Method of Shortening Settling Time Using Final State Control for High‐Precision Stage with Decouplable Structure of Fine and Coarse Parts |
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| Authors: | YUMA YAZAKI HIROSHI FUJIMOTO YOICHI HORI KOICHI SAKATA ATSUSHI HARA KAZUAKI SAIKI |
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| Affiliation: | 1. Graduate School of Frontier Science, University of Tokyo, Japan;2. Nikon Corporation, Japan |
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| Abstract: | High‐precision stages require high‐speed and high‐precision control to improve their production throughput and quality. However, their motion speed and accuracy are expected to reach a limit in the near future if the conventional high‐precision stage structure is used. Therefore, the authors designed and fabricated a “catapult stage,” which has a structure that can be decoupled into a fine stage and coarse stage. The catapult stage is different from conventional dual stages in which the fine stage is disturbed by the coarse stage because they contact each other. This paper proposes a novel control system design for the catapult stage and a control method that shortens the settling time by using final state control (FSC). So far, FSC has mainly been used for applications such as hard disk drives, for which the initial states are zero. However, it is important to consider the initial states for the catapult stage because the initial position, velocity, and acceleration of the catapult stage are not equal to zero. Simulations and experiments were performed to demonstrate the effectiveness of the proposed methods. |
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| Keywords: | precise positioning high‐precision stage dual stage settling time shortening final state control |
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