A lunar shelter and low-cost construction and operation method and special equipment

Abstract

The application discloses a lunar surface shelter structure and a low-cost construction and operation method and special equipment, and belongs to the technical field of lunar base construction. The application is proposed in order to meet the needs of low-cost and rapid construction of future lunar base. The lunar surface shelter structure comprises a lunar base cabin and a lunar surface protection layer arranged on the lunar base cabin. The lunar base cabin is prefabricated on the ground and is launched to the lunar surface by a carrier. An inflatable film above the cabin body is rapidly unfolded by being inflated and pressurized, so that a shelter is formed. The outer surface of the inflatable film is subjected to rigidization treatment to form a rigidized outer surface. A lunar surface protection layer is arranged on the outer layer of the inflatable film structure subjected to the rigidization treatment. The lunar surface protection layer comprises a loose layer and a dense layer from inside to outside. The loose layer is high and is provided with a plurality of thermoelectric modules and various sensors. Corresponding thermoelectric modules are arranged on the top layer of the inflatable film structure and are used for generating electricity by using the temperature difference between the surface temperature of the lunar soil protection layer which changes greatly day and night and the temperature of the top of the inflatable film which is relatively stable. Temperature, stress and radiation sensors are arranged in the loose lunar soil above the flexible inflatable film to form a multi-dimensional sensing system. The health state of the protection structure is analyzed in real time through multi-dimensional data analysis, and performance change and life prediction are carried out, so that the purpose of intelligent operation and maintenance of the protection layer is achieved.

Description

Technical Field

[0001] The present invention is aimed at the low-cost construction of a lunar base, and involves the structural design and forming of a lunar surface protective layer, lunar soil temperature difference power generation, and an intelligent operation and maintenance system for the protective layer, belonging to the technical field of lunar base construction. Background Art

[0002] Exploring and developing the moon is a crucial step in humanity's exploration of deep space. Since the 1950s, humanity has conducted numerous lunar exploration missions, generating a wealth of scientific data and returning lunar soil samples, significantly promoting the development of new technologies and industries. While these lunar explorations have significantly advanced aerospace technology, they have also enabled humanity to gain a more systematic understanding of the lunar environment and significantly enhanced our knowledge of the Moon, Earth, and even the solar system.

[0003] As the closest celestial body to Earth, the moon possesses a geographical environment vastly different from our own. Its high vacuum, lack of magnetic fields, and weak gravitational field create ideal conditions for conducting scientific experiments and astronomical observations. The moon's abundant mineral resources offer a new solution to humanity's future energy depletion challenges. Its abundant helium-3 resources, a clean fuel for nuclear fusion, will provide a strategic energy source for humanity. The moon is also a crucial gateway and transit point on the journey toward deep space. Therefore, establishing a lunar base would not only enable the development of lunar resources and energy in situ, but also allow for the testing of deep-space exploration technologies, laying the foundation for the exploration and development of Mars and other planets. However, existing technologies rarely document the low-cost equipment and methods for the construction and maintenance of lunar surface protective layers.

[0004] Reference [1] analyzes the 3D printing technology in the construction process of lunar protective structures, explains the constraints imposed by the lunar high and low temperature, vacuum, microgravity and other environmental conditions on the 3D printing of sintered lunar soil, and compares three methods of lunar soil sintering: solar sintering does not require additional energy consumption, but the equipment is heavy and requires real-time tracking and focusing; microwave sintering can achieve a higher thermal diffusion rate, but the energy conversion rate is low; laser sintering is suitable for load-bearing structures, but it consumes a lot of energy and is time-consuming. In addition, the protective structure also requires a concrete layer. The document explains the aggregate, temperature, pressure, etc. for producing sulfur concrete and concrete polymer. Finally, considering the high risk of human participation in 3D printing under the extreme environment of the lunar surface, the document proposes a multi-machine collaborative fully automatic printing system: through the robot team, data and information exchange between multiple machines is realized, so as to carry out division of labor and decision-making during construction. The redundancy of multi-machine collaboration can provide a certain degree of fault tolerance for the construction process of the protective structure, and this fully automatic printing method can be simulated on the ground to maximize the approximation to the real scene on the lunar surface. The document provides a detailed analysis of the overall technical approach and raw material preparation for lunar 3D printing. However, 3D printing has its drawbacks in terms of high requirements for both the process and the equipment system. For example, forming the concrete layer requires specific additives and precise control of temperature and prestressing. Collaborative printing with multiple machines also requires consideration of equipment transportation and inter-device communication.

[0005] Reference [2] discussed the construction of a manned research station in a lunar lava tube. Compared with the construction on the lunar surface or in the near-lunar orbit, the environmental advantages of the lava tube are more prominent: the radiation is almost zero; it is free from the impact of micrometeors, meteorites, etc.; there is no charged lunar dust; the temperature range is between -20℃ and 30℃, which is much smaller than the temperature range of the lunar surface. Therefore, building a lunar base in a lava tube reduces the requirements for cabin thermal control, radiation protection, and impact protection to a certain extent. In addition, the diameter of a lava tube is usually more than 60m and the depth is more than 50m. The internal space is large. In addition to building a manned cabin and a scientific research cabin, the mild environment can be fully utilized for plant planting and microbial cultivation to provide continuous life support for astronauts. Using the natural lava tube structure as a cover for the lunar base, there is no need to mechanically repair the protective structure. Only a flexible inflatable cabin needs to be carried into the tube, saving space for round-trip transportation. However, the lava tube lunar base proposed in the literature also has its drawbacks. For example, the lava tube's location is limited by the lava tube's location; exploration for in-situ resources such as lunar water ice, metal minerals, and helium-3 is impossible at depths of tens of meters; and specialized tracking and control facilities would be required on the lunar surface to maintain communication with the ground. These are all challenges facing a lava tube lunar base.

[0006] [1]Ulubeyli S.Lunar shelter construction issues:The state-of-the-arttowards 3D printing technologies[J].Acta Astronautica,2022,195:318-343.

[0007] [2]Sakurai M,Shima A,Kawano I,et al.A Guideline for a SustainableLunar Base Design for Constructed in Lunar Lava Tubes and Their VerticalSkylights[C].50th International Conference on Environmental Systems,2021.

