A lunar surface plume dust diffusion characteristics ground calibration system and method

Abstract

The application relates to the field of aerospace technology, in particular to a lunar surface plume dust diffusion characteristic ground calibration system and method, which comprises a vacuum chamber, a solar simulator, a test platform, a dust raising device and a measuring device, wherein: the test platform is arranged in the interior of the vacuum chamber; the measuring device is arranged on one side of the interior of the vacuum chamber and comprises a dust raising sensor, a control circuit and an analysis display module; the dust raising sensor is arranged on the test platform through a rotary table and is electrically connected with the analysis display module through the control circuit; the dust raising device is arranged on the test platform in the interior of the vacuum chamber and is used for forming a dust raising area; and the solar simulator is arranged outside the vacuum chamber and is used for simulating a solar light source. The application can realize quantitative measurement of dust raising concentration under different angles and different concentrations, can satisfy calibration of dust raising concentration of all moon exploration missions, and can realize low-cost and high-reliable dust raising concentration calibration ground experiment with a calibration error of less than 15%.

Description

Technical Field

[0001] This application relates to the field of aerospace technology, and more specifically, to a ground calibration system and method for the diffusion characteristics of lunar plume dust. Background Technology

[0002] During the soft landing of a spacecraft on the moon, the engine is activated as it approaches the lunar surface to achieve a soft landing. After the plume is ejected from the engine, it impacts the lunar surface and stirs up lunar dust particles from the regolith. The lunar surface is a low-gravity, vacuum environment. These lunar dust particles stirred up by the plume will gradually diffuse after being coupled with the plume for a period of time, forming a dust cloud on the lunar surface. This dust cloud will not only deposit on the sensitive surfaces of the detection equipment, reducing the equipment's functionality or even causing it to fail, but it will also obstruct the lander's descent view, affecting the success or failure of the entire mission.

[0003] A sensor was designed for in-situ measurement of plume dust, as described in CN 2024114062384. The dust concentration characteristics are inverted by measuring the changes in the output characteristics of solar cells. The sensor consists of three solar cells and their support.

[0004] However, there are currently no reports on ground calibration methods for measuring dust concentration using solar cells. Therefore, it is necessary to design a calibration system that can measure dynamic dust concentration, collect the short-circuit current of solar cells under different dust concentrations, establish a nonlinear mapping relationship between short-circuit current and dust concentration, and lay the foundation for reliable inversion results for on-orbit dust concentration inversion. Summary of the Invention

[0005] This application provides a ground calibration system and method for the diffusion characteristics of lunar plume dust, which can realize equivalent measurement and calibration on the ground, construct a quantitative function relationship between dust concentration and sensor output, and provide an on-orbit accurate inversion basis for plume dynamic dust measurement instruments.

[0006] To achieve the above objectives, this application provides a ground calibration system for the diffusion characteristics of lunar plume dust, including a vacuum chamber, a solar simulator, a test platform, a dust suppression device, and a measuring device. The test platform is located inside the vacuum chamber. The measuring device, located on one side inside the vacuum chamber, includes a dust sensor, a control circuit, and an analysis and display module. The dust sensor is mounted on the test platform via a turntable and is electrically connected to the analysis and display module via the control circuit. The dust suppression device is located on the test platform inside the vacuum chamber to create a dust suppression area. The solar simulator is located outside the vacuum chamber to simulate a solar light source, illuminating the dust suppression area inside the vacuum chamber. The center of the light-emitting surface of the solar simulator, the center of the dust suppression area, and the center of the measured surface of the dust sensor are aligned in a straight line. Furthermore, the vacuum chamber is equipped with a vacuum pumping device and a temperature control module, wherein the vacuum pumping device maintains a vacuum level of 10⁻⁶ inside the vacuum chamber.-4 ~10 - 5 Pa; The temperature inside the vacuum chamber is maintained at -20℃ to 60℃ via the temperature control module.

