Robot system, robot teaching method and control device therefor

A control device for controlling an operation of a robot including a robot arm, and a first hand and a second hand which are connected to the robot arm and which are provided to independently rotate about an axis on the robot arm, the control device comprising:

• a storage means;
• and
• a control means,
• wherein the control means includes:
• a first generation unit configured to, when the robot arm and the first hand are operated so that the first hand reaches a predetermined target position, generate teaching values for the first hand in the target position;
• an error acquiring unit configured to, when the first hand and the second hand are rotated based on the teaching values for the first hand, acquire a relative error in rotation amount around the axis between the first hand and the second hand and store the acquired relative error in the storage means;
• and
• a second generation unit configured to generate teaching values for the second hand from the teaching values for the first hand based on the acquired relative error.