[0008] Based on the above, it is necessary to propose a low-cost construction and operation and maintenance equipment and method for the lunar surface protection layer to provide support for the subsequent construction of a manned lunar base. Summary of the Invention

[0009] The technical problem to be solved by the present invention is: in order to meet the demand for low-cost and rapid construction of future lunar bases, the present invention further proposes a lunar surface shelter structure and a low-cost construction and operation method and special equipment.

[0010] The technical solution adopted by the present invention to solve the above technical problems is:

[0011] A lunar surface shelter structure includes a lunar base cabin and a lunar surface protection layer for being set on the lunar base cabin. The lunar base cabin includes a cabin body 7, a bracket 3, a plurality of supporting links 1 and a flexible inflatable membrane 2. The bracket 3 axially arranged on the cabin body 7 is hinged with the radially arranged supporting link 1 to form an integral support of the inflatable membrane 2. The cabin body 7 is connected to the inflatable membrane 2 through the integral support. The lunar base cabin is prefabricated on the ground and launched to the lunar surface by a carrier. The inflatable membrane above the cabin body is quickly expanded by inflation and pressurization to form a shelter. The outer surface of the inflatable membrane is then rigidified to form a rigid Outer surface; a lunar surface protection layer is set on the outer layer (top layer) of the over-rigidified abandoned gas membrane structure, and the lunar surface protection layer includes a loose layer and a dense layer from the inside to the outside; multiple thermoelectric power generation modules and various sensors are arranged at the top of the loose layer; corresponding thermoelectric power generation modules are arranged on the top layer of the inflatable membrane structure to generate electricity by utilizing the temperature difference generated by the large temperature changes on the surface of the lunar soil protection layer during the day and night and the relatively stable temperature on the top of the inflatable membrane; temperature, stress, and radiation sensors are arranged in the loose lunar soil above the flexible inflatable membrane to form a multi-dimensional sensing system, which is used to obtain thermal, force, and radiation sensing data in an environment with large fluctuations on the lunar surface.

[0012] A low-cost construction and maintenance method for the above-mentioned lunar shelter structure includes the following steps:

[0013] Step S1: First, a lunar base module is prefabricated on the ground and then launched to the lunar surface via a carrier. The lunar base module is composed of a rigid module body, telescopic connecting rods, and a flexible inflatable membrane (also known as a flexible inflatable structure or membrane structure) prefabricated on the ground, which serves as the bottom support structure of the lunar surface protection layer.

[0014] Step S2: Inflating and unfolding the inflatable membrane (membrane structure), rigidifying it, and arranging the thermoelectric power generation structure

[0015] The membrane structure is unfolded by the telescopic connecting rod of the cabin support, and then inflated and unfolded through the inflation device inside the cabin; the membrane structure is used to bear the weight of the lunar soil protection layer and rigidify the upper part of the inflatable membrane structure.

[0016] A corresponding thermoelectric power generation module is arranged on the top layer of the inflatable membrane structure to generate electricity by utilizing the temperature difference between the large temperature fluctuations on the surface of the lunar soil protective layer during the day and the relatively stable temperature on the top of the inflatable membrane;

[0017] Step S3: Protective layer lunar soil stacking and dense layer formation

[0018] After the membrane structure is inflated and expanded and rigidified, a lunar soil layer needs to be laid on top of it. The lunar soil layer is stacked in a mesh grid composed of a thermoelectric power generation system; the equipment for lunar soil construction uses a foldable, lightweight, large-load mobile operating robotic arm, which can achieve rapid deployment and mobile operation capabilities on the lunar surface; the end effector of the robotic arm adopts an autonomously detachable design, which can cooperate with the mobile tool cabin to complete the replacement of the end effector, and realize the adaptability of multiple tasks such as transportation, assembly, and shoveling, and complete the lifting, stacking of lunar soil, and densification of the lunar soil layer during the construction of the protective layer.

[0019] Step S4: Protective layer structural health monitoring and operation and maintenance

[0020] Construct a digital twin system to conduct real-time health monitoring and operation and maintenance of the protective layer structure. First, place temperature, stress, and radiation sensors in the loose lunar soil above the flexible air membrane to form a multi-dimensional sensing system to obtain thermal, force, radiation and other sensor data in an environment with large fluctuations on the lunar surface. At the same time, based on the proxy model of heat, force, and radiation of the protective layer, optimize the objective function and build a deep neural network, and train the network using training data. Utilize the trained neural network, combined with the sensor data obtained by the multi-dimensional sensing system, to diagnose damage to the protective layer (such as local deformation, crack extension, strength reduction, etc.), including but not limited to identifying the damage location, determining the damage level, classifying different damage modes, and systematically identifying them. After completing the damage diagnosis, use foldable working equipment to repair the protective layer accordingly.

[0021] After completing the damage diagnosis and repair of the protective layer, it is also necessary to predict its thermal, mechanical, radiation resistance and other physical properties. In view of the possible structural damage to the protective layer under the extreme environment on the lunar surface, a digital twin system is constructed by combining the entire process of diagnosis-repair-prediction to achieve health management and maintenance of the protective layer.

[0022] In S2, the telescopic connecting rod of the bottom support structure of the protective layer drives the flexible structure to unfold, forming a rigid cabin protection layer with a certain curvature according to the terrain, and the flexible membrane is inflated and formed.

[0023] In S2, the stiffness of the supporting structure is increased by space radiation or heating stiffening treatment.

[0024] In S2, through mechanical simulation, appropriate materials, internal pressure, membrane thickness, and rib diameter are selected, and the stiffness requirements and the frequencies of each vibration mode are comprehensively considered to ensure a stable overall structure. The supports on both sides help reduce the impact of moonquakes and impacts on the overall structure.

[0025] The materials used for thermoelectric power generation are semiconductors, metal materials or heat pipes.

[0026] When semiconductor materials are used, under the influence of temperature difference, according to the Seebeck effect, the positive charges (holes) in the P-type semiconductor will transfer in the direction away from the heat source, while the opposite is true for the N-type semiconductor, where the electrons transfer in the direction away from the heat source, thereby forming an electric current. The magnitude of the generated electromotive force is related to the internal and external temperature difference and the material, and has nothing to do with the size of the PN-type semiconductor. Connecting multiple thermocouples formed by such PN semiconductors in series can generate a larger electromotive force to provide electrical energy.

