Displacement compensation device and displacement compensation method for machine tool

A displacement compensation device for a machine tool, the displacement compensation device estimating a displacement of a machine tool based on temperature information from a temperature sensor installed on the machine tool and compensating an axis command value, the displacement compensation device comprising:

• a temperature information acquiring unit that acquires the temperature information from the temperature sensor;
• a floor information acquiring unit that acquires floor information using a floor state sensor measuring a state of a surface or an inside of a floor on which the machine tool is installed;
• a displacement amount computing unit that calculates an estimated displacement amount of the machine tool with a preset displacement estimation formula using the temperature information acquired by the temperature information acquiring unit and the floor information acquired by the floor information acquiring unit as inputs;
• and
• a compensating unit that compensates the axis command value based on the estimated displacement amount calculated by the displacement amount computing unit.