The Effect of Tip Design on Technological Performance During the Exploration of Earth, Lunar, and Martian Soil Environments
Authors
Pirrone S.R.M., Del Dottore E., Just G., Mazzolai B., Sibille L.
Reference
Journal of Field Robotics, 2025
Description
This paper investigates the penetration performance of soil-burrowing probes with different tip designs during shallow-depth penetration in various media, including terrestrial soils (Hostun sand) and well-characterized planetary soil simulants (LHS-1 Lunar regolith simulant and MGS-1 Martian regolith simulant). The analysis evaluates performance based on the pressure required to successfully penetrate the soil, comparing a conical tip design (i.e., the traditional tip design of penetrometers) with a plant root-inspired design. For each soil type, three different levels of soil compaction were considered to verify how initial soil porosity affects penetration performance. The study involves both experimental and numerical analyses. Experimentally, penetration tests were conducted in chambers filled with Hostun sand, LHS-1, and MGS-1. Numerically, a three-dimensional Discrete Element Model was developed to simulate probe penetration in soil packings with geomechanical properties of Hostun sand, LHS-1, and MGS-1, respectively. In accordance with the experimental findings, the modeling results show significant advantages of the plant root-inspired tip design over the conical tip. Indeed, the plant root-inspired design encountered lower soil resistance pressure during penetration across all soil types and compaction levels: the arithmetic mean values of the pressure reductions associated with the use of the bioinspired tip design resulted 25.5% experimentally and 25.4% numerically compared with the non-bioinspired tip.
