Calibration apparatus for calibrating mechanism error parameter for controlling robot

A robot controller for calibrating a mechanism error parameter for adjusting control of a robot based on a motion program, comprising:

• a processor configured to:
• invalidate a first mechanism error parameter from among a plurality of preset mechanism error parameters for adjusting the control of the robot, wherein each of the plurality of mechanism error parameters causes an error in a position and orientation of the robot when driven, and wherein the first mechanism error parameter includes all the mechanism error parameters of at least one drive axis of the robot;
• drive the robot with a plurality of orientations at a plurality of positions by using only a second mechanism error parameter of the plurality of mechanism error parameters other than the invalidated first mechanism error parameter and acquire an actual measurement position and orientation of the robot and information on a status of the robot including a rotation angle of robot drive motors when the actual measurement position and orientation are measured;
• store combined information on the actual measurement position and orientation of the robot and the information on the status of the robot;
• calculate an updated first mechanism error parameter based on the combined information on the actual measurement position and orientation of the robot and the information on the status of the robot;
• and
• change only the first mechanism error parameter invalidated by the processor to the calculated updated first mechanism error parameter without changing the second mechanism error parameter in the plurality of the mechanism error parameters, wherein the second mechanism error parameter retains a same value as a value prior to the change of the first mechanism error parameter,
• wherein the processor is further configured to control the robot based on the operation program while using the changed first mechanism error parameter and the second mechanism error parameter when driving the robot.