A Novel Serial-Parallel Hybrid Robot for Rehabilitation Training of Gait and Balance

Abstract

Robot-assisted rehabilitation training for lowerlimb function recovery has gained increasing acceptability, but simultaneous training of gait and balance has not been well explored. In this paper, we propose a novel 5-DOF serial-parallel hybrid end-effort robot to provide gait training, balance training, as well as gait and balance training. Each side of the robot is composed of a 2-DOF gait generator and a 3-DOF parallel balance module. The gait generator takes the H-Bot mechanism, which distributes the heavy load of the patient to the two motors during walking, which are connected in serial. For the balance module, its virtual rotation center of the footplate is designed to be aligned with the ankle joint, enabling natural balance adjustment and training. Further, two displacement sensors and an inclinometer are employed to measure the pose, and closed-loop control of the 2-DOF position and 3-DOF orientation of the robot end-effector is realized. The robotic system has been built up, and achieved good performance on position and pose tracking, promising an effective rehabilitation platform for independent and simultaneous training of gait and balance.