Welding robots are industrial robots that are engaged in welding, including cutting and painting. According to the International Organization for Standardization (ISO) industrial robots, which are defined as standard welding robots, the industrial robot is a versatile, reprogrammable Manipulator with three or more programmable axes for Industrial automation field. In order to adapt to different purposes, the mechanical interface of the last axis of the robot, usually a connecting flange, can be fitted with different tools or end effectors. The welding robot is to attach a welding tong or a welding (cutting) gun to the end shaft flange of an industrial robot, so that it can be welded, cut or thermally sprayed.