2자유도 저관성 능동 발목 의족 개발 및 비평탄면 보행을 위한 임피던스 제어

Abstract

In this paper, a lightweight low-inertia 2-DOF ankle prosthesis is presented. This prosthesis is designed to reduce the heterogeneity of amputees and enable them to walk comfortably with low effort. The compact size and low height of this prosthesis means that it can be widely used by amputees with various physical conditions. The proposed ankle prosthesis has two active joints in the sagittal and the coronal planes, and these joints are actuated by a parallel linkage mechanism, which helps amputees to walk normally and maintain balance when stepping on obstacles or uneven ground. A unique spring mechanism helps with propulsion without increasing the distal mass. This paper describes the kinematics of the proposed prosthesis and joint-level impedance control and presents a balancing control algorithm based on the human gait cycle. The height and weight of the developed ankle prosthesis are 220 ㎜ and 2.25 ㎏, respectively, which are comparable to those of commercial 1-DOF prostheses. The experiments conducted using the proposed prosthesis on even and uneven terrains demonstrated that the proposed 2-DOF prosthesis appropriately adapts to various ground conditions and consistently assists users with balance and propulsion.