Curved excavation by a sub-seafloor excavation robot

Sub-seafloor exploration is an important area of biological and geological research, and often requires samples of seafloor mud to be recovered. The minerals and marine sediments trapped in this mud are also potentially valuable resources. However, seabed exploration has been limited by the complexity and cost of the traditional equipment used. Wide area exploration can be made possible by deploying multiple robots to autonomously search beneath the ocean floor. In this study, we prototyped a sub-seafloor excavation robot for use in seabed exploration. The key system comprised a propulsion unit and an excavation unit that allow the robot to move freely within the seabed. We experimentally demonstrated the ability of the excavation robot to produce curved boreholes with a diameter of 160 mm, a turning radius of 1.67 m, and a depth of 613 mm. Our experimental results confirm that nonlinear excavation is possible using the excavation robot developed.