Spacecraft attitude planning method, device and equipment for avoiding observation task

Abstract

The invention relates to a spacecraft attitude planning method, device and equipment for avoiding an observation task, and the method comprises the steps: carrying out the processing according to a target method motion track and own track information and attitude information under an observability judgment condition; the method comprises the steps of obtaining an observable time period data set which is obtained by observing the own side in a preset time period and comprises multiple pieces of discontinuous observable time period data, and based on the observable time period data set, planning the attitude of the observable time period under qualitative avoidance constraints by adopting a quaternion spherical linear interpolation method so as to realize observation of a target avoidance method. With the adoption of the method, observation of a specific non-cooperative target can be avoided under the condition that track maneuver is not carried out.

Description

Technical Field

[0001] The present application relates to the technical field of spacecraft attitude planning, and particularly to a method, device and equipment for spacecraft attitude planning for avoiding observation tasks. Background Art

[0002] In recent years, the safety issues of spacecraft have received more and more attention from researchers. One type of scenario is that a non-cooperative target with observation capabilities observes a specific target. In order to avoid the non-cooperative target, most studies propose to avoid it through orbital maneuvers. Among them, for the orbital game problem under continuous small thrust, a game problem model can be established through differential game theory, and a two-point boundary value problem can be derived and solved based on the Pontryagin maximum principle. In this regard, various methods have been developed to solve the game strategy, such as the indirect method, semi-direct method, direct method, and methods combined with artificial intelligence. For the orbital game problem under impulsive thrust, a complete game model has not been established, and most researchers analyze the game strategy based on the reachable domain calculation and reinforcement learning methods.

[0003] However, for some specific spacecraft, performing orbital maneuvers will cause their payload functions to be ineffective. Summary of the Invention

[0004] Based on this, in view of the above technical problems, it is necessary to provide a method, device and equipment for spacecraft attitude planning for avoiding observation tasks, which can achieve the avoidance of the observation of a specific non-cooperative target without performing orbital maneuvers.

[0005] A method for spacecraft attitude planning for avoiding observation tasks, the method is applied to the scenario of avoiding observation tasks, in which there is a target party and an avoiding party. The target party is a non-cooperative target spacecraft for performing observation, and the avoiding party is the spacecraft to be observed. The method is implemented in the avoiding party and includes:

[0006] Obtain the orbital information and attitude information of the own party within a preset time period, and the motion trajectory of the target party;

[0007] Under the condition of observability judgment, process the motion trajectory of the target party and the orbital information and attitude information of the own party to obtain an observable time period data set of the own party being observed within a preset time period. The observable time period data set includes a plurality of discontinuous observable time period data;

[0008] Based on the observable time period data set, use the quaternion spherical linear interpolation method to plan the attitude during the observable time period under the qualitative avoidance constraint to achieve the avoidance of the observation of the target party.

[0009] In one embodiment, the observability judgment condition is set based on the observability of the critical payload surface;

[0010] The observability judgment conditions include: the distance between the target party and the evasion party is less than the preset minimum observation distance, the solar angle is less than the preset maximum observable solar angle, the line-of-sight angle is less than the preset maximum line-of-sight angle, and the attitude angle is less than the preset maximum attitude angle.

[0011] In one embodiment, the preset minimum observation distance is 100 km;

[0012] The preset maximum observable solar angle is 120°;

[0013] The preset maximum line-of-sight angle and the preset maximum attitude angle are 90°.

[0014] In one embodiment, according to the motion trajectory of the target method and the orbital information and attitude information of one's own side, the quaternion description method is used for processing to obtain the observable time period data set.

[0015] In one embodiment, when using the quaternion spherical linear interpolation method to plan the attitude of the observable time period, the attitude planning is carried out respectively under the sun avoidance strategy and the target avoidance strategy;

[0016] For the attitude planning results obtained under the two avoidance strategies, according to the preset selection rule, one of the attitude planning results is selected to achieve avoidance observation.

[0017] In one embodiment, when using the quaternion spherical linear interpolation method to plan the attitude of the observable time period under the qualitative avoidance constraint:

[0018] If the result of the quaternion dot product is negative, then any one of the two quaternions is negated;

[0019] If the angle θ between the quaternions p and q causes sinθ→0, then linear interpolation is used instead, and the solution equation degenerates to Slerp(p, q, t)=(1 - t)·p + t·q.

[0020] The present application also provides a spacecraft attitude planning device for an avoidance observation task, and the device includes:

[0021] A situation information acquisition module, configured to acquire the orbital information and attitude information of one's own side within a preset time period, and the motion trajectory of the target party;

[0022] An observable period acquisition module, configured to process according to the target method's motion trajectory, as well as its own orbital information and attitude information under the condition of observability judgment, to obtain an observable period dataset in which the own side is observed within a preset time period, and the observable period dataset includes a plurality of discontinuous observable period data;

[0023] An avoidance attitude planning module, configured to plan the attitude of the observable period under qualitative avoidance constraints by using the quaternion spherical linear interpolation method based on the observable period dataset, so as to avoid the observation of the target method.

[0024] A computer device, comprising a memory and a processor, where the memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0025] Obtain its own orbital information and attitude information within a preset time period, as well as the motion trajectory of the target party;

[0026] Under the condition of observability judgment, process according to the target method's motion trajectory, as well as its own orbital information and attitude information, to obtain an observable period dataset in which the own side is observed within a preset time period, and the observable period dataset includes a plurality of discontinuous observable period data;

[0027] Based on the observable period dataset, plan the attitude of the observable period under qualitative avoidance constraints by using the quaternion spherical linear interpolation method, so as to avoid the observation of the target method.