[0027] In step S3, during the construction of the fluffy lunar soil layer, the robotic arm of the lunar multifunctional lightweight working robot is connected to the bucket in the lunar mobile tool cabin through an autonomous docking mechanism, and the safety and stability of the bucket connection are ensured by a self-locking mechanism; the lunar multifunctional lightweight working robot is controlled by remote operation or semi-autonomous means to shovel and stack lunar soil, covering the lunar soil more evenly in the grid composed of the thermoelectric power generation system, completing the construction of the loose lunar soil part; next, the lunar multifunctional lightweight working robot completes the return of the bucket tool and the installation of the solar energy concentrating system. The solar light spot focused by the solar energy concentrating system follows the movement of the print head to realize the sintering of the lunar soil layer, forming a densified lunar soil layer of a certain thickness.

[0028] In step S4, a dynamic evolution analysis model is constructed using a dynamic Bayesian network to represent the dependencies between the various factors influencing the independent variables and address issues such as nonlinearity, temporal order, and uncertainty. Based on this, the performance of the protective layer is analyzed, and the evolution of relevant physical parameters over time is calculated. This provides early warnings for potential future failures and provides corresponding protective recommendations. Operational equipment is then instructed to preemptively reinforce locations where damage to the protective layer may occur, minimizing the negative impact of local failures on the protective layer's functionality.

[0029] A special equipment for a low-cost lunar surface protective layer construction method, comprising a multifunctional lightweight lunar surface operation robot 8, a lunar surface mobile tool cabin, and a communication radar 13 mounted on the multifunctional lightweight lunar surface operation robot and the communication radar 13 mounted on the lunar surface mobile tool cabin;

[0030] The multifunctional lightweight lunar operation robot mainly includes a mobile robot chassis 10 ( Foldable Mobile chassis), a foldable robotic arm 11, an end-effector docking device 12, the base of the foldable robotic arm 11 is mounted on the mobile chassis 10, and the end of the foldable robotic arm 11 is connected to the end-effector docking device 12;

[0031] The lunar mobile tool cabin mainly consists of a foldable tool cabin mobile chassis 20 and a transport fork 14, a lunar solar energy concentrating system 15, a hook 16, a lunar soil stacking tool 17, a bucket 18, and a welding actuator 19 mounted thereon; the end effector docking device 12 docks with the transport fork 14, the lunar solar energy concentrating system 15, the hook 16, the lunar soil stacking tool 17, the bucket 18, or the welding actuator 19;

[0032] The lunar base module (prefabricated module) is hoisted from the landing vehicle on the lunar surface to a predetermined position by means of the hook 16;

[0033] shoveling lunar soil from the lunar surface by means of a bucket 18;

[0034] The lunar soil stacking tool 17 is used to transport the lunar soil dug out by the shovel and stack it on the inflatable membrane of the lunar base cabin to form a loose lunar soil layer on the inflatable membrane.

[0035] The lunar solar concentrating system 15 is used to collect sunlight and use the heat energy of sunlight to sinter the outer surface of the loose lunar soil layer to complete the densification of the lunar soil layer;

[0036] The transport fork 14 is used to transport the boxed cargo containing the materials required for the thermoelectric power generation module from the landing lunar surface to a predetermined location near the lunar base cabin;

[0037] The welding actuator 19 is used to weld the components of the thermoelectric power generation module to form a series connection;

[0038] Remotely operate the end effector docking device 12 to dock or replace one of the transport fork 14, lunar solar concentrating system 15, hook 16, lunar soil stacking tool 17, bucket 18, and welding actuator 19, and perform the above operations;

[0039] The communication radar 13 of the lunar multifunctional lightweight operation robot and the communication radar 13 carried on the lunar mobile tool cabin are used to control the lunar multifunctional lightweight operation robot in a remote or semi-autonomous manner. The two communication radars can exchange information.

[0040] The solar concentrating system consists of a light-tracking system, a Fresnel lens concentrating device and a print head. The solar spot focused by the concentrating device follows the movement of the print head to achieve the sintering of the lunar soil layer and form a densified lunar soil layer of a certain thickness.

[0041] The present invention has the following beneficial technical effects:

[0042] This invention addresses the need for low-cost, rapid construction of future lunar bases by proposing a combined inflatable membrane structure and lunar soil protective layer. The cabin is prefabricated on Earth and launched to the lunar surface via a carrier. The inflatable membrane above the cabin is rapidly expanded by inflation and pressurization, forming a shelter. After deployment, the upper surface of the membrane is rigidified to increase its support strength and prevent collapse and leakage under stress, which could lead to structural failure. A lunar soil protective layer covers the membrane, providing thermal insulation, radiation protection, and impact protection. This combined inflatable membrane structure and lunar soil effectively shields against the extremes of the lunar surface, including high and low temperature cycles, strong cosmic rays, and moonquakes. This ensures low radiation levels and a near-constant temperature on the exterior of the cabin, ensuring safety for astronauts during long-term stays within the lunar base cabin and conducting related scientific research. The flexible, expandable inflatable membrane significantly reduces transportation space and facilitates modular assembly. Utilizing in-situ lunar soil as a protective layer eliminates the cost of prefabrication on Earth, enabling rapid and low-cost construction throughout the lunar surface. The proposed modular shield structure, with its inflatable membrane structure, supporting links, and cabin prefabricated on the ground, requires only simple lunar soil accumulation and densification. This leverages the unique characteristics of in-situ lunar soil resources and the high reliability of ground-based prefabrication. Compared to lunar bases constructed with fully functional (radiation- and temperature-resistant) rigid or flexible cabins, this reduces the cabin's inherent radiation protection and thermal control requirements, resulting in a lighter structure and significant savings in precious Earth-Moon transport weight. Compared to monolithic 3D-printed building structures, this significantly simplifies the construction process and equipment requirements.

[0043] The lunar soil protection layer in the present invention adopts a sandwich structure of loose lunar soil and dense lunar soil. The loose lunar soil has a low thermal conductivity and acts as a heat insulator, keeping the temperature inside the protective layer stable; the dense lunar soil has good resistance to cosmic radiation, and can also protect against the impact of micrometeorites and micrometeorites, and fix the loose lunar soil to prevent it from sliding. The dense lunar soil is solidified by methods such as solar concentrating sintering, and there is no need to bring any additives from the ground. The present invention uses foldable multifunctional working equipment to construct the lunar soil protection layer. According to different task characteristics, the end actuator of the working equipment can be automatically adjusted to enter different working modes, such as excavation, covering, sintering, hoisting, etc.

