Abstract
A fall prevention device that aims to protect user from injury when fall happens has been proposed. In the previous research, Origami Spring was proposed as an extendable mechanism to implement the fall prevention device and an extendable rigid link mechanism based on Origami Spring has been developed. However, the extendable mechanism was too large to equip for people because of the thickness of links and actuators. Also, the repeatability of its extension motion was rather low due to rattling and less constraints. In this research, improvement of portability of the extendable mechanism and repeatability has been investigated from mechanical design point of view. From the perspective of portability, a new prototype of the extendable mechanism has been fabricated by using thin links and thin actuators. As for the improvement of repeatability, constraint elements using spiral spring has been designed to implement desired relative motion between links. The feasibility of desired relative motion of the extendable mechanism was confirmed by kineto-static analysis of a planar model. Through experimental study of extension, effectiveness of proposed elements was validated.
