Design And Research Of Wearable Power Assisted Exoskeleton Mechanism

In recent years,exoskeleton robot technology has become a hot field of robot research in today's society.The purpose of its research and development is to reduce the burden of human body and improve the work efficiency of human body.In this paper,the structure design,kinematics and dynamics analysis,structural performance analysis and virtual simulation analysis of the lower limb exoskeleton assist mechanism are carried out.First of all,this paper designs a lower limb exoskeleton power mechanism.By analyzing the movement characteristics of human walking,the space coordinate system of human body and the angle range of lower limb joints are defined.Through the analysis of human walking gait,the movement law of human walking is preliminarily determined.According to the standard of human height,the size of each component of the lower limb exoskeleton assist mechanism is determined.The advantages and disadvantages of hydraulic drive,pneumatic drive and motor drive are analyzed,and the driving mode of lower limb exoskeleton power assisted mechanism is defined.Finally,the structure of each joint of exoskeleton power assisted mechanism is designed based on human bionics,and the 3D virtual model is established with Solidworks.Secondly,the kinematics and dynamics of the lower limb exoskeleton power mechanism are analyzed.Combined with the walking characteristics of human body,through the analysis and comparison of common lower limb exoskeleton assist mechanism models,a seven bar mechanism model is established.The displacement,velocity and acceleration of each joint of the lower extremity exoskeleton and the displacement,velocity and acceleration of the toe and heel at the end of the movement were calculated by geometric analysis method;The velocity Jacobian matrix is calculated,which provides the basis for the dexterity analysis of the lower limb exoskeleton power assisted mechanism;The displacement of the center of mass of each member and the displacement and acceleration of the whole mechanism are calculated,which lays the foundation for the dynamic analysis of the mechanism.The kinetic energy and potential energy of each component of the exoskeleton mechanism and the kinetic energy and potential energy of the whole mechanism are calculated.The energy consumption of the exoskeleton mechanism and the work done by the external force distance are calculated.Finally,the dynamic equation of the lower limb exoskeleton power assisted mechanism and the torque of the lower limb joints are obtained by Newton Euler dynamic balance method.Thirdly,the structure and performance of the lower limb exoskeleton assist mechanism are analyzed.Firstly,the static analysis of the lower limb exoskeleton assist mechanism is carried out,and the displacement and stress deformation of the exoskeleton assist mechanism in standing state,single support phase,double support phase and swing phase are analyzed.Through the ANSYS software,the safety factor cloud of the exoskeleton assist mechanism is obtained,and the safety of the mechanism is analyzed.By improving the size of exoskeleton,the structure is more stable and safe.The transfer accuracy of exoskeleton power assisted mechanism is analyzed,and the dexterity of exoskeleton power assisted mechanism is obtained by combining with velocity Jacobian matrix.The error of the lower limb exoskeleton mechanism is analyzed,and the error mapping matrix and error size are obtained.Finally,the three-dimensional virtual model of the lower limb exoskeleton power assisted mechanism is established in Solid Works software,which is imported into ADAMS software,and the corresponding kinematic pairs and constraints are added to obtain the virtual prototype of the lower limb exoskeleton power assisted mechanism.Input the driving parameters to get the displacement,velocity and acceleration of the lower limb exoskeleton mechanism in different motion process,analyze its motion law,and verify the accuracy of kinematics and dynamics equations.