A semi-physical simulation method for space debris

Abstract

A semi-physical simulation method for space debris includes the following steps: (1) inputting the attitude and orbit parameters, simulation period and step length of space debris and detection payload; (2) establishing a detection scene and obtaining the geometric position relationship of the sun-space debris-detection payload at multiple times; (3) converting the geometric position relationship into the semi-physical simulation platform coordinate system, determining the platform motion plan, and calculating the proportional coefficient of the detection distance; (4) designing a space debris model and a ground experimental payload according to the proportional coefficient; (5) making a space debris model and a ground experimental payload and installing them on the platform, executing the platform motion plan, and using the payload to measure the model at the same time to obtain sequence semi-physical simulation data; (6) downsampling the simulation data and outputting simulation data with the same number of target pixels as the real data. The method can design and carry out semi-physical simulation of space debris in various scenarios, and provide ground experimental verification for space-based detection schemes.

Description

Technical Field

[0001] The present invention relates to a semi-physical simulation method for space debris, belongs to the field of optical remote sensing data acquisition and space debris simulation, and is suitable for research on a semi-physical simulation method for space debris in a space-based detection scenario. Background Art

[0002] Space debris detection is of great significance in protecting the space environment and the safety of spacecraft, and in the safe and sustainable development and utilization of space resources. Space-based detection is not affected by the atmosphere and has all-day, all-weather, and all-sky monitoring capabilities, which is the current hot development direction. At present, there are problems in space-based detection research, such as the high cost of launching and operating space-based payloads and the difficulty in obtaining measured data, which requires the use of simulation methods to supplement the data.

[0003] In the space environment, there are various detection scenarios such as hovering, flying, and approaching. The orbital parameters and self-motion characteristics of space debris and detection payloads will change the observation geometry of the sun-space debris-detection payload, which in turn affects the detection data, making the characteristics of space debris in the detection data show different temporal variation patterns. These patterns are an important basis for identifying space debris. Therefore, it is necessary to carry out space debris simulation experiments under different detection scenarios to support the verification of detection plans and the study of target characteristics.

[0004] Space debris simulation methods are mainly divided into numerical simulation methods based on physical models, numerical simulation methods based on artificial intelligence, and semi-physical simulation methods. Among them, the numerical simulation method based on physical models can simulate a variety of detection scenarios, including hovering scenarios with simple relative motion relationships and approaching scenarios with relatively complex relative motion relationships, but this type of method requires highly accurate geometric and characteristic modeling of space debris to achieve realistic effects, and the amount of calculation is very large; the numerical simulation method based on artificial intelligence requires a large amount of measured data as supervision for training, but this is exactly what is lacking now; the semi-physical method combines physical and numerical processing, and can obtain realistic data with less workload, and has a high implementation value, but it can only simulate simple scenarios at present, and the observation geometric relationship of the sun-space debris-detection payload in complex scenarios such as approach is not simulated in place.

[0005] In summary, to address the problem that semi-physical simulation methods have poor simulation capabilities for observed geometric relationships in complex scenarios, a semi-physical simulation method for space debris is proposed, which can obtain sequential space debris simulation data in different scenarios. Summary of the invention

[0006] The purpose of the present invention is to improve the simulation capability of space debris semi-physical simulation on complex detection scenes, and to provide a space debris semi-physical simulation method.

[0007] The technical solution of the present invention is as follows: firstly, the orbital attitude parameters of the detection payload and the space debris are input, the space-based detection scene is simulated, the geometric position relationship between the two in the geocentric coordinate system is calculated, and the relationship is converted into the semi-physical simulation platform coordinate system to obtain the platform motion plan. By designing a scaled model of space debris and a ground experiment load coefficient, it is ensured that the semi-physical simulation data can obtain a target pixel number equal to or greater than that of the real detection data, a space debris model and a ground experiment payload are made, and a semi-physical simulation experiment is carried out after installation. The platform motion plan is executed to obtain a sequence of semi-physical simulation data, and the simulation data is downsampled to a target pixel number consistent with the real detection data.

