Ground task planning simulation method and system

Abstract

The invention provides a ground task planning simulation method, which comprises the following steps of: performing ground simulation before a satellite is launched, comparing the ground simulation with an on-satellite calculation result to verify the accuracy of an on-satellite task planning module, then calculating constraint conditions on the ground based on satellite orbit, direction and task information before an instruction is uploaded, comparing the constraint conditions with a preset condition, and finally determining the accuracy of the on-satellite task planning module. And if the preset condition is met, uploading the instruction to execute the task, otherwise, cancelling the task. A ground simulation result and an on-satellite calculation result are compared and confirmed before the satellite is launched, and the accuracy and reliability of an on-satellite task planning system can be verified. Before an instruction is uploaded to a satellite, the satisfaction degrees of various constraint conditions are calculated and confirmed in advance, so that the on-satellite risk can be effectively reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of aerospace technology, in particular to a ground task planning simulation method and system. BACKGROUND

[0002] As the core platform for performing tasks such as cosmic exploration, space environment monitoring, and earth observation, the safety and task reliability of the satellite in orbit directly determine the efficiency of achieving the detection target and the on-orbit life of the satellite. When the satellite performs observation tasks on specific cosmic targets such as deep space celestial bodies, space debris, and specific orbital targets, on the one hand, it needs to ensure stable and long-time tracking observation on the target to obtain continuous and complete detection data; on the other hand, it needs to ensure the normal operation of the satellite core system. Specifically, the power supply efficiency of the solar panel, the charge-discharge balance of the battery, and the like need to be maintained within the safety threshold, while the load device needs to avoid temperature exceeding the normal working range due to long-time work, which may cause performance degradation or hardware damage. In addition, the observation angle, resolution, data transmission link, and other parameters need to be adjusted to ensure that the observation data obtained finally has effective analysis value and avoids invalid data occupying storage and transmission resources.

[0003] To reduce the impact of ground command transmission delay on real-time observation tasks, most of the existing observation task planning and execution management of satellites in orbit are completed autonomously on board. This mode can quickly respond to dynamic observation needs such as sudden space target capture, and reduce the dependence on ground station bandwidth and scheduling resources, which is the mainstream technical path for satellite task management at present. However, due to the strict limitations on satellite launch cost, on-orbit load volume and weight, there are significant bottlenecks in on-board hardware resources and software resources. On the one hand, parallel judgment of complex constraint conditions requires a large amount of computing power, and on-board processors are difficult to quickly complete multi-parameter collaborative operation, which may cause observation window to be missed or constraint judgment to be deviated; on the other hand, the simplified design of software resources may reduce the completeness of constraint conditions, such as ignoring thermal control redundancy judgment or energy fluctuation warning under extreme working conditions, which may cause on-board operation risks, such as abnormal shutdown of load device, overload of energy system, invalid observation data, and even affect the on-orbit safety and task life cycle of the satellite. SUMMARY

[0004] To reduce the on-board risk, the first aspect of the present application provides a ground task planning simulation method, which comprises: Before the satellite is launched, ground simulation is performed, and the results are compared with the on-board calculation results to verify the accuracy of the on-board task planning module; and Before the command is uploaded, the constraint conditions are calculated based on the satellite orbit, pointing, and task information on the ground, and compared with the preset conditions. If the preset conditions are met, the command is uploaded to perform the task, otherwise the task is cancelled.

[0005] Furthermore, the mission information includes the position of the observation target in the J2000 coordinate system and the start time of the observation mission.

[0006] Furthermore, the constraints include: the quaternion of the observation target, the angles between the satellite's +X axis, +Y axis, -Y axis, and -Z axis and the line connecting the Sun and Earth, and the angle between the satellite's +X axis and the line connecting the Moon and the satellite.

[0007] Furthermore, the constraints calculated based on satellite orbit, pointing, and mission information include: Calculate the solar vector and attitude matrix at the mission start time, wherein the attitude matrix is ​​the attitude matrix when the satellite's +X axis points to the target and the solar vector is located in the satellite's XOZ plane; The quaternion of the observed target is calculated based on the attitude matrix; Based on the solar vector, calculate the angles between the satellite's +X axis, +Y axis, -Y axis, and -Z axis and the line connecting the Sun and Earth; and Calculate the angle between the satellite's +X axis and the line connecting the moon and the satellite.

[0008] Based on the method described above, a second aspect of the present invention provides a ground mission planning simulation system, comprising: The input module is used to input satellite orbit, pointing, and mission information for calculation; and The calculation module, which is communicatively connected to the input module, is used to receive information input by the user, calculate constraints as described above, and compare them with preset conditions.

