Research on a Magnetic Levitation system by a new electromagnetic Transducer Element using Giant Magnetostrictive and Piezoelectric Materials

研制了一种由超磁致伸缩材料和压电材料两种功能材料组成的磁电复合元件，用于无线圈磁力控制。这种力的控制是基于磁致伸缩电机的逆磁致伸缩效应，通过在磁轭中加入永磁体组成一个闭合的并联磁路来实现的。通过控制磁致伸缩杆的应变，可以调节两轭之间的磁力。为了有效地控制超磁致伸缩杆的应变，构建了一种磁电复合元件，将超磁致伸缩杆和堆叠压电致动器两种功能材料通过应变进行机械耦合。通过调节压电驱动器的电压，可以控制GMM棒内的磁化强度。结果表明，该元件具有调节磁力的作用，具有较宽的频率带宽。作为该元件的应用，提出了一种磁悬浮系统，并通过简单的PD控制实现了活动磁轭的悬浮。与传统的电磁线圈系统相比，该系统具有功耗低、发热量低的优点。

A magneto-electric composite element of two functional materials: giant magnetostrictive (GMM) and piezoelectric materials, is developed for coil-less magnetic force control. This force control is based on the inverse magnetostrictive effect of GMM and realized by composing a closed parallel magnetic circuit with a permanent magnet in magnetic yoke. The magnetic force between two yokes can be adjusted by controlling the strain in the magnetostrictive rod. For the purpose of efficiently controlling the strain of the GMM rod, a magneto-electric composite element is constructed, in which the two functional materials: a giant magnetostrictive rod and a stack piezoelectric actuator, are mechanically coupled via strain. The magnetization in the GMM rod can be controlled by adjusting the voltage of the piezoelectric actuator. It is confirmed that this element works to adjust magnetic force and has wide frequency bandwidth. As an application of this element, a magnetic levitation system is proposed and the movable yoke was levitated by simple PD control. This system has advantages of low power consumptions and low heat generation compared with a conventional system with electromagnetic coils.