Numerical control device

A numerical control device to control a servomotor on the basis of a machining program, comprising:

• a processor;
• and
• a memory to store a program which, when executed by the processor, performs steps of:
• generating a command position on the basis of path information described in the machining program;
• generating direction-reversal-information that includes:
• information on description part in the machining program of an instruction that causes reversal in a moving direction of a mechanical system driven in a direction of a movement axis by the servomotor,
• path information indicated by an instruction to be executed later than the instruction that causes the reversal of the moving direction, and
• a movement amount of the mechanical system along the movement axis, on which the reversal of the moving direction occurs, in a predetermined section of a movement path following a position where the reversal of the moving direction occurs, on the basis of the path information;
• determining unit determining whether or not to perform correction on the reversal of the moving direction on the basis of the command position and the direction-reversal-information, and setting a correction amount at reversal to zero when the movement amount is smaller than a predetermined movement amount threshold, the correction amount at reversal being an amount of the correction, and
• a servo circuit to perform servo control so that a motor position of the servomotor follows the command position corrected by the correction.

A numerical control device to control a servomotor on the basis of a machining program, comprising:

• a processor;
• and
• a memory to store a program which, when executed by the processor, performs steps of:
• generating a command position on the basis of path information described in the machining program;
• generating, on the basis of the path information, direction-reversal-information including information on description part in the machining program of an instruction that causes reversal of a moving direction of a mechanical system driven in a direction of a movement axis by the servomotor, path information indicated by an instruction to be executed later than the instruction that causes the reversal of the moving direction, and a coordinate value on the movement axis of the mechanical system at a position where the reversal of the moving direction occurs;
• determining whether or not to perform correction on the reversal of the moving direction on the basis of the command position and the direction-reversal-information, and setting a correction amount at reversal to zero when no other reversal of the moving direction occurs within a predetermined distance from the coordinate value, the correction amount at reversal being an amount of the correction, and
• a servo circuit to perform servo control so that a motor position of the servomotor follows the command position corrected by the correction.