Numerically controlled feeding apparatus having feeding error correcting system

A numerically controlled feeding apparatus having at least two linear feeding devices having intersected feeding directions for performing a numerical feeding control in a feedign space defining a plurality of feeding areas on the basis of an instruction value representing a desired feeding position, comprising:

• memory means for storing representative correction vectors for representative instruction values indicating a predetermined number of reference feeding positions in the feeding space, each representative correction vector having information on deviation amount and deviation direction between a reference feeding position indicated by each of the representative instruction values and a real feeding position corresponding to each of the representative instruction values, the deviation amount and deviation direction being indicative of an error of each said linear feeding device caused by at least one component of a feeding error of the other feeding devices;
• correcting means for calculating a correction vector for an instruction value indicating any desired feeding position on the basis of a correction vector group of representative correction vectors for representative instruction values indicating plural feeding positions located in adjacent feeding areas of the desired feeding position, the correction vector group being read out of said memory means, and the instruction value indicating the desired feeding position, thereby to obtain a corrected feeding amount;
• and
• control means for controlling a feeding operation of said linear feeding devices on the basis of the corrected feeding amount.