[0044] The outside of the lunar soil protective layer is an extreme lunar environment, with a day and night temperature range of nearly 300 degrees Celsius, while the inside of the protective layer is close to a constant temperature. The present invention utilizes the temperature difference between the inside and outside of the protective layer to generate electricity using heat pipes or PN semiconductor temperature differences, which can provide all-weather energy support for the lunar base. In addition, the present invention designs a digital twin operation and maintenance system to achieve health management and damage repair of the combined protective layer. Mechanical, temperature, and radiation sensors are placed inside the protective layer to obtain multi-dimensional sensor data in real time. A diagnostic model is generated and analyzed within the system to provide damage pattern identification and fault repair methods. Finally, the lunar surface operation equipment repairs the damaged parts of the protective layer to ensure the structural safety of the protective layer and the sustainability of its functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 A flowchart of the low-cost construction and maintenance method for the lunar shelter structure;

[0046] Figure 2 It is a three-dimensional diagram of the lunar shielding structure with a partial cutaway view;

[0047] Figure 3 A three-dimensional image of the lunar surface shielding structure with an unfinished lunar soil sintering layer;

[0048] Figure 4 Schematic diagram of the structure of the loose lunar soil layer and the thermoelectric power generation module (semiconductor) on the inflatable membrane;

[0049] Figure 5 A three-dimensional diagram of the lunar surface shielding structure to complete the lunar soil sintering layer;

[0050] Figure 6 This is the main cross-sectional view of the lunar shielding structure;

[0051] Figure 7 This is a schematic diagram of the structure of the multifunctional lightweight lunar operation robot;

[0052] Figure 8 Schematic diagram of the structure of the lunar mobile tool module;

[0053] Figure 9 This is a structural diagram of the cabin transport fork 14, lunar solar energy concentrating system 15, hook 16, lunar soil stacking tool 17, bucket 18, and welding actuator 19 in the lunar surface transportation tool. The black dot in the figure is the part that docks with 12.

[0054] In the figure: 1-connecting rod, 2-inflatable membrane, 3-bracket, 4-loose lunar soil layer, 5-dense lunar soil layer (sintered layer), 6-sensor, 7-cabin, 8, special equipment, 9-semiconductor. DETAILED DESCRIPTION

[0055] Combined with attachment Figure 1-9 The implementation of the present invention is described and explained as follows:

[0056] A lunar surface shelter structure includes a lunar base cabin and a lunar surface protection layer for being set on the lunar base cabin. The lunar base cabin includes a cabin body 7, a bracket 3, a plurality of supporting links 1 and a flexible inflatable membrane 2. The bracket 3 axially arranged on the cabin body 7 is hinged with the radially arranged supporting link 1 to form an integral support of the inflatable membrane 2. The cabin body 7 is connected to the inflatable membrane 2 through the integral support. The lunar base cabin is prefabricated on the ground and launched to the lunar surface by a carrier. The inflatable membrane above the cabin body is quickly expanded by inflation and pressurization to form a shelter. The outer surface of the inflatable membrane is then rigidified to form a rigid Outer surface; a lunar surface protection layer is set on the outer layer (top layer) of the over-rigidified abandoned gas membrane structure, and the lunar surface protection layer includes a loose layer and a dense layer from the inside to the outside; multiple thermoelectric power generation modules and various sensors are arranged at the top of the loose layer; corresponding thermoelectric power generation modules are arranged on the top layer of the inflatable membrane structure to generate electricity by utilizing the temperature difference generated by the large temperature changes on the surface of the lunar soil protection layer during the day and night and the relatively stable temperature on the top of the inflatable membrane; temperature, stress, and radiation sensors are arranged in the loose lunar soil above the flexible inflatable membrane to form a multi-dimensional sensing system, which is used to obtain thermal, force, and radiation sensing data in an environment with large fluctuations on the lunar surface.

[0057] A low-cost construction and maintenance method for the above-mentioned lunar shelter structure includes the following steps:

[0058] Step S1: First, a lunar base module is prefabricated on the ground and then launched to the lunar surface via a carrier. The lunar base module is composed of a rigid module body, telescopic connecting rods, and a flexible inflatable membrane (also known as a flexible inflatable structure or membrane structure) prefabricated on the ground, which serves as the bottom support structure of the lunar surface protection layer.

[0059] Step S2: Inflating and unfolding the inflatable membrane (membrane structure), rigidifying it, and arranging the thermoelectric power generation structure

[0060] The membrane structure is unfolded by the telescopic connecting rod of the cabin support, and then inflated and unfolded through the inflation device inside the cabin; the membrane structure is used to bear the weight of the lunar soil protection layer and rigidify the upper part of the inflatable membrane structure.

[0061] A corresponding thermoelectric power generation module is arranged on the top layer of the inflatable membrane structure to generate electricity by utilizing the temperature difference between the large temperature fluctuations on the surface of the lunar soil protective layer during the day and the relatively stable temperature on the top of the inflatable membrane;

[0062] Step S3: Protective layer lunar soil stacking and dense layer formation

[0063] After the membrane structure is inflated and expanded and rigidified, a lunar soil layer needs to be laid on top of it. The lunar soil layer is stacked in a mesh grid composed of a thermoelectric power generation system; the equipment for lunar soil construction uses a foldable, lightweight, large-load mobile operating robotic arm, which can achieve rapid deployment and mobile operation capabilities on the lunar surface; the end effector of the robotic arm adopts an autonomously detachable design, which can cooperate with the mobile tool cabin to complete the replacement of the end effector, and realize the adaptability of multiple tasks such as transportation, assembly, and shoveling, and complete the lifting, stacking of lunar soil, and densification of the lunar soil layer during the construction of the protective layer.

[0064] Step S4: Protective layer structural health monitoring and operation and maintenance

[0065] Construct a digital twin system to conduct real-time health monitoring and operation and maintenance of the protective layer structure. First, place temperature, stress, and radiation sensors in the loose lunar soil above the flexible air membrane to form a multi-dimensional sensing system to obtain thermal, force, radiation and other sensor data in an environment with large fluctuations on the lunar surface. At the same time, based on the proxy model of heat, force, and radiation of the protective layer, optimize the objective function and build a deep neural network, and train the network using training data. Utilize the trained neural network, combined with the sensor data obtained by the multi-dimensional sensing system, to diagnose damage to the protective layer (such as local deformation, crack extension, strength reduction, etc.), including but not limited to identifying the damage location, determining the damage level, classifying different damage modes, and systematically identifying them. After completing the damage diagnosis, use foldable working equipment to repair the protective layer accordingly.