[0008] The present invention is a semi-physical simulation method of space debris, and the steps are as follows:

[0009] (1) Input the orbital attitude parameters, simulation period, and simulation step size of the space debris and detection payload;

[0010] (2) Establish a detection scenario on STK based on the orbital attitude parameters, simulation period, and simulation step size of the space debris and detection payload input in step (1), and obtain the geometric position relationship between the sun, space debris, and detection payload in the geocentric coordinate system at multiple times;

[0011] (3) By means of coordinate transformation, the geometric position relationship at multiple moments obtained in step (2) is transformed from the geocentric coordinate system to the semi-physical simulation platform coordinate system, the platform motion scheme consisting of the position coordinates and attitude coordinates of the solar simulator, the space debris model and the ground experimental payload is determined, and the proportional coefficient of the detection distance in the two coordinate systems is calculated;

[0012] (4) Based on the proportional coefficient of the detection distance obtained in step (3), design the scale factor of the space debris model, the field of view angle and the number of pixels of the ground test payload to ensure that the number of pixels occupied by the target in the semi-physical simulation data is equal to or greater than the number of pixels occupied by the target in the actual detection data;

[0013] (5) Produce the space debris model and ground experimental payload designed in step (4) and install them on the semi-physical simulation platform, so that the platform moves according to the platform motion plan obtained in step (3), and at the same time use the ground experimental payload to measure the space debris model to obtain sequential space debris semi-physical simulation data;

[0014] (6) If the number of pixels occupied by the target in the simulation data obtained in step (5) is greater than the number of pixels occupied by the target in the real detection data, downsample the simulation data to make the two equal, and then output the sequence space debris semi-physical simulation data.

[0015] In the step (1), the orbital attitude parameters, simulation period and simulation step length of the space debris and the detection payload are input: the orbital parameters are in the format of six orbital numbers or two rows of numbers, the attitude parameters include the spin axis and the spin speed, when the spin speed is zero, it is a three-axis stable state, when the spin speed is greater than zero, it is a single-axis spin state, the simulation period includes the start time and the end time, and the simulation step length refers to the sampling interval time within the period.

[0016] Wherein, the step (2) establishes a detection scenario on STK according to the orbital attitude parameters, simulation period and simulation step of the space debris and the detection payload input in step (1), and obtains the geometric position relationship of the sun, space debris and the detection payload in the geocentric coordinate system at multiple times: the orbital attitude parameters, simulation period and simulation step are input into STK, a scenario of the detection payload performing space-based observation of the space debris is established, and STK is commanded to output a report, in which multiple times are demarcated in the simulation period according to the simulation step, and the geometric position relationship of the sun, space debris and the detection payload at each time is output, specifically the geocentric coordinate system The vector of space debris pointing to the sun , the vector of space debris pointing to the detection payload , the attitude quaternion of space debris .

[0017] The step (3) converts the geometric position relationship at multiple moments obtained in step (2) from the geocentric coordinate system to the semi-physical simulation platform coordinate system through coordinate conversion, determines the platform motion scheme composed of the position coordinates and attitude coordinates of the solar simulator, the space debris model and the ground experimental payload, and calculates the proportional coefficient of the detection distance in the two coordinate systems: the first step is to fix the position of the space debris model, the position of the solar simulator and the irradiation direction in the semi-physical simulation platform, and define the simulation platform coordinate system The specific definition method is to take the center of the space debris model as the origin, the irradiation direction of the solar simulator as the positive direction of the Y axis, the vertical upward direction as the positive direction of the Z axis, and the right-hand coordinate system;

[0018] The second step is to calculate the solar phase angle. The solar phase angle is defined as the angle between the sun's irradiation direction and the load detection direction. The specific calculation method is:

[0019]

[0020] in is the solar phase angle, is the vector of the space debris pointing to the sun, A vector pointing the detection payload towards the space debris;

[0021] Step 3: Knowing the solar phase angle 、Direction of solar simulator irradiation , given the ground test load in the platform coordinate system Z-axis coordinate and detection distance in , the combined formula is used to solve the ground test load The X-axis and Y-axis coordinates in are

[0022]

[0023] in is the position coordinate of the ground test load in the simulation platform;

