Design And Development Of Lightweight And Multiple Degree Of Freedom Upper Limb Prosthetics

The number of amputees in China is large because of factors such as traffic accidents,work-related injuries and natural disasters.In order to restore the health,improve the ability of life self-care,and return to basic social work,the installation of artificial limbs,especially lightweight and multiple degrees of freedom upper limb prosthesis is urgent for amputees.But most of the current domestic research and design of upper limb prosthetics stays on the basis of the traditional artificial limbs,which can only provide single degree of freedom of movement function and even with only adornment effect.A few degrees of freedom upper limb prosthesis with complicated structure and large size could not match the size of actual human arm,which even increases the the patient's physical burden,thus it is important to develop a lightweight,multiple degrees of freedom upper limb prosthesis.This paper studies a kind of lightweight and multiple degrees of freedom upper limb prosthesis to meet the needs of most amputees,which has lower quality,man-like shape and enough functionality to meet the requirements of the amputees.Firstly,fully understanding the hot and difficult points in the design of upper limb prosthesis by analyzing the existing domestic prosthesis mainstream products.Recognizing that the upper limb prosthesis is primarily a single degree of freedom prosthesis and there is no mature shoulder prosthesis.The study is carried out for the light quantification design.Secondly,analyzing the physiological parameters and motion of the upper extremity of the body,which is used as the basis for the design of upper limb prosthesis.After confirming the artificial limb movement function,the method of joint distribution of limb prosthesis is designed,and the design requirement of the size and range of the upper limb prosthesis is proposed.Thirdly,building a three-dimensional modeling of limb prostheses and selecting the appropriate drivers.Adopting differential mechanism to realize the compact requirement.According to the design requirement of light quantification,the traditional gear transmission is replaced by a rope drive.The DC servo motor with the planetary gearbox is chosen as the driving mechanism.In the design process,the important structural parts of upper limb prosthesis are also verified and the effect of bending stiffness on rope drive are analyzed.Fourthly,in order to realize the intelligent control of upper limb prosthesis,the kinematics of prosthesis are analyzed.The D-H coordinate system are established based on the structure of the upper limb prosthesis and the forward kinematics analysis are completed.The inverse kinematics analysis of prosthesis are carried out by geometric method and iterative method.Also,the work space of the prosthesis are solved by Monte Carlo method.Finally,the control system for upper limb prosthesis are designed and the joint test and the basic motion test of the upper limb prosthesis are completed.The experimental results satisfy design requirement.