CONTROL DEVICE, MACHINE TOOL, CALCULATION METHOD, AND PROGRAM

The present invention has an object to provide a device that automatically performs a thermal displacement correction in a machine tool.To realize this object, a controller according to the present invention includes: a machining data collector 67 configured to collect machining data including a date and a time when at least one machined portion that is a part of a workpiece and that was set as a learning target was machined by a machine tool; a temperature collector 29 configured to collect, at predetermined time intervals, temperature data obtained at a plurality of positions on the machine tool; a dimension data input receiver 75 configured to receive an input of dimension measurement data obtained by measuring a dimension of the at least one machined portion after the at least one machined portion has been machined; a learning data generator 85 configured to generate learning data including the machining data and the dimension measurement data; and a machine learning executor 95 configured to execute a machine learning based on the temperature data and the learning data, and configured to calculate a correction coefficient used in a thermal displacement correction equation for correcting a displacement caused by a change in a temperature of the machine tool.