Design And Analysis Of A Passive Knee Assisted Exoskeleton

Based on the study of ergonomics and the characteristics of human lower limb gait,this paper proposes a unpowered exoskeleton device which can produce a power assist effect at the knee joint.According to the characteristics that energy generated by elastic deformation in the process of movement can be stored and released immediately,it is used to compensate the energy loss during the negative work of lower limbs,to achieve the purpose of reducing human metabolic energy,so as to improve human walking durability and load-bearing capacity.The main research work and achievements of this paper are as follows:(1)Ergonomic characteristics of knee assisted exoskeleton.Physiological characteristics of the knee joint were analyzed based on anatomical principles,and the lower limb kinematics model was established based on D-H method and biomechanical analysis was carried out.At the same time,Vicon motion capture system and three-dimensional scanning technology were used to obtain the relevant parameters of the knee joint,which laid a foundation for the subsequent device design.(2)Design of knee assisted exoskeleton.Considering the factors of function realization,safety and feasibility,the energy storage unit selection,structure design and finite element simulation of important parts of the knee assisted exoskeleton device were completed.(3)Dynamic analysis and man-machine coupling verification.Based on Lagrange modeling method,the dynamics model of human lower limbs was constructed from the perspective of system energy and the joint torque was solved by Matlab.The model of exoskeleton prototype was input in Adams environment,and the joint torque curve was obtained through simulation analysis.Comparative analysis shows the correctness of the model and the effectiveness of the prototype design.(4)Experimental verification and analysis of knee assisted exoskeleton.Based on 3D printing and machining,a prototype of knee assisted exoskeleton was made.Experiments were conducted with Nokov motion capture system and Delsys wireless surface electromyography testing equipment to verify the effectiveness of the exoskeleton assisted device.