HAG-SR hand: Highly-anthropomorphic-grasping under-actuated hand with naturally coupled states

Abstract

Three key requirements are needed in hands: humanoid appearance and self-adaptation in grasping; simple and low in cost; recoverability function allowing touch from unexpected directions. Most of dexterous hands could not obtain these characteristics. This paper proposed a novel under-actuated finger with highly-anthropomorphic-grasping (HAG) function. A hand with HAG function, called HAG-SR Hand, is developed. The HAG-SR Hand could achieve these characteristics perfectly. Each finger in the HAG-SR Hand has HAG function, and is actuated by only one motor embedded in the first middle phalanx. Analysis and Experimental results show that the HAG-SR Hand is most perfect under-actuated hand compared with traditional all kinds of under-actuated fingers (coupled, self-adaptive or hybrid under-actuated fingers): the HAG finger is more human-friendly for the following three key reasons: firstly, the operating of HAG finger is easy to master as its working process is similar to the human finger's; secondly, the finger can self-adapt objects of different shapes, thus power grip can be realized well; thirdly, the finger's coupled states are recoverable, which reduces the possibility of hurting people when working. © 2012 Springer-Verlag.