Positioning control apparatus and method capable of reducing relative position error without increasing gain and frequency band of transfer characteristics of control system

Abstract

A positioning control apparatus for controlling a moving member to trace the position of a target member which almost equally repeats the position shift at a predetermined period comprises a position detector for detecting a relative position error, a first adder for adding a delay signal and a position error signal, a signal delay unit for outputting the delay signal which is obtained by delaying an output signal of the first adder at a period corresponding to the position shift of the target member, a second adder for adding the position error signal and the delay signal, a third adder for adding an output of the second adder and the delay signal via a filter, a compensating unit for performing the compensation for offset and/or the compensation for stabilization of the positioning control apparatus based on an output of the third adder, a drive unit for driving the moving member based on an output of the compensating unit, and a delay-amount setting unit for setting the amount of delay of a signal delayed by the signal delay unit.