Product Code: PIC2008_P128

Seam Tracking during Laser Beam Welding of Tailored Blanks with Vision Sensor
Authors:
Yuanyuan Zou, Shenyang Institute of Automation, Chinese Academy of Sciences; Shenyang Peoples Republic of China
Mingyang Zhao, Shenyang Institute of Automation, Chinese Academy of Sciences; Shenyang Peoples Republic of China
Lei Zhang, Shenyang Institute of Automation, Chinese Academy of Sciences; Shenyang Peoples Republic of China
Chunying Jiang, Shenyang Institute of Automation, Chinese Academy of Sciences; Shenyang Peoples Republic of China
Presented at PICALO 2008

The main challenges in modern design of automobile bodies are reduction in weight and maximization of the structural stiffness and passive safety. The tailored blank has contributed to achieving a significant weight reduction which is single flat sheets joined by laser welding into the desired configuration without filler wire. Production of laser beam welded tailored blanks requires high speed, high precision and high quality. The welding robots that follow a preprogrammed path are often not able to guarantee a sufficient weld seam quality. Therefore, a seam tracking system is used to improve the reliability of the seam quality prediction. This paper describes the development of the seam tracking system for laser beam welding of tailored blanks. The system consists of DSP based vision camera and stripe-type laser diode. The total system is assembled into a compact module which can be attached ahead of welding torch. The images taken by the camera are analyzed using image processing algorithms. Especially, new algorithms for extracting the feature points of weld seam are discussed depending on the characteristics of laser beam welding of tailored blanks. Some experiments are carried out and some applications are given.