海底探査用掘削ロボットの掘削効率向上化に関する研究

―掘削効率に対する貫入力の影響―

抄録

Valuable seabed mineral resources such as rare earth elements are deposited 2–3 meters into the deep sea floor, and sampling and analyzing the seafloor is necessary to clarify how they are generated and distributed. We have developed a seafloor robotic explorer that can excavate horizontally and collect samples of rare earth elements, which may enable wide-area exploration as multiple robots could be simultaneously implemented to autonomously search beneath the seabed. The seafloor robotic explorer may excavate sediments such as clay and sand before reaching the rare earth layer. In previous studies, it has been discovered that the rotation speed, penetration force, and characteristics of the sediment affected the excavation resistance. Therefore, we assumed that controlling the rotation speed and penetration force would enable an efficient excavation according to the ground characteristics. Therefore, in this paper, we examined the effect of penetration force on drilling efficiency using both dry and underwater silica sand ground with different ground characteristics.