Design And Performance Analysis Of Horizontal Lower Limb Rehabilitation Robot

At present,there are many patients with hemiplegia caused by stroke,cerebrovascular disease and many other factors.The daily training of hemiplegia patients requires repeated movement to stimulate and reconstruct the nervous system to complete rehabilitation.This process usually requires the help of physical therapists.It is used to replace physical therapists in daily training of patients.This paper mainly studies the horizontal lower limb rehabilitation robot from the following aspects:The configuration design of the horizontal lower limb rehabilitation robot was carried out.The lower limb is divided into legs and feet,and the motion characteristics and range of the hip joint and knee joint of the leg and the ankle joint of the foot are analyzed.According to the motion mechanism of the lower limb of the human body,combined with the design principles of rehabilitation robot,a series and parallel mechanism(2UCU-2SPS)+(2SPU-RRPU)is designed.The mechanism can realize the lower limb straight leg elevation,knee flexion kick,knee flexion adduction and abduction,knee flexion exercises and ankle toe flexion and dorsal extension,adduction and abduction rehabilitation movement,to achieve better rehabilitation effect.The kinematics analysis of the horizontal lower limb rehabilitation robot is carried out.Based on the modified G-K formula and spiral theory,the degrees of freedom of the seriesparallel mechanism are analyzed and verified.The leg mechanism 2UCU-2SPS has 6 degrees of freedom,and the foot mechanism 2SPU-RRPU has 5 degrees of freedom.Through the closed-loop vector method,D-H method and vector geometry theory,the kinematics of the lower limb rehabilitation robot is analyzed,and the inverse kinematics solution of the series parallel mechanism is obtained,and the working space range of the mechanism is obtained by space search method.The analysis results show that the series parallel mechanism can meet the needs of the lower limb rehabilitation movement.The first-order influence coefficient matrix of the serial and parallel mechanism is established,and the kinematics simulation of the horizontal lower limb rehabilitation robot is carried out based on Adams.Based on the first-order influence coefficient matrix,the speed of the mechanism is analyzed,and the speed relationship between the drive and output of the single mechanism and the whole mechanism is obtained.The virtual prototype is imported into Adams,and the inverse kinematics simulation of the mechanism is carried out after adding materials,gravity,motion pairs,constraints and corresponding driving,and the curve of displacement,velocity,Angle and angular velocity of the corresponding driving parameters is obtained.The simulation results show that the mechanism runs smoothly in the process of rehabilitation movement,the speed is gentle,and the curve has no break point and mutation.There is no shock to the patient.Biomechanical simulation analysis of(2UCU-2SPS)+(2SPU-RRPU)serial-parallel mechanism based on Any Body.The virtual prototype is imported into Any Body,and the motion pair and reasonable constraints are added to the mechanism and human body in Any Body simulation software.Then the corresponding drive is added to simulate six rehabilitation exercises of lower limb,namely,straight leg raising,knee flexion and kick,knee flexion and abduction,knee flexion and ankle flexion and dorsal extension,adduction and abduction.Three parameters of muscle Activity,contraction Fm and muscle strength Lm were selected from the simulation results for analysis.The results show that this mechanism can effectively exercise the lower limbs and help the rehabilitation of hemiplegic patients.