Time difference setting device and numerical control device

A time difference setting device in a laser processing system including a laser oscillator that generates a laser beam, a laser head that emits the laser beam, a driving mechanism that determines a relative position of the laser head and a workpiece, and a numerical control device that generates, based on a machining program, a laser command for the laser oscillator and a positioning command for the driving mechanism, the time difference setting device being configured to set a command time difference which is a time difference in output timing of the laser command with respect to the positioning command, the time difference setting device comprising a memory and a processor, wherein the memory stores instructions configured to cause the processor to:

• acquire a change in speed of the driving mechanism with respect to the positioning command that is based on the machining program;
• calculate, based on the change in speed of the driving mechanism, a mechanism delay time which is a delay time in positioning by the driving mechanism with respect to the positioning command;
• calculate a change in output of the laser oscillator with respect to the laser command that is based on the machining program, using an oscillator model for simulating an operation of the laser oscillator;
• calculate, based on the change in output of the laser oscillator, a laser delay time which is a delay time in output of the laser oscillator with respect to the laser command;
• and
• set the command time difference for a section in which an emission of the laser beam is designated in the machining program, based on the mechanism delay time and the laser delay time.