Design And Analysis Of Lower Limb Rehabilitation Exoskeleton Mechanism Based On Human-machine Closed Chain

Most the lower limb rehabilitation exoskeletons are tightly connected to the human,the human-machine interfaces of exoskeletons use bandages or clamping sleeves.Ideally,the exoskeleton forms a parallel chain with the human body,the human-machine size is completely matched,the human-machine movement is coordinated.However,during the actual use of such exoskeletons,due to the periodic movement of the exoskeleton,the relative sliding of human-machine generates motion deviation.The relative sliding causes deformation and dislocation,if the human-machine interface cannot compensate for it,the exoskeleton forces the body to move,it may not only create pressure on the legs to paraesthesia,but also cause secondary damage.Aiming at the motion deviation,which caused by the relative sliding of human-machine in the use of lower limb rehabilitation exoskeleton,according to the human-machine motion model and adjustment model,the lower limb rehabilitation exoskeleton was designed,the kinematics analysis kinetic analysis and structural optimization design of exoskeleton were carried out.The main research contents of this paper include the following four parts:(1)Aiming at the motion deviation caused by the relative sliding of human-machine,using the theory of human-machine deviation variable and the theory of human-machine compatibility,the passive degrees of freedom were added to the human-machine motion model,and the human-machine adjustment model was established.According to the two models,the lower limb rehabilitation exoskeleton was designed.The exoskeleton provided the human-machine motion mode and the human-machine adjustment mode,through the human-machine sliding deviation detection device switched the human-machine movement mode and the human-machine adj ustment mode.(2)The kinematics model of exoskeleton was established,the motion equation and the linkage transformation matrix were solved.Using MATLAB and Adams software simulated the exoskeleton model and human-exoskeleton model,the simulation results were compared and analyzed to verify the rationality of the lower limb rehabilitation exoskeleton.(3)In the human-machine motion mode,the dynamic modeling and simulation of human-exoskeleton simulation model were carried out.The driving torque and driving torque deviation curves of each joint were solved,the drive moment of each joint was obtained.Under the human-machine adjustment mode,the obtained torques were applied to the human-exoskeleton simulation model,the dynamic simulation verification was carried out.(4)According to kinematics,kinetic analysis results,as well as ergonomic needs,the lower limb rehabilitation exoskeleton was optimized design.The lower limb rehabilitation exoskeleton based on human-machine closed-chain,that could compensate the movement deviation,the exoskeleton avoids the secondary damage caused by human-machine sliding.It can be used for reference in the practical design of exoskeleton,which provides a theoretical basis for exoskeleton mechanism.