A Digital Lunar Surface Generation Method for Probe Soft Landing Simulation

Abstract

The present invention discloses a digital lunar surface generation method for detector soft landing simulation, which relates to the technical field of digital lunar surface generation. The method includes determining a lunar standard crater model and a standard rock model based on the terrain type and terrain area of the detector soft landing area, obtaining the minimum and maximum values of the diameters of the craters and rocks, and further obtaining the total number of craters and rocks in the detector soft landing area. By repeatedly obtaining the random coordinates of the craters and rocks corresponding to the diameters of each crater and rock respectively, a random lunar crater terrain and a random lunar rock terrain are obtained, and thus a random digital lunar surface containing craters and rocks is obtained. Therefore, by using a digital lunar surface generation method for detector soft landing simulation, a digital lunar surface terrain can be quickly generated according to actual terrain parameters, with strong flexibility, and accurate terrain data can be provided for verification simulation.

Description

Technical Field

[0001] The present invention relates to the technical field of digital lunar surface generation, and more particularly to a digital lunar surface generation method for probe soft landing simulation. Background Art

[0002] During the soft landing process of a probe, in order to comprehensively verify the rationality of the landing mechanism scheme, in addition to conducting corresponding ground simulation verification tests and obtaining some dynamic characteristics through dynamic analysis, numerical simulation and simulation of various landing conditions are also required according to the initial landing conditions and lunar surface characteristics to study the landing stability of the landing buffer mechanism.

[0003] The study of landing stability is an important task in the development stage of a probe. Due to the complexity and uncertainty of lunar surface conditions, the pits and protrusions on the lunar surface have a great impact on stable landing. General dynamic analysis is difficult to comprehensively simulate the landing conditions of all lunar surface conditions. Especially when the lunar surface conditions are relatively poor (with large pits or protrusions), the stability of the probe is worse, although the probability of this kind of working condition is extremely small, it cannot be ignored for a probe with extremely high reliability requirements.

[0004] During the soft landing process of a probe on the lunar surface, contact and collision occur between the probe footpad and the lunar surface. In order to judge the contact and collision process between the probe footpad and the lunar surface, a lunar topographic map with a resolution smaller than the geometric feature size resolution of the footpad is required, that is, the resolution requirement of the lunar topographic map is in the centimeter range. This digital lunar surface generation technology is different from the usual lunar surface topography simulation technology. Compared with the traditional sand table manufacturing method, the traditional sand table manufacturing method is mainly used for display and has too low precision to be used for landing simulation. Compared with some real-time lunar surface topography simulation methods based on optical and remote sensing data, its precision is higher, but for general landing mechanism verification tests, the required technology is too complex and the cost is too high.

[0005] Therefore, there is an urgent need for a high-precision digital lunar surface generation method to provide reliable landing area data for the dynamic verification test of the probe, with strong flexibility. For the landing requirements and landing areas of different probes to be verified, it can generate the lunar surface morphology according to the actual parameters locally, such as the number, diameter, and distribution of lunar surface pits and protrusions, and quickly provide accurate terrain data for the subsequent verification and simulation work. Summary of the Invention

[0006] The object of the present invention is to provide a digital lunar surface generation method for probe soft landing simulation, which can quickly and accurately generate the random terrain features including lunar impact craters and rock protrusions in the soft landing analysis area of the probe on the lunar surface, and realize the construction of reliable lunar surface features for the stable landing test of the probe.

[0007] To achieve the above object, the present invention provides a digital lunar surface generation method for the soft landing simulation of a detector, comprising the following steps:

[0008] S1. Obtain the position parameters of the soft landing area of the detector, and determine the terrain type and terrain area of the soft landing area of the detector;

[0009] S2. According to the terrain type of the soft landing analysis area of the detector, respectively determine the standard lunar crater model and the standard lunar rock model;

[0010] S3. According to the standard lunar crater model and the standard lunar rock model, respectively determine the minimum and maximum values of the lunar crater diameter and the lunar rock diameter;

[0011] S4. According to the lunar crater diameter and the lunar rock diameter, respectively determine the number of lunar craters and lunar rocks corresponding to the respective diameters, and calculate the total number of lunar craters and lunar rocks in the soft landing area of the detector;

[0012] S5. Based on the terrain area, use a random function to loop and obtain the random coordinates of the craters and rocks corresponding to each crater diameter and rock diameter, and then respectively obtain the random terrain of lunar craters and the random terrain of lunar rocks;

[0013] S6. Superimpose the random terrain of lunar craters and the random terrain of lunar rocks to obtain a random digital lunar surface containing lunar craters and lunar rocks.

