Positioning control method

A positioning control method in which an object is accelerated up to a target velocity VS, and then decelerated, to thereby perform position control of the object at a position that is a predetermined distance YS away from an original position of the object, by providing an output pulse of a frequency corresponding to an instructed velocity Vp to the object, comprising:

• a deceleration-start distance calculation step of executing processing for obtaining a deceleration-start distance YSd, being a distance until deceleration of the object is started, and being a sum of an integer part YSdq of the deceleration-start distance and a decimal part YSdr of the deceleration-start distance, separately for each of the integer part YSdq and the decimal part YSdr, with the integer part YSdq being in a unit of one pulse of the output pulse, and the decimal part YSdr being in a unit of 1/D1 pulse, when a control frequency is denoted by fc, the minimum velocity of the output pulse is denoted by 1/n, the number of seconds is denoted by n, and D1=fc×n, before executing acceleration control of the object;
• and
• a deceleration-start point judgment step of judging a point in time when a value obtained by counting the output pulse becomes equal to or greater than the integer part YSdq, and the result of addition θ1 obtained by adding a velocity set value (VP×n) for each 1/fc time becomes equal to or greater than the value YSdR obtained by rounding off the decimal part YSdr to the nearest integer, after the object is acceleration-controlled, as a deceleration start time, and controlling the object to start deceleration from the point in time judged.