Signal Patterns of High Speed Rotational Arc Sensor for Gas Metal Arc Welding

High speed rotational arc sensing is an important method to detect the torch deviation during automatic seam tracking of arc welding. In this paper, a mathematic model of high speed rotational arc sensing is analyzed. Simulations have been implemented in two conditions, namely considering or without considering weld bead profile. The simulation results are consistent with the experimental results. The current waveforms at the beginning of the welding are different from those at middle of the welding because of the formation of the weld bead profile. The signal patterns for seam tracking and end-point detection are proposed. A phase shift between the rotation and the current variation is also discovered in the experiments. The mathematical model can be helpful for the interpretation and improvement of arc sensing systems