[0024] The fourth step is to rotate the azimuth axis, pitch axis, and rotation axis of the ground test load in sequence to align it with the space target model. The azimuth axis and rotation axis rotate positively around the Z axis, and counterclockwise rotation is positive. The pitch axis rotates negatively around the Y axis, and counterclockwise rotation is positive. The specific rotation amount is

[0025]

[0026] in are the attitude coordinates of the ground test load, which are the rotation axis, pitch axis and azimuth axis coordinates;

[0027] The fifth step is to convert the attitude quaternion of the space debris Convert to rotation matrix ,Right now

[0028]

[0029] According to the irradiation direction of the solar simulator and the position coordinates of the ground experimental load, the geocentric coordinate system is solved. Transform to the simulation platform coordinate system The rotation matrix , the posture of the space debris model in the simulation platform is , the rotation matrix Convert to

[0030]

[0031] in are the attitude coordinates of the space debris model, which are the rotation axis, pitch axis and azimuth axis coordinates respectively, ;

[0032] The sixth step is to combine the position coordinates and attitude coordinates of the ground experimental payload at multiple moments and the attitude coordinates of the space debris model into a platform motion plan, and calculate the proportional coefficient of the detection distance in the geocentric coordinate system and the simulation platform coordinate system at each moment, that is,

[0033]

[0034] in is the proportionality coefficient.

[0035] In step (4), the scale factor of the space debris model, the field of view angle and the number of pixels of the ground test payload are designed according to the proportional coefficient of the detection distance obtained in step (3), so as to ensure that the number of pixels occupied by the target in the semi-physical simulation data is equal to or greater than the number of pixels occupied by the target in the real detection data: the number of pixels occupied by the target in the detection image data is divided into the number of pixels occupied in the horizontal direction and the number of pixels occupied in the vertical direction on the image plane, and the calculation method is:

[0036]

[0037] in is the number of pixels in the horizontal direction, is the number of pixels in the vertical direction, is the maximum length of space debris in the horizontal direction, is the maximum length of space debris in the vertical direction, is the number of pixels in the horizontal direction of the image, that is, the image width, is the number of pixels in the vertical direction of the image, that is, the image height, To detect the distance, is the horizontal field of view of the detection payload, is the vertical field of view of the detection payload; the scale factor of the space debris model compared to the real space debris is , that is, the ratio of the actual size to the model size is , the image width of the ground test load is , the image height is , horizontal field of view is , vertical field of view is , the ratio coefficient between the real detection distance and the simulated detection distance is , calculate the ratio of the number of pixels occupied by the target in the semi-physical simulation data to the number of pixels occupied by the target in the real detection data in the horizontal and vertical directions, that is,

[0038]

[0039] design , , , , The value of is such that at any moment in the semi-physical simulation, and .

[0040] The step (5) is to manufacture the space debris model and ground experimental load designed in the step (4) and install them on the semi-physical simulation platform, so that the platform moves according to the platform motion plan obtained in the step (3), and at the same time use the ground experimental load to measure the space debris model to obtain sequential space debris semi-physical simulation data: manufacture a space debris model with the same main structure and surface material as the real space debris and a scaled-down The space debris model is made based on the same principle as the detection payload and has an image width of , the image height is , horizontal field of view is , vertical field of view is The space debris model and the ground experimental payload are installed on the semi-physical simulation platform, and the platform motion plan is executed. The platform is controlled to move the space debris model and the ground experimental payload to the specified position coordinates and attitude coordinates in sequence according to the time sequence. After the coordinates are in place, the ground experimental payload is used for measurement. After the measurement is completed, the platform continues to move. After completing all the moments in the platform motion plan, the sequence of space debris semi-physical simulation data is obtained.

[0041] Wherein, in step (6), if the number of pixels occupied by the target in the simulation data obtained in step (5) is greater than the number of pixels occupied by the target in the real detection data, the simulation data is downsampled to make the two equal, and then the sequence of space debris semi-physical simulation data is output: if the ratio of the number of pixels occupied by the target in the space debris semi-physical simulation data to the number of pixels occupied by the target in the real detection data in the horizontal direction or the vertical direction is greater than 1, that is, or , then the average downsampling is adopted, and the width of the original image is , the original image height is The semi-physical simulation data is resampled. After resampling, the image width is , the image height is , output sequence space debris semi-physical simulation data.

