Method and apparatus for controlling driver mechanism in NC machine tool

A control apparatus for use with an NC machine tool comprising a main spindle, two first driver mechanisms for relatively moving the main spindle along a first axis, and a second driver mechanism for relatively moving the main spindle at least along a second axis different from the first axis, a control apparatus for controlling operations of the first and second driver mechanisms, the control apparatus comprising:

• position data generating sections respectively provided for the first and second driver mechanisms for generating target position data indicative of a destination of the main spindle for the first and second driver mechanisms on the basis of position data provided by the machining program;
• first and second drive controlling sections respectively provided for the first and second driver mechanisms for driving and controlling the first and second driver mechanisms on the basis of the target position data generated by the respective position data generating sections so as to cause the main spindle to reach the target position;
• a correction data storage section storing therein correction amounts for the movement of the main spindle along the first axis in connection with position data indicative of positions at least on the second axis;
• and
• a correction data generating section which, when the main spindle is to be relatively moved along the first axis during machining, calculates a correction value for the movement of the main spindle along the first axis on the basis of a correction amount acquired from the correction data storage section and, if the calculated correction value indicates that the main spindle is to be relatively moved in a positive direction along the first axis, outputs the correction value to one of the first drive controlling sections to drive a corresponding one of the first driver mechanisms to relatively move the main spindle in the positive direction along the first axis and, if the calculated correction value indicates that the main spindle is to be relatively moved in a negative direction along the first axis, outputs the correction value to the other first drive controlling section to drive a corresponding the other first driver mechanism to relatively move the main spindle in the negative direction along the first axis.