[0007] Furthermore, the dust control device includes a dust generation unit, a dust parameter setting and acquisition unit, and simulated lunar dust. The dust generation unit, located on the test platform, consists of an aerosol generator and an aerosol distributor, and is used to generate dust. The simulated lunar dust is placed inside the dust-generating area, with a particle size ≤100μm. The dust parameter setting and acquisition unit is used to set the dust parameters, with a dust concentration range of 0~20mg / cm³. 2 .

[0008] Furthermore, the simulated lunar dust needs to be dried at a temperature of 200~220℃ for half an hour before calibration testing.

[0009] Furthermore, the turntable has horizontal rotation and angle adjustment functions. The horizontal rotation angle range of the turntable is 0~360°, and the angle adjustment range of the turntable is 0~90°.

[0010] Furthermore, the turntable is mounted on the test platform via a moving device, and the turntable moves horizontally on the test platform using the moving device.

[0011] Furthermore, the dust sensor is equipped with solar cells, including a first cell, a second cell, and a third cell, which are respectively disposed on the three surfaces of the dust sensor cube, and the three solar cells are installed in the same direction.

[0012] Furthermore, the first, second, and third solar cells are all connected to the analysis and display module via a control circuit. The data acquisition frequency of the control circuit is 0.1s / time, ensuring that the output short-circuit current of the three solar cells is measured simultaneously, and it also has on-orbit overcooling or overheating protection functions.

[0013] In addition, this application also provides a method for a ground calibration system utilizing the dispersion characteristics of lunar plume dust, comprising the following steps:

[0014] Step 1: Turn on the vacuum chamber and solar simulator to maintain a vacuum level of 10. -4 The output of a standard solar cell is measured under the simulated solar light source. If the short-circuit current fluctuation is within 1%, the output of the light source is considered stable.

[0015] Step 2: Install the dust sensor on the test platform inside the vacuum chamber, maintaining a vacuum level of 10. -4pa, align the first solar cell with the light-emitting surface of the solar simulator, adjust the distance between the dust sensor and the solar source so that its short-circuit current deviates from the output short-circuit current under the standard solar cell by less than 5%, record its short-circuit current, and then adjust the angle of the turntable to record a short-circuit current data every 5°.

[0016] Step 3: Adjust the positions of the second and third solar cells by rotating the turntable and moving the device. Repeat step 2 to measure the second and third solar cells and obtain the output characteristics of the three solar cells under no-load conditions.

[0017] Step 4: Set up the dust-generating device on the test platform inside the vacuum chamber to create a dust-generating area containing simulated lunar dust. Set the dust concentration range to 0~20 mg / cm³. 2 The concentration interval was 0.2 mg / cm³. 2 When the variation range of a single concentration value remains within 5%, repeat steps 2-3 to measure the current output value under different dust concentrations.

[0018] Step 5: By analyzing and displaying the output short-circuit current and the parameters of the dust-generating area, the dust concentration measurement functions of the three solar cells are obtained respectively.

[0019] The ground calibration system and method for lunar plume dust dispersion characteristics provided in this application have the following beneficial effects:

[0020] This application enables quantitative measurement of dust concentration at different angles and concentrations, providing a reliable inversion method for in-orbit dust concentration inversion. It meets the calibration requirements for dust concentration in all lunar exploration missions, with a calibration error within 15%. It can achieve low-cost and highly reliable ground-based dust concentration calibration experiments. At the same time, it can also be used for efficiency evaluation of solar cells at different solar altitude angles under no-load conditions, providing a simpler and more effective method for calculating dust concentration efficiency. Attached Figure Description

[0021] The accompanying drawings, which form part of this application, are used to provide a further understanding of the application and to make other features, objects, and advantages of the application more apparent. The illustrative embodiments and descriptions of this application are used to explain the application and do not constitute an undue limitation of the application.