[0042] The advantages of the present invention over the prior art are as follows: a semi-physical simulation method for space debris is designed, which is closely integrated with specific application scenarios and can simulate the observation geometric relationship between the sun, space debris and detection payload in a variety of space-based detection scenarios. Through experimental parameter design, the detection capabilities reflected in the semi-physical simulation and the actual detection are basically consistent. DETAILED DESCRIPTION

[0043] In order to better illustrate the semi-physical simulation method of space debris involved in the present invention, experiments are conducted using visible light imaging payload and satellite model. The present invention is a semi-physical simulation method of space debris, and the specific implementation steps are as follows:

[0044] (1) Input the orbital attitude parameters, simulation period and simulation step of the space debris and detection payload: The orbital parameters are in the format of six orbital elements or two rows of elements. The attitude parameters include the spin axis and spin speed. When the spin speed is zero, it is a three-axis stable state. When the spin speed is greater than zero, it is a single-axis spin state. The simulation period includes the start time and the end time. The simulation step refers to the sampling interval within the period. The orbital elements of the space debris are semi-major axis 42167km, eccentricity 0.001028, orbit inclination 97.802deg, near The argument of perigee is 190.940deg, the longitude of the ascending node is 226.811deg, and the mean anomaly is 208.944deg. The attitude parameters are single-axis spin about the earth and a rotation speed of 6° / s. The orbital elements of the detection payload are semi-major axis 42167km, eccentricity 0.001028, orbit inclination 137.802deg, argument of perigee 190.940deg, longitude of the ascending node 226.811deg, and mean anomaly 208.944deg. The simulation period is from 2024-10-27 13:20:00 to 2024-10-27 13:21:00, and the simulation step is 6s.

[0045] (2) According to the orbital attitude parameters, simulation period and simulation step of the space debris and detection payload input in step (1), a detection scenario is established on STK to obtain the geometric position relationship between the sun, space debris and detection payload in the geocentric coordinate system at multiple times: the orbital attitude parameters, simulation period and simulation step are input into STK to establish a scenario in which the detection payload performs space-based observation of space debris. The STK is commanded to output a report. In the report, the simulation period is divided into 11 moments according to the simulation step, and the geometric position relationship between the sun, space debris and detection payload at each moment is output, specifically the geocentric coordinate system. The vector of space debris pointing to the sun , the vector of space debris pointing to the detection payload , the attitude quaternion of space debris .

[0046] (3) Through coordinate transformation, the geometric position relationship at multiple moments obtained in step (2) is transformed from the geocentric coordinate system to the semi-physical simulation platform coordinate system, the platform motion scheme consisting of the position coordinates and attitude coordinates of the solar simulator, the space debris model and the ground experimental payload is determined, and the proportional coefficient of the detection distance in the two coordinate systems is calculated: The first step is to fix the position of the space debris model, the position of the solar simulator and the irradiation direction in the semi-physical simulation platform, and define the simulation platform coordinate system The specific definition method is to take the center of the space debris model as the origin, the irradiation direction of the solar simulator as the positive direction of the Y axis, the vertical upward direction as the positive direction of the Z axis, and the right-hand coordinate system;

[0047] The second step is to calculate the solar phase angle. The solar phase angle is defined as the angle between the sun's irradiation direction and the load detection direction. The specific calculation method is:

[0048]

[0049] in is the solar phase angle, is the vector of the space debris pointing to the sun, A vector pointing the detection payload towards the space debris;

[0050] Step 3: Knowing the solar phase angle 、Direction of solar simulator irradiation , given the ground test load in the platform coordinate system Z-axis coordinate and detection distance in , , , the combined formula is used to solve the ground test load The X-axis and Y-axis coordinates in are

[0051]

[0052] in is the position coordinate of the ground test load in the simulation platform;

[0053] The fourth step is to rotate the azimuth axis, pitch axis, and rotation axis of the ground test load in sequence to align it with the space target model. The azimuth axis and rotation axis rotate positively around the Z axis, and counterclockwise rotation is positive. The pitch axis rotates negatively around the Y axis, and counterclockwise rotation is positive. The specific rotation amount is

[0054]

[0055] in are the attitude coordinates of the ground test load, which are the rotation axis, pitch axis and azimuth axis coordinates;

