Zarate Juan Jose, Shea Herbert
IEEE Trans Haptics. 2017 Jan-Mar;10(1):106-112. doi: 10.1109/TOH.2016.2591951. Epub 2016 Jul 19.
We present the design, fabrication, characterization, and psychophysical testing of a scalable haptic display based on electromagnetic (EM) actuators. The display consists of a 4 × 4 array of taxels, each of which can be in a raised or a lowered position, thus generating different static configurations. One of the most challenging aspects when designing densely-packed arrays of EM actuators is obtaining large actuation forces while simultaneously generating only weak interactions between neighboring taxels. In this work, we introduce a lightweight and effective magnetic shielding architecture. The moving part of each taxel is a cylindrical permanent magnet embedded in a ferromagnetic pot, forming a pot-magnet. An array of planar microcoils attracts or repels each pot-magnet. This configuration reduces the interaction between neighboring magnets by more than one order of magnitude, while the coil/magnet interaction is only reduced by 10 percent. For 4 mm diameter pins on an 8 mm pitch, we obtained displacements of 0.55 mm and forces of 40 mN using 1.7 W. We measured the accuracy of human perception under two actuation configurations which differed in the force versus displacement curve. We obtained 91 percent of correct answers in pulling configuration and 100 percent in pushing configuration.
我们展示了一种基于电磁（EM）致动器的可扩展触觉显示器的设计、制造、特性表征及心理物理学测试。该显示器由一个4×4的触觉像素阵列组成，每个触觉像素都可以处于凸起或降低位置，从而产生不同的静态配置。在设计密集排列的电磁致动器阵列时，最具挑战性的方面之一是在获得较大驱动力的同时，仅在相邻触觉像素之间产生微弱的相互作用。在这项工作中，我们引入了一种轻量级且有效的磁屏蔽架构。每个触觉像素的移动部分是一个嵌入铁磁罐中的圆柱形永久磁铁，形成一个罐式磁铁。一组平面微线圈吸引或排斥每个罐式磁铁。这种配置将相邻磁铁之间的相互作用降低了一个多数量级，而线圈/磁铁之间的相互作用仅降低了10%。对于间距为8mm、直径为4mm的销，使用1.7W功率时，我们获得了0.55mm的位移和40mN的力。我们在两种驱动力与位移曲线不同的驱动配置下测量了人类感知的准确性。在拉的配置中，我们获得了91%的正确答案，在推的配置中获得了100%的正确答案。
