Design of bio-joint shaped knee exoskeleton assisting for walking and sit-to-stance

Abstract

In this study, a bio-joint shaped knee joint exoskeleton is presented. This design is meant for avoiding misalignment of the exoskeleton joint with the biological knee joint. For this purpose a cam mechanism has been designed to prevent the misalignment from translation of the femur on tibia. Additionally, walking and sit-to-stance is passively assisted with a spring element that is activated with the heel contact. A single spring is used for both walking and sit-to-stance, due to the similar characteristics of the gait cycle and initial phases of the sit-to-stance in joint stiffness.