Wearable Ankle Rehabilitation Device Based on Novel Series Elastic Actuator

Abstract

To assist patients with ankle diseases in completing rehabilitation training, a wearable ankle orthosis was presented in this paper. Firstly, the SEA-DTS (the series elastic actuator based on the double-tendon-sheath transmission mechanism and torsion spring), the execution mechanism of the ankle joint and the control system were described. Then, a series of experiments regarding trajectory tracking, moment step response, and position frequency response are carried out to study the mechanical characteristics of the wearable ankle orthosis. Results show that the participation of the SEA-DTS helps the orthosis work smoothly, while causes a maximum deviation of 3.56° in the trajectory tracking, a 10ms-delay and a maximum 16% overshoot in the moment step response performance, the bandwidth of the orthosis is 5.5Hz. Finally, the results obtained from two isokinetic dynamometer experiments prove the effectiveness of the wearable ankle orthosis, which means the proposed orthosis can assist patients with ankle diseases in completing rehabilitation training.