| Passive power-assisted exoskeleton is a wearable mechanical device that supports the wearer’s weight and aids the body’s movement.Traditional active drive-assisted exoskeleton is limited by battery technology and cannot be worn continuously for long periods of time,affecting practical applications outdoors.Passive exoskeleton using lightweight design,without the help of external energy,relying on exoskeleton mechanical structure and the principle of human weight bearing to achieve mobility assistance to the human body,with light,easy to wear,long-term use and other advantages,but passive exoskeleton still has the problem of leg support and comfort.By optimizing the design of the support of passive exoskeleton knee joint and the comfort of size leg structure,this paper aims to reduce the wearing burden and discomfort of exoskeleton legs and improve the support of exoskeleton knee joints during walking,so as to improve the power-assisted performance of passive exoskeleton for long-term weight-bearing use.According to the anatomical characteristics of the lower limbs of the human body,the lower limb movement information of the weight-bearing walking of the human body,the human-machine coordination of the exoskeleton lower limbs and the wearing comfort analysis,and the passive power-assisted exoskeleton knee joint and upper and lower leg structures are proposed for joint support and wearing comfort.Design scheme.First,a self-locking six-bar knee joint structure of the exoskeleton during the support period was designed to solve the problem of insufficient leg support during the passive assisted exoskeleton walking.According to the trajectory information of the lower extremity joints of the human body,the optimal method is used to design the exoskeleton knee joint six-bar linkage mechanism,so that the exoskeleton leg movement can be as close as possible to the normal gait leg movement of the human body.The self-locking of the six-bar linkage mechanism is used to realize the angle locking of the exoskeleton knee joint during the walking gait support period,thereby improving the support of the passive exoskeleton to the human body during weight-bearing walking,and reducing the burden on the human joints.Then,in view of the long-term wearing comfort of the exoskeleton,a semi-wrapped exoskeleton structure with enhanced heat dissipation was designed.Through the threedimensional scanning of the human leg,the exoskeleton semi-wrapped large and small structure that fits the human leg surface is designed to reduce the human-machine interaction force when the exoskeleton is worn.The thermal infrared images of the legs collected before and after exercise are used to obtain the thermal comfort sensitivity distribution of the human legs,so as to establish the thermal comfort evaluation model of the exoskeleton on the human legs,and optimize the thermal comfort topology design of the exoskeleton and legs,so that the leg semi-wrapped structure has good air permeability,so as to achieve the best leg comfort when the human body wears the exoskeleton.Finally,the design of the passive power-assisted exoskeleton leg and the realization of the overall structure are introduced,and the strength analysis and functional analysis of the exoskeleton knee joint structure and the semi-wrapped structure of the upper and lower legs are carried out. |
