High-Speed Positioning Method for Fine Motion Mechanism Using a Piezo Element.

The piezo element as a representative displacement type actuator elicits a high-speed response in comparison with the electromagnetic motor. Recently, there has been much research carried out using this feature. However, most of the studies are aimed at realizing higher precision, while there is very little research regarding high-speed. When the positioning mechanism is given, improvement of the positioning performance is entrusted to the feedback loop. At this point, we expect that some methods are prepared in order to improve the positioning performance, because an optimal method can be selected under an actual constrained condition. When we try to realize higher positioning via the feedback loop, we can enumerate technical items, such as realization of the high-speed drive amplifier, optimal tuning of the compensator, and the tuning degree of freedom extension by adding a minor loop. In this paper, these engineering techniques are summarized.