[0022] In the attached diagram:

[0023] Figure 1 This is a schematic diagram of the structure of a ground calibration system for lunar plume dust diffusion characteristics provided in an embodiment of this application;

[0024] Figure 2This is an installation diagram of a solar cell according to an embodiment of this application;

[0025] In the diagram: 1-vacuum chamber, 2-solar simulator, 3-test platform, 4-dust control device, 5-dust control area, 6-turntable, 7-dust sensor, 8-first solar cell, 9-second solar cell, 10-third solar cell. Detailed Implementation

[0026] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0027] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0028] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0029] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0030] In addition, the term "multiple" should mean two or more.

[0031] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0032] like Figure 1 As shown, this application provides a ground calibration system for the diffusion characteristics of lunar plume dust, including a vacuum chamber 1, a solar simulator 2, a test platform 3, a dust suppression device 4, and a measuring device. The test platform 3 is located inside the vacuum chamber 1. The measuring device is located on one side inside the vacuum chamber 1 and includes a dust sensor 7, a control circuit, and an analysis and display module. The dust sensor 7 is mounted on the test platform 3 via a turntable 6 and is electrically connected to the analysis and display module via the control circuit. The dust suppression device 4 is located on the test platform 3 inside the vacuum chamber 1 to form a dust suppression area 5. The solar simulator 2 is located outside the vacuum chamber 1 to simulate a solar light source and irradiate the dust suppression area 5 inside the vacuum chamber 1. The center of the light-emitting surface of the solar simulator 2, the center of the dust suppression area 5, and the center of the measured surface of the dust sensor 7 are aligned on a straight line.

[0033] Specifically, the ground calibration system for lunar plume dust diffusion characteristics provided in this application creates a uniform dust region 5 in a vacuum environment, measures the output parameters of the dust characteristic measuring device after sunlight passes through the dust region 5, and establishes the relationship between the dust parameters and the output of the measuring device. This enables ground calibration of dust diffusion characteristics, providing a reliable calibration system and testing method for subsequent lunar plume dust diffusion characteristic measurements, and laying a technical foundation for in-orbit dust data inversion. The vacuum chamber 1 provides a vacuum environment; the solar simulator 2 simulates sunlight irradiation; the dust-generating device 4 mainly simulates the generation of the dust region 5 containing lunar dust; and the measuring device analyzes and processes the measured parameters to calibrate the dust diffusion characteristics.

[0034] Furthermore, vacuum chamber 1 is equipped with a vacuum pumping device and a temperature control module, wherein the vacuum pumping device maintains a vacuum level of 10 inside vacuum chamber 1. -4 ~10 -5 Pa; the temperature inside vacuum chamber 1 is maintained at -20℃ to 60℃ via a temperature control module. The vacuum pumping device preferably consists of a vacuum pump and a molecular pump, primarily used to control the vacuum level inside vacuum chamber 1 and maintain it at 10 Pa. -4 ~10 -5 Pa. The temperature control module is used to control the temperature inside vacuum chamber 1, with a control accuracy of 0.5℃ and a temperature adjustment range of -20℃ to 60℃.

[0035] Furthermore, the dust suppression device 4 includes a dust generation unit, a dust parameter setting and acquisition unit, and simulated lunar dust. The dust generation unit, located on the test platform 3, consists of an aerosol generator and an aerosol distributor, and is used to generate dust. The simulated lunar dust is located within the dust suppression area 5, with a particle size ≤100μm. The dust parameter setting and acquisition unit is used to set the dust parameters, with a dust concentration range of 0~20mg / cm³. 2 .

[0036] Furthermore, the simulated lunar dust needs to be dried at a temperature of 200~220℃ for half an hour before calibration testing.