[0066] After completing the damage diagnosis and repair of the protective layer, it is also necessary to predict its thermal, mechanical, radiation resistance and other physical properties. In view of the possible structural damage to the protective layer under the extreme environment on the lunar surface, a digital twin system is constructed by combining the entire process of diagnosis-repair-prediction to achieve health management and maintenance of the protective layer.

[0067] In S2, the telescopic connecting rod of the bottom support structure of the protective layer drives the flexible structure to unfold, forming a rigid cabin protection layer with a certain curvature according to the terrain, and the flexible membrane is inflated and formed.

[0068] In S2, the stiffness of the supporting structure is increased by space radiation or heating stiffening treatment.

[0069] In S2, through mechanical simulation, appropriate materials, internal pressure, membrane thickness, and rib diameter are selected, and the stiffness requirements and the frequencies of each vibration mode are comprehensively considered to ensure a stable overall structure. The supports on both sides help reduce the impact of moonquakes and impacts on the overall structure.

[0070] The materials used for thermoelectric power generation are semiconductors, metal materials or heat pipes.

[0071] When semiconductor materials are used, under the influence of temperature difference, according to the Seebeck effect, the positive charges (holes) in the P-type semiconductor will transfer in the direction away from the heat source, while the opposite is true for the N-type semiconductor, where the electrons transfer in the direction away from the heat source, thereby forming an electric current. The magnitude of the generated electromotive force is related to the internal and external temperature difference and the material, and has nothing to do with the size of the PN-type semiconductor. Connecting multiple thermocouples formed by such PN semiconductors in series can generate a larger electromotive force to provide electrical energy.

[0072] In step S3, during the construction of the fluffy lunar soil layer, the robotic arm of the lunar multifunctional lightweight working robot is connected to the bucket in the lunar mobile tool cabin through an autonomous docking mechanism, and the safety and stability of the bucket connection are ensured by a self-locking mechanism; the lunar multifunctional lightweight working robot is controlled by remote operation or semi-autonomous means to shovel and stack lunar soil, covering the lunar soil more evenly in the grid composed of the thermoelectric power generation system, completing the construction of the loose lunar soil part; next, the lunar multifunctional lightweight working robot completes the return of the bucket tool and the installation of the solar energy concentrating system. The solar light spot focused by the solar energy concentrating system follows the movement of the print head to realize the sintering of the lunar soil layer, forming a densified lunar soil layer of a certain thickness.

[0073] In step S4, a dynamic evolution analysis model is constructed using a dynamic Bayesian network to represent the dependencies between the various factors influencing the independent variables and address issues such as nonlinearity, temporal order, and uncertainty. Based on this, the performance of the protective layer is analyzed, and the evolution of relevant physical parameters over time is calculated. This provides early warnings for potential future failures and provides corresponding protective recommendations. Operational equipment is then instructed to preemptively reinforce locations where damage to the protective layer may occur, minimizing the negative impact of local failures on the protective layer's functionality.

[0074] A special equipment for a low-cost lunar surface protective layer construction method, comprising a multifunctional lightweight lunar surface operation robot 8, a lunar surface mobile tool cabin, and a communication radar 13 mounted on the multifunctional lightweight lunar surface operation robot and the communication radar 13 mounted on the lunar surface mobile tool cabin;

[0075] The multifunctional lightweight lunar operation robot mainly includes a mobile robot chassis 10 ( Foldable Mobile chassis), a foldable robotic arm 11, an end-effector docking device 12, the base of the foldable robotic arm 11 is mounted on the mobile chassis 10, and the end of the foldable robotic arm 11 is connected to the end-effector docking device 12;

[0076] The lunar mobile tool cabin mainly consists of a foldable tool cabin mobile chassis 20 and a transport fork 14, a lunar solar energy concentrating system 15, a hook 16, a lunar soil stacking tool 17, a bucket 18, and a welding actuator 19 mounted thereon; the end effector docking device 12 docks with the transport fork 14, the lunar solar energy concentrating system 15, the hook 16, the lunar soil stacking tool 17, the bucket 18, or the welding actuator 19;

[0077] The lunar base module (prefabricated module) is hoisted from the landing vehicle on the lunar surface to a predetermined position by means of the hook 16;

[0078] shoveling lunar soil from the lunar surface by means of a bucket 18;

[0079] The lunar soil stacking tool 17 is used to transport the lunar soil dug out by the shovel and stack it on the inflatable membrane of the lunar base cabin to form a loose lunar soil layer on the inflatable membrane.

[0080] The lunar solar concentrating system 15 is used to collect sunlight and use the heat energy of sunlight to sinter the outer surface of the loose lunar soil layer to complete the densification of the lunar soil layer;

[0081] The transport fork 14 is used to transport the boxed cargo containing the materials required for the thermoelectric power generation module from the landing lunar surface to a predetermined location near the lunar base cabin;

[0082] The welding actuator 19 is used to weld the components of the thermoelectric power generation module to form a series connection;

[0083] Remotely operate the end effector docking device 12 to dock or replace one of the transport fork 14, lunar solar concentrating system 15, hook 16, lunar soil stacking tool 17, bucket 18, and welding actuator 19, and perform the above operations;

[0084] The communication radar 13 of the lunar multifunctional lightweight operation robot and the communication radar 13 carried on the lunar mobile tool cabin are used to control the lunar multifunctional lightweight operation robot in a remote or semi-autonomous manner. The two communication radars can exchange information.

[0085] The solar concentrating system consists of a light-tracking system, a Fresnel lens concentrating device and a print head. The solar spot focused by the concentrating device follows the movement of the print head to achieve the sintering of the lunar soil layer and form a densified lunar soil layer of a certain thickness.

