Toyoharu Nakatake

Soil circulating system for a lunar subsurface explorer robot using a peristaltic crawling mechanism

We have been developing an excavation robot for lunar subsurface investigations. The robot locomotion is based on the peristaltic crawling of an earthworm, which enables stable movement. The robot comprises three units: propulsion, excavation, and discharging units. In our previous research, we demonstrated that the propulsion and excavation units can excavate down to 650 mm without the discharging unit. However, when all three units were incorporated into the robot, excavation was limited by soil dropping from the discharging unit. To overcome this problem, we developed a novel soil circulating system. This paper presents the new system and experimentally verifies its feasibility. Finally, the contribution of the proposed system is confirmed in an excavation experiment. The robots performance was remarkably improved by the system, and its excavation depth increased to 938 mm.

Development of a curving excavation method for a lunar-subsurface explorer using a peristaltic crawling mechanism

We have developed an excavation robot for lunar-subsurface exploration. This robot moves using a mechanism based on the peristaltic crawling of earthworms, which can move stably. In our previous study, we demonstrated that the robot can excavate down to 938 mm using this technique. However, it can only excavate in a straight configuration. If it can excavate while curving, its exploration range would expand. Therefore, in this paper, we develop a curving-excavation method for this robot. Firstly, this method is proposed and developed. Secondly, we design the propulsion units necessary to realize this method. Finally, we conduct experiments to confirm curving motion using a robot equipped with the designed unit and evaluate the performance of this method.