A method for identifying geometric errors in a machine tool includes the steps of: positioning a reference sphere so as to align its center with a centerline of a tool spindle; attaching a position measuring device having a gauge head to a rotation unit so as to direct the gauge head toward a rotation centerline of the rotation unit; acquiring displacement data relative to the center of the reference sphere by measuring positions of the reference sphere with the gauge head while rotating a rotation target (the swivel unit or the rotation unit) with the gauge head directed toward the center of the reference sphere, the displacement data being dependent on rotation angles of the rotation target; and identifying the geometric errors by least squares method using a mathematical expression having terms containing the geometric errors and representing displacement dependent on the rotation angles, and the displacement data.

A method for calibrating a robot is disclosed. A working space of the robot at least partly overlaps with a working space of a machining and/or production tool. The robot is moved such that a reference point of the robot is at a first position within the working space of the machining and/or production tool. A first position value for the robot at the first position is compared with a first position value for the machining and/or production tool at the position. If the first position value for the robot differs from the first position value for the machining and/or production tool, the first position value for the robot is corrected or the first position value for the machining and/or production tool is corrected such that the first position value for the robot and the first position value for the machining and/or production tool are the same.