The Analysis And Research Of Knee Joint Isokinetic Exercise Mechanism

With the deepening of the aging population and expanding of physical disabled population caused by frequent occurrence of various natural disasters,war,traffic accidents and diseases,the demand for rehabilitation are growing constantly.Rehabilitation robot can replace human beings to carry out repetitive and strenuous rehabilitation nursing work,which has the advantages of good stability and high efficiency.In this thesis,based on the analysis of the rehabilitation robot at home and abroad,combined with the principle of constant velocity motion,a kind of knee isokinetic exercise mechanism was proposed:Firstly,this thesis summarized the domestic and foreign research and development status of rehabilitation of lower limb rehabilitation robot,and found the study of this field are mainly in track training,less involved in isokinetic exercise,isokinetic exercise has the advantages of isotonic and isometric exercise both,which can promote effect for the rehabilitation of weak muscle strength patients.Therefore,it is necessary to develop a kind of lower limb rehabilitation training robot which can realize isokinetic exercise.Secondly,this thesis analyzed the physiological structure of the lower limb and mobility of the lower limb joints.Based on the 4R-P linkage mechanism,the mapping relation between the rod and the physical entity was determined.Thirdly,the D-H method was used to establish the coordinate system of the 4R-P type linkage mechanism,and the kinematics equation was deduced,and the motion law of the crank and knee joint was designed.The kinetic equation was established by using the kinetic energy theorem,and the dynamic input of the linkage mechanism was solved.Univariate analysis was performed for the influence of different lower limb size parameters,sitting height,length of crank kinematics on dynamics input,the adaptability of isokinetic exercise for different groups was determined,the reasonable range of sitting height and the length of the crank were defined.Finally,a virtual man-machine based on ADAMS was established,the kinematics and dynamics motion law was imported to make man-machine model work,The angular displacement and angular velocity of knee joint was measured to verify the feasibility of knee isokinetic exercise mechanism,and lay a foundation for development of prototype in the future.