[0086] Embodiments of the present invention:

[0087] Step S1: Overall structure of protective layer

[0088] The protective layer's bottom support structure consists of a prefabricated rigid cabin with telescopic linkages and a flexible inflatable structure. The telescopic linkages drive the flexible structure to deploy, forming a rigid cabin protective layer with a specific curvature based on the terrain. The flexible membrane is inflated and shaped, and then stiffened through space radiation or heat treatment to increase the support structure's stiffness. Mechanical simulations are used to select appropriate materials, internal pressure, membrane thickness, and rib diameter, taking into account stiffness requirements and the frequencies of various vibration modes, resulting in a stable overall structure. The side supports help mitigate the impact of moonquakes and impacts on the overall structure. A thermoelectric power generation system, such as a heat pipe array or a PN-type semiconductor material array, is placed on the inflatable structure, forming multiple grid structures. This grid structure ensures the integral formation of the lunar regolith layer while fully utilizing temperature differences to generate electricity. A sufficient thickness of loose lunar regolith is deposited within the thermoelectric power generation network. Mechanical and thermal modeling and simulations ensure sufficient thickness redundancy in the loose regolith. The top layer of the loose regolith is solidified using methods such as solar sintering to form a dense regolith layer of sufficient thickness, enhancing the structural strength of the entire protective layer. A fluffy and dense lunar soil layer of sufficient thickness can absorb strong solar radiation. The lunar soil's heat transfer coefficient is extremely low in a vacuum environment, effectively isolating the heat transfer between lunar day and night, creating a nearly constant temperature environment within the protective layer. To monitor the mechanical, radiation protection, and thermal insulation properties of the entire protective layer, multi-dimensional sensors for mechanics, temperature, and radiation levels were incorporated at multiple locations throughout the construction process. This multi-dimensional data analysis provides real-time analysis of the protective structure's health, predicts performance changes, and predicts lifespan, enabling intelligent operation and maintenance of the protective layer.

[0089] Step S2: Inflation and expansion of the membrane structure, rigidification and arrangement of the thermoelectric power generation structure

[0090] The membrane structure deploys under the drive of the telescopic linkage of the cabin support and is then inflated and deployed via an inflatable device inside the cabin. The membrane structure must bear the weight of the lunar soil shield. Insufficient rigidity could cause deflation and collapse, resulting in structural instability. Therefore, the upper portion of the inflatable membrane structure requires rigidification. The membrane structure proposed in this invention can be rigidified using heat, using thermosetting resins and fiber-reinforced materials as the raw materials for the inflatable structure. This has the advantage of a predictable rigidification process. It is important to note that the duration of the heating process must be strictly controlled to prevent over-curing of the material and damage to its bonding properties. Radiation rigidification can also be performed using ultraviolet radiation from lunar solar energy. The advantages of ultraviolet radiation rigidification are low energy consumption and a fast and efficient rigidification process. The raw materials for the inflatable deployment structure can be glass fiber or epoxy composite materials. To further enhance the structural strength and load-bearing capacity of the rigidified membrane structure, support rods connected to the cabin and capable of automatically folding and unfolding can be added below the membrane structure, increasing the overall structural strength of the shield while reducing structural complexity.

[0091] A thermoelectric power generation module is placed atop the inflatable membrane structure, utilizing the temperature difference between the large day-to-night temperature fluctuations on the surface of the lunar regolith shield and the relatively stable temperature at the top of the membrane to generate electricity. In practical applications, materials used for thermoelectric power generation can include semiconductors, metals, heat pipes, and other materials. For example, under the influence of a temperature difference, the Seebeck effect causes positive charges (holes) in a P-type semiconductor to migrate away from the heat source. In contrast, the Seebeck effect causes electrons in an N-type semiconductor to migrate away from the heat source, generating an electric current. The magnitude of the generated electromotive force depends on the internal and external temperature difference and the material, and is independent of the size of the PN-type semiconductor. Connecting multiple thermocouples in series to form a large electromotive force generates electrical energy. Due to the real-time nature of the Seebeck effect, electromotive force is generated as long as there is a temperature difference between the two ends of the system. Based on the real-time temperature fluctuations of the lunar regolith shield, power generation can be achieved around the clock, except for certain times of the day when the internal and external temperatures are the same. By optimizing the configuration and arranging the density of thermocouple elements within a limited space, the system's power generation capacity can be significantly increased. At the same time, through modular construction, the system can be easily expanded, and an installation-free (easy to install) power generation device can be achieved through integrated molding with the inflatable membrane structure. The thermoelectric power generation module can be in an installed state when the air membrane is unfolded.

[0092] Step S3: Protective layer lunar soil stacking and dense layer formation

[0093] After the membrane structure is inflated and rigidified, a lunar regolith layer is laid on top. The lunar regolith layer is stacked in a grid formed by a thermoelectric power generation system. The equipment used for lunar regolith construction utilizes a foldable, lightweight, high-load mobile robotic arm, enabling rapid deployment and maneuverable operations on the lunar surface. The robotic arm's end effector features a self-detachable design and can be replaced with a mobile tool cabin, enabling multi-tasking capabilities such as handling, assembly, and shoveling. The multifunctional, lightweight lunar surface operation robot primarily consists of a foldable mobile chassis, a foldable robotic arm, and an end effector. The lunar surface mobile tool cabin primarily consists of a foldable mobile chassis and a tool cabin. The tool cabin houses actuators such as a hook, bucket, and lunar solar concentrating system, which perform tasks such as lifting, stacking lunar regolith, and densifying the lunar regolith layer during the construction of the protective layer.

[0094] During the construction of the fluffy lunar regolith layer, the robotic arm of the multifunctional lightweight lunar surface operation robot connects to the bucket in the lunar mobile tool bay via an autonomous docking mechanism, with a self-locking mechanism ensuring the safety and stability of the bucket connection. The robot is controlled remotely or semi-autonomously to scoop and pile lunar regolith, evenly covering the grid formed by the thermoelectric power generation system, completing the construction of the loose lunar regolith layer. Next, the robot returns the bucket tool to its original position and installs the solar concentrating system, replacing the end effector and reconnecting the circuit. The solar concentrating system consists of a tracking system, a Fresnel lens concentrating device, and a print head. The solar spot focused by the concentrating device follows the movement of the print head, sintering the lunar regolith layer to form a densified lunar regolith layer of a certain thickness.

