Structure design and experiment of multi-finger dexterous hand based on underactuated principle

SONG Zhen-dong1, LI Gang2, WU Tong2, WANG Yu-juan3, HE Yuan-yi2
(1.School of Mechatronic Engineering, Shenzhen Polytechnic, Shenzhen 518055, China; 2.Center Research
Institute, SIASUN Robot & Automation Co. Ltd., Shenyang 110169, China; 3.Education Center of
Experiments and Innovations, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China)

Abstract: Aiming at the problems of the traditional multi-finger dexterous hand, such as many driving sources, complex structure, high heat and short life caused by the driving motor in the process of grasping; at the same time, it was unable to accurately perceive the position and pose of the target object and exert reasonable grasping force, so that the finger structures, system configuration and sensors of the dexterous hand were studied. A multi-finger dexterous hand with underactuated and self-locking characteristics and a tendinous transmission structure with different bearing capacity were proposed. The system configurations of two-finger, three-finger and five-finger dexterous hands were designed. A high sensitivity, low-cost one-dimensional force sensor and a touch sensor were developed. Taking the three-finger dexterous hand as an example, the experimental prototype was processed, and relevant experiments were carried out with the experimental prototype. The results indicate that the finger structure of the dexterous hand can effectively reduce the number of driving sources and realize the weight reduction of the mechanism. By changing the tendinous transmission mechanism, the dexterous hand can bear different loads with better safety and reliability. The one-dimensional force sensor and tactile sensor have higher sensitivity, accuracy and low cost characteristics. The dexterous finger has higher repeated positioning accuracy and can achieve stable and reliable grasping tasks of various objects with different shapes.

Key words: multi-finger dexterous hand; structure design; underactuated finger; tendinous transmission structure