Research And Design Of A New Type Of Variable Stiffness Humanoid Elbow Joint

Robotic technology has reached a high level over the past century.And the application of the robots is so mature that industrial robots have been used in most factories.The traditional industrial robots are rigid in order to achieve high accuracy and large bearing load capacity.However,the industrial robots cannot be applied in complex environments due to the limitation of the rigidity.Now the robotic technology is not limited to use in the industry,and it is used in health care,service,entertainment and other fields.So it is necessary for robotic technology to meet new requirement of application by adjusting the joint stifness.Variable stiffness joints are designed to overcome the defects of the traditional robots.In this thesis,a variable stiffness joint is proposed to mimic the human elbow.The joint stiffness is varied by changing the effective length of the leaf spring.The prototype of the joint is manufactured.The new joint can connect a mechanical hand to a robot in order to assemble a whole mechanical arm that is similar to a human arm shape.The main research contents of this thesis are as follows.1)Based on the relevant references,the present development of variable stiffness joints at home and aboard is studied,and the comparisons of the structural properties of the existing joints are carried out.2)The variable stiffness principles and the configurations of the variable stiffness joints are researched.According to the analysis of the principles,a variable stiffness principle is used to design a new joint,and the kinetic characteristic is analyzed.3)A new humanoid variable stiffness elbow joint is designed,mainly including transmission,fixed base and the variable stiffness mechanism.3D model of the new joint is established.The overall layout is analyzed.The structure is also optimized.4)The new variable stiffness joint is modeled and simulated by using Adams and ANSYS.The system dynamics model is established to verify the kinetic and dynamic characteristics of the variable stiffness mechanism.5)The prototype of the new joint is manufactured and assembled.The parameters of the prototype are obtained.The performance of the joint is verified by the experiment.