Development of Walking Assist Machine Using Linkage Mechanism - Mechanism and its Fundamental Motion -

This paper proposes a walking assist machine, which is driven by a single actuator to reduce weight and cost, and describes its mechanism and fundamental motions. The machine is worn by a user for assistance with the motions of his lower extremities during walking. The machine is composed of a leg, which is responsible for assisting the motions of the lower extremities, and a waist, which contains the actuator. The leg is composed of sections for assisting the thigh, lower thigh, and foot, and the sections for assisting the thigh, lower thigh, which are composed of a fourbar mechanism. As a result, the mechanism provides only a monotonic motion. Therefore, the effects of link lengths on leg motions are clarified and the machine is designed based on this knowledge. The machine can ensure a user’s physical safety by limiting the range of movement of the machine’s joints, keeping the range within the range of movement of the pertinent joint. The effectiveness of the proposed walking assist machine is verified through experiments.