[0009] Furthermore, the system also includes a display module for displaying the calculation results of the calculation module.

[0010] This invention provides a ground mission planning simulation method and system that pre-calculates and confirms the satisfaction of various constraints before assigning commands to the satellite, thereby effectively reducing onboard risks. Furthermore, during ground testing before satellite launch, the ground simulation results can be compared and confirmed with the onboard calculation results to verify the accuracy and reliability of the onboard mission planning system. Attached Figure Description

[0011] To further illustrate the above and other advantages and features of the various embodiments of the present invention, a more specific description of the various embodiments of the present invention will be presented with reference to the accompanying drawings. It is to be understood that these drawings depict only typical embodiments of the invention and are therefore not intended to limit its scope. In the drawings, identical or corresponding parts will be indicated by identical or similar reference numerals for clarity.

[0012] Figure 1A flowchart illustrating a ground mission planning simulation method according to an embodiment of the present invention is shown; and Figure 2 The diagram shows the input module and display module of a ground mission planning simulation system according to an embodiment of the present invention. Detailed Implementation

[0013] In the following description, the invention is described with reference to various embodiments. However, those skilled in the art will recognize that the embodiments may be practiced without one or more specific details or in conjunction with other alternatives and / or additional methods or components. In other instances, well-known structures or operations are not shown or described in detail so as not to obscure the inventive points of the invention. Similarly, for illustrative purposes, specific numbers and configurations are set forth in order to provide a comprehensive understanding of embodiments of the invention.

[0014] In this specification, references to "an embodiment" or "this embodiment" mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment of the invention. The phrase "in one embodiment" appearing throughout this specification does not necessarily refer to the same embodiment in all instances.

[0015] It should be noted that the embodiments of the present invention describe the method steps in a specific order; however, this is only for illustrating the specific embodiment and not for limiting the order of the steps. On the contrary, in different embodiments of the present invention, the order of the steps can be adjusted according to actual needs.

[0016] Currently, there is a lack of ground-based verification systems capable of calculating and confirming the satisfaction of various constraints before satellite launch, thereby reducing onboard risks. Based on this, this invention provides a ground-based mission planning simulation method and system. On one hand, during ground testing before satellite launch, ground simulations are performed, and the simulation results are compared and confirmed with onboard calculations to verify the performance of the onboard system. On the other hand, mission constraints are confirmed before launch, and missions that do not meet the requirements are shut down, thus saving onboard resources and reducing onboard risks.

[0017] As previously stated, the present invention provides a ground mission planning simulation method that performs ground simulation in two stages. Specifically, it calculates constraints based on satellite orbit, pointing, and mission information. The mission information includes the position of the observation target in the J2000 coordinate system and the start time of the observation mission. The constraints include attitude constraints such as the quaternion of the observation target, the angles between the satellite's +X-axis, +Y-axis, -Y-axis, and -Z-axis and the line connecting the Sun and Earth under the target's pointing direction, and the angle between the satellite's +X-axis and the line connecting the Moon and the satellite.

[0018] As mentioned above, in the embodiments of the present invention, the two stages include pre-satellite launch and pre-command uploading. During the pre-satellite launch bottom-plane testing stage, simulation results can be compared with the calculation results of the on-board system to verify the performance of the on-board system. Before command uploading, simulations can be performed based on the command information to calculate constraints, which are then compared with preset conditions. If the preset conditions are met, the command is uploaded to execute the task; otherwise, the task is canceled. These preset conditions include, for example, threshold values ​​for the angles between the satellite's +X-axis, +Y-axis, -Y-axis, and -Z-axis and the line connecting the Sun and Earth, as well as the angle between the satellite's +X-axis and the line connecting the Moon and the satellite. If the calculated angles between the satellite's +X-axis, +Y-axis, -Y-axis, and -Z-axis and the line connecting the Sun and Earth, as well as the angle between the satellite's +X-axis and the line connecting the Moon and the satellite, are within the threshold values, the task is considered successful, and the command is uploaded to execute the task; otherwise, the task is considered unsuccessful, and the current task is canceled.

