2017 年 83 巻 848 号 p. 16-00512
Parallel magnetic suspension has been proposed which levitates multiple floators with a single power amplifier. This study applies this concept to a multi-degree-of-freedom system. In such systems, multiple electromagnets are used to stabilize multi-degree-of-freedom motions of the floator. In conventional system, each electromagnet is driven by the corresponding power amplifier. In contrast, multiple electromagnets are driven by a single power amplifier simultaneously in the case of parallel magnetic suspension. This study shows the feasibility of multi-degree-of-freedom control with a single power amplifier. First, the controllability of two-degree-of-freedom system controlled by parallel magnetic suspension is discussed. Second, an experimental apparatus is fabricated in which the vertical translational motion and the rotational motion around a horizontal axis are controlled by two pairs of electromagnets operated in a differential mode. Third, stable levitation is achieved in the apparatus. In addition, the dynamic characteristics are evaluated based on step response and frequency response with respect to external force. It is observed that the two suspended points vibrate in common phase with respect to the disturbance in a low-frequency region.