Design of 4-attachment Point Active Knee Exoskeleton for Sit to Stand Movement

Abstract

Abstract—This paper introduces the design principles for an active knee exoskeleton for sit to stand movement based on 4 attachments. Assistive devices enable people to regain their mobility, a critical function of human life. Many exoskeletons currently exist, however, most products assist in gait cycles of walking and running. Because the range of motion in these activities are relatively small and requires little torque, they’re not suitable for activities such as sit to stand or stair climbing. The design presented aims to achieve 50% of the required torque for sit to stand movement for an 80 kg male. Comfort and safety are also important factors to maximize via mechanical design. In this paper, Arduino Mega 2560 board is employed to control the motion of the exoskeleton. The Arduino board serves as the microcontroller to control a stepper motor while logic gates and EMG sensors provide the input signal. The experimental results show significant decreases in metabolic metrics when using the exoskeleton, suggesting that the exoskeleton is successful in assisting the user.