Research Of Interaction Between Lunar Regolith And Drilling Tool Based On Single-blade Cutting Model

The goal of the third stage of lunar exploration is to accomplish automated drillingwork and return to the earth. It's a key point to make expected drilling depth and getenough sample. When drilling hole on lunar, interactive properties between drill andlunar regolith is basement to design drill device and research drilling&coring strategy.This paper present a way which base on single-blade cutting model to researchinteractive properties between drill and lunar regolith. This paper also introduces imageprocess method to measure the volume of accumulation zone above the hole, which isrelated to drill cutting model, while drilling lunar regolith.A new way is presented in this paper which translate the rotary&penetratingmotion of drill blade into linear motion. By using basic principle of soil mechanics,force model which describe the relation between cutting force and parameters of cuttingblade is established. While cutting simulate lunar regolith, cut soil in front of bladegenerally have two kind of fail pattern. Thus, two kind of cutting model are presentedrespond to two kind of fail pattern. In order to test and verify the accuracy of the cuttingmodel, a single blade cutting test-bed is designed.Models which describe interactive properties between drill and lunar regolith areestablished basing on single-blade cutting model which is tested and verified. Themodels consist of two parts. One is the model which represent the relation betweencutting force and size parameters of drill bit while cutting rigid simulate lunar regolith.The other is the model which represent the relation between chip removing force andsize parameters of drill stem and drilling strategy while remove the drill solids out of thedrill hole.When drilling device drive drill to get samples, rigid lunar regolith is cut into fineparticles. Some of the particles move into coring device turning into sample. Theremanent particles is removed out of the hole by drill stem to form a cone-shapeaccumulation zone. This paper present a model to describe the movement of drill solids.Image identification method is introduced in this paper. Firstly,2-dimensional picturesof accumulation zone while drilling are took by cameras. Secondly, the pictures aretransmitted into MATALB and processed by image processing toolbox of the soft toidentify the feature of accumulation zone. Lastly, volume of accumulation zone couldbe calculated using the feature of accumulation zone.