SMA驱动的模块化仿人手指设计与研究

采用模块化的欠驱动手指结构设计,形状记忆合金丝作为驱动器,永磁铁装置提供预拉紧和复位功能,使得SMA驱动器的输出力比弹簧预紧提高了6 N以上.通过驱动位移放大滑轮,使SMA驱动器的输出位移增大了2.1倍.最后,通过3D打印技术打印手指模型并组装了单根手指,实现了对日常用品的抓取操作.本研究有效解决了SMA驱动器驱动位移小、预拉伸和输出力相矛盾的问题,为形状记忆合金材料作为仿生驱动装置的应用提供了设计思路.

Research and Design on Modular Humanoid Finger with SMA Actuator

Modularized underactuated mechanical fingers are designed.For the actuator， SMA(shape memory alloy) wires are adopted， and permanent magnet devices are also used as the source of pre-stretching and restoring forces. This novel design increases the SMA output force for over 6N more than the conventional SMA actuators， in which bias springs are adopted as the pre-stretching elements. A pulley system is also developed for amplifying the displacement output capacity of the actuator by 2.1 times. The mechanical fingers are fabricated by 3D printing technology， and general grasping experiments are carried out with daily commodities. This paper proposes the method for resolving the conflicts among the displacement output capacity， the pre-stretching force and the output force. The achievements will facilitate the further application of the SMA materials in biomimetic actuating fields.