Study Of The Control System Of Ankle Rehabilitation Robot

With the increasing of the life rhythm in modern society,ankle injury will seriously reduce the ability of human activity,and it has a great effect on people's normal work and life.As a new medical device,the ankle rehabilitation robot is used to assist even replace the rehabilitation physician,which would help the ankle injury patients to complete the training of the joint flexibility and muscle strength.A new type of ankle rehabilitation robot control system is studied in this paper.Based on the analysis of some typical ankle rehabilitation robot in domestic and foreign,and the ankle injury and recovery mechanism,this paper proposes a scheme of control system more in line with the actual demand,and conducts a feasibility analysis for the combine of smartphone and ankle rehabilitation robot in motion control.The original drive unit is replaced by an electric push rod to reduce the mechanical clearance on the addiction-abduction mechanism.Aiming at the improved robot,the dynamic is established,and the model of the addiction-abduction mechanism and LuGre friction model is completed.Combined with the dSPACE HIL simulation system,the control system of the ankle rehabilitation robot is designed with CAN bus,RS232 and Bluetooth.Hardware of the robot is consisting of ARM microprocessor,Android smartphone,Bluetooth module and other electronic components.Both of the feed forward-feedback controller and the compound two-degree-of-freedom IMC controller characteristics are simulated under the same disturbance,and the latter is chosen for the robot.Besides,the slave computer control program,Android application,and PC control program are completed.Putting up the experimental environment with d SPACE,uC/OSIII embedded operating system,IAR software,App Inventor software and Simulink/Stateflow,the parameters of the LuGre model are identified and the improved mechanism is verified.Through man-machine experiments,single degree of freedom passive motion and predetermined trajectory experiment with different amplitudes and frequencies is complsted.The experiment has been done to research the dynamic and static characteristics of the push-pull torque load in active control mode.The effectiveness of the predetermined trajectory passive motion control strategy,the autonomous trajectory passive motion control strategy and the andresistance training control strategy are demonstrated through the results of the experiments.At last,the problems in the experiments are analyzed and summarized,and the improved methods are given.