Robust Control Of Rehabilitation Walking Training Robot With Speed Constraints

As the elderly population and patients with lower limb dysfunction are increasing year by year,it is impossible to carry out comprehensive rehabilitation training for patients only with the help of drugs and surgical treatment,so the rehabilitation walking training robot is widely concerned by researchers at home and abroad.Rehabilitation robots are required to track the doctor’s designated path to help patients gradually restore lower limb function.Many algorithms have been researched on tracking control,but they have ignored the impact of quality changes on the robot during rehabilitation training for different patients,and the importance of speed constraints to achieve safe robot motion.In order to solve this problem,the robust control of the speed-limited rehabilitation walking training robot is being studied.The main work includes:Analyze the kinematics and dynamics of the rehabilitation walking training robot according to the structural characteristics of the rehabilitation robot,consider the position and speed of the robot,and establish a kinematic model suitable for the mass change of the rehabilitation;establish a dynamic model suitable for changes in the quality of rehabilitation,taking into account the control input force,speed,and acceleration of the robot.Considering that the quality of different patients undergoing rehabilitation training will change,a nonlinear robust control algorithm is proposed.By designing a non-linear robust controller that compensates for uncertain time-varying parts of the system,the system has excellent anti-interference capabilities.The stability of the system is proved based on the Lyapunov function.Use MATLAB to compare,simulate,and analyze simulation results.It was verified that the proposed robust control could improve the tracking performance of the system.Further considering the impact of the robot’s motion speed on the safety of the rehabilitation,propose an algorithm that combines robust control and predictive control to limit the actual speed of the rehabilitation walking training robot.According to the predictive control,get the optimal control increment for the system.The designed robust controller to accurately track the path,even if the speed is limited within a specified range.Based on the Lyapunov function,the stability of the system is proved,a comparative simulation is performed,and the simulation results are analyzed.It is verified that the proposed robust predictive control can limit the speed of the rehabilitation robot and still accurately track the path.