Robot welding system and method for operating a robot welding system

Robotic welding system comprising:

• a welding torch with a consumable electrode;
• a robot, which is configured to guide the welding torch;
• a welding power source, which is designed to form a voltage between the consumable electrode and a second electrode, which can be connected to at least one workpiece;
• a sensor unit, which is configured to carry out a scanning program by means of the robot and the welding torch, wherein the scanning program is configured to scan and detect a geometry of the at least one workpiece at least in sections by means of the consumable electrode of the welding torch, wherein the scanning program is further configured to detect at least one position and/or orientation of the robot at the same time, wherein the sensor unit is configured, in order to detect the geometry of the at least one workpiece, to repeat a periodic cycle, wherein the cycle comprises:
• advancing an electrode tip of the consumable electrode until a short circuit between the consumable electrode and the at least one workpiece is detected via the second electrode while the latter is connected to the at least one workpiece,
• storing the position of the consumable electrode at the time of the detected short circuit, and
• retracting the electrode tip until the short circuit breaks;
• and
• a computing unit, which is configured to obtain a specification of a welding task to be carried out on the at least one workpiece and, based on the specification obtained and on a result of the scanning program, to generate an output signal which is designed to generate or set at least one parameter of the welding task to be carried out.