DEVELOPMENT AND sEMG-BASED HIERARCHICAL CONTROL OF A HYBRID RIGID-SOFT KNEE EXOSUIT FOR CLIMBING STAIRS

Abstract

Climbing stairs is relatively challenging for seniors, post-stroke individuals or even healthy young men when carrying heavy objects. In this paper, we have developed a rigid-soft hybrid exosuit that helps the wearer to climb the stairs by offering a driving torque to the knee joint. By combining the advantage of rigid and soft exoskeletons, the exosuit is more comfortable when assisting wearers at a high level of assistance. To simplify the detection system, but keep it versatile, only the surface electromyography sensor is used to detect human movement. This paper uses a hierarchical control strategy based on gait detection and force tracking. To verify the capability of this exosuit system, we conducted experiments with four healthy users walking upstairs in different levels of assistance and climbing speeds. By comparing the muscle activity of participants with exosuit and without exosuit, the vastus lateralis activity was reduced by 3% to 15%, depending on the subject. This research shows the assisting capability of this exosuit under different assistance levels and climbing speeds.