Position compensation system and position compensation method for tool changer

A position compensation system of a tool changer including a turret in which a plurality of grips capable of holding tools to be attached to a spindle of a machine tool are arranged along a circumferential direction, and a rotary driver that rotationally drives the turret about a rotary shaft to index an arbitrary one of the grips,

• the position compensation system comprising:
• a storage unit configured to store a reference rotary position coordinate of the turret corresponding to an index position of one of the grips as a coordinate representing a reference position of the turret;
• a rotary position coordinate detector configured to detect a rotary position coordinate of the turret;
• a compensation necessity determiner configured to determine whether or not it is necessary to perform a rotational compensation to return the turret to the reference position, in accordance with a rotational deviation of the rotary position coordinate of the turret detected by the rotary position coordinate detector from the reference rotary position coordinate of the turret stored in the storage unit;
• and
• a compensation request part configured to request an operation or work related to the rotational compensation when the compensation necessity determiner determines that the rotational compensation needs to be performed.