Active disturbance rejection backstepping control system for wrist rehabilitation robot

An active disturbance rejection backstepping control (ADRBSC) system for a wrist rehabilitation robot, wherein the wrist rehabilitation robot comprises two pneumatic artificial muscle (PAM) systems as driving components, the two PAM systems are a first PAM system and a second PAM system, and the first PAM system and the second PAM system form a PAM system module;

• and the ADRBSC system comprises:
• a tracking differentiator, configured to track and differentiate a target angle signal input thereinto to generate a tracking signal and a differential signal;
• an extended state observer, configured to estimate a system state and a total system disturbance in real time, and output an estimated state value;
• a nonlinear error feedback controller, configured to form an error feedback signal and generate a control torque based on the tracking signal, the differential signal, and the estimated state value;
• a backstepping controller, configured to calculate and allocate, based on the control torque and using a dynamic model of a single-joint mechanical arm, an output pressure of the first PAM system and an output pressure of the second PAM system;
• proportion-integration-differentiation (PID) controllers, configured to dynamically correct the output pressure of the first PAM system and the output pressure of the second PAM system to compensate for a hysteresis effect of proportional pressure valves;
• and
• an adaptive combination valve, comprising two proportional pressure valves, a control unit, and a pressure sensor, and configured to execute control commands and monitor a pressure within the PAM system module.