Shank shock absorption mechanism of a powered exoskeleton for reduction of ground impact

Abstract

Powered exoskeletons for people with paraplegia are subjected to repetitive and large impacts due to the repeated ground contacts. The repetitive impact forces not only deteriorate the wear comfort but also cause a serious damage to the muscles and bones of the human wearing the powered exoskeleton. To address this issue, a shock absorption mechanism for powered exoskeletons is designed in this paper. Unlike previous studies, the proposed shock absorption mechanism is installed on the exoskeleton’s shank and the movement of the absorption mechanism is transmitted under the sole, where the shock occurs. As a result, gratifying shock absorption performance can be achieved in the compact system. The proposed shock absorption mechanism is integrated into the WalkON Suit, a powered exoskeleton for people with paraplegia. To obtain the desired performance of the proposed mechanism, the gait pattern of the powered exoskeleton is also modified. The proposed mechanism and gait pattern generation algorithm are verified by experimental results with a human subject in this paper also.