Closed loop control of laser welding processes with Cellular Neural Network (CNN) cameras

Research output: Contribution to conferencesPaperContributedpeer-review

Contributors

  • Felix Abt - , University of Stuttgart (Author)
  • L. Nicolosi - , TUD Dresden University of Technology (Author)
  • D. Carl - , Fraunhofer Institute for Physical Measurement Techniques (Author)
  • A. Blug - , Fraunhofer Institute for Physical Measurement Techniques (Author)
  • M. Geese - , University Hospital Frankfurt (Author)
  • F. Dausinger - , Dausinger and Giesen GmbH (Author)
  • C. Deininger - , University of Stuttgart (Author)
  • Heinrich Höfler - , Fraunhofer Institute for Physical Measurement Techniques (Author)
  • R. Tetzlaff - , Chair of Fundamentals of Electronics (Author)

Abstract

The growing number of laser welding applications from automobile production to micro mechanics require fast and reliable process control systems. The high process dynamics in time, space and intensity, especially in scanner based remote welding or high speed micro welding, demand extremely fast and spatially resolved in-process control systems to create closed loop control for error prevention and correction. Today's conventional micro processor based image processing architectures (as used for example in [1]) are not able to provide the high frame rates needed for the real-time closed loop control of high speed laser welding. With "Cellular Neural Networks" (CNN) it is possible to implement Single-Instruction-Multiple-Data (SIMD)-architectures in the electronic circuitry of each pixel of the camera chip itself in order to produce a so called Focal Plane Processor (FPP). Such pixel parallel systems provide extremely fast real-time image processing. With these new CNN-cameras it is now possible to implement a camera based high speed in-process control system for laser welding that enables closed loop control of various quality features. With a multi modal diagnostic approach we were able to identify direct and explicit image attributes for a variety of quality features as a base for the process control. It could be shown that closed loop control of the "full- penetration" quality feature is possible with frame rates of 10 kHz and beyond with a CNN-camera system.

Details

Original languageEnglish
Pages817-825
Number of pages9
Publication statusPublished - 2008
Peer-reviewedYes

Conference

Title27th International Congress on Applications of Lasers and Electro-Optics
Abbreviated titleICALEO 2008
Conference number27
Duration20 - 23 October 2008
CityTemecula
CountryUnited States of America

External IDs

ORCID /0000-0001-7436-0103/work/142240294