[0056] The fifth step is to convert the attitude quaternion of the space debris Convert to rotation matrix ,Right now

[0057]

[0058] According to the irradiation direction of the solar simulator and the position coordinates of the ground experimental load, the geocentric coordinate system is solved. Transform to the simulation platform coordinate system The rotation matrix , the posture of the space debris model in the simulation platform is , the rotation matrix Convert to

[0059]

[0060] in are the attitude coordinates of the space debris model, which are the rotation axis, pitch axis and azimuth axis coordinates respectively, ;

[0061] The sixth step is to combine the position coordinates and attitude coordinates of the ground experimental payload at multiple times and the attitude coordinates of the space debris model into a platform motion plan, and calculate the proportional coefficient of the detection distance in the geocentric coordinate system and the simulation platform coordinate system at each moment, that is,

[0062]

[0063] in is the proportionality coefficient, .

[0064] (4) According to the proportional coefficient of the detection distance obtained in step (3), design the scale factor of the space debris model, the field of view angle and the number of pixels of the ground test payload to ensure that the number of pixels occupied by the target in the semi-physical simulation data is equal to or greater than the number of pixels occupied by the target in the real detection data: the number of pixels occupied by the target in the detection image data is divided into the number of pixels occupied in the horizontal direction and the number of pixels occupied in the vertical direction on the image plane, and the calculation method is:

[0065]

[0066] in is the number of pixels in the horizontal direction, is the number of pixels in the vertical direction, is the maximum length of space debris in the horizontal direction, is the maximum length of space debris in the vertical direction, is the number of pixels in the horizontal direction of the image, that is, the image width, is the number of pixels in the vertical direction of the image, that is, the image height, To detect the distance, is the horizontal field of view of the detection payload, is the vertical field of view of the detection payload; the scale factor of the space debris model compared to the real space debris is , that is, the ratio of the actual size to the model size is , the image width of the ground test load is , the image height is , horizontal field of view is , vertical field of view is , the ratio coefficient between the real detection distance and the simulated detection distance is , calculate the ratio of the number of pixels occupied by the target in the semi-physical simulation data to the number of pixels occupied by the target in the real detection data in the horizontal and vertical directions, that is,

[0067]

[0068] design , , , , , so that at any moment in the semi-physical simulation, and .

[0069] (5) Make the space debris model and ground experimental payload designed in step (4) and install them on the semi-physical simulation platform, so that the platform moves according to the platform motion plan obtained in step (3). At the same time, use the ground experimental payload to measure the space debris model to obtain sequential space debris semi-physical simulation data: Make a space debris model with the same main structure and surface material as the real space debris and a scaled-down The space debris model is made based on the same principle as the detection payload and has an image width of , the image height is , horizontal field of view is , vertical field of view is The space debris model and the ground experimental payload are installed on the semi-physical simulation platform, and the platform motion plan is executed. The platform is controlled to move the space debris model and the ground experimental payload to the specified position coordinates and attitude coordinates in sequence according to the time sequence. After the coordinates are in place, the ground experimental payload is used for measurement. After the measurement is completed, the platform continues to move. After completing all 11 moments in the platform motion plan, the sequence space debris semi-physical simulation data is obtained.

[0070] (6) If the number of pixels occupied by the target in the simulation data obtained in step (5) is greater than the number of pixels occupied by the target in the real detection data, downsample the simulation data to make the two equal, and then output the sequence of space debris semi-physical simulation data: If the ratio of the number of pixels occupied by the target in the space debris semi-physical simulation data to the number of pixels occupied by the target in the real detection data in the horizontal direction or the vertical direction is greater than 1, that is, or , then the average downsampling is adopted, and the width of the original image is , the original image height is The semi-physical simulation data is resampled. After resampling, the image width is , the image height is , output sequence space debris semi-physical simulation data.

