NUMERICAL CONTROLLER AND NUMERICAL CONTROL METHOD FOR NC MACHINE TOOLS

A feed velocity of a control axis and acceleration thereof do not exceed a maximum feed velocity and a maximum acceleration defined in mechanical specifications even if a radial operation is carried out for the purpose of a cut-in or escape operation in a contour describing control. A radial permissible maximum velocity (Vnp) and a radial permissible maximum acceleration (&agr;np) in a contour describing control using a circular interpolation is set separately from a setting value of a maximum feed velocity (Vm) of a control axis and that of a maximum acceleration (&agr;m) thereof set as mechanical specifications, and when a command of the circular interpolation is given, limitations are given to a radial velocity (Vn) and acceleration (&agr;n) so that the radial velocity (Vn) and acceleration (&agr;n) do not exceed the radial permissible maximum velocity (Vnp) and permissible maximum acceleration (&agr;np).