Seam welding apparatus, seam welding method, robot control device, and robot control method

A seam welding apparatus that performs seam welding on layered steel palates,

• the seam welding apparatus comprising:
• an articulated robot capable of setting a predetermined tolerance for a joint;
• and
• a welding device attached to the robot,
• the welding device comprising:
• a pair of rotating electrodes;
• an electrode supporting frame that supports the rotating electrodes;
• a supporting frame that rotatably supports the electrode supporting frame so that it is possible to change a direction of running when the rotating electrodes run on the steel plates;
• a revolving means configured to revolve the electrode supporting frame provided on the supporting frame;
• a distance measuring means provided on the supporting frame or the electrode supporting frame, the distance measuring means being configured to measure a distance to an edge of the steel plate;
• and
• a controller configured to control the revolving means to adjust a running direction of the rotating electrodes so that a deviation comes into zero when a distance actually measured by the distance measuring means deviates from a predetermined distance.

A robot control device comprising:

• an error acquiring unit configured to acquire error between a measured or estimated position of an end effector mounted on a robot including a plurality of drive sections and a target position of the end effector;
• a convertor configured to convert the error to a correction angle for a predetermined revolving angle of the end effector;
• and
• a robot control unit configured to control the robot so that the end effector revolves based on the correction angle.

A robot control method comprising:

• acquiring an error between a measured or estimated position of an end effector mounted on a robot including a plurality of drive sections and a target position of the end effector;
• converting the error to a correction angle for a predetermined revolving angle of the end effector;
• and
• controlling the robot so that the end effector revolves based on the correction angle.