Patent ID: 8145347

Claim:
A numerical control apparatus that numerically controls movement of a movable portion according to a machining program including commands for a tool-tip position determined by a position of a translation axis and for a tool posture determined by a rotation angle of a rotation axis, the numerical control apparatus comprising: an analysis processor that generates analysis data required to determine interpolation points for each of the translation axis and the rotation axis based on result of analyzing an instruction for each block commanded from the machining program; an interpolation processor that performs interpolation based on the analysis data to obtain interpolation points for each of the translation axis and the rotation axis in each control cycle; a rotation-axis filtering processor that subjects an angle change amount between interpolation points between rotation angles of the rotation axis to a smoothing process according to a preset filter time constant; a translation-axis timing synchronization unit that synchronizes timing of rotation of the rotation axis subjected to the smoothing process and timing of movement of the translation axis; a coordinate transformation unit that transforms the tool-tip position into coordinates of a machine position of the translation axis, from each tool-tip position after timing synchronization between axes of the translation axis is performed and from each rotation angle of the rotation axis subjected to the smoothing process; and an acceleration/deceleration processor that performs an acceleration/deceleration process on the machine position of the translation axis of which coordinates are transformed and on the rotation angle of the rotation axis subjected to the smoothing process.