[0071] The embodiments of the present invention are described in detail above, but the contents are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. The implementation methods of each step can be changed, and all equal changes and improvements made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. A method for semi-physical simulation of space debris, characterized by: It contains the following steps: (1) Input the orbital attitude parameters, simulation period, and simulation step size of the space debris and detection payload; (2) Establish a detection scenario on STK based on the orbital attitude parameters, simulation period, and simulation step size of the space debris and detection payload input in step (1), and obtain the geometric position relationship between the sun, space debris, and detection payload in the geocentric coordinate system at multiple times; (3) By means of coordinate transformation, the geometric position relationship at multiple moments obtained in step (2) is transformed from the geocentric coordinate system to the semi-physical simulation platform coordinate system, the platform motion scheme consisting of the position coordinates and attitude coordinates of the solar simulator, the space debris model and the ground experimental payload is determined, and the proportional coefficient of the detection distance in the two coordinate systems is calculated; (4) Based on the proportional coefficient of the detection distance obtained in step (3), design the scale factor of the space debris model, the field of view angle and the number of pixels of the ground test payload to ensure that the number of pixels occupied by the target in the semi-physical simulation data is equal to or greater than the number of pixels occupied by the target in the actual detection data; (5) Produce the space debris model and ground experimental payload designed in step (4) and install them on the semi-physical simulation platform, so that the platform moves according to the platform motion plan obtained in step (3), and at the same time use the ground experimental payload to measure the space debris model to obtain sequential space debris semi-physical simulation data; (6) If the number of pixels occupied by the target in the simulation data obtained in step (5) is greater than the number of pixels occupied by the target in the real detection data, downsample the simulation data to make the two equal, and then output the sequence space debris semi-physical simulation data.

2. A method for semi-physical simulation of space debris according to claim 1, characterized in that: The step (1) inputs the orbital attitude parameters, simulation period and simulation step of the space debris and the detection payload: the orbital parameters are in the format of six orbital numbers or two rows of numbers, the attitude parameters include the spin axis and the spin speed, when the spin speed is zero, it is a three-axis stable state, when the spin speed is greater than zero, it is a single-axis spin state, the simulation period includes the start time and the end time, and the simulation step refers to the sampling interval time within the period.

3. The method for semi-physical simulation of space debris according to claim 1, characterized in that: The step (2) establishes a detection scenario on STK according to the orbital attitude parameters, simulation period and simulation step of the space debris and the detection payload input in step (1), and obtains the geometric position relationship of the sun, space debris and the detection payload in the geocentric coordinate system at multiple times: the orbital attitude parameters, simulation period and simulation step are input into STK, a scenario of the detection payload performing space-based observation of the space debris is established, and STK is commanded to output a report, in which multiple times are defined in the simulation period according to the simulation step, and the geometric position relationship of the sun, space debris and the detection payload at each time is output, specifically the geocentric coordinate system The vector of space debris pointing to the sun , the vector of space debris pointing to the detection payload , the attitude quaternion of space debris .

4. The method for semi-physical simulation of space debris according to claim 1, characterized in that: The step (3) converts the geometric position relationship at multiple moments obtained in step (2) from the geocentric coordinate system to the semi-physical simulation platform coordinate system through coordinate conversion, determines the platform motion plan composed of the position coordinates and attitude coordinates of the solar simulator, the space debris model and the ground experimental payload, and calculates the proportional coefficient of the detection distance in the two coordinate systems: the first step is to fix the position of the space debris model, the position of the solar simulator and the irradiation direction in the semi-physical simulation platform, and define the simulation platform coordinate system The specific definition method is to take the center of the space debris model as the origin, the irradiation direction of the solar simulator as the positive direction of the Y axis, the vertical upward direction as the positive direction of the Z axis, and the right-hand coordinate system; The second step is to calculate the solar phase angle. The solar phase angle is defined as the angle between the sun's irradiation direction and the load detection direction. The specific calculation method is: ； in is the solar phase angle, is the vector of the space debris pointing to the sun, A vector pointing the detection payload towards the space debris; Step 3: Knowing the solar phase angle 、Direction of solar simulator irradiation , given the ground test load in the platform coordinate system Z-axis coordinate and detection distance in , the combined formula is used to solve the ground test load The X-axis and Y-axis coordinates in are ； in is the position coordinate of the ground test load in the simulation platform; The fourth step is to rotate the azimuth axis, pitch axis, and rotation axis of the ground test load in sequence to align it with the space target model. The azimuth axis and rotation axis rotate positively around the Z axis, and counterclockwise rotation is positive. The pitch axis rotates negatively around the Y axis, and counterclockwise rotation is positive. The specific rotation amount is ； in are the attitude coordinates of the ground test load, which are the rotation axis, pitch axis and azimuth axis coordinates respectively; The fifth step is to convert the attitude quaternion of the space debris Convert to rotation matrix ,Right now According to the irradiation direction of the solar simulator and the position coordinates of the ground experimental load, the geocentric coordinate system is solved. Transform to the simulation platform coordinate system The rotation matrix , the posture of the space debris model in the simulation platform is , the rotation matrix Convert to ； in are the attitude coordinates of the space debris model, which are the rotation axis, pitch axis and azimuth axis coordinates respectively, ; The sixth step is to combine the position coordinates and attitude coordinates of the ground experimental payload at multiple times and the attitude coordinates of the space debris model into a platform motion plan, and calculate the proportional coefficient of the detection distance in the geocentric coordinate system and the simulation platform coordinate system at each moment, that is, ； in is the proportionality coefficient.

