Development And Balance Control Of Powered Wheel Driving Exoskeleton For The Paraplegic Patients

Paraplegia is a serious disease of lower-limb locomotive system,which has a profound impact on the quality of lives of patients and also results in the heavy burden for the patient’s family and society.China has a large paraplegic population.It is the crucial issue for the researchers in the area of rehabilitation engineering to help the patients get out of bed,get rid of wheelchair,and integrate into the community.Recently,the applications of powered lower-limb exoskeleton in clinic provide the new options for paraplegic patients for the upright ambulation and rehabilitation training.However,most of current exoskeletons belong to joint driving exoskeleton which are developed based on designing philosophy of the robot.Such kind of exoskeletons showed a series of problems in practical use,which limited the wide application of exoskeleton in clinic.Therefore,this study introduced a wheel driving exoskeleton,which verified the usability of this novel exoskeleton in the aspect of moving assistant and rehabilitation training by developing the real prototypes and building the theoretical model,mainly finished the following work:For the problems of limited clinical application in current joint driving exoskeleton caused by the complicated electromechanical system,this study oriented from the fundamental needs of paraplegic patients,developed a low-cost,high-power-efficiency,and simple exoskeleton for upright ambulation.This exoskeleton adopted a motor-beltwheel driving module,Bluetooth wireless control,HKAF type mechanical structure,and a walker for balance maintain.Using experiments were performed on two healthy subjects and a patient with the paraplegic level of T10.The fluctuations of the joint angles and corresponding responses of major muscles were evaluated in a motion analysis system from start to the 4-seconds operation.For the problems of rehabilitation training engagement affected by limited selfcontrol capability,this study developed a rehabilitation training exoskeleton based on the patients-responsive protocol,which could assist the patients complete the alternative upright walking.This exoskeleton correlated the user’s finger movements with gait parameters for motion control,driven by a custom-made hub motor,balanced by a wireless-controller embedded crutch,which could enable the user to control the walking process at a real-time level.Two healthy subjects with different body characteristics finished the using experiments by adopting different gait modes.The spatial-temporal parameters,kinematic data and EMG data were quantitatively evaluated between wearing exoskeleton trial and without wearing exoskeleton trial by the 3D gait analysis.For the problems of current portable exoskeleton failing to cover the whole SCI population,this study introduced a self-support wheel driving exoskeleton concept.Maple software was used to calculate the kinematic and kinetic functions based on the Euler transformation and Lagrange equation.The balance functions were obtained based on the geometrical analysis and principle of moment balance.The calculated model was graphically verified by drawing the 3D sketches in Matlab.The bionic general control model was designed based on the analysis of balance mechanism of human walking.To reduce the power consumption of current lower-limb exoskeleton caused by body weight fluctuation in gait cycle and improve the human-machine interaction,this study completed the prototype design of self-support exoskeleton that had energy saving joint actuator and weight support mechanism.The exoskeleton’s motion trajectories were obtained through gait planning based on the joint rotation angle acquisition in a 3D gait analysis system.The motion capability was preliminary verified by using Adams + Simulink co-simulation.