[0037] Specifically, the dust-generating device 4 is mainly used to generate dust, and the dust parameter setting and acquisition unit is mainly used to set the dust parameters and collect and measure the concentration and particle size distribution of the dust. Simulated lunar dust is used to simulate lunar dust particles in a vacuum environment. In this embodiment, the particle size of the simulated lunar dust is ≤100μm, and it needs to be dried at 200~220℃ for half an hour before calibration testing. The dust concentration measurement range of the dust-generating area 5 is 0~20mg / cm³. 2 The dust concentration monitoring accuracy is better than 95%, and it can maintain a uniformity of 5% within 3 hours.

[0038] Furthermore, the turntable 6 has horizontal rotation and angle adjustment functions. The horizontal rotation angle range of the turntable 6 is 0~360°, and the angle adjustment range of the turntable 6 is 0~90°.

[0039] Furthermore, the turntable 6 is mounted on the test platform 3 via a moving device, and the turntable 6 moves horizontally on the test platform 3 using the moving device.

[0040] Specifically, the turntable 6 is mainly used to adjust the rotation angle of the dust sensor 7. The horizontal rotation angle range of the turntable 6 is 0~360°, and the accuracy of the turntable 6 is preferably 0.5°; the angle adjustment range of the turntable 6 is 0~90°, and the accuracy is preferably 0.5°. The moving device is mainly used to move the dust sensor 7 horizontally on the test platform 3, thereby adjusting the distance between the dust sensor 7 and the dust area 5.

[0041] Furthermore, such as Figure 2 As shown, the dust sensor 7 is equipped with solar cells, including a first solar cell 8, a second solar cell 9, and a third solar cell 10, which are respectively disposed on the three surfaces of the cubic dust sensor 7. The three solar cells are installed in the same direction. The solar cells are disposed on the three sides of the dust sensor 7 and are used to invert the dust concentration characteristics based on the changes in the output characteristics of the solar cells during the calibration process.

[0042] Furthermore, the first solar cell 8, the second solar cell 9, and the third solar cell 10 are all connected to the analysis and display module via a control circuit. The control circuit outputs data at a frequency of 0.1 s / time, ensuring simultaneous measurement of the short-circuit current of the three solar cells and providing on-orbit overcooling or overheating protection. The analysis and display module, through the control circuit, collects the short-circuit current of the solar cells under different dust concentrations, establishing a nonlinear mapping relationship between short-circuit current and dust concentration, providing reliable inversion results for on-orbit dust concentration inversion.

[0043] In addition, this application also provides a method for a ground calibration system utilizing the dispersion characteristics of lunar plume dust, comprising the following steps:

[0044] Step 1: Open vacuum chamber 1 and solar simulator 2 to maintain a vacuum level of 10. -4 The output of a standard solar cell under the simulated solar light source is measured in Pa range. The solar simulator 2 is preheated for 40-60 minutes. If the short-circuit current fluctuation is within 1%, the output of the light source is considered stable.

[0045] Step 2: Install the dust sensor 7 on the test platform 3 inside the vacuum chamber 1, maintaining a vacuum level of 10. -4 pa, align the first solar cell 8 with the light-emitting surface of the solar simulator 2, adjust the distance between the dust sensor 7 and the solar source so that its short-circuit current deviates from the output short-circuit current under a standard solar cell by less than 5%, record its short-circuit current, and then adjust the angle using the turntable 6, recording a short-circuit current data point I every 5°. sc01 ;

[0046] Step 3: By rotating the turntable 6 and translating the moving device, adjust the positions of the second solar cell 9 and the third solar cell 10 respectively. Repeat step 2 to measure the second solar cell 9 and the third solar cell 10, and obtain the output characteristics I of the three solar cells under no-load conditions. sc0i (i=1, 2, 3);

[0047] Step 4: Set up the dust-generating device 4 on the test platform 3 inside the vacuum chamber 1. Use the dust-generating device 4 to create a dust-generating area 5 containing simulated lunar dust, and set the dust concentration range to 0~20 mg / cm³. 2 The concentration interval was 0.2 mg / cm³. 2 When the variation range of a single concentration value remains within 5%, repeat steps 2-3 to measure the current output value I under different dust concentrations. sci (i=1, 2, 3);

[0048] Step 5: By analyzing and displaying the output short-circuit current and the parameters of dust-generating area 5, the dust concentration measurement functions for the three solar cells are obtained respectively. ,

[0049] Among them, i=1, 2, 3; A i is the dust concentration expansion coefficient; e is the background of the exponential function; x i Dust concentration; t i is the dust concentration diffusion constant.

