Development of an Inchworm-type 6-DOF Positioning Device

尺蠖是一种具有无限工作面积和小位移的装置。压电致动器（piezo）实现一微米或更小的变形。为了加工自由曲面，需要六个自由度（6-DOF）的定位装置; 3-DOF用于直线运动，3-DOF用于旋转运动。所开发的定位装置是基于尺蠖的六足机器人。它由六个压电和六个电磁铁。六足机器人中的线性滑块被叠层式压电元件所取代。六个电磁铁被放置在两个压电之间。底部的三个电磁铁接触底座，其他三个支撑一个平台。利用半球平台实现了往复运动。电磁铁的激励和压电元件的变形由所需的运动决定。获得了5 μ m的线性位移和1.3mrad的倾斜。当施加40 g载荷时，角度减小到0.6 mrad。负载特性取决于电磁力。

An inchworm is a device which has unlimited working area with small displacement. A piezoelectric actuator (piezo) realizes one micron or smaller deformation. In order to manufacture free-form surface, six degree-of-freedom (6-DOF) positioning device is required; 3-DOF for linear motion and 3-DOF for rotational motion. The developed positioning device is an inchworm based hexapod. It consists of six piezos and six electromagnets. The linear slides in the hexapod are replaced by the stacked-type piezos. Six electromagnets are placed between two piezos. Three electromagnets at the bottom touch the base, and the other three support a platform. Tilt motion is obtained by a hemisphere platform. The electromagnets' excitation and the piezos' deformation are determined by the desired motion. The 5 um linear displacement and 1.3 mrad tilt were obtained. The angle reduced to 0.6 mrad when the 40 g load is applied. The load characteristic depended on the electromagnetic force.