[0019] Figure 1 This diagram illustrates a flowchart of a ground mission planning simulation method according to an embodiment of the present invention. Figure 1 As shown, the ground simulation includes: First, in step 101, the solar vector is calculated. The solar vector at the mission start time is calculated. In one embodiment of the invention, the solar vector is calculated according to the following formula: , in, The correction matrix is ​​calculated as follows: , in, , ,in The Julian century number, expressed in centuries, is calculated from the satellite's current onboard time and the accumulated seconds relative to 00:00:00 on January 1, 2020. ; For the true ecliptic longitude of the sun, ,in The angle of the sun's near point. ;as well as The inclination of the sun's orbit. ; Next, in step 102, the attitude matrix is ​​calculated. Based on the solar vector, the attitude matrix at the mission start time is calculated, wherein the attitude matrix aligns with the satellite's +X axis pointing towards the target, and the solar vector lies within the satellite's XOZ plane. The attitude matrix can be used as a coordinate transformation matrix to transform the solar vector to the local coordinate system, etc. In one embodiment of the invention, the attitude matrix... Based on the vector direction of the observed target in the J2000 coordinate system and the solar vector Sure: , in, , where RA and Dec are the right ascension and declination of the observed target in the J2000 coordinate system, respectively; Next, in step 103, the quaternion of the observed target is calculated. The quaternion of the observed target is calculated based on the attitude matrix. In one embodiment of the present invention, the attitude matrix is ​​first represented as a square matrix: ; Then calculate and compare the following four values: , , ,as well as Then, based on the maximum value among the four values, the quaternion is determined. ,include: If the maximum value is ,but: ; If the maximum value is ,but: ; If the maximum value is ,but: ;as well as If the maximum value is ,but: ;as well as Finally, the quaternions are normalized. If the value is less than 0, then a negative value is taken; and Finally, in step 104, angular constraints are calculated. Based on the solar vector, angular constraints are calculated, including the angles between the satellite's +X-axis, +Y-axis, -Y-axis, and -Z-axis and the line connecting the Sun and Earth, and the angle between the satellite's +X-axis and the line connecting the Moon and the satellite. In one embodiment of the invention, calculating the angles between the satellite's +X-axis, +Y-axis, -Y-axis, and -Z-axis and the line connecting the Sun and Earth based on the solar vector includes: Calculate the solar vector in this system. : ;as well as Calculate the angles between the satellite's +X axis and the line connecting the Sun and Earth, the +Y axis and the line connecting the Sun and Earth, the -Y axis and the line connecting the Sun and Earth, and the -Z axis and the line connecting the Sun and Earth, respectively: .

[0020] In one embodiment of the present invention, the angle between the satellite's +X axis and the line connecting the lunar satellite is calculated according to the following steps: First, calculate the Moon-Earth vector in the inertial frame. ,in: ,in , ;as well as ,in , , , ,in: , , , in, , ; Next, based on the aforementioned inertial frame Moon-Earth vector and the satellite's position vector relative to Earth Determine the lunar satellite vector in the inertial frame. : ; Next, based on the lunar satellite vector in the inertial frame... and attitude matrix Determine the lunar satellite vector within this system. : ;as well as Finally, based on the lunar satellite vector in this system, the vector... Determine the angle between the satellite's + X-axis and the line connecting the lunar satellite. .

[0021] Therefore, based on the satellite orbit, the position of the observed target in the J2000 coordinate system, the current satellite pointing direction, and the mission start time, the quaternion of the observed target, the angle between the satellite +X axis and the line connecting the Sun and Earth, the angle between the satellite +Y axis and the line connecting the Sun and Earth, the angle between the satellite -Y axis and the line connecting the Sun and Earth, the angle between the satellite -Z axis and the line connecting the Sun and Earth, and the angle between the satellite +X axis and the line connecting the Moon and the Moon can be calculated. These values ​​are then compared with thresholds to determine whether the mission is feasible.

[0022] Based on the methods described above, the present invention further provides a ground mission planning simulation system, comprising an input module, a calculation module, and a display module. The input module is used to input satellite orbit, pointing, and mission information for calculation. The calculation module is communicatively connected to the input module and is used to receive user input information, calculate constraints using the methods described above, and compare them with preset conditions. The display module displays the calculation results of the calculation module. In one embodiment of the present invention, the input module and the display module are software interfaces, such as... Figure 2 As shown, after selecting GP mode from the drop-down menu, users can enter UTC time, current satellite position, quaternion, and target right ascension and declination information at the top of the interface. Then, they can click the Calculate button and wait for the calculation results. The final calculation results will be displayed at the constraint angle and target quaternion.

[0023] This invention provides a ground mission planning simulation method and system that pre-calculates and confirms the satisfaction of various constraints before assigning commands to the satellite, thereby effectively reducing onboard risks. Furthermore, during ground testing before satellite launch, the ground simulation results can be compared and confirmed with the onboard calculation results to verify the accuracy and reliability of the onboard mission planning system.

