barbara

Abstract. Future unmanned laser cutting machines will require the capability to automatically detect and adapt to process states avoiding critical defects. In the fusion laser cutting of metals with low thickness (1-3 mm) the process can rapidly evolve from successful separation to plasma-dominated or loss of cut due to uncontrolled factors. Thus industrial systems set the cut velocity conservatively to ensure separation while avoiding low quality or incomplete cuts. This work proposes a novel switching supervisory control architecture to increase process productivity by regulating the velocity in real-time accordingly to the detected condition. A coaxial camera-based vision system was employed to develop a classification framework capable of a low latency process state identification during the cutting of 2 mm thick mild steel. The control logic allowed high quality cutting of 2 mm thick mild steel with a productivity increase of 10-33% hence validating the architecture for autonomous machines.

Keywords
Laser Cutting, Machine Learning, Process Control

Published online 9/10/2025, 9 pages
Copyright © 2025 by the author(s)
Published under license by Materials Research Forum LLC., Millersville PA, USA

Citation: CAPRIO Leonardo, GUERRA Sofia, PACHER Matteo, GANDOLFI Davide, SAVARESI Sergio Matteo, TANELLI Mara, PREVITALI Barbara, Switching supervisory control in fusion laser cutting with vision-based process state detection, Materials Research Proceedings, Vol. 57, pp 335-343, 2025

DOI: https://doi.org/10.21741/9781644903735-39

The article was published as article 39 of the book Italian Manufacturing Association Conference

Content from this work may be used under the terms of the Creative Commons Attribution 3.0 license. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

References
[1] Y. Kawahito, H. Wang, S. Katayama, D. Sumimori, Ultra high power (100 kW) fiber laser welding of steel, Opt Lett 43 (2018) 4667–4670.
[2] M. Kardan, N. Levichev, S. Castagne, J.R. Duflou, Cutting thick aluminum plates using laser fusion cutting enhanced by dynamic beam shaping, J Laser Appl 35 (2023). https://doi.org/10.2351/7.0001095.
[3] H.-T. Nguyen, C.-K. Lin, P.-C. Tung, V.-C. Nguyen, J.-R. Ho, Manufacturing motor core lamination from thin non-oriented silicon steel sheet direct by pulsed laser cutting using multi-quality optimized process parameters, The International Journal of Advanced Manufacturing Technology (2024). https://doi.org/10.1007/s00170-024-13661-1.
[4] M. Schleier, B. Adelmann, B. Neumeier, R. Hellmann, Burr formation detector for fiber laser cutting based on a photodiode sensor system, Opt Laser Technol 96 (2017) 13–17. https://doi.org/10.1016/j.optlastec.2017.04.027.
[5] N. Levichev, G.C. Rodrigues, J.R. Duflou, Real-time monitoring of fiber laser cutting of thick plates by means of photodiodes, Procedia CIRP 94 (2020) 499–504. https://doi.org/10.1016/j.procir.2020.09.171.
[6] B. Adelmann, M. Schleier, B. Neumeier, R. Hellmann, Photodiode-based cutting interruption sensor for near-infrared lasers, Appl Opt 55 (2016) 1772. https://doi.org/10.1364/ao.55.001772.
[7] B. Adelmann, M. Schleier, R. Hellmann, Laser cut interruption detection from small images by using convolutional neural network, Sensors (Switzerland) 21 (2021) 1–13. https://doi.org/10.3390/s21020655.
[8] M. Pacher, L. Franceschetti, S.C. Strada, M. Tanelli, S.M. Savaresi, B. Previtali, Real-time continuous estimation of dross attachment in the laser cutting process based on process emission images, J Laser Appl 32 (2020) 042016. https://doi.org/10.2351/7.0000145.
[9] M. Pacher, S. Strada, M. Tanelli, B. Previtali, S.M. Savaresi, Real-time velocity regulation for productivity optimization in laser cutting, in: IFAC-PapersOnLine, Elsevier B.V., 2021: pp. 1230–1235. https://doi.org/10.1016/j.ifacol.2021.08.146.
[10] M. Pacher, L. Caprio, G. Delama, D. Gandolfi, S.M. Savaresi, B. Previtali, M. Tanelli, Real-time roughness estimation in laser oxidation cutting via coaxial process vision, in: WLT (Ed.), Lasers in Manufacturing Conference2023, WLT, 2023.
[11] S. Guerra, L. Vazzola, L. Caprio, M. Pacher, D. Gandolfi, M. Tanelli, S.M. Savaresi, B. Previtali, Velocity-based closed-loop control in fusion laser cutting for multi-directional and curved geometries, J Laser Appl 37 (2025). https://doi.org/10.2351/7.0001617.