Research On Human Lower Limb Exoskeleton Rehabilitation Robot

Lower limb exoskeleton rehabilitation robot is a wearable humanoid dynamic device,which is designed for elderly or disabled persons with walking disorders in the lower limbs.The device is mainly used in medical field to provide assistance for the patients with lower extremity dyskinesia.Based on the research status of lower limb exoskeleton rehabilitation robot and the mastering of key technology,a multi-degree-of-freedom exoskeleton rehabilitation robot driven by motor is designed in this paper.The specific works are as follows:(1)The establishment of three-dimensional model and static analysis: According to the theory of human engineering t,the structure types and sizes of each joint of are designed.The corresponding types and specifications of the motor and parts are designed for lower limb exoskeleton rehabilitation robot that uses motor drive mode.Depending on the different driving modes of motors that install in hip and knee joints,the 3D models of two different types of lower limb exoskeleton robots are designed.The static analysis of each joint is executed when thelower limb exoskeleton is in different positions.The stress and deformation of hip joints and knee joints in different motion angle are acquired.(2)Research on Kinematics:On the basis of the motion mechanism of each joint of human lower limbs,By establishing the D-H model of lower limb exoskeleton robot,the coordinate equations of hip joint,knee joint and ankle joint are derived.The kinematics simulation of lower limb exoskeleton is performed under ADAMS environment.The coordinate curves of hip,knee and ankle joints are analyzed.The results show that the joints of lower limb exoskeleton have a continuous trajectory in space,which are in accord with the theoretical analysis.(3)Research on dynamics:In a gait cycle,as to the characteristics of normal walking of human,The dynamic models of three different standing patterns are established,namely single-foot contact with the ground,double-foot full contact with the ground and double-foot partial contact with the ground.The torques of hip joint and knee joint oflower limb exoskeletonare solved by using Lagrange method,which provides a mathematical model for the analysis of subsequent chapters.(4)Research on gait planning :According to ZMP stability decision theory,the lower limb gait is studied.The equations established by five-point methods of gait planningare solved based on the X=csapi(x,y)function in MATLAB.Adjust the parameters of the lower extremity model and simulate the ZMP trajectory curve of the lower extremity exoskeleton robot based on the known dynamic walking trajectory equation.Compare it with the ZMP trajectory curve of the lower extremity exoskeleton robot.The ZMP trajectory curve that can be simulated meets the requirements of human gait stability.Affirming the rationality of parameter settings.(5)Control algorithm design:According to the design objective,therobust adaptive PD control algorithm is used to analyze the stability of the dynamic models of the lower limb exoskeleton in MATLAB/Simulink environment.The simulation resultsreveal that the response time ofthe system model is short under the disturbance of the step signal ?,and the tracking error curve of each joint can also quickly tend to 0,indicating the robust adaptive PD control algorithm possesses good stability.According to the dynamic model introduced in the simulation program,the torque curves of the hip and knee joints are simulated.Finally,a simple experimental prototype is built.Through the research of the above theoretical knowledge,this paper provides a solid foundation for the further research of lower limb exoskeleton rehabilitation robot.