Patent ID: 11892820
Assignee: OKUMA CORPORATION
Field: Control (Instruments)
Classification: CPC G | IPC G

Claim 6:
7. A machine tool configured to compensate a motion error of a translational axis in accordance with a compensation parameter, wherein
the machine tool includes two or more translational axes, a table configured to hold a workpiece, and a main spindle configured to hold a tool, the translational axes enable a relative motion of two degrees or more of translational freedom of the tool held onto the main spindle with respect to the workpiece, and the machine tool including an output unit,
the machine tool comprising:
a calibration-master condition outputting unit that outputs at least one of a plurality of calibration-master conditions to the output unit, the calibration-master conditions including a type of a calibration master that includes a plurality of targets, an installation direction of the calibration master, and an installation position of the calibration master;
a calibration master measuring unit that obtains measurement values of positions of the targets by detecting the positions of the plurality of targets under the calibration-master condition using a sensor mounted to the main spindle in a state where the calibration master is installed on the table in accordance with the output calibration-master condition;
an error value calculating unit that calculates an error value using the measurement value obtained under the calibration-master condition and a calibration value of the position of the target; and
a compensation parameter calculating unit that approximates a relation between the measurement values and the error values by a curve and a straight line, calculates the compensation parameter of a positioning error of the translational axis based on an approximate curve in a partial range of a stroke of the translational axis, and calculates the compensation parameter of the positioning error based on an approximate straight line in another range of the stroke of the translational axis.