A welding gun height detection method in compulsively short circuiting transfer mode of rotational arc GMAW

The characteristics of welding current in rotational arc GMAW were analyzed in this paper. It was found that the compulsively short circuiting transfer would take place when the electrode rotating to the sides of V groove. During the period of short circuiting transfer, the welding currents would sharply increase, so as to affect the average value of welding current in one rotational cycle. A novel method was proposed to detect the height of welding gun in this paper. The method use of least-square fitting method to fit the welding currents into a plane in three dimensions, and then through compute the distance between origin of coordinates and the plane to detect the height of welding gun. In the last, the validity of the method was proved through experiments.