무릎을 지지하는 새로운 하이브리드 강성 엑소-스켈레톤

Abstract

Joint alignment between an exoskeleton and the user is a must to reduce discomfort and prevent injuries. Knee joint misalignment problem is a classic problem due to the knee’s anatomical structure, as the knee joint center changes in both the Sagittal and the Frontal planes, unlike any 1 Degree-of-Freedom (DOF) joint. Also, the knee is subjected to large torques, and lower-limb knee-support exoskeletons must generate large assistive torques at the knee to provide meaningful support. Past rigid-type exoskeletons, in spite of high force transmission, focus on joint alignment in 2D Sagittal plane, and misalignment exists in the 3rd axis. Soft-exoskeletons, despite 3D joint alignment, cannot provide large enough support due to poor force transmission. In this thesis, a novel, hybrid-stiffness knee joint mechanism for lower-limb exoskeletons is proposed, that has a 3D directional compliance along the trajectory of the knee and rigidity in all other directions. For the first time, 3D joint alignment was addressed in all 3 directional axes, and a significant misalignment reduction was achieved. Furthermore, an EMG experiment for a shin raise task revealed minimal quadricep muscle activation to indicate the high force transmission capability of the proposed exoskeleton.