Mechanical Reconstruction Principles And Methods Of Natural Motor Functions Of Human Hands

Exploring the mystery of human hand motion and reconstructing the natural motion function of human hand by engineering science method is both a hot and difficult problem in the field of human-robot research and a dream of the majority of scientists and technicians.In this thesis,we have conducted a systematic and in-depth study on the basic principles of how to establish the mechanical reconstruction of the natural motion function of human hands,including the exploration of morphological characteristics of human hands and the natural movement law of human hands,the decomposition and reconstruction of biological natural movements,and the underactuated prosthetic mechanisms carrying the natural motion characteristics of human hands.The main research results are as follows:1.On the aspect of the exploration of morphological characteristics of human hands and the natural movement law of human hands: using a multi-eye motion capture system,experimental studies on the morphology and grasping functions of the human hands were carried out to reveal the distribution laws of digits in a human hand and the synergic movement law between digits,and to establish a method for extracting postural characteristics and fingertip position distribution characteristics during natural thumb-finger opposition,and to establish a method for extracting the synergistic movements of the human hand in daily grasping/manipulation tasks.The obtained results provide physiological bases for the design of prosthetic hands that reproduce the natural movements of human hands.2.On the aspect of the decomposition and reconstruction of biological natural movements: a method of extracting the construction characteristics of biological natural movements is proposed;a decomposition model of complex biological natural movements with a characterization method of basic motions such as scaling motion and affine motion is established,and on this basis the theory of reconstructing biological natural motion with limited fundamental motions is proposed,revealing the common laws of biological natural movement construction and laying a theoretical foundation for bionic robot design.3.A method for the design of underactauted prosthetic mechanisms that replicate the natural motion of human hands is proposed.Aiming at the unique feature of thumb-finger opposition movement of human among all primates,a design principle of two-actuated thumb mechanism which can reproduce the flexion/extension and abduction/adduction movement of human thumb is established.Aiming at the postural synergic characteristics in fingers,the thesis builds up a dual-actuated mechanical design theory reproducing synergistic movements of four fingers on the basis of the proposed theory of reconstruction of biological natural movements.The design principle of underactuated prosthetic mechanism is verified experimentally.4.A design theory of compact few-actuated prosthetic hands that reproduce the self-adaptive grasping functions of human hands is developed.A design theory of thumb mechanism with a hybrid actuating scheme — thumb flexion/extension is actively controlled by a motor,and abduction/adduction is manually adjusted — is established.A mechanism design theory of adaptively gripping arbitrary-shape object with drag axis-gear differential mechanism is proposed.A design principle of compact prosthetic hand with few actuators is established to reproduce the self-adaptive grasping functions of human hands.Experiments are carried out to verify the correctness of the theory and method proposed in this thesis.