[0095] Step S4: Protective layer structural health monitoring and operation and maintenance

[0096] The extreme lunar surface environment, such as diurnal temperature swings, high-energy cosmic radiation, and micrometeoroid impacts, can negatively impact the service life and mechanical properties of the combined shield. These adverse factors, accumulated over time, can easily lead to localized structural fatigue and failure, posing a threat to the daily activities of astronauts within the manned cabin. To promptly mitigate these negative effects and maintain the sustainability of the shield's functionality, the present invention constructs a digital twin system for real-time health monitoring and maintenance of the shield's structure. First, temperature, stress, and radiation sensors are placed within the loose lunar soil above the flexible air membrane, forming a multidimensional sensing system. This system acquires thermal, force, and radiation data under the highly volatile lunar surface. Simultaneously, based on proxy models of the shield's thermal, force, and radiation characteristics, the objective function is optimized and a deep neural network is constructed. The network is trained using training data. The trained neural network, combined with sensor data from the multidimensional sensing system, performs shield damage diagnosis (e.g., localized deformation, crack propagation, strength reduction, etc.), including but not limited to identifying damage locations, determining damage severity, and classifying and systematically identifying different damage patterns. After completing the damage diagnosis, use foldable working equipment to repair the protective layer accordingly. When formulating the phase fault repair strategy, on the one hand, it is necessary to ensure that the structural failure position is restored to the greatest extent possible. On the other hand, the designed repair method should not be too cumbersome to avoid increasing unnecessary construction difficulty.

[0097] After completing the damage diagnosis and repair of the protective layer, it is also necessary to predict its thermal, mechanical, radiation resistance and other physical properties. Taking into account that the values ​​of the state parameters such as internal strength, stiffness, thermal stress of the protective layer not only depend on the state at the previous moment, but are also affected by a variety of random factors, the present invention uses a dynamic Bayesian network to construct a dynamic evolution analysis model to express the dependency between the various factors affecting the independent variables, and to deal with issues such as the nonlinearity, temporal sequence and uncertainty of the parameters. Based on this, the performance of the protective layer is analyzed, the evolution process of the relevant physical parameters over time is calculated, and an early warning is given for possible failure crises in the future, and corresponding protection suggestions are given. Then, the operating equipment is ordered to reinforce the locations where the protective layer may be damaged in advance, thereby further reducing the negative impact of local failure on the function of the protective layer. In summary, the present invention aims at the structural damage that may occur to the protective layer in the extreme environment of the moon, combines the whole process of diagnosis-repair-prediction to build a digital twin system, and realizes the health management and maintenance of the protective layer.

Claims

1. A low-cost construction and maintenance method for a lunar shelter structure, characterized by: The lunar surface shielding structure includes a lunar base cabin and a lunar surface protection layer for being arranged on the lunar base cabin. The lunar base cabin includes a cabin body (7), a bracket (3), a plurality of supporting links (1) and a flexible inflatable membrane (2). The bracket (3) and the radially arranged supporting links (1) connected to the cabin body (7) are hinged to form an integral support of the flexible inflatable membrane (2). The cabin body (7) is connected to the flexible inflatable membrane (2) through the integral support. The lunar base cabin is prefabricated on the ground and launched to the lunar surface by a carrier. The inflatable membrane above the cabin body is rapidly expanded by inflation and pressurization to form a shelter. The outer surface of the inflatable membrane is then subjected to a rigidification treatment to form a rigidified outer surface. A lunar surface protection layer is provided on the outer layer of the rigidified inflatable membrane structure. The lunar surface protection layer includes a loose layer and a dense layer from the inside to the outside. The loose layer is provided with a plurality of thermoelectric power generation modules and various sensors. A corresponding thermoelectric power generation module is placed on the top layer of the inflatable membrane structure to generate electricity by utilizing the temperature difference between the large temperature fluctuations on the surface of the lunar soil protection layer during the day and night and the relatively stable temperature on the top of the inflatable membrane. Temperature, stress, and radiation sensors are placed in the loose lunar soil above the flexible inflatable membrane to form a multi-dimensional sensing system for obtaining thermal, force, and radiation sensing data in an environment with large fluctuations on the lunar surface. The low-cost construction and operation and maintenance method of the lunar shelter structure includes the following process: Step S1: First, a lunar base module is prefabricated on the ground and then launched to the lunar surface via a carrier. The lunar base module is composed of a rigid module body, supporting rods, and a flexible inflatable membrane prefabricated on the ground, which serves as the bottom support structure of the lunar surface protection layer. Step S2: Inflatable membrane expansion, rigidification and thermoelectric power generation structure arrangement The membrane structure is deployed under the drive of the cabin support link and then inflated and deployed by the inflation device inside the cabin. The membrane structure is used to bear the weight of the lunar soil protection layer and rigidify the inflatable membrane structure as a whole. A corresponding thermoelectric power generation module is arranged on the top layer of the inflatable membrane structure to generate electricity by utilizing the temperature difference between the large temperature fluctuations on the surface of the lunar soil protective layer during the day and the relatively stable temperature on the top of the inflatable membrane; Step S3: Protective layer lunar soil stacking and dense layer formation After the membrane structure is inflated and rigidified, a lunar soil layer needs to be laid on top of it. The lunar soil layer is stacked in a mesh grid composed of a thermoelectric power generation system. The equipment for lunar soil construction uses a foldable, lightweight, large-load mobile operation robot arm, which can achieve rapid deployment and mobile operation capabilities on the lunar surface. The end effector of the robot arm adopts an autonomous detachable design, which can be used in conjunction with the mobile tool cabin to complete the end effector replacement, realizing the multi-task adaptability of handling, assembly, and shoveling, respectively completing the lifting, stacking, and densification of the lunar soil layer during the construction of the protective layer. Step S4: Protective layer structural health monitoring and operation and maintenance Construct a digital twin system to conduct real-time health monitoring and operation and maintenance of the protective layer structure. First, place temperature, stress, and radiation sensors in the loose lunar soil above the flexible air membrane to form a multi-dimensional sensing system to obtain thermal, force, and radiation sensing data in an environment with large fluctuations on the lunar surface. At the same time, based on the proxy model of heat, force, and radiation of the protective layer, optimize the objective function and build a deep neural network, and train the network using training data. Utilize the trained neural network, combined with the sensor data obtained by the multi-dimensional sensing system, to diagnose damage to the protective layer, including but not limited to identifying the damage location, determining the damage level, and classifying and systematically identifying different damage patterns. After completing the damage diagnosis, use foldable working equipment to repair the protective layer accordingly. After completing the damage diagnosis and repair of the protective layer, it is also necessary to predict its thermal, mechanical, and radiation-resistant physical properties. In view of the possible structural damage to the protective layer under the extreme environment on the lunar surface, a digital twin system is constructed by combining the entire process of diagnosis-repair-prediction to achieve health management and maintenance of the protective layer.

