Design Of Lower Limb Rehabilitation Exoskeleton Based On Dynamic Solution

In recent years,the number of patients with diseases such as Multiple sclerosis,Parkinson’s disease who have lost control or complete motor function of their lower limb muscles is increasing.This situation can limit the patients’ mobility and even result in complete loss of it.To meet the rehabilitation needs of these patients,more and more scholars are paying attention to the research and development of lower limb rehabilitation exoskeletons.Lower limb rehabilitation exoskeleton is a device for the rehabilitation treatment of patients with lower limb movement disorders,which helps patients to recover and improve their motor abilities.However,in the design and use of exoskeletons,issues such as compliance with human movement mechanisms,reasonable driving methods,lightweight structures,and human-machine interaction remain challenges in the research of lower limb rehabilitation exoskeletons.According to the above research background,this paper designs a lower limb rehabilitation exoskeleton based on a cable driven system and conducts relevant theoretical research and feasibility verification.The main contents of the paper are as follows:(1)Analyzing the basic theory of human movement and calculating human kinematic data.First,using the knowledge of human anatomy and kinematics,the relationship between human lower limb joint movements,gait cycles,and foot motion states is analyzed.According to the human body’s movement state,the human gait is divided,and a simplified model of the human body’s seven limb segments is established.Inertial sensors are used to collect human limb angle data,and a foot pressure plate is used to collect foot reaction force data.Human inertial parameters are calculated based on the above data to calculate human kinematics,providing theoretical and data foundations for dynamic calculation.(2)We established a seven-segment human dynamic model and a human-robot interaction dynamic model using two methods.Firstly,the Newton-Euler equation was used to establish the dynamic model of the complete gait cycle.Subsequently,we developed a hybrid dynamic model using the Lagrange equation to describe the dynamic characteristics of the single-leg support and double-leg support phases in the gait cycle.The joint torque of the human body was obtained by incorporating the kinematic data into the dynamic model.The accuracy of the models was verified by comparing the joint torques obtained from the two methods.Finally,a human-robot interaction dynamic model was established to clarify the functional form of the exoskeleton in assisting the human body’s rehabilitation movement.(3)Establish the overall design scheme of the lower limb rehabilitation exoskeleton.First,the exoskeleton design principles are determined based on the human movement mechanism,and then the driving scheme based on the cable driven system is determined.A three dimensional model of the lower limb rehabilitation exoskeleton is built in Catia,and related components are selected.Finally,the length of the cable.driven joint motion is obtained by position inverse solution during the human gait,and the cable tension is solved using the D’Alembert principle,providing support for the safety verification and simulation of the exoskeleton.(4)Safety verification and feasibility verification of the exoskeleton.Firstly,the maximum working condition of the exoskeleton during the human movement is determined,and finite element analysis is performed on the key components of the exoskeleton using Ansys Workbench.Safety verification is performed based on the solution results,and structural improvements are made to the components that do not meet the requirements to ensure the safety of exoskeleton use.Finally,a human lower limb bone model is established,and it is imported into Adams along with the exoskeleton to build a human-machine exoskeleton...