Numerical controller for speed control according to instructed path speed condition

A numerical controller that controls a multi-axis machine tool in which a workpiece that is attached to a table is machined by at least three linear axes and one rotation axis, the numerical controller comprising:

• an instructed path speed condition input unit that inputs, as an instructed path speed condition, an instructed path speed and an instructed path allowable acceleration of a tool center point with respect to the workpiece in an instructed path, which is a relative path of the tool center point with respect to the workpiece and is instructed by a machining program;
• a driving axis speed condition input unit that inputs, as a driving axis speed condition, a driving axis allowable speed and a driving axis allowable acceleration for a driving axis;
• a clamp value computation unit that computes an instructed path interval allowable speed and an instructed path interval allowable acceleration on the basis of the instructed path speed condition, for each of division intervals resulting from dividing the instructed path into a plurality of intervals, further computes a driving axis interval allowable speed and a driving axis interval allowable acceleration on the basis of the driving axis speed condition, sets the smaller value from among the instructed path interval allowable speed and the driving axis interval allowable speed to a speed clamp value, and sets the smaller value from among the instructed path interval allowable acceleration and the driving axis interval allowable acceleration to an acceleration clamp value;
• a speed curve computation unit that computes a speed curve as a largest speed on the instructed path that does not exceed the speed clamp value or the acceleration clamp value;
• and
• an interpolation unit that performs interpolation of the instructed path according to speed based on the speed curve, and computes a driving axis movement amount through conversion of an interpolated instructed path interpolation position to a driving axis position,
• wherein each axis is driven in accordance with the driving axis movement amount.