Numerical control device and numerical control method

A numerical control device for controlling a machine tool configured to machine a workpiece with a tool attached to a spindle by moving the tool and the workpiece relatively to each other, in accordance with machining conditions, comprising:

• a machining control unit configured to at least control a spindle motor of the machine tool so as to perform machining in accordance with the machining conditions;
• a vibration acquisition unit configured to acquire vibration occurring in the tool;
• a machining stopping unit configured to stop the machining on the workpiece performed by the machining control unit when vibration of a predetermined amplitude or greater occurs in the tool;
• a state acquisition unit configured to acquire state data indicating a state of the spindle motor configured to rotate the spindle;
• a compensation plan calculating unit configured to calculate, based on the state data, multiple compensation plans for compensating the state of the spindle motor in order to suppress vibration occurring in the tool when vibration of the predetermined amplitude or greater occurs in the tool;
• and
• a display control unit configured to cause a display unit to display the state of the spindle motor at a time of occurrence of vibration having the predetermined amplitude or greater in the tool, together with the calculated multiple compensation plans, when vibration of the predetermined amplitude or greater has occurred in the tool.