Design and analysis of a bio-inspired digging robot

Abstract

A numerous number of researches has been conducted in order to improve the excavation performance to conquer the depth and the strength of soil leading to the creation of robust drilling equipment but bulky and colossal in size. In addition, excavated soil removal has always become an issue and the existing digging tools try to compensate this by utilizing mud or slurry. Consequently, excavation in a shallow area filled with loose and weak soil becomes highly challenging. In order to overcome these limitations, digging manner of burrowing animals is investigated and implemented. The key components for digging are their teeth and limbs, which also take a huge role in removing the soil waste. In this design, a combination of a drill bit and linkage mechanism are utilized to represent the function of burrowing animals’ teeth and forelimbs. Regarding the high degree-of-freedom in the movement of animals’ head, they are able to establish holes that are bigger compared to the size of their head. Therefore, to generate a similar outcome yet simplifying the complexity, the expandable drill bit structure is proposed in this study. By applying this method, a collision between drill bit and forelimbs can be avoided. Additionally, since this design focuses on providing small-scale digging tools for shallow excavation, a novel mechanism, which allows both rotating and expanding/folding the drill bit with only one actuator, is introduced. The excavation performance of the proposed system is evaluated using dynamic simulation.