Development And Experimental Analysis Of Lunar Impact Penetrator

With the development of the lunar surface detection field in China,the detection task has changed from in orbit remote sensing observation to in situ detection.In December 2020,China’s Chang’e 5 lunar probe successfully completed the drilling and sampling of in situ lunar soil,and brought back 1731 g of in situ lunar soil,laying an important foundation for the study of the origin and development of the moon and the establishment of a lunar base.The drilling scheme used in Chang’e 5 is a multi-pipe combination type,which has many successful precedents,such as Apollo in the United States and the Lunar mission in the former Soviet Union.However,volume,quality,and power consumption are unavoidable problems in this scheme.On the one hand,it increases the difficulty of the detector’s transmission,and on the other hand,it is impossible to arrange other equipment,which limits the functionality of the detector.In addition,the rapid temperature rise of drilling tools and large disturbances to in-situ lunar soil are also problems to be solved in this scheme.The penetrator studied in this thesis is a lunar drilling device with a small volume lightweight ht,low power consumption and self-penetration.It compacts the lunar soil around it through its internal periodic impact,thus diving to the target depth.The heat flow detection device can be carried inside the penetrator,and the heat flow measurement of in-situ lunar soil can be completed after reaching the predetermined diving depth.In addition,because the object of penetration is lunar soil,some physical and mechanical parameters of lunar soil directly affect the penetration of the penetrator.Therefore,it is of high application value to develop a high-efficient and stable penetrator suitable for the lunar surface.Firstly,the influence of lunar soil’s physical and mechanical parameters on the penetration performance of the penetrator is studied.Then introduces the system composition and working principle of the penetrator establishes a friction calculation model between the penetrator and the lunar soil by using the integral method,analyzes the change of the friction between the penetrator and the lunar soil with the depth of penetration,a new type of penetrator with the auxiliary device is proposed in this thesis.The mass and stiffness parameters of the penetrator determine its diving capacity and the size of the recoil force.In order to obtain the optimal parameters,the dynamic model needs to be established.Using the ergodic optimization method,the influence of the mass stiffness parameters on the diving ability and the recoil force is studied,and the optimal parameters meeting the requirements are obtained.The dynamic software is used to simulate the actuating process of the penetrator,and the single-cycle submergence depth of the penetrator corresponding to the mass stiffness parameters before and after optimization is simulated and compared,which verifies the effect of parameter optimization.According to the design requirements and the obtained optimal parameters,the hammer,suppressor,and casing are designed in detail,and the selection of the driving motor is completed according to the operating conditions.Meanwhile,based on the functional requirements of the auxiliary device mentioned above,it is designed in detail.Finally,several groups of ground penetration test platforms are built to verify the improvement of the penetration capacity and stability of the new prototype with an auxiliary device compared with the original prototype.The test results show that the diving efficiency of the new penetrator prototype is 43% higher than that of the original prototype,and it can better restrain the recoil force at the initial stage of diving,specifically,the diving rate is more stable.This thesis presents a new method to solve the contradiction between highefficiency diving and low recoil force of the penetrator,and provides a new idea for insitu lunar surface detection.