Basic Image Measurement for Laser Welding Robot Motion Control
Akihiko Matsushita*, Masahiro Yamanaka*, Shun'ichi Kaneko*, Hitoshi Ohfuji**, and Kaoru Fukuda**
*System Sensing and Control Laboratory, Hokkaido University
North 14 West 9, Sapporo, Japan
**SANKO-STEEL, Zenibako 3-515-1, Otaru, Japan
Laser welding, provides high-density energy, is easy to control, and is low in heat input but deep in depth, enabling it to be used for small-area precision welding. However, Automating welding using robots has been considered, but laser welding requires accurate alignment and direction of irradiation because of its capability of sensitive welding. In this paper, basic image measurement method is proposed for Hand-Eye Laser Welding System equipped with an optical microscope and a CMOS camera, as follows.
1) A core line detection method of a slit laser image that has robustness against variation of observation direction and speckle patterns is proposed.
2) The parameter identification method of laser planes utilizing the core line detection method is proposed for measurement.
3) It is derived measurement equations of the position and the posture of the metal plate from geometric consideration utilizing the identified parameters and the core line detection.
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