Patent ID: 7764039

Claim:
A numerical controller for drivingly controlling a movable part of a machine according to commands in a program, while using an interference checking device to repeatedly execute interference check processing on the program to determine an interference between the movable part and other objects, so that motion of the movable part is decelerated to be stopped when the interference is determined in advance by the interference checking device, said numerical controller comprising: pre-reading means for pre-reading the program to be converted into execution data; advanced time determining means for determining a future time to execute the next interference check processing based on a time period spent in the preceding interference check processing by the interference checking device and a time of termination of the preceding interference check processing; advanced position calculating means for calculating an advanced position of the movable part predicted at the future time determined by said advanced time determining means, using a commanded position of the movable part at the time of termination of the interference check processing and the execution data obtained by said pre-reading means; and output means for outputting the advanced position calculated by said advanced position calculating means to the interference checking device, so that the next interference check processing is performed for determining an interference between the movable part and other objects at the advanced position.