HIT/DLR仿人假手拇指机构的研究

为了使假手在外观和抓握方式上更加仿人化，基于欠驱动原理系统地设计了仿人假手的拇指．它由一个电机驱动，2个关节组成．其设计和以往假手的拇指有较大的不同：倾斜于手掌放置，其电机、带轮和谐波减速器全部嵌入在手掌内部；可以在抓握时沿空间上一锥面运动；将欠驱动原理在手指的运用上，从平面运动拓广到空间的运动．这使得假手拇指在外型和运动方式上和人的拇指极其相似．并对拇指的空间连杆机构进行了运动学分析，以确定其结构参数．实验表明，所设计的仿人拇指和人的拇指极其接近，并且在抓握时和其他手指配合，具有很强的自适应能力，能够实现对复杂物体的包络、精确抓握和力量抓握．使该假手更加美观、仿人、实用．

Thumb mechanism of HIT bio-prosthetic hand

To make the prosthetic hand more like hand,the thumb hand has been designed systematically on the basis of the underactuated mechanism.The thumb is integrated by two joints,and actuated by one motor.The designation of the thumb is much different from previous prosthetic hand: 1) It is placed tilted on the hand,and its motor,synchronous pulleys and harmonic gear are embedded in the palm;2) It can move along a cone surface;3) In the application of underactuated mechanism,the planar finger motion is extended to three-dimensional space.These make the thumb wondrously resemble human thumb.The kinematics of the thumb spatial linkage is analyzed to decide structural parameters.It is verified from experimentation that the thumb possesses great capacity of self-adaptation,and can accomplish accurate and power grasp.This makes the hand more handsome and practical.