Research On Dynamic Modeling And Control Simulation Of The Amputation Side Of Asymmetric Lower Limb Exoskeleton

Intelligent lower limb prosthesis is an ideal lower limb function compensation tool for amputation patients.At present,the intelligent lower limb prosthesis researched by domestic and foreign scholars is mainly passive/semi-active,although it can help amputated patients to achieve daily walking function,but It is difficult to achieve weight-bearing walking.The lower extremity exoskeleton is a wearable human-machine integrated mechanical device that is currently used to expand or enhance the physiology of the human body.For example,it is used in military operations for individual combat,carrying heavy loads,and used for hemiplegia in the field of rehabilitation.The patient’s help assisted.The current lower extremity exoskeleton is designed for the needs of the lower limbs.This group designed an asymmetric lower extremity exoskeleton for the needs of the shoulder amputation patient for weight-bearing walking function.In addition,the skeleton can not only assist the knee amputation patient to complete the daily walking function,but also help the amputated patient to achieve weight-bearing walking.Features.In this thesis,the control study of the amputation side of this new type of asymmetric lower extremity exoskeleton is carried out.The main research contents include:(1)Acquisition of human lower limb joint motion data.In this thesis,the trajectory of the joints of the lower limbs is measured by the experimental method.After the human gait is divided,the "two-state" method is adopted for the change of the movement state of the human legs,that is,a complete gait cycle is divided into No swing leg phase(NSP)with one leg supporting one leg swinging with a swinging swing leg phase(CSP)state and both legs in a supporting period or one leg in a supporting period Based on the seven-bar model,the kinematics and dynamics of the human lower limbs were modeled,and the joint torque curves of the lower limbs of the human body during the gait cycle were obtained.Finally,the correctness of the dynamic model was verified by Adams simulation software..(2)Dynamic modeling of asymmetrical limb exoskeleton amputation side.On the basis of the design of the asymmetric lower extremity exoskeleton mechanism,the amputation side dynamics model of the lower extremity exoskeleton robot was established.The dynamic model was simulated and verified by using the full gait cycle data of human walking.(3)Modeling of the control system of the asymmetric lower extremity exoskeleton amputation side.Based on the analysis of the specificity of the amputation side structure,the control model of the exoskeleton of the amputation side was established.Considering the existence of the thigh stump in the knee amputation patient,the admittance control method is adopted for the hip joint in order to have better followability and flexibility;for the amputation side knee joint,the control method of calculating the torque plus PD is adopted.(4)Simulation and performance evaluation of exfoliate side control of lower extremity exoskeleton.According to the established control model,the control data of the amputation side swing phase is simulated by using the human lower limb joint motion data.Based on the simulation results,the performance of the lower extremity exoskeleton control system is evaluated from the following aspects of followability and interference.