Underwater Excavation by Excavation Robot Equipped with Propulsion Unit Based on Earthworm Setae

Sampling of marine sediments is important in investigating ocean floor environments. In general sampling methods, equipment such as drills and pipes are made to penetrate the seafloor from ships and collect sediments. However, it is necessary to use large ship as existing exploration devices, resulting in enormous cost. In addition, this method is inefficient because the search range is limited to one point. To overcome this problem, we developed a sub-seafloor excavation robot called SEAVO that consists of an excavation unit and a propulsion unit. The excavation unit excavates and creates a borehole for propulsion. SEAVO is propelled by a propulsion unit based on the movement method employed by earthworms. In this paper, we present a setae propulsion subunit that imitates the earthworm's setae to realize underwater excavation and SEAVO II, which is equipped with the setae propulsion subunit. In the experiments conducted, SEAVO II effectively carried out underwater excavation, which verifies the usefulness of the developed subunit in underwater environments.