Highspeed footage of an automated inline rewelding process based on detection of process anomalies during laser deep penetration welding

During laser deep penetration welding, disturbances of the nominal process can lead to seam imperfections. Due to their possibly impairing characteristics on the mechanical properties of the seam, it is of high interest to reliably detect these defects. This can be achieved by means of sensor based inline process monitoring. While the sensor data can be employed to identify the defect location and perform post process repair work, it can also build the foundation to reweld the detected seam segments inline to enhance the seam quality and possibly eliminate necessary post process work.

This highspeed footage shows a demonstration of an in-situ rewelding process based on an automized detection of a disturbed welding process.

The process monitoring is done by means of pyrometry. When the analog output voltage of the pyrometer falls below a predetermined threshold, a process disturbance is registered. As the voltage level exceeds the threshold again, the length of the disturbance is calculated and the laser spot is deflected by the calculated distance. After that, the spot is deflected back to the inital position. The deflection is carried out by a 1D scanner within the welding optics.

For further information about the process parameters as well as the data processing and controler design, please see the authors published paper "Automated inline rewelding processes based on detection of process anomalies during laser deep penetration welding " in Lasers in Manufacturing Conference 2025