Kinematics And Rehabilitation Effect Of Ankle Rehabilitation Mechanism

Rehabilitation robot is the product of the combination of modern medical technology and robot technology.It is an important part of medical robot.At present,the aging process in China leads to the increasing number of patients.There is a contradiction that cannot be ignored between more patients with lower limb motor function limitation and fewer rehabilitation physiotherapists in China.At present,the research of upper limb rehabilitation robot has been relatively mature,covering shoulder,elbow and wrist.There are few studies on low-er limb rehabilitation,and there are still problems.In view of the shortcomings of the current research,this topic designs a new hybrid ankle rehabilitation robot,and analyzes its kinematics and rehabilitation effect.The main contents are summarized as follows:This paper expounds the structure of ankle,analyzes the range of motion,and obtains the rotation angle and traction freedom of ankle joint.According to the rehabilitation requirements and degrees of freedom of ankle,a hybrid ankle rehabilitation robot is designed based on virtual chain method.The rehabilitation robot meets the rehabilitation needs of three turns and one movement,and the adjustment device ensures that the position of the rotating center of the mechanism coincides with that of the ankle joint,thus enhancing the applicability.Based on the screw theory and G-K formula,the degree of freedom of the hybrid ankle rehabilitation mechanism is analyzed.The 2-URS / PRU mechanism is a three rotation and one movement parallel mechanism,4-RPR mechanism is a three degree of freedom mechanism.The space coordinate system is established,and the forward and in-verse kinematics of the robot are solved by combining the closed-loop vector method,D-H parameter method and coordinate transformation.The working space and corner space of 2-URS / PRU mechanism are obtained by the limit search method.After re-search,the mechanism meets the needs of ankle rehabilitation.Based on the influence coefficient matrix,the velocity and acceleration of 2-urs / PRU mechanism are analyzed,and the relationship between input and output is solved.The kinematics of the robot is simulated,and the change curves of displacement,velocity,acceleration,angular velocity and angular acceleration of ankle are obtained.The inverse kinematics simulation is carried out,and the change diagram of driving numerical curve is obtained.The whole process is stable without sudden change and rigid impact.Based on anybody,the rehabilitation analysis of the robot is carried out,and a man-machine simulation system is established to simulate the back extension toe flexion,varus valgus and adduction abduction movements.The numerical changes of the maxi-mum muscle activity,muscle length,activity and muscle strength in the whole rehabilitation cycle are analyzed.The muscle activity is obvious in the process of rehabilitation and has a good rehabilitation effect.In this paper,a hybrid 2URS / PRU-4RPR mechanism is designed by combining theoretical analysis and simulation,and its feasibility is verified.It provides a scheme for the treatment of ankle injury,which has theoretical value and application prospect.