A robotic catapult based on the closed elastica and Its application to robotic tasks

In this paper, we propose a novel robotic catapult for generating repeated impulsive motions which are considered as a key to achieve creature-like motions by a compact autonomous robot. The proposed robotic catapult is just a bended elastic strip whose two ends are fixed to two rotational joints, i.e., a mechanical closed-loop of an elastic material named the 'closed elastica'. By only driving one joint back and forth gradually, we can obtain repeated impulsive motions of the elastic strip. It is shown that this robotic catapult can be applied to some robotic tasks such as impulsive robotic swimming and fly casting manipulation.