The Design And Mechanism Optimization Of The Exoskeleton Robot With The Help Of Lower Limbs

In recent years,the problem of aging in China is becoming more and more serious,among which,the number of people who are affected by lower limb movement due to normal aging is increasing,and a large number of people are affected by the lack of lower limb strength due to various diseases.In this context,the walking aid robot for the lack of lower limb strength has become a research hotspot.In this paper,aiming at the deficiency of traditional exoskeleton,a weight supported exoskeleton walking aid robot for lower limbs is proposed.In the process of walking,on the one hand,it provides the support force pointing to the wearer’s center of gravity,and achieves the purpose of assisting walking by reducing the "burden" of weight on each joint of lower limbs;on the other hand,it provides leg lifting assistance to assist the wearer to achieve leg walking.In this paper,the structure design,system dynamics,mechanism optimization and prototype test of the system are studied.The degrees of freedom of the joints of the lower limbs,the size and length of each part of the lower limbs and the inertia parameters are analyzed and studied,which provides the basis for the design of the lower limb exoskeleton.The simplified model of human body is established,the moment expressions of hip joint and knee joint are deduced by Lagrange equation,the joint moment of human body is calculated by MATLAB software,and the moment change curve of hip joint and knee joint is obtained.According to the moment change curve,the best assisting stage and the most needed assisting joint of walking are analyzed.This paper analyzes the force of human body in the process of walking,and draws the conclusion that reducing the force of human body on the ground can reduce the internal force of human body’s lower limbs.From the perspective of the way of power assistance,the preliminary design of the body structure of the lower limb exoskeleton is made,and a kind of lower limb walking exoskeleton robot with less binding weight support is proposed,which can reduce the binding on the wearer and greatly improve the comfort of wearing Suitability.The strength and rigidity of the mechanism are checked to ensure the safety of the robot.The simplified model of human-machine system is established,the dynamic analysis is carried out,and the dynamic equation is derived.ADAMS software is used to simulate the walking of the system,and the torque change curve of each joint of the lower limbs is obtained.Compared with the theoretical calculation results of the robot without the lower limb walking aid,the results show that the robot with the lower limb walking aid can reduce the joint force in the walking process Moment,the leg walking exoskeleton robot has a certain assistance effect,but the walking cycle has been extended.Based on the dynamic analysis,the optimization model is established to optimize the leg length of the lower extremity walking exoskeleton robot,and the topology of other key components is optimized.After optimization,the overall mass of the lower extremity walking exoskeleton robot is reduced,and the assistance effect is significantly improved.Compared with the same kind of exoskeleton,the assistance effect is ideal.The walking experiment of the prototype is carried out,and the corresponding experiment is designed from the perspective of wearing comfort,actual assistance effect and follow-up.By analyzing the experimental data,the wearing comfort of the lower limb walking exoskeleton robot is verified,and the actual assistance effect and system follow-up are good.