The Mechanism Design And Kinematic Research Of Lower Limb Rehabilitation Exoskeleton

With the transformation and upgrading of the industry and the development of robot technology,the application of robots has expanded from the field of manufacturing to the service sector.Lower limb rehabilitation exoskeleton robot is a typical medical service robot which has great market potentials.It is difficult to research and develop the rehabilitation exoskeleton robot,because it involves many subjects,such as mechanics,biology,control science and so on.In this paper,the mechanism of human motion is studied from the point of view of mechanics and kinematics,the mechanism of the exoskeleton and the lower limb of human body are analyzed from the point of view of mechanism,a new type of flexible exoskeleton mechanism was designed,the multi-bar linkage is used to design the joint drive mechanism,The researches are as follows.Firstly,the structural characteristics and movement characteristics of lower limb joints are analyzed,the equivalent mechanism model of the lower limb is established on the basis of the movement of each joint;On the basis of the equivalent mechanism model,the kinematics model and dynamic model of the lower limb were established,which provided the theoretical basis for the exoskeleton design and the motion analysis of the lower limb exoskeleton.Then,aiming at the problem that the traditional exoskeleton robot will be over constrained,a kind of flexible connection exoskeleton mechanism is designed.The exoskeleton robot and the lower limb are analyzed as a whole mechanism,and the constraint of the spatial mechanism is analyzed by using the screw theory to verify the exact constraint of the structure.The kinematics model of the exoskeleton lower limb spatial mechanism was established,and the influence of axis offset on system output was analyzed by matlab;the influence of the axis angle deviation and the axial position offset of each direction on the output is discussed.The effect of the mechanism parameters on the output is analyzed,and the optimal parameters of the connecting mechanism are selected.Finally,aiming at the typical gait requirements of lower limb rehabilitation,the lower limb rehabilitation exoskeleton robot driving mechanism was designed.According to the characteristics of the target gait curve,the structure of the drive mechanism is selected andthe mathematical model of the driving mechanism is established.The genetic algorithm is introduced as the design method of the driving mechanism,and the global optimal solution of the driving mechanism is obtained.The structural parameters of the drive mechanism are simulated and analyzed,and the simulation results are compared with the target motion function to verify the validity of the design.