Research On Excavation Technology Of Imitation Mole Lunar Soil Excavation Robot

After the completion of the three-step strategy of China’s lunar exploration project,the construction of a lunar base has become a new target for future deep space exploration activities.With the continuous development of science and technology,it has gradually had the actual conditions required to obtain lunar soil in-situ resources by excavating on the lunar surface and using resources in the excavation location to establish a lunar base,so on the basis of in situ resource utilization(ISRU)technology,for the problem of lunar soil in-situ resource mining,a design of imitation mole lunar soil excavation robot with the function of excavating lunar soil was proposed.Based on the theory of bionic mechanics,the mole creatures that are good at underground excavation were selected as bionic objects,and the motion laws and design requirements of the bionic excavation robot were clarified by analyzing the physiological structure and excavation trajectory of moles.On this basis,the structural design analysis of the imitation mole excavation robot is completed,which mainly includes the determination of the excavation mechanism(forelimb),soil discharge mechanism(hind limb)and touching mechanism(claw toe),that is,the surface alignment form of the excavation shovel.In order to complete the excavation work of the bionic mole excavation robot,an excavation mechanism composed of a crank slider mechanism and a crank rocker mechanism coupled in parallel is proposed,and a soil discharge mechanism composed of a slider linkage mechanism is proposed.According to the analysis of the motion characteristics of the imitation mole excavation robot,the kinematic and dynamic equations of the excavation mechanism and the soil removal mechanism were established,and the dynamic simulation software Recurdyn was used to simulate and analyze the motion characteristics of the excavation mechanism and the soil discharge mechanism and the change law of the driving force and moment of the excavation mechanism,and the simulation results verified the rationality of the excavation structure of the bionic robot and provided a theoretical basis for the optimization analysis of motion performance.Aiming at the analysis of the touching part-excavation shovel that directly responds to the dynamic contact with the lunar soil,the excavation motion analysis model of the excavation shovel and the excavation shovel-lunar soil interaction model are established,the bionic excavation shovel model is established by using the claw toe contour curve equation of three soil organisms as the excavation shovel surface collimator,and the simulation experiment is carried out by discrete element method,and the change trend of excavation resistance and shovel surface pressure between three bionic excavation shovels and ordinary excavation shovels in the process of flat pushing,rotation and offset rotation excavation is analyzed.The optimal excavation mechanism excavation shovel configuration and soil discharging mechanism excavation shovel configuration suitable for imitation mole excavation robot were determined.Based on the DEM-MBD cosimulation method,the coupling analysis of discrete element particle model and multibody dynamics model was carried out by using the discrete element analysis software EDEM and the multibody dynamics software Recurdyn,which simulated the actual excavation state of the excavation process and verified the practical feasibility of the structure design of the bionic excavation robot.