Controller for machine tool

A controller for controlling a machine tool that performs machining on a workpiece with a cutting tool by operating a spindle and a feeding axis in coordination with each other, the controller comprising:

• a processor configured to:
• calculate an oscillation command for relatively oscillating the cutting tool and the workpiece, from a rotation speed of the spindle and a position command of a relative position of the cutting tool with respect to the workpiece;
• calculate a compensation amount corresponding to a notification delay of the rotation speed of the spindle to the processor when calculating the oscillation command;
• and
• superimpose the compensation amount on the oscillation command,
• wherein the processor is configured to calculate the oscillation command from an oscillation phase calculated based on the rotation speed of the spindle and an oscillation amplitude calculated based on the position command, and
• wherein the processor is configured to calculate, as the compensation amount, a change in oscillation phase corresponding to a notification delay time of the rotation speed of the spindle, and superimpose the compensation amount on the oscillation phase in the oscillation command.