Design And Simulation Of Passive Wearable Lower Limb Exoskeleton

With the aging of population in our country and the deterioration of lower limb motor function caused by different degrees of injury,which has seriously affected people’s quality of life.In recent years,wearable lower limb exoskeleton,as a kind of equipment to assist human daily walking,has gradually become a research hotspot,which brings a lot of convenience to people’s life.Therefore,this paper designed a lightweight and comfortable passive lower limb exoskeleton device that can effectively enhance the wearer’s motion ability.The main research contents are as follows:On the basis of anatomical theory,the physiological structure and joint movement mechanism of human lower limbs were studied deeply.In order to better adapt to the physiological characteristics of human body,the size parameters of exoskeleton were determined according to the Chinese adult size standard.The gait characteristics of lower limbs were analyzed,the normal walking process of human body was simulated by Opensim,and the law of the changes of the angles of each joint with time was obtained.According to the biomechanical model of lower limb,the stress of lower limb bones under the action of muscles and ligaments was analyzed.Based on the finite element analysis method,a finite element model of human lower limb bones was constructed that is close to the actual physiological state of the human body,clarifying the biomechanical characteristics of lower limb bones In order to simulate muscle and ligament constraints,finite element models of lower limb bones under different passive spring combination mechanisms were established,and the changes of stress and deformation were analyzed.The optimal combination scheme was obtained to achieve better wearing experience and power assisting performance of lower limb exoskeleton.Based on the principle of structure design,the mechanical structure of the lower limb exoskeleton was modeled in three dimensions.Finite element modeling and static mechanics analysis were carried out for the exoskeleton in the standing phase,the double leg supporting phase,the single leg supporting phase and the swinging phase,and the mechanical structure safety was verified.The kinematics modeling and workspace analysis of lower limb exoskeleton were completed based on D-H parameters,and the human-exoskeleton compatibility was verified.In order to realize the lightweight of lower limb exoskeleton,the topology optimization design of main parts was carried out,and the strength of the optimized parts was verified.Based on the virtual prototype simulation platform,a collaborative walking simulation analysis was conducted on the human exoskeleton dynamics simulation model to obtain the dynamic characteristic parameters of the hip,knee,and ankle joints.The simulation results verified the smoothness and human-machine compatibility of the lower limb exoskeleton movement.The physical prototype was developed,and the human-exoskeleton collaborative walking experiment was carried out,which proved that the exoskeleton could provide stable support and safety guarantee for users,and verified the feasibility and effectiveness of the passive lower limb exoskeleton.