Development of a Soft Exosuit System for Walking Assistance During Stair Ascent and Descent

An exosuit is a wearable robot that supports human muscular strength from outside the human body through multiple actuators. These actuators, which have similar functions to human muscles, reduce the weight compared to existing exoskeletons and minimize awareness of the different degrees of freedom. In this study, we developed an exosuit system that assists stair ascent and descent by supporting the power of the knee joint. To develop the hardware, we designed the entire system including functional apparel and a wire-driven actuator module. To provide the exosuit wearer with walking assistance, we established control strategies based on gait analysis and a force controller by applying the admittance control method. Then, to verify the usability of this system, we conducted an experiment comparing the muscle activity of users with and without the exosuit. The results revealed that the overall muscle activity of users decreased when they wore the proposed exosuit system. Specifically, the system reduced the muscle activity of the rectus femoris by up to 47% and 31% during stair ascent and descent, respectively. Therefore, the proposed exosuit system provides effective walking assistance.