Joint Design Of A Compound Drivd Prosthetic Arm

Communion refers to the mechanical itself and the interaction between people and the environment,good communion characteristics of the mechanical device can cooperate with people to complete a lot of action,and can guarantee the safety of work.The prosthetic arm,as a supplement to the lack of human motor function,interacts with other objects in the environment,requiring it to have good communion properties.Unlike conventional mechanical devices,prosthetic arm movements with cohesive properties should be flexible,and because of the particularity of the movement of the arm,it is necessary to be able to stabilize the motion accuracy.To solve the problem,this paper designed a compound drived prosthetic hand based on shape memory alloy spring,and did further study in the following aspects:(1)Study the current history of the development of prostheses home and abroad,the status quo and future trends,summed up the current research and development of prosthetic arm hot and difficult,observe new materials,new institutions in the application of prosthetic arm,conduct depth work in mechanism and characteristics of shape memory alloy driven system.(2)Analyze the skeletal and muscle structure of the human arm,study the muscle composition and mechanism of the human elbow joint,the structure and function of the wrist and the finger-driven structure,and use the memory alloy and motor compound drive to simulate the movement of the elbow muscles So that the joints in the promotion of the drive performance at the same time with the characteristics of the cohesion;design of a magnetically controlled shape memory alloy clutch two degrees of freedom wrist joints,so that the joint flexibility in the basis of flexibility to simplify the structure;Drive the way,with the memory alloy spring to drive the movement of the fingers.(3)The factors influencing the mechanical properties of the memory alloy spring were analyzed,and the semi-flexible driving model of the composite elbow was established.The kinematic simulation of the elbow joint was made by ADAMS.The equivalent force of the magnetron shape memory alloy in the two degrees of freedom Learning model,according to the relationship between the two degrees of freedom of the joint movement of the relationship between the speed of movement;the establishment of multi-fingered dexterity of the static model,analysis of the object when the joints of the force of the situation,The size of the force,according to the stiffness of the return spring to determine the movement of the order of the dexterous hand ADAMS motion simulation.(4)In order to achieve stable and precise control,the speed control method commonly used in DC motor is summarized,and the simulation model of speed control system is established in SIMULINK.The temperature control strategy of temperature control shape memory alloy is determined to increase The life of the spring and the corresponding speed at the time of work.The memory alloy-motor compound control mechanism is established to realize the optimization of the control characteristics of the composite drive joint and enhance its covariance Special characteristics.In this paper,the mechanical structure design of the new compound driven prosthetic arm based on the shape memory alloy is completed.The corresponding mathematical model is established.The kinematics analysis of the elbow joint and the finger is carried out.The control strategy of joint movement is made,Finger model to verify the memory alloy drive in the use of artificial limbs feasibility,for the follow-up study of the integration of the robot provides a basis.