NUMERICAL CONTROL APPARATUS

PROBLEM TO BE SOLVED: To restore each stage to an origin position, while preventing moving objects from colliding with one another, even if the temporarily stored position information of each stage is lost. SOLUTION: A work-holding tool 101 holding a work W is supported by an XY stage 103, and the XY stage 103 is supported by a rotating stage 105. A measuring unit 117 is supported on a turning measuring unit stage 115. A numerical control apparatus makes the turning stage turn in the same direction, in a state where the relative positional relation between the work W and the work-holding tool 101 and the measuring unit 117 is held; and after either of them is detected at the turning edge, makes the rotating stage turn in the opposite direction; and when it is made to turn in the opposite direction, the amount of turn is detected. The relative positional relation between the work W and the work holding tool 101 and the measurement unit 117 is determined by this operation. Then, an XY stage 103 is restored to an origin position, in accordance with a preliminarily stored initialization pattern corresponding to the determined positional relation. COPYRIGHT: (C)2011,JPO&INPIT