2. The low-cost construction and operation and maintenance method for a lunar shelter structure according to claim 1, characterized in that: In S2, the supporting connecting rods of the bottom supporting structure of the protective layer drive the flexible structure to unfold, forming a rigid cabin protection layer with a certain curvature according to the terrain, and the flexible membrane is inflated and formed.

3. The low-cost construction and maintenance method for a lunar shelter structure according to claim 2, characterized in that: In S2, the stiffness of the supporting structure is increased by space radiation or heating stiffening treatment.

4. The low-cost construction and maintenance method for a lunar shelter structure according to claim 3, characterized in that: In S2, through mechanical simulation, appropriate materials, internal pressure, membrane thickness, and rib diameter are selected, and the stiffness requirements and the frequencies of each vibration mode are comprehensively considered to ensure a stable overall structure. The supports on both sides help reduce the impact of moonquakes and impacts on the overall structure.

5. The low-cost construction and maintenance method for a lunar shelter structure according to claim 4, characterized in that: The materials used for thermoelectric power generation are semiconductors, metal materials or heat pipes.

6. The low-cost construction and maintenance method for a lunar shelter structure according to claim 5, characterized in that: When using semiconductor materials, under the influence of temperature difference, according to the Seebeck effect, the positive charge in the P-type semiconductor will transfer away from the heat source, while the opposite is true for the N-type semiconductor, where the electrons transfer away from the heat source, thereby forming an electric current. The magnitude of the generated electromotive force is related to the internal and external temperature difference and the material, and has nothing to do with the size of the PN-type semiconductor. Connecting multiple thermocouples formed by such PN semiconductors in series can generate a larger electromotive force to provide electrical energy.

7. The low-cost construction and maintenance method for a lunar shelter structure according to claim 6, characterized in that: In step S3, during the construction of the fluffy lunar soil layer, the robotic arm of the lunar multifunctional lightweight working robot is connected to the bucket in the lunar mobile tool cabin through an autonomous docking mechanism, and the safety and stability of the bucket connection are ensured by a self-locking mechanism; the lunar multifunctional lightweight working robot is controlled by remote operation or semi-autonomous means to shovel and stack lunar soil, covering the lunar soil more evenly in the grid composed of the thermoelectric power generation system, completing the construction of the loose lunar soil part; next, the lunar multifunctional lightweight working robot completes the return of the bucket tool and the installation of the solar energy concentrating system. The solar light spot focused by the solar energy concentrating system follows the movement of the print head to realize the sintering of the lunar soil layer, forming a densified lunar soil layer of a certain thickness.

8. The low-cost construction and maintenance method for a lunar shelter structure according to claim 7, characterized in that: In step S4, a dynamic evolution analysis model is constructed using a dynamic Bayesian network to express the dependency relationship between the various factors affecting the independent variables and to handle the nonlinearity, temporal nature, and uncertainty of the parameters. Based on this, the performance of the protective layer is analyzed, and the evolution of relevant physical parameters over time is calculated. This provides an early warning of possible failure crises in the future, and gives corresponding protection recommendations. The operating equipment is then instructed to reinforce the locations where damage to the protective layer may occur in advance, so as to reduce the negative impact of local failures on the function of the protective layer.

9. A special equipment for the low-cost construction and operation and maintenance method of a lunar shelter structure according to claim 7 or 8, characterized in that: The special equipment includes a multifunctional lightweight lunar surface operation robot (8), a lunar surface mobile tool cabin, a communication radar (13) mounted on the multifunctional lightweight lunar surface operation robot, and a communication radar (13) mounted on the lunar surface mobile tool cabin; The multifunctional lightweight lunar operation robot mainly comprises a mobile robot chassis (10), a foldable robotic arm (11), and an end-effector docking device (12), wherein the base of the foldable robotic arm (11) is mounted on the mobile robot chassis (10), and the end of the foldable robotic arm (11) is connected to the end-effector docking device (12); The lunar surface mobile tool cabin includes a foldable tool cabin mobile chassis (20) and a transport fork (14), a lunar surface solar energy concentrating system (15), a hook (16), a lunar soil stacking tool (17), a bucket (18), and a welding actuator (19) loaded thereon; the end actuator docking device (12) is docked with the transport fork (14), the lunar surface solar energy concentrating system (15), the hook (16), the lunar soil stacking tool (17), the bucket (18), or the welding actuator (19); The lunar base module is hoisted from the carrier landing on the lunar surface to a predetermined position by means of a hook (16); Shoveling lunar soil from the lunar surface using a bucket (18); The lunar soil stacking tool (17) is used to transport the lunar soil dug out by the shovel and stack it on the inflatable membrane of the lunar base cabin to form a loose lunar soil layer on the inflatable membrane. The lunar solar concentrating system (15) is used to concentrate sunlight and use the heat energy of sunlight to sinter the outer surface of the loose lunar soil layer to complete the densification of the lunar soil layer; The transport fork (14) is used to transport the box-type cargo containing the materials required for the thermoelectric power generation module from the landing lunar surface to a predetermined location near the lunar base cabin; The welding actuator (19) is used to weld the components of the thermoelectric power generation module to form a series connection; docking or replacing one of the transport fork (14), lunar solar energy concentrating system (15), hook (16), lunar soil piling tool (17), bucket (18), and welding actuator (19) by remotely operating the end-effector docking device (12), and performing the above-mentioned operations; The communication radar (13) of the multifunctional lightweight lunar surface operation robot and the communication radar (13) mounted on the lunar surface mobile tool cabin are used for remote operation or semi-autonomous control of the multifunctional lightweight lunar surface operation robot. The two communication radars can exchange information.

10. The special equipment for the low-cost construction and maintenance method of the lunar shelter structure according to claim 9, characterized in that: The solar concentrating system consists of a light-tracking system, a Fresnel lens concentrating device and a print head. The solar spot focused by the concentrating device follows the movement of the print head to achieve the sintering of the lunar soil layer and form a densified lunar soil layer of a certain thickness.

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