Spectroscopic measurement of the arc and the weld pool in robotic welding

In an automatic welding system using a visual sensor, it is necessary to clearly observe the weld pool to control the welding phenomenon with a visual sensor. However, since the arc light is too strong, it is difficult to take clear weld pool images. It is important to reduce the influence of the arc light. Therefore, the spectral distribution of the weld pool and arc light in plasma arc welding and pulse MAG welding was measured changing the current. Based on the measurement results, the characteristics of the spectral distribution in each welding method were found. Using the results, a filter suitable for the weld pool observation was selected. © 2020 Japan Welding Society. All rights reserved.