Robot controller and robot control method

A robot controller for controlling a robot including a robot arm having a free end, and drive shafts, comprising:

• a data acquiring device that acquires angular displacements of the drive shafts measured by the robot;
• an inverse correction device that converts the angular displacements acquired by the
• an inverse correction device that converts the angular displacements acquired by the data acquiring device into position-attitude data through a forward conversion and corrects the position-attitude data obtained through the forward conversion to provide correct position-attitude data that does not cause any positional deviation attributable to predetermined and stored inherent errors in the robot;
• and
• an output device that outputs the corrected position-attitude data corrected by the inverse correction device and the angular displacements acquired by the data acquiring device.

A method for controlling a robot including a robot arm having a free end, and drive shafts, the method comprising:

• entering input data into an input device, the input data comprising angular displacements by which the drive shafts of the robot arm are to be turned and position-attitude data indicating a position of the free end of the robot arm and an attitude of the robot in a rectangular coordinate system;
• correcting, using a correcting device, the position-attitude data entered into the input device based on predetermined and stored inherent errors in the robot;
• wherein the predetermined and stored inherent errors include at least one of a machining error, an assembling error, an error in origins of axes and an error by a deflection of the robot;
• converting, using an inverse conversion device, the corrected position-attitude data corrected by the correcting device into angular displacements through an inverse conversion;
• selecting, using an instructing device, either the angular displacements entered by the input device or the angular displacements obtained through the inverse conversion by the inverse conversion device in accordance with a predetermined condition;
• and
• instructing the robot with the selected angular displacements.