Numerical controller with interference check function

A numerical controller which controls respective axes for moving a movable element and has a function of defining interference regions respective for a plurality of machine structural objects including the movable element, moving the interference regions based on machine coordinate values of the machine structural objects obtained by interpolation processing at every interpolation period, and checking whether or not the interference regions interfere with each other, said numerical controller comprising:

• interference check computation time calculating means that calculates computation time required for the interference check;
• interference check computation period automatic adjusting means that automatically adjusts an interference check computation period based on a value obtained by dividing the computation time required for the interference check by occupancy time preset for the interference check in one interpolation period;
• interference region expanding means that expands one or more of the interference regions based on a highest one of feed velocities of the respective axes and the interference check computation period;
• and
• checking means that checks whether or not the expanded interference regions interfere with each other.