Machine learning device, arc welding control device, arc welding robot system, and welding system

An arc welding control device, comprising:

• a machine learning device which learns to determine at least one arc welding condition;
• and
• an arc welding execution unit which executes arc welding in accordance with the determined at least one arc welding condition output from the machine learning device,
• the machine learning device comprising:
• a state observation unit which observes a state variable comprising (i) at least one physical quantity regarding the arc welding at least during or after the arc welding and (ii) the at least one arc welding condition,
• wherein the at least one arc welding condition includes one of an amount of adjustment of a weld waveform, push/drag angles of a welding torch, an aim angle of a welding torch, a torch aim position, a weaving condition, an arc sensor condition, and an offset amount of the welding position in a multi-layer welding, and
• wherein the at least one physical quantity includes at least one of an outer appearance of a weld bead, an excess weld metal height of the weld bead, a bead width of the weld bead, which are obtained by processing image data picked up by an image pickup unit, an amount of generated spatter, and an amount of penetration obtained by a penetration measurement unit;
• and
• a learning unit which learns to determine the at least one arc welding condition by updating a function that determines the at least one arc welding condition based on the state variable,
• wherein the learning unit comprises (i) a reward computation unit which computes a reward for a result of the determined at least one arc welding condition and (ii) a function update unit which updates the function based on the reward computed by the reward computation unit,
• wherein the at least one arc welding condition is learned so as to increase the reward computed by the reward computation unit, by repeatedly carrying out the updating of the function in the function update unit.