Numerical control unit with corner path generation function considering acceleration / deceleration after interpolation

摘要

A numerical control unit (100) that controls a machine tool including a plurality of control axes to compensate for an error by an inward displacement by inserting a new curved movement path into a corner portion between two consecutive blocks in a machining program including a plurality of blocks wherein the numerical control unit (100) comprises: an allowable inward displacement amount setting unit configured to set an allowable inward displacement amount (I _S ) generated at the corner portion between the blocks; and a corner path generation unit (140) configured to insert the curved movement path with an inward displacement amount (I) not larger than the allowable inward displacement amount (I _S ) into the corner portion between the blocks; wherein the corner path generation unit (140) is configured to generate an estimated inward displacement amount (S) generated when the corner portion is subjected to acceleration / deceleration after the interpolation, based on the radius of curvature of the curve and allowable accelerations of the axes To calculate a machine tool and such a curved new path of movement, so that the inward new offset amount has a value obtained by subtracting the estimated inward displacement amount (S) from the allowable inward displacement amount (I _S ) in the Corner portion between the blocks in the case where the sum of the inward displacement amount (I) of the curve and the estimated inward displacement amount (S) is greater than the allowable inward displacement amount (I _S ).