Excavation Mechanism for a Planetary Underground Explorer Robot

In recent decades, several planetary investigations have been carried out, primarily from above. However, much poorly explored terrain remains, especially underground. This therefore constitutes an area where progress can be made for science. To take advantage of this opportunity, we have developed a small, underground explorer. We have focused on the peristaltic crawling of an actual earthworm as the propulsion mechanism for this explorer. In this paper, we explain the concept of our underground explorer robot using peristaltic crawling as a propulsion mechanism and an earth auger as the excavation tool. We have also developed 4 types of earth augers with differences in their tip types and number of spirals and have carried out several excavation experiments. In those experiments, excavation velocities and motor torques were evaluated against motor rotation speeds. Finally, we have introduced a different diameter earth auger between the excavation mechanism and the transport mechanism.