5. The method for semi-physical simulation of space debris according to claim 1, characterized in that: In step (4), the scale factor of the space debris model, the field of view angle and the number of pixels of the ground test payload are designed according to the proportional coefficient of the detection distance obtained in step (3), so as to ensure that the number of pixels occupied by the target in the semi-physical simulation data is equal to or greater than the number of pixels occupied by the target in the real detection data: the number of pixels occupied by the target in the detection image data is divided into the number of pixels occupied in the horizontal direction and the number of pixels occupied in the vertical direction on the image plane, and the calculation method is: ； in is the number of pixels in the horizontal direction, is the number of pixels in the vertical direction, is the maximum length of space debris in the horizontal direction, is the maximum length of space debris in the vertical direction, is the number of pixels in the horizontal direction of the image, that is, the image width, is the number of pixels in the vertical direction of the image, that is, the image height, To detect the distance, is the horizontal field of view of the detection payload, is the vertical field of view of the detection payload; the scale factor of the space debris model compared to the real space debris is , that is, the ratio of the actual size to the model size is , the image width of the ground test load is , the image height is , horizontal field of view is , vertical field of view is , the ratio coefficient between the real detection distance and the simulated detection distance is , calculate the ratio of the number of pixels occupied by the target in the semi-physical simulation data to the number of pixels occupied by the target in the real detection data in the horizontal and vertical directions, that is, ； design , , , , The value of is such that at any moment in the semi-physical simulation, and .

6. The method for semi-physical simulation of space debris according to claim 1, characterized in that: The step (5) manufactures the space debris model and ground experimental load designed in step (4) and installs them on a semi-physical simulation platform, so that the platform moves according to the platform motion plan obtained in step (3), and at the same time uses the ground experimental load to measure the space debris model to obtain sequential space debris semi-physical simulation data: manufacture a space debris model with the same main structure and surface material as the real space debris and a scaled-down The space debris model is made based on the same principle as the detection payload and has an image width of , the image height is , horizontal field of view is , vertical field of view is The space debris model and the ground experimental payload are installed on the semi-physical simulation platform, and the platform motion plan is executed. The platform is controlled to move the space debris model and the ground experimental payload to the specified position coordinates and attitude coordinates in sequence according to the time sequence. After the coordinates are in place, the ground experimental payload is used for measurement. After the measurement is completed, the platform continues to move. After completing all the moments in the platform motion plan, the sequence of space debris semi-physical simulation data is obtained.

7. The method for semi-physical simulation of space debris according to claim 1, characterized in that: In step (6), if the number of pixels occupied by the target in the simulation data obtained in step (5) is greater than the number of pixels occupied by the target in the real detection data, the simulation data is downsampled to make the two equal, and then the sequence of space debris semi-physical simulation data is output: if the ratio of the number of pixels occupied by the target in the space debris semi-physical simulation data to the number of pixels occupied by the target in the real detection data in the horizontal direction or the vertical direction is greater than 1, that is, or , then the average downsampling is adopted, and the width of the original image is , the original image height is The semi-physical simulation data is resampled. After resampling, the image width is , the image height is , output sequence space debris semi-physical simulation data.

Images