Research On Tracking Control Of Rehabilitation Robot With Speed Decision Under Uncertain Disturbance

With the increasing number of patients with walking disorders,rehabilitation robots have been widely developed.When the rehabilitation robot tracks the specified trajectory for training,it often faces the problems of center of gravity shift and disturbance uncertainty,so it is difficult to realize accurate trajectory tracking.In practical application,as the walking ability of the convalescents improve,they will have the intention to actively participate in the training,so the robot needs to constantly adjust the movement speed to assist the training of the rehabilitated,so as to realize the coordination of the human-machine movement speed.However,the existing rehabilitation training robots often do not have the ability to make decisions about the movement speed.In order to solve the above problems,this thesis takes a rehabilitation robot as the research object to study its motion speed decision and trajectory tracking problem under the condition of uncertain disturbance.The main contents include:Considering the problem that the center of gravity of the rehabilitation robot changes due to uncertain factors,such as body posture changes and mass inertia,when the user performs rehabilitation training through the rehabilitation robot,the mechanical structure characteristics of the rehabilitation robot are analyzed,and the kinematics model and dynamics model of the rehabilitation robot after the center of gravity shift are established.Aiming at the problem of uncertain disturbance in the movement of rehabilitation robot,based on the center of gravity offset model of rehabilitation robot and the idea of inverse control,a sliding mode adaptive controller is designed.According to Lyapunov stability theory,it is proved that the system can achieve asymptotic stability under the action of the designed controller.Matlab simulation experiments show that the designed controller can make the rehabilitation robot accurately track the specified training trajectory.In order to improve the user’s awareness of active participation in training,and study the decision-making problem of the motion speed of the rehabilitation robot,the motion speed of the rehabilitation robot is decided based on the sarsa algorithm in reinforcement learning,and a trajectory tracking controller adapted to the user’s motion speed is designed,in order to coordinate the man-machine motion speed,and ensure the safety of the man-machine system.The stability of the system is analyzed by using Lyapunov stability theorem.The MATLAB simulation results verify that the designed algorithm can achieve man-machine motion speed coordination,and the controller can make the rehabilitation robot accurately track the predetermined trajectory.