Human force observation and assistance for lower limb rehabilitation using wire-driven series elastic actuator

Abstract

This study involves proposing an assistive device using a wire-driven Series Elastic Actuator (SEA) for leg rehabilitation that can design and provide assistive force for exercises based on the physical ability of a patient. The proposed assistive device possesses a force estimation ability to measure the mass of the leg along with the force exerted by a user in real-time. In order to achieve precise human force estimation and assistive force generation, a compact Planetary-geared Elastic Actuator, which is a type of Series Elastic Actuator is applied in the proposed device. Various algorithms to provide robust assistive force and to estimate force and work performed by the user are proposed in the study. Pilot tests were conducted with an exercise scenario that fully utilizes the functions and algorithms proposed in this study, and the effectiveness of the proposed system was validated based on two types of experiments: a healthy subject case and a patient case. The results of pilot test approve that the proposed device and algorithm enable patients to perform the exercise with ease, and increase their physical capabilities effectively. © 2018 Elsevier Ltd