Development and experimental study of a bio-inspired anthropomorphic robotic hand with human-hand-like biomechanical advantages and performance

Abstract

Human hands are versatile and capable of dealing with a mass of daily activities. Exploring their fundamental biomechanical features residing in the anatomical structures and applying them to the robotic hands has proven to be an effective approach to enhance the practical performance, however, has been a challenge all along. The obstacles exist not only in replicating the human-hand-like anatomical structures by using present technologies in fabrication and materials but also in the lack of investigation on the biomechanical principles of human hands. Thus, the overall aim of this project was to develop a novel highly biomimetic robotic hand with human-hand-like structures, biomechanical advantages as well as grasping and manipulation capabilities. The framework of this research included three stages: (1) design and fabrication of a multi-layered anthropomorphic robotic hand, (2) analysis of three underlying biomechanical advantages that exist in the human-hand-like structures by using mathematical models and experiments, (3) tests of the grasping and manipulation capabilities of the proposed robotic hand with the customized actuation system and control strategies. The design of the robotic hand highly mimicked the human hand features in terms of the morphological structures and the material properties. The human hand bones, ligaments, joint capsules, tendon sheaths, tendons and the skin were all replicated on the robotic hand. Subsequently, three biomechanical properties were investigated through theoretical analysis and experimental verification. Both the theoretical and experimental results show that the variable joint stiffness was obtained with the ligamentous joint structures, the feasible force space was enlarged by the reticular extensor compared with the linear extensor, and the fingertip force-velocity workspace was augmented by the flexible tendon sheaths compared with the rigid tendon sheaths. Finally, the grasping and manipulation tests were conducted in both robotic finger and robotic hand models. The result showed the robotic finger performed a comparable grasping success rate with the human fingers in all the five target objects and three interaction surfaces. For the robotic hand, a 24 motors actuation system was built and the data glove-based position control strategy was developed. The grasping result showed that 16 grasp types in Cutkosky taxonomy and 33 types in Feix taxonomy were all accomplished. Besides, the robotic hand also successfully performed the dynamic grasping capability. In addition, six common manipulations in daily lives were tested on the prototype, which were all completed. The results showed the human-hand-like grasping and manipulation capabilities, to a certain extent, were realized on the proposed robotic hand. From another aspect, the bio-inspired rigid-flexible coupled robotic hand combined the advantages of the rigid robotic hand (good manipulability) and the soft robotic hand (good grasping capability).

Date of Award	1 Aug 2022
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Zhenmin Zou (Supervisor) & Lei Ren (Supervisor)