[0050] The embodiments of this application will be described in more detail below with reference to different parameters and different dust concentration data, wherein the solar cells are triple-junction gallium arsenide cells from the same batch.

[0051] Example 1

[0052] The output values ​​of the short-circuit current of the first battery cell 8 on the dust sensor 7 at different incident angles in a dust-free environment are shown in Table 1:

[0053] ,

[0054] Table 1. Output short-circuit current of the first solar cell under dust-free environment.

[0055] Example 2

[0056] The first battery cell 8 on the dust sensor 7 operates when the dust concentration is 0.086 mg / cm³. 2 Table 2 shows the output values ​​of the short-circuit current under different incident angles in the environment:

[0057] ,

[0058] Table 2 0.086 mg / cm 2 At a certain concentration, the output short-circuit current of the first solar cell is...

[0059] Example 3

[0060] The first battery cell 8 on the dust sensor 7 operates when the dust concentration is 1.00 mg / cm³. 2 Table 3 shows the output values ​​of the short-circuit current under different incident angles in the environment:

[0061] ,

[0062] Table 3 1.00 mg / cm 2 At a certain concentration, the output short-circuit current of the first solar cell is...

[0063] Example 4

[0064] The first battery cell 8 on the dust sensor 7 operates when the dust concentration is 5.71 mg / cm³. 2 The output values ​​of the short-circuit current under different incident angles in the environment are shown in Table 4:

[0065] ,

[0066] Table 4 5.71 mg / cm 2 At a certain concentration, the output short-circuit current of the first solar cell is...

[0067] Example 5

[0068] The first battery cell 8 on the dust sensor 7 operates when the dust concentration is 13.71 mg / cm³. 2 Table 5 shows the output values ​​of the short-circuit current under different incident angles in the environment:

[0069] ,

[0070] Table 5 13.71 mg / cm 2 At a certain concentration, the output short-circuit current of the first solar cell is...

[0071] Example 6

[0072] The fitted values ​​of the short-circuit current output by the first battery cell 8 on the dust sensor 7 at different incident angles are shown in Table 6:

[0073] ,

[0074] Table 6 Fitted values ​​of the output short-circuit current of the first solar cell at different incident angles

[0075] This shows that in the absence of dust dispersion, the short-circuit current decreases exponentially with increasing solar incidence angle; in the presence of dust, with the same solar incidence angle, the short-circuit current decreases more significantly with increasing dust concentration; and with the same dust concentration, the short-circuit current decreases exponentially with increasing solar incidence angle. For the same solar cell, with the same dust concentration, the dust concentration diffusion coefficient exhibits a cosine variation with increasing solar incidence angle, while the dust concentration diffusion constant changes relatively little (value range approximately 3.3~3.8). The ground calibration system for lunar plume dust diffusion characteristics provided in this application embodiment enables quantitative measurement of dust concentration at different angles and concentrations.

