Development of a Mole-Like Drilling Robot System for Shallow Drilling

Abstract

Drilling systems are widely used today for various purposes, but in harsh environments, such as the Arctic or space, it is hard to utilize these conventional systems because they require large amounts of equipment and labor. Various research projects have attempted to resolve this issue, but they are still in development stages owing to poor drilling performance. To solve this problem, we exploit the digging habits of the mole that is one of the representative animals living underground. In this paper, we propose the excavation mechanism for an embedded drilling robot, including cutting removal and balancing in the hole, which is inspired by a type of a mole known as the African mole-rat. To find the rate of penetration (ROP) trends of the proposed drilling system, simple drilling experiments are performed on autoclaved lightweight concrete blocks with a drill bit that imitates the polycrystalline diamond compact bit. The maximum ROP is obtained with the experiments and finite-element modeling simulations.

Keywords

• Digging pattern
• embedded drilling
• rate of penetration (ROP)
• smoothed particle hydrodynamics (SPH)
• weight on bit (WOB)