Quality and process control of laser welding using multisensorsystems and methods of pattern recognition

Due to many advantages, such as low heat input and high welding speed, laser-welding technology is increasingly used for manufacturing. For example, the proportion of laser welding seams in car-body construction at VW Saxony has increased from 5 % to 35 % during the last years. It is important for the user of laser welding technologies to optimally use the plant capacities, to ensure high availability, and to avoid downtimes, rejections and rectifications of rejects. In order to solve the respective problems, the Fraunhofer Institute for Machine Tools and Forming Technology, in cooperation with Volkswagen Sachsen GmbH and other partners, is developing a multi-sensor system for in-line process monitoring based upon fuzzy pattern recognition. The work was carried out in the frame of the Cooperative Project MAINE X, supported by the Free State of Saxony.