Process and Beam Control

Monitoring systems are needed to promote process understanding and facilitate certification purposes of complex laser-based additive manufacturing and micro- and nanostructuring processes since the industry places such high demands upon their quality and productivity. Fraunhofer ILT develops and implements a wide range of technologies for inline process monitoring and control, in particular for improving product and process quality. Pyrometric and camera-based systems with analysis tools for thermal or plasma radiation as well as laser-based measurement methods are used here and allow efficient inline process monitoring. This way, defective components or processes can be quickly detected and downstream quality controls replaced.

Not only is acquiring process information important, but it is also crucial to record the process flow through intermediate and trend information. In this context, process sensor technology is an important element for optimizing laser machining processes. The efficient and stable use of sensors in industrial environments requires a high level of process understanding; knowledge and experience from the areas of process development and modeling, system technology as well as beam source development flow into the development and integration of systems for process monitoring. In order to promote process-specific advantages of laser material processing, non-contact measurement processes are commonly used, such as spectroscopy, triangulation, pyrometry, thermography and camera-based methods.

Process data are evaluated with new analysis methods in order to meet the high demands of laser material processing in real time. Modern AI-based processes are used here, which, among other things, make it possible to sharpen process classification.

The range of services we offer includes running feasibility studies, developing and implementing technologies for process visualization and process diagnostics, process monitoring and process control, integrating them in industrial manufacturing environments as well as consulting on an individual basis.

Range of services: Process and beam monitoring

• Monitoring, control and regulation of laser manufacturing processes for many applications of laser technology at different processing wavelengths
• Process monitoring with high spatial and temporal resolution camera systems and fast hardware-based real-time image processing
• Feasibility studies on the feasibility of process monitoring and control
• Integration of process monitoring and control in existing production facilities
• Development of application-oriented tailor-made sensors, e.g. for the seam sequence in laser beam welding, distance measurement in laser buildup welding
• Design of networked multi-sensor systems, e.g. for production data acquisition or multi-parameter control

Özmert, A., Neisser-Deiters, P., Drenker, A.:
Detectability of penetration depth based on weld pool geometry and process emission spectrum in laser welding of copper
Proc. SPIE 9135, 91351W (7 S.) (2014)

Thombansen, U., Ungers, M.:
Cognition for robot scanner based remote welding
Proc. SPIE  8963, 89630N (8 S.) (2014)

Thombansen, U., Gatej, A., Pereira, M.:
Tracking the course of the manufacturing process in selective laser melting
Proc. SPIE 8963, 89630O (7 S.) (2014)

Oezmert, A., Drenker, A., Nazery, V.:
Detectability of penetration based on weld pool geometry and process emission spectrum in laser welding of copper
Physics Procedia  41, 502-507 (2013)

Thombansen, U., Purrio, M., Buchholz, G., Hermanns, T., Molitor, T., Willms, K., Schulz, W., Reisgen, U.:
Measurement of process variables in melt based manufacturing processes
In: ISMTII 2013 - The 11th International Symposium on Measurement Technology and Intelligent Instruments
Aachen /Braunschweig July 1st-5th 2013 (6 S.) (2013)

Thombansen, U., Beckers, M., Buchholz, G., Hermanns, T., Molitor, T.,
Willms, K., Reisgen, U., Schulz, W.:
Signal processing for self-optimising manufacturing systems in
laser-cutting and gas-metal-arc-welding
In: 1st Joint International Symposium on System-Integrated
Intelligence, 114-116, (2012)

Frank, S., Ungers, M., Rolser, R.:
Coaxial control of aluminium and steel laser brazing processes.
Phys. Proced. 12, Part A, 752-760, (2011)

Franz, C., Abels, P., Rolsner, R., Becker, M.:
Energy input per unit length - high accuracy kinematic metrology in laser material processing.
Phys. Proced. 12, Part B, 411-420, (2011)

Franz, C., Abels, P., Merz, M., Singpiel, H., Trein, J.:
Real-time process control by machine vision.
ICALEO 30. Int. Congr. on Applications of Lasers and Electro-Optics, October 23-27, 2011. Paper 205, 6 S., (2011)

Franz, C., Singpiel, H., Trein, J.:
Tracking the contour.
Laser Technik J. 8, Nr. 5, 41-44, (2011)

Gatej, A., Thombansen, U., Loosen, P.:
Kombinierte thermo-optische Simulation für optische Systeme .
DGaO-Proc. 112, 2 S., (2011)

Gatej, A., Thombansen, U., Loosen, P.:
Simulation des thermischen Linseneffekts in hochbelasteten Lasersystemen.
Photonik 5, 54-56, (2011)

Thombansen, U., Schüttler, J., Auerbach, T. [u.a.]:
Model-based self-optimization for manufacturing systems.
Proc. of the 2011 Int. Conf. on Concurrent Enterprising (ICE 2011). Eds.: K.-D. Thoben [u.a.] Piscataway, NJ : IEEE 2011. 9 S.