[0014] Preferably, the function corresponding to the lunar standard crater model is:

[0015]

[0016] In the formula, (x 坑 , y 坑 , z 坑 ) are the three-dimensional coordinates of the lunar crater, and D_crater is the diameter of the lunar crater;

[0017] The function corresponding to the lunar standard rock model is:

[0018]

[0019] In the formula, (x 石 , y 石 , z 石 ) are the three-dimensional coordinates of the lunar rock, and D_rock is the diameter of the lunar rock.

[0020] Preferably, the relationship between the number of lunar craters and the crater diameter is:

[0021]

[0022] The relational expression between the cumulative number of lunar rocks and the rock size is as follows:

[0023] lgN 石 = -2.5883lgD 石 -3.5301, 0.04m < D 石 < 0.4m;

[0024] Wherein, N 坑 、N 石 are the number of lunar impact craters and the number of rocks respectively.

[0025] Therefore, the present invention adopts the above-mentioned digital lunar surface generation method for the soft landing simulation of a detector, and has the following technical effects:

[0026] (1) By using the position parameters of the landing area and selecting appropriate statistical models of impact craters and rocks according to the terrain type, it is possible to simulate the pits and protrusions on the lunar surface, realize the construction of lunar surface terrain features, and build a reliable lunar surface feature for the stable landing test of the detector.

[0027] (2) It has strong flexibility. For the landing requirements and landing areas of different detectors to be verified, it can change the generated lunar surface morphology according to the actual parameters according to local conditions, such as the number, diameter, distribution, etc. of the pits and protrusions on the lunar surface, and can quickly provide relatively accurate terrain data for its verification simulation.

[0028] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Description of the Drawings

[0029] Figure 1 is a flowchart for establishing a digital lunar surface in an embodiment of a digital lunar surface generation method for the soft landing simulation of a detector;

[0030] Figure 2 is a flowchart of a terrain analysis method in an embodiment of a digital lunar surface generation method for the soft landing simulation of a detector;

[0031] Figure 3 is a cross-sectional view of a standard lunar impact crater in an embodiment of a digital lunar surface generation method for the soft landing simulation of a detector;

[0032] Figure 4 is a cross-sectional view of a standard lunar rock in an embodiment of a digital lunar surface generation method for the soft landing simulation of a detector;

[0033] Figure 5 is a random topographic map of lunar impact craters in an embodiment of a digital lunar surface generation method for the soft landing simulation of a detector;

[0034] Figure 6It is a random topographic map of lunar rocks in an embodiment of a digital lunar surface generation method for probe soft landing simulation;

[0035] Figure 7 It is a schematic diagram of a random digital lunar surface in an embodiment of a digital lunar surface generation method for probe soft landing simulation. Detailed implementation manner

[0036] The present invention can be more detailedly explained through the following embodiments. The purpose of disclosing the present invention is to protect all changes and improvements within the scope of the present invention. The present invention is not limited to the following embodiments.

[0037] In the existing analysis of the stable landing of a probe, due to the complexity and uncertainty of the lunar surface conditions, the pits and bumps on its surface have a great impact on the stable landing, making it difficult for subsequent dynamic analysis to comprehensively simulate the landing conditions of all lunar surface conditions. Based on this, the present invention provides a digital lunar surface generation method for probe soft landing simulation, as Figure 1 shown, including the following steps:

[0038] S1. Obtain the position parameters of the probe soft landing area, and determine the terrain type and terrain area of the probe soft landing area, so as to analyze the distribution of pits and bumps in the probe soft landing area, as Figure 2 shown.

[0039] S2. Since the impact crater is mainly composed of a crater bottom and a crater lip, in order to facilitate the calculation of the shape of a typical crater, it is simplified to obtain a standard lunar impact crater model, and the corresponding standard lunar impact crater profile diagram, as Figure 3 shown, and the corresponding function is:

[0040]

[0041] In the formula, (x 坑 , y 坑 , z 坑 ) are the three-dimensional coordinates of the lunar impact crater, and D crater is the diameter of the lunar impact crater.

[0042] Since the diameters and shapes of rocks cover a wide range, the ratio of the minimum scale to the maximum scale of the standard lunar rock shape is between 0.5 and 1, the surface is circular or rectangular, there may be pits, weathering or vesiculation, and the standard height is equal to half of the diameter. In this embodiment, an ideal parabola is used as the standard rock model, and the corresponding standard rock model profile diagram, as Figure 4 shown, and the corresponding function is:

[0043]

[0044] In the formula, (x 石, y 石 , z 石 ) are the three-dimensional coordinates of the lunar rock, and D_stone is the diameter of the lunar rock.

[0045] Since the soft landing position of the detector is in a flat mare region, which meets the standard lunar crater model, therefore, through the determined standard lunar impact crater model and standard lunar rock model, it is possible to simulate the concave and convex terrains on the lunar surface, providing a theoretical basis for the construction of a digital lunar surface.

