| 摘要 |
PROBLEM TO BE SOLVED: To provide an XY stage capable of ensuring effective ripple reduction effect at a cogging frequency or a ripple frequency beyond a control band. SOLUTION: In the XY stage, a slider is controlled to be moved in an X-axis direction and a Y-axis direction by alternating current signals supplied to an X axis motor and a Y axis motor, and ripple caused by a disturbance thrust generated in the slider is suppressed by a disturbance compensation signal calculated based on commutation phase angles of the alternating current signals corresponding to X-axis and Y-axis positions. The XY stage is provided with a computing means estimating and computing a second parameter value at a frequency above a constant control band based on a first parameter value giving the disturbance thrust compensation signal at a frequency within the control band of the slider and a switch means calculating the cogging frequency or the ripple frequency of the slider to switch the first parameter value to the second parameter value when the frequency is a predetermined value or more. COPYRIGHT: (C)2008,JPO&INPIT
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