Thombansen, U., Auerbach, T.:
Der Weg zu Selbstoptimierenden Fertigungstechnologien.
In: Brecher, C. (Hrsg.): Integrative Produktionstechnik für Hochlohnländer, pp. 849-909, (2011)

Fiedler, W., Drenker, A., Kaierle, S.:
Process monitoring and control during hybrid laser-arc welding of medium section steel sheets
ICALEO 2010. 29th International Congress on Applications of Lasers & Electro Optics, Anaheim/Ca., Paper 205, 7 S., (2010)

Franz, C., Abels, P.:
Measuring welding velocity at tool center point
ICALEO 2010. 29th International Congress on Applications of Lasers & Electro Optics, Anaheim/Ca., Paper 1909, 8 S., (2010)

Kaierle, S., Kowalick, K., Regaard, B.:
Laser process monitoring: The next generation approach in industrial application.
PICALO 2010, March 23-25, 2010
4th Pacific International Conference on Applications of Lasers and Optics. Wuhan, Peoples Republic of China, Paper 405, (2010)

Kaierle, S., Ungers, M., Franz, C., Mann, S., Abels, P.:
Understanding the laser process
Laser Technik J. 7, Nr 2, 49-52, (2010)

N. Stache, J. Dieckelmann, R. Firnich, J. Gedicke, P. Abels, A. Olowinsky, T. Aach:
High speed video-based melt pool surveillance in laser spot welding
Proc. of the 27th Int. Congress on Applications of Lasers & Electro-Optics 2008, ICALEO, Temecula, CA, USA, October 20-23, (2008)

S. Kaierle, P. Abels, W. Fiedler, S. Mann, B. Regaard:
Online-Qualitätssicherung für das Laserstrahlschweissen
MB-Revue 132-135, (2008)

S. Kaierle:
Process monitoring and control of laser beam welding
Laser Technik J. 5, Nr. 3, 41-43, (2008)

P. Abels, A. Roesner, S. Kaierle, S. Mann, A. Olowinsky, N. Matsuo, A. Hino:
Various process monitoring approaches of transparent thermoplastics laser beam welding
Proc. of the 27th Int. Congress on Applications of Lasers & Electro-Optics 2008, ICALEO, Temecula, CA, USA, 99-104, (2008)

J. Gedicke, A. Olowinsky, U. Jansen, W. Schulz, A. Gillner:
Weld depth control in fiber laser welding of thin metal sheets
Proc. of the 27th Int. Congress on Applications of Lasers & Electro-Optics 2008, ICALEO, Temecula, CA, USA, October 20-23, (2008)

S.Kaierle, M. Dahmen, S. Mann, R. Poprawe:
Autonomous Production Cell for Laser Beam Welding
Proc. Int. Conf. on Competitive Manufacturing "COMA 07", Stellenbosch, Südafrika, 6 S., (2007)

C. Franz, S. Mann, S. Kaierle:
Comparison of process monitoring strategies for laser transmission welding of plastics
Proc. of ICALEO 2007, Orlando, Fl. 602-606, (2007)

M. Dahmen, W. Fiedler, B. Regaard, S. Kaierle:
Continuous process control during laser beam welding of small section Aluminium sheet
Proc. of WLT Conf. Lasers in Manufacturing, Munich, 5 S., (2007)

B. Regaard, W. Fiedler, S. Kaierle:
Error detection in lap welding applications using on-line melt pool contour analysis by coaxial process monitoring with external illumination
Proc. of WLT Conf. Lasers in Manufacturing, Munich, 5 S., (2007)

W. Fiedler, M. Dahmen, S. Kaierle:
Process control of laser beam welded small section aluminum sheets
Proc. of ICALEO 2007, Orlando, Fl., 271-276, (2007)

J. Gedicke, B. Regaard, K. Klages, A. Olowinsky, S. Kaierle:
Comparison of different process monitoring methods for laser beam micro welding
Proceedings of ICALEO 2006, 8 S., (2006)

J. Gedicke, B. Regaard, A. Gillner, S. Kaierle:
Kontrolle beim Mikroschweißen - Automatisierte Prozessüberwachung durch koaxiale Prozesskontrolle mit Fremdbeleuchtung
Laser Technik Journal 3, 33-37, (2006)

B. Regaard, S. Kaierle, R. Poprawe:
Self guided laser welding
Proceedings of ICALEO 2006, 7 S., (2006)