Research On Design And Joint Control Of Pneumatic Tendon-Driven Lower Limb Rehabilitation Robot

The lower limb rehabilitation robot is an automated medical device that assists patients with lower limb movement disorders to carry out rehabilitation training.In an aging society,it is a key resource to solve the problems of insufficient medical resources,poor manual training,and low recovery rate of affected limbs.At present,most of the lower limb rehabilitation robots on the market are mainly driven by precision motors,which have limitations such as large rigid impact,insufficient flexibility,and poor rehabilitation experience.Pneumatic tendon-driven lower limb rehabilitation robot(referred to as pneumatic tendon-type lower limb rehabilitation robot)has the characteristics of good flexibility,high safety,smooth movement,high stability,clean and environmental protection.However,the current market lacks such practical products.Therefore,in this paper,the pneumatic tendon is used as the driving element to develop a lower limb rehabilitation robot suitable for different training modes and different rehabilitation stages,and to study its joint modeling and control methods.The main research contents are as follows:(1)Analyze,classify and summarize the existing research results at home and abroad,and propose a lower limb rehabilitation robot driven by pneumatic tendons.Combined with the structure of the lower limbs of the human body,the movement characteristics and the rehabilitation mechanism of the affected limbs,the design parameters and overall scheme of the lower limb rehabilitation robot are determined,and its mechanical structure and pneumatic drive system are designed.(2)The kinematics equations of the lower limb rehabilitation robot are established,and the forward / inverse solutions are obtained.Based on the kinematics equations and Monte Carlo method,the working space is simulated and analyzed.The MATLAB /Robotics Toolbox is used to build a structural simulation model of the lower limb rehabilitation robot,and its motion trajectory planning process is analyzed to verify the rationality of its structure.The dynamic equations of the lower limb rehabilitation robot are derived,which lays a theoretical foundation for the design of the controller of the later prototype.(3)Design and build an experimental platform and formulate an experimental plan for the characteristics of pneumatic tendons.Based on the experimental fitting method and the theoretical derivation method,the static / dynamic mathematical model of the pneumatic tendon is established.The PID and second-order ADRC methods are proposed and analyzed,and the valve-controlled single pneumatic tendon position experiment is carried out to verify the effectiveness of its control and provide a reference for the selection of joint control methods.(4)Develop the first-generation prototype of a pneumatic tendon-type lower limb rehabilitation robot,designed its control system,formulated a multi-joint control plan,and laid the foundation for later prototype control research.Build a joint control experiment platform,and verify the feasibility and effectiveness of the valve-controlled single-joint method through simulation analysis and experimental research of valvecontrolled single-joint,and lay the foundation for the realization of robot multi-joint control later.