US Patent 10434655 Robot apparatus and method for controlling robot apparatus

A robot system includes a fixed camera that obtains first measurement data by detecting a plurality of features positioned within a detection range, the detection range including at least part of a range in which a robot arm is movable, a hand camera movable with the robot arm, and a control apparatus that controls the robot arm. A calibration function that relates a value obtained as part of the first measurement data to a command value provided to the robot arm at each of a plurality of positions and orientations at which the hand camera obtains second measurement data by detecting each mark.