Numerical control device and method for controlling additive manufacturing apparatus

A numerical control device that controls, in accordance with a machining program, an additive manufacturing apparatus that includes a machining head emitting a beam and produces a modeled object by adding a material molten by irradiation of the beam to a workpiece, the numerical control device comprising:

• program analyzing circuitry to analyze a transition of a moving velocity of the machining head relative to the workpiece and a transition of a supply amount of the material supplied to an irradiation position of the beam on the basis of the machining program;
• movement distance calculating circuitry to calculate a second distance on the basis of a result of analysis performed by the program analyzing circuitry, the second distance being a length of a second movement section from a second position at which addition of the material to the workpiece is stopped, the second movement section being a linear section through which the machining head is moved while the head is decelerated from a constant velocity value to zero;
• and
• condition command generating circuitry to generate a supply command to decrease the supply amount of the material per hour to the irradiation position of the beam from a command value according to a machining condition to zero while the machining head is moved through the second movement section;
• wherein the condition command generating circuitry generates an output command to stop output of the beam when the machining head reaches the second position.