Research On Prosthetic Hand Based On Tendon Actuation Approach

New-type of multi-DOF prosthetic hands are developed with the tendencies of high humanoid, minitype, low weight, high reliability, using convenience. Based on the project of national high-tech research and development program of China (863 program)"Research on multi-DOF prosthetic hand mechanical structure and its autonomous control", a novel multi-DOF humanoid prosthetic hand is presented. The hand is composed of five fingers, and each finger can be actuated independently. The human-like motion of the thumb, including the adduction, abduction and the flexion movements, can be realized by single-motor-actuation. The appearance of the prosthetic hand is very similar with a nature hand. Its size is slightly smaller than the adult hand, and its total weight is 350 gram. It can grasp various objects with adaption to their shapes.In this thesis, the status of prosthetic hand research is introduced, the skeletal anatomy and grasp type of human hand are analyzed. Based on the study and comparation between the typical mechanisms used in prosthetic hand finger, the under-actuated and tendon transmission scheme is adopted. Then, the detail structure design of fingers, wrist, humanoid appareance and arrangement of fingers are introduced. The simulation of the grasp motion is made in computer, then the finger motion pattern and grasp capability are verified through the prototype experiment.The kinematic characteristic of prosthetic hand finger is analyzed. By comparing the movement of natural finger, the motion of robot finger is optimized to mimic the natural finger and extend the work space. The static model is established based on the virtual work principle, contact forces of phalanges are studied, and the contact force law is testified through ADAMS.The dynamic analysis method for typical tendon transmission mechanism—tendon-pulley mechanism is studied, and the method is applied to investigate prosthetic finger. Dynamic model of the finger is built, and the equations are derived. Finally, the result is proven according with the simulation by numerical calculation.