[0046] S3. According to the determined standard lunar impact crater model and standard lunar rock model, respectively determine the minimum and maximum values of the lunar impact crater diameter and the lunar rock diameter, and generate several groups of diameters of lunar impact craters and lunar rocks through a random algorithm.

[0047] In this embodiment, lunar impact craters can be classified by size, such as fresh craters, young craters, mature craters, and old craters, etc. For each category, within the range of the maximum and minimum diameters of the lunar impact crater, a set of values is generated using linear interpolation as the diameters that may appear in a certain category, for determining the distribution of lunar impact craters. The method for determining the distribution of lunar rocks is basically the same as that of lunar impact craters.

[0048] S4. According to the generated diameters of each lunar impact crater and lunar rock, respectively determine the corresponding number of impact craters and rocks, and calculate the total number of lunar impact craters and lunar rocks within the soft landing area of the detector.

[0049] Among them, there is a good exponential inverse relationship between the number of lunar craters per square kilometer on the lunar surface and their diameter, that is, the smaller the diameter of the circular structure, the denser its distribution. The number of lunar impact craters N 坑 and its diameter satisfy the relationship:

[0050]

[0051] According to the distribution of rock blocks on the lunar surface, the cumulative number of lunar rocks N 石 and its diameter satisfy the relationship:

[0052] lgN 石 = -2.5883lgD 石 - 3.5301, 0.04m < D 石 < 0.4m.

[0053] S5. Based on the obtained terrain type and terrain area of the detector soft landing area, cyclically obtain the random coordinates of the impact craters and rocks corresponding to each impact crater diameter and rock diameter, thereby respectively obtaining the random terrain of lunar impact craters and the random terrain of lunar rocks, such as Figure 5 and Figure 6as shown

[0054] In this embodiment, the random coordinates of lunar craters and lunar rocks are generated by using the rand function. According to the obtained terrain area, the generated random numbers are multiplied by the terrain area to be converted into coordinate values proportional to the terrain area, so as to simulate the distribution of lunar craters and lunar rocks in the soft landing area of the detector.

[0055] S6. Superimpose the random terrain of lunar craters and the random terrain of lunar rocks to obtain a random digital lunar surface containing craters and rocks, that is, generate a topographic map of the soft landing area of the detector, as Figure 7 as shown

[0056] Therefore, by adopting the above-mentioned method for generating a digital lunar surface for detector soft landing simulation, the present invention can quickly and accurately generate the random terrain features of lunar craters and rock protrusions in the soft landing analysis area of the detector on the lunar surface, construct a reliable lunar surface feature for the stable landing test of the detector, and facilitate the subsequent research on analyzing the stability of the detector landing.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A digital lunar surface generation method for the soft landing simulation of a detector, characterized in that Including the following steps: S1. Obtain the position parameters of the soft landing area of the detector, and determine the terrain type and terrain area of the soft landing area of the detector; S2. According to the terrain type of the soft landing analysis area of the detector, respectively determine the standard lunar crater model and the standard lunar rock model; Among them, the function corresponding to the standard lunar crater model is: where (x 坑 , y 坑 , z 坑 ) are the three-dimensional coordinates of the lunar crater, and D 坑 is the diameter of the lunar crater; S3. According to the standard lunar crater model and the standard lunar rock model, respectively determine the minimum and maximum values of the lunar crater diameter and the lunar rock diameter; S4. According to the lunar crater diameter and the lunar rock diameter, respectively determine the number of lunar craters and lunar rocks corresponding to the respective diameters, and calculate the total number of lunar craters and lunar rocks in the soft landing area of the detector; S5. Based on the terrain area, use a random function to loop to obtain the random coordinates of the craters and rocks corresponding to each crater diameter and rock diameter, and then respectively obtain the random terrain of lunar craters and the random terrain of lunar rocks; S6. Superimpose the random terrain of lunar craters and the random terrain of lunar rocks to obtain a random digital lunar surface containing lunar craters and lunar rocks.

2. A digital lunar surface generation method for detector soft landing simulation according to claim 1, characterized in that, The function corresponding to the lunar standard rock model is: Wherein, (x 石 , y 石 , z 石 ) are the three-dimensional coordinates of the lunar rock, and D 石 is the diameter of the lunar rock.

3. A digital lunar surface generation method for probe soft landing simulation according to claim 1, characterized in that, The relationship between the number of lunar craters and the crater diameter is: The relationship between the cumulative number of lunar rocks and the rock size is: lgN 石 = -2.5883lgD 石 -3.5301, 0.04m < D 石 <0.4m Where N 坑 and N 石 are the number of lunar impact craters and the number of rocks, respectively.

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