[0024] Although various embodiments of the invention have been described above, it should be understood that they are presented by way of example only and not as limitations. It will be apparent to those skilled in the art that various combinations, modifications, and alterations can be made without departing from the spirit and scope of the invention. Therefore, the breadth and scope of the invention disclosed herein should not be limited by the exemplary embodiments disclosed above, but should be defined solely by the appended claims and their equivalents.

Claims

1. A ground mission planning simulation method, characterized in that, include: Before the satellite launch, a ground simulation is conducted and compared with the onboard calculation results to verify the accuracy of the onboard mission planning module. as well as Before the command is sent, the constraints are calculated on the ground based on the satellite orbit, pointing and mission information, and compared with the preset conditions. If the preset conditions are met, the command is sent and the mission is executed; otherwise, the mission is canceled.

2. The ground mission planning simulation method as described in claim 1, characterized in that, The mission information includes the position of the observation target in the J2000 coordinate system and the start time of the observation mission.

3. The ground mission planning simulation method as described in claim 1, characterized in that, The constraints include: the quaternion of the observed target, the angles between the satellite's +X axis, +Y axis, -Y axis, and -Z axis and the line connecting the Sun and Earth, and the angle between the satellite's +X axis and the line connecting the Moon and the satellite.

4. The ground mission planning simulation method as described in claim 3, characterized in that, The constraints calculated based on satellite orbit, pointing, and mission information include: Calculate the solar vector and attitude matrix at the mission start time, wherein the attitude matrix is ​​the attitude matrix when the satellite's +X axis points to the target and the solar vector is located in the satellite's XOZ plane; The quaternion of the observed target is calculated based on the attitude matrix; Based on the solar vector, calculate the angles between the satellite's +X axis, +Y axis, -Y axis, and -Z axis and the line connecting the Sun and Earth; and Calculate the angle between the satellite's +X axis and the line connecting the moon and the satellite.

5. The ground mission planning simulation method as described in claim 4, characterized in that, The solar vector is calculated according to the following formula: ， in, The correction matrix is ​​calculated as follows: ， in, , ,in The Julian century number is as of 12:00 on January 1, 2000, in centuries; For the true ecliptic longitude of the sun; and This represents the tilt angle of the sun's orbit.

6. The ground mission planning simulation method as described in claim 4, characterized in that, The attitude matrix Based on the vector direction of the observed target in the J2000 coordinate system and the solar vector Sure: ， in, , where RA and Dec are the right ascension and declination of the observed target in the J2000 coordinate system, respectively.

7. The ground mission planning simulation method as described in claim 4, characterized in that, Calculating the quaternion of the observed target based on the attitude matrix includes: The attitude matrix is ​​represented in square matrix form: ； Calculate and compare the following four values: , , ,as well as ; Determine the quaternion based on the maximum value among the four values. : If the maximum value is ,but: ； If the maximum value is ,but: ； If the maximum value is ,but: ;as well as If the maximum value is ,but: ;as well as Normalize the quaternion if If the value is less than 0, then a negative value is taken.

8. The ground mission planning simulation method as described in claim 4, characterized in that, Based on the solar vector, the angles between the satellite's +X axis, +Y axis, -Y axis, and -Z axis and the line connecting the Sun and Earth are calculated as follows: Calculate the solar vector in this system. : ;as well as Calculate the angles between the satellite's +X axis, +Y axis, -Y axis, and -Z axis and the line connecting the Sun and Earth: 。 9. The ground mission planning simulation method as described in claim 4, characterized in that, The calculation of the angle between the satellite's +X axis and the line connecting the moon and the satellite includes: Calculate the Moon-Earth vector in the inertial frame; Based on the inertial frame Moon-Earth vector and the satellite's position vector relative to Earth, determine the Moon-Satellite vector in the inertial frame; Based on the lunar satellite vector in the inertial frame and its attitude matrix, determine the lunar satellite vector in this frame; and The angle between the satellite's +X axis and the line connecting the moon and satellite is determined based on the lunar satellite vector in this system.

10. A ground mission planning simulation system, characterized in that, include: The input module is configured to input satellite orbit, pointing, and mission information for calculation. A calculation module, which is communicatively connected to the input module, and is configured to receive user input information, calculate constraints by means of the method described in any one of claims 1 to 9, and compare them with preset conditions; as well as A display module is configured to display the calculation results of the calculation module.

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