Fundamental Development and Evaluation of Body Weight Load Reduction System Driven by Rubberless Artificial Muscle

This paper describes a body weight load reduction system for elderly people to use while walking. This system is driven by rubberless artificial muscle by anticipating the soft movements of users. A force feedback control is applied to the rubberless artificial muscle to realize a body weight load reduction movement that is synchronized with a vertical movement of the walking user. The system validity is evaluated from the perspective of floor reaction force, three muscle activities of the lower limb, vertical movement of the waist position during the walking experiment, and the reaction force applied by this system to a user at that time. Experimental results demonstrate that, using this system, the floor reaction force during walking is reduced. Moreover, for the two muscles of the lower limb, the effect for muscle activity reduction was confirmed. The feedback control response was delayed, but the change of the reaction force imparted to the walking user was suppressed by the passive compliance characteristics of air pressure. Experimentally obtained results confirmed that the proposed system presents the possibility of realizing walking support of elderly people appropriately.