[0076] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A ground calibration system for the diffusion characteristics of lunar surface plume dust, characterized in that, It includes a vacuum chamber, a solar simulator, a testing platform, a dust suppression device, and measuring equipment, among which: The test platform is located inside the vacuum chamber; The measuring device is located on one side inside the vacuum chamber and includes a dust sensor, a control circuit, and an analysis and display module. The dust sensor is mounted on the test platform via a turntable and is electrically connected to the analysis and display module via the control circuit. The dust-generating device is installed on the test platform inside the vacuum chamber to create a dust-generating area; The dust control device includes a dust generation unit, a dust parameter setting and acquisition unit, and a simulated lunar dust, wherein: The dust generation unit is set on the test platform and consists of an aerosol generator and an aerosol distributor, used to generate dust. The simulated lunar dust is placed inside the dust-generating area, with a particle size ≤100μm; The dust parameter setting and acquisition unit is used to set dust parameters, with a dust concentration range of 0~20 mg / cm³. 2 ; The turntable has horizontal rotation and angle adjustment functions. The horizontal rotation angle range of the turntable is 0~360°, and the angle adjustment range of the turntable is 0~90°. The solar simulator is located outside the vacuum chamber and is used to simulate a solar energy source to irradiate the dusty area inside the vacuum chamber. The center of the light-emitting surface of the solar simulator, the center of the dust-generating area, and the center of the measured surface of the dust sensor are aligned in a straight line.

2. The ground calibration system for the diffusion characteristics of lunar plume dust according to claim 1, characterized in that, The vacuum chamber is equipped with a vacuum pumping device and a temperature control module, wherein: The vacuum chamber is evacuated to a vacuum level of 10 using the vacuum pumping device. -4 ~10 -5 Pa; The temperature control module maintains the temperature inside the vacuum chamber at -20℃ to 60℃.

3. The ground calibration system for the diffusion characteristics of lunar plume dust according to claim 1, characterized in that, The simulated lunar dust needs to be dried at a temperature of 200~220℃ for half an hour before calibration testing.

4. The ground calibration system for the diffusion characteristics of lunar plume dust according to claim 1, characterized in that, The turntable is mounted on the test platform via a moving device, and the turntable moves horizontally on the test platform using the moving device.

5. The ground calibration system for the diffusion characteristics of lunar plume dust according to claim 1, characterized in that, The dust sensor is equipped with solar cells, which include a first cell, a second cell, and a third cell, respectively disposed on the three surfaces of the dust sensor cube, and the three solar cells are installed in the same direction.

6. The ground calibration system for the diffusion characteristics of lunar plume dust according to claim 5, characterized in that, The first, second, and third solar cells are all connected to the analysis and display module via a control circuit. The control circuit outputs data at a frequency of 0.1s / time to ensure that the short-circuit current of the three solar cells is measured simultaneously, and it also has on-orbit overcooling or overheating protection functions.

7. A method for a ground calibration system utilizing the lunar plume dust dispersion characteristics according to any one of claims 1-6, characterized in that, Includes the following steps: Step 1: Turn on the vacuum chamber and solar simulator to maintain a vacuum level of 10. -4 The output of a standard solar cell is measured under the simulated solar light source. If the short-circuit current fluctuation is within 1%, the output of the light source is considered stable. Step 2: Install the dust sensor on the test platform inside the vacuum chamber, maintaining a vacuum level of 10. -4 pa, align the first solar cell with the light-emitting surface of the solar simulator, adjust the distance between the dust sensor and the solar source so that its short-circuit current deviates from the output short-circuit current under the standard solar cell by less than 5%, record its short-circuit current, and then adjust the angle of the turntable to record a short-circuit current data every 5°. Step 3: Adjust the positions of the second and third solar cells by rotating the turntable and moving the device. Repeat step 2 to measure the second and third solar cells and obtain the output characteristics of the three solar cells under no-load conditions. Step 4: Set up the dust-generating device on the test platform inside the vacuum chamber to create a dust-generating area containing simulated lunar dust. Set the dust concentration range to 0~20 mg / cm³. 2 The concentration interval was 0.2 mg / cm³. 2 When the variation range of a single concentration value remains within 5%, repeat steps 2-3 to measure the current output value under different dust concentrations. Step 5: By analyzing and displaying the output short-circuit current and the parameters of the dust-generating area, the dust concentration measurement functions of the three solar cells are obtained respectively.

Images