Design of a Passive Exoskeleton Chair with an Auxiliary Support Mechanism for Assembly Tasks

Aiming at problems of low stability and inconvenient posture adjustment with using the existing exoskeleton chair to provide support during assembly tasks, a new type of passive lower extremity exoskeleton chair mechanism is designed in this paper. This exoskeleton chair is a multi-bar mechanism composed of a thigh bar, a calf bar, an adjustable link, a slider and foot connecting rods, and the sitting posture can be adjusted by changing the length of the adjustable link; in addition, in order to expand the wearer's stable support area effectively, an auxiliary support mechanism based on a planar four-bar mechanism is innovatively designed; on this basis, the dimension synthesis of the exoskeleton chair is carried out to improve the support stability; finally, a wearing test was carried out, and the effectiveness of the exoskeleton chair was verified by testing the electromyography (EMG) signals and plantar pressure. Experiments have shown that compared with the case without exoskeleton, the EMG signals of different muscles monitored decreased by 41% - 87%, and the plantar pressure decreased by 70% - 80%.