Method and apparatus for circular interpolation

Claim 1

A method of automatically correcting the circular path of a numerically controlled machine tool in which a circulator interpolation operation is performed in accordance with a given arc center 0, machine tool arc starting point P s and machine tool arc end point P e , comprising the steps of: a. computing a distance r A from the given arc center 0 to the given machine tool arc starting point P s , and a distance r B from the given arc center 0 to the given machine tool arc end point P e ; b. determining whether the distances r A and r B are equal; c. computing a new arc center 0 N of an arc passing through said starting point P s and said end point P e when the distance r A and the distance r B are unequal; and d. executing a circular interpolation operation on the basis of the computed arc center 0 N , the given machine tool arc starting point P s and the given machine tool arc end point P e wherein the circular path of the machine tool is corrected and joins the machine starting point P s and the machine tool ending point P e .

Claim 2

A method of automatically correcting the circular path of a numerically controlled machine tool in which a circulator interpolation operation is performed in accordance with a given arc center 0, machine tool arc starting point P s and machine tool arc end point P e , comprising the steps of: a. computing a distance r A from the given arc center 0 to the given machine tool arc starting point P s , and a distance r B from the given arc center 0 to the given machine tool arc end point P e ; b. determining whether the distances r A and r B are equal; c. computing a new arc center 0 N of an arc passing through said starting point P s and said end point P e when the distance r A and the distance r B are unequal; and d. executing a circular interpolation operation on the basis of the computed arc center 0 N , the given machine tool arc starting point P s and the given machine tool arc end point P e wherein the circular path of the machine tool is corrected and joins the machine starting point P s and the machine tool ending point P e .

Claim 5

An apparatus for automatically correcting the circular path of a numerically controlled machine tool and performing a circular interpolation operation in accordance with a given arc center 0, machine tool arc starting point P s and machine tool arc end point P e , comprising: first means for receiving said given arc center 0, said machine tool arc starting point P s and said machine tool arc end point P e ; a first arithmetic unit operatively connected to said first means, for computing a distance r A from the given arc center 0 to the given machine tool arc end point P s , and a distance r B from the given arc center 0 to the given machine tool arc end point P e ; a comparator unit operatively connected to said first arithmetic unit, for determining whether the distances r A and r B are equal; a second arithmetic unit operatively connected to said first arithmetic unit, to said first means and to said comparator unit for computing a new arc center 0 N of an arc passing through said machine tool arc starting point P s and said machine tool arc end point P e in response to the distance r A and the distance r B being unequal; and a circular interpolation unit operatively connected to said comparator unit, to said first means and to said second arithmetic unit, for executing a circular interpolation operation in accordance with the computed arc center 0 N , the given machine tool arc starting point P S and the given machine tool arc end point P e and for controlling the numerically controlled machine tool.

Claim 6

An apparatus for automatically correcting the circular path of a numerically controlled machine tool and performing a circular interpolation operation in accordance with a given arc center 0, machine tool arc starting point P s and machine tool arc end point P e , comprising: first means for receiving said given arc center 0, said machine tool arc starting point P s and said machine tool arc end point P e ; a first arithmetic unit operatively connected to said first means, for computing a distance r A from the given arc center 0 to the given machine tool arc end point P s , and a distance r B from the given arc center 0 to the given machine tool arc end point P e ; a comparator unit operatively connected to said first arithmetic unit, for determining whether the distances r A and r B are equal; a second arithmetic unit operatively connected to said first arithmetic unit, to said first means and to said comparator unit for computing a new arc center 0 N of an arc passing through said machine tool arc starting point P s and said machine tool arc end point P e in response to the distance r A and the distance r B being unequal; and a circular interpolation unit operatively connected to said comparator unit, to said first means and to said second arithmetic unit, for executing a circular interpolation operation in accordance with the computed arc center 0 N , the given machine tool arc starting point P S and the given machine tool arc end point P e and for controlling the numerically controlled machine tool.