Design And Simulation Of Lower Limb Rehabilitation Robot Based On Human Physiological Characteristics

Body weight support treadmill training based on the principle of neural plasticity has shown good effect in treating patients with functional dysfunction.However,this training method is labor intensive,bad repetitiveness and low efficiency,which limits its clinical application.Lower limb rehabilitation robot has become a hot research topic for its labor saving,good repetitiveness and efficiency.According to the requirements of the robot-assisted gait rehabilitation,this thesis investigates the human motion analysis,robot model design,simulation of human-robot system and functional rehabilitation training process,etc.The achievements are as follows.1.Research on human motion characteristics.Gait cycle of human walking process is divided,and data collection experiment is conducted by Vicon 3D optical acquisition system.Ankle trajectory and attitude are calculated by establishing the kinematic model of human lower limb.Finally,curve-fitting of human motion information is completed.2.Design of rehabilitation robot mechanism.According to the movement characteristics of human lower limb,a hybrid mechanism composed of the 4SPS-RPRR parallel mechanism in series with horizontal rail is utilized as human motion simulation mechanism.Rehabilitation model including weight support system,double adjustable pedal and horizontal guide is designed.This mechanism can realize 2 translational mobility and 3 rotation mobility.The rotation center of the model coincides with the rotation center of the ankle joint so that the rehabilitation robot model can simulate the motion of human lower limb well.3.Research on human-machine system simulation.Human-robot coupling dynamics model is established in Anybody Modeling System.Twelve major muscles of lower limb are chosen based on maximum muscle activity by normal walking process simulation.Five sets of simulation experiments are carried out with different gestures of the robot pedal.According to the length and contraction rate of the twelve major muscles,the influences of different postures on muscle characteristics are analyzed,and the effectiveness of the rehabilitation robot designed is verified.The results show that different mobility of the pedal can meet the patients' demand for the rehabilitation training of specific muscle groups.4.Research on functional rehabilitation training.Based on human-robot coupling dynamics model,three kinds of functional movement including normal walking,stair climbing and uphill slope climbing are analyzed through reverse dynamics simulation.The changes of muscle length,contraction rate and maximum muscle activity during these three kinds of functional movement are analyzed and compared respectively.The results show that in the stair climbing process,more than 90% of the muscles reached 50% in the normal walking process,training intensity of most of the muscles in uphill slope processes were strengthen.As a result,equivalent movement can be designed and chosen to train specific muscle groups to meet individualized rehabilitation training needs.