The Biomimetic Design On Mars Surface Sampler And Research On The Machine And Soil’s Interaction

Mars landing detection is the key of the deep space exploration around theworld, as it did in the case of China.As one of the most effective sampling methods,table for sampling is an inevitable way to explore whether there is water and evenlife sign on Mars. Table for sampling executives digging, shoveling, and holding toget soil and rock samples from Mars surface. The mechanical properties ofwell-designed sampler actuator has important significance for improving thelander/rover’s efficiency and stability. This study through the engineering bionicsprinciple researched of the bionic design and the sampler performance analysis, inorder to provide new methods and ideas of the sampler design.Burrowing animals in nature have excellent features of mining and turning overthe soil, and their claws in structure and function are similar with shovel forsampling. Through the similarity analysis, I chose Himalaya marmot forepaw toe asthe biological prototype. By measuring the size of spatial structure of each claw toe,analyzing the different space position, select the second toe as the main object ofbiological research. By using a stereo microscope and scanning electron microscopeto observe the surface of claw, we gained its micro structure. Based on the basicprinciple of reverse engineering, three-dimensional laser scanner was used to obtainthe point cloud of the second toe’s characteristics. Use the reverse engineeringprocessing software to process the feature point cloud, three-dimensional model ofthe claw toe was obtained. Mathematical software Matlab was used to do numericalsimulation, obtained the curve equation of bionic design.Bionic structure is a combination of the basic method of organism structureresearch and engineering mechanics, which may achieve the original structureoptimization by transforming the mechanical device to make machines have betterperformances. Based on the basic principles of bionics, and the successfulapplication cases of sampling scoop in sampling process, design a different structureform of bionic sampling shovel. Use table sampling test bench and simulatedMartian soil to validate the verification of analog simulation, and inspect theregularity in force and torque of both bionic shovel and prototype sample shovel.And through the experiment of basic parameters of the simulated Martian soil prepared by volcano soil, basic physical parameters were received. According to thetest results, when the bionic shovel with an penetration angle of45degrees, thesampling rate of different levels respectively at200mm/min,400mm/min,600mm/min,800mm/min,1000mm/min, the maximum sampling resistance of thebionic sampling shovel decreased36.5%,34.9%,28.1%,44.8%,38.9%in the axialdirection respectively compared with the prototype shovel. For the diggingoperation, the torque consumption value of the bionic shovel WI-2was reduced by55.6%,49.6%and57.6%respectively at the sampling rate of0.11r/min,0.33r/min,0.56r/min, compared with the prototype sample shovel when the penetration anglewas the same.The interaction of shovel and soil during sampling process was simulated bydiscrete element software. The effectiveness of the simulation based on sphericalparticles was determined by discrete element method. At the meantime, through thediscrete element method the simulation of claw digging process was analyzed toinvestigate the different effects of internal and external contour.It turned out that theinner contour beard higher force in the process of digging. Through the discreteelement software to simulate sampling process under low gravity conditions, theeffects of gravity and bionic factors on sampling behavior in mesoscopic scale wereanalyzed. The contents of this paper may provide reference for the design of Martiansurface sampling equipments.