Design and Human-Robot Coupling Performance Analysis of Flexible Ankle Rehabilitation Robot

In response to the problems of mismatched human-robot motion and poor human-robot coupling (HRC) performance in ankle rehabilitation robots, this study proposes a cable-driven flexible ankle rehabilitation robot (FARR) based on biomimetic design and analyzes its HRC performance. Firstly, based on the motion characteristics and physiological structure of the ankle joint, an equivalent model of the ankle joint is proposed to solve the workspace of the ankle joint. Secondly, a design configuration of a cable-driven FARR with a flexible equivalent axis is proposed, and the structure of the FARR is designed. The robot's kinematics and dynamics are analyzed to solve the robot's workspace. By comparing the workspace of the ankle joint with the robot's workspace, the completeness of the robot's motion function is verified. Furthermore, the HRC dynamic theory model and the HRC dynamic simulation model are established to solve the HRC joint torque during the HRC system motion. The results show that the HRC joint torque is small in magnitude and stable in variation, indicating that the burden on the joint during robot motion is minimal. Finally, a prototype of the FARR is built, and motion function experiments of the HRC system are conducted to verify the matching between actual human motion and FARR motion under the HRC system.