Five-Step Parametric Prediction and Optimization Tool for Lunar Surface Systems Excavation Tasks

NASA systems engineers require an accurate assessment of excavator mass, power and energy requirements to correctly design lunar surface systems' overall architecture. In order to properly determine excavator mass and energy for various excavation tasks, we recommend a 5-step process. It starts with selection of appropriate soil that is analogous to lunar regolith. The second step refers to soil preparation methods; the desire is to make the soil's relative density similar to in-situ lunar regolith's relative density. The third step requires measuring excavation forces by deploying instrumented digging end effectors in carefully prepared soil bins and preferably in vacuum. After forces are measured, they need to be scaled for lunar gravity. The scaling factor varies depending on soil properties (cohesion and friction angle) and also on the size of an excavating blade/scoop. Once the forces are scaled they can be used to accurately estimate excavators' parameters for various tasks. This paper describes in detail all of the 5 steps mentioned above.