Superposition control method using numerical controller

A numerical control device to control a first machine tool in a first and a second axis, and a second machine tool in the first and second axis, comprising:

• a reference axis system to output a first reference motion command value to control motion of the first machine tool in the first axis upon execution of corresponding first reference acceleration/deceleration processing, and to output a second reference motion command value to control motion of the first machine tool in the second axis upon execution of corresponding second reference acceleration/deceleration processing;
• and
• a superimposed axis system to output a first superimposed motion command value to control motion of the second machine tool in the first axis upon execution of corresponding second axis acceleration/deceleration processing, and to output a second superimposed motion command value to control motion of the second machine tool in the second axis upon execution of corresponding second acceleration/deceleration processing,
• wherein the second reference motion command value to control motion of the first machine tool in the second axis is subjected to corresponding third reference acceleration/deceleration processing, different from the second reference acceleration/deceleration processing, and the resulting value is added to the first superimposed motion command value upon execution of corresponding second axis acceleration/deceleration processing, to thereby control the first axis of the second machine tool.

A control system for a machine tool having a plurality of control systems operable independently of one another, and controlled by a numerical control device, in which a motion command value for a first axis in a first control system of said plurality of control systems is superimposed on a motion command value for a second axis in a second control system of said plurality of control systems, said control system comprising:

• means for performing first acceleration/deceleration processing on a first motion command value distributed for said first axis in said first control system from said numerical control device, to obtain a first accelerated/decelerated motion command value for said first axis;
• means for driving a first servo motor in the first axis in the first control system in response to the first accelerated/decelerated motion command value;
• means for performing second acceleration/deceleration processing, different from the first acceleration/deceleration processing, on the motion command value distributed for said first axis in said first control system to obtain a second accelerated/decelerated motion command value for said first axis, different from said first accelerated/decelerated motion command value for said first axis;
• means for performing acceleration/deceleration processing on a motion command value distributed for said second axis in said second control system from said numerical control device, to obtain an accelerated/decelerated motion command value for said second axis;
• means for adding the obtained accelerated/decelerated motion command value for said second axis to the obtained second accelerated/decelerated motion command value for said first axis when a superimposition command is inputted;
• and
• means for driving a second servo motor in the first axis in the second control system in response to the added accelerated/decelerated motion command values.

A numerical control device to simultaneously control a first machine tool and a second machine tool, comprising:

• a reference system to output a reference motion command value to control motion of the first machine tool upon subsequent execution of a corresponding first reference acceleration/deceleration processing;
• and
• a superimposed system to output a superimposed motion command value to control motion of the second machine tool upon subsequent execution of a corresponding superimposed acceleration/deceleration processing,
• wherein the reference motion command value is subjected to corresponding second reference acceleration/deceleration processing, different from the first reference acceleration/deceleration processing, and the resulting value is added to the superimposed motion command value which has been subjected to corresponding subsequent superimposed acceleration/deceleration processing, to thereby control said second machine tool simultaneously with said first machine tool.