Design And Control On Cable-Driven Lower Limb Rehabilitation Robot

In recent years,patients with limb movement disorders due to illness and accidents have shown an increasing trend.With the continuous improvement of people's demand for rehabilitation medical care,rehabilitation robots have developed rapidly.Combining robotic techniques with rehabilitation methods,the mechanical structure drives the limbs to perform repetitive motions,thereby stimulating and reconstructing the neurophysiological system and helping the limbs recover motor function.This thesis presents a design scheme of lower limb rehabilitation robot based on cable-driven technology by studying the development status of lower limb rehabilitation robot at home and abroad and gait rehabilitation theory of human lower limbs.Simulation analysis and experimental verification of the lower limb mechanism model are performed.The main research work is as follows:According to the standard gait trajectory of the lower limbs,the design of the overall scheme of the rope traction lower limb rehabilitation robot system is proposed.Through the analysis of the characteristics of the lower extremities and rehabilitation treatment methods,a judicious system structure scheme is established.The components of the system are designed separately and a three-dimensional model is established through Pro/E.At the same time,the control mode of the lower limb rehabilitation robot system is also determined.The D-H method and Newton-Raphson iterative method are applied in the preparation of a forward and inverse kinematic model of cable-driven lower limb rehabilitation robot,and trajectory planning is performed.The relationship between cable length and joint angle in gait movement is calculated by MATLAB software to verify the correctness of the forward and inverse kinematics.The static characteristics of the lower limb rehabilitation robot are analyzed,and the Lagrangian equation is utilized to establish its dynamic model to solve the tension distribution of the cable,and to pave the way for the simulation of the control strategy.Finally,the Monte-Carlo algorithm is utilized to optimize the configuration of the cabledriven lower limb rehabilitation robot.Different motion control strategies are proposed for the control system of the lower limb rehabilitation robot.Based on the PID control theory,the gravity-compensated PD control and fuzzy adaptive PID control are used to track and simulate the gait trajectory of the lower extremities.Through the analysis of the results,we can see that the fuzzy PID control algorithm can carry out self-tuning on the controller parameters within a certain range online,and has a fine control effect.Based on the theoretical analysis and the results of numerical simulation,the frame structure and control system of the cable-driven lower limb rehabilitation robot system is established.Using C# language to edit the interactive interface and use position control to send instructions to the motion control card through the upper computer,the motion control of the gait trajectory of lower limb rehabilitation robot is realized.Finally,the optical 3-D motion capture system is utilized to collect the motion trajectory of the lower limb rehabilitation robot,and the Pro Analyst motion analysis software is used to track the collected video data and output the motion trajectory data of the lower limb.The MATLAB software is used to process the lower extremity movement data and the theoretical data are compared with the measured data.The experiment and the theoretical simulation are verified by each other,which proved the rationality of the theoretical analysis and the feasibility of the cable-driven lower limb rehabilitation robot system.