[0028] A computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the following steps are implemented:

[0029] Obtain its own orbital information and attitude information within a preset time period, as well as the motion trajectory of the target party;

[0030] Under the condition of observability judgment, process according to the target method's motion trajectory, as well as its own orbital information and attitude information, to obtain an observable period dataset in which the own side is observed within a preset time period, and the observable period dataset includes a plurality of discontinuous observable period data;

[0031] Based on the observable period dataset, plan the attitude of the observable period under qualitative avoidance constraints by using the quaternion spherical linear interpolation method, so as to avoid the observation of the target method.

[0032] The above spacecraft attitude planning method, device and equipment for avoiding observation tasks process according to the target method's motion trajectory and the own orbit information and attitude information under the observability judgment condition, to obtain an observable period data set including multiple discontinuous observable period data that can be observed by the own side within a preset time period. Based on the observable period data set, the quaternion spherical linear interpolation method is used to plan the attitude during the observable period under the qualitative avoidance constraint, so as to achieve the avoidance of the observation of the target method. Using this method can achieve the avoidance of the observation of specific non-cooperative targets without orbital maneuvering. Description of the Drawings

[0033] Figure 1 It is a schematic flowchart of the spacecraft attitude planning method for avoiding observation tasks in an embodiment;

[0034] Figure 2 It is an application scenario diagram of the spacecraft attitude planning method for avoiding observation tasks in an embodiment;

[0035] Figure 3 It is a schematic diagram of the observation angle in an embodiment;

[0036] Figure 4 It is a schematic diagram of the relative motion trajectory scenario between the avoiding party and the target party in an embodiment;

[0037] Figure 5 It is a schematic diagram of the change in relative distance in a simulation experiment;

[0038] Figure 6 It is a schematic diagram of the change in angle before avoidance in a simulation experiment;

[0039] Figure 7 It is a schematic diagram of the attitude quaternion of the avoiding party before avoidance in a simulation experiment;

[0040] Figure 8 It is a schematic diagram of the visible window of the key payload surface before avoidance in a simulation experiment;

[0041] Figure 9 It is a schematic diagram of the attitude quaternion of the avoiding party after the water-drop type sun-pointing avoidance in a simulation experiment;

[0042] Figure 10 It is a schematic diagram of the change in angle after the water-drop type sun-pointing avoidance in a simulation experiment;

[0043] Figure 11 It is a schematic diagram of the visible window after the sun-pointing avoidance in a simulation experiment;

[0044] Figure 12 It is a schematic diagram of the attitude quaternion of the avoiding party after the target-pointing avoidance in a simulation experiment;

[0045] Figure 13 It is a schematic diagram of the angular change after target-oriented avoidance in a simulation experiment;

[0046] Figure 14 It is a schematic diagram of the visible window after target-oriented avoidance in a simulation experiment;

[0047] Figure 15 It is a structural block diagram of a spacecraft attitude planning device for avoiding observation tasks in an embodiment;

[0048] Figure 16 It is an internal structure diagram of a computer device in an embodiment. Specific implementation manners

[0049] In order to make the objectives, technical solutions and advantages of the present application clearer and more understandable, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0050] In the prior art, orbital maneuvers are usually used to avoid observation, but this will cause the payload on the avoiding side to fail. In the present application, as Figure 1 shown, a spacecraft attitude planning method for avoiding observation tasks is provided. This method is applied to the scenario of avoiding observation tasks, in which the scenario includes a target side and an avoiding side. The target side is a non-cooperative target spacecraft performing observation, and the avoiding side is the observed spacecraft. The method is implemented in the avoiding side and specifically includes the following steps:

[0051] Step S100: Obtain the orbital information and attitude information of one's own side within a preset time period, as well as the motion trajectory of the target side.

[0052] Step S110: Under the condition of observability judgment, process the motion trajectory of the target side and the orbital information and attitude information of one's own side to obtain an observable period data set of one's own side being observed within a preset time period. The observable period data set includes multiple discontinuous observable period data.

[0053] Step S120: Based on the observable period data set, use the quaternion spherical linear interpolation method to plan the attitude during the observable period under the qualitative avoidance constraint to achieve the observation of the target method of avoidance.

[0054] In the present application, the proposed method is applied as Figure 2As shown in the figure, it is a typical observation scenario. In the figure, the red ray is the observation line of sight from the target spacecraft to the evading spacecraft, the blue ray is the direction of the normal of the key payload surface (here, the normal direction is defined as the direction perpendicular to the key payload surface of the spacecraft and pointing away from the spacecraft's center of mass), and the black ray is the direction of the sun's rays. This method predicts multiple observable time periods based on the current postures of the current evading party (itself) and the target party, and then adjusts the posture of the evading party during these observable time periods to achieve observation avoidance.

[0055] In step S100, the preset time period can be any preset period of time, such as 24 hours, or a time period of 3 days, etc. The orbital information and attitude information of itself include the orbital radius length, axial eccentricity, inclination angle, right ascension of the ascending node, argument of perigee, and true anomaly at the initial moment. The motion trajectory of the target party can be calculated using the two-body motion equation, and its calculation process will be mentioned in the elaboration of subsequent step S110, so it will not be elaborated here.

[0056] In step S110, when calculating the observable time period, it is necessary to further clarify the observability judgment conditions. As Figure 3 shown, further definitions of each ray and the angles between them in Figure 2 are given. Among them, the solar angle is the angle between the sun's rays and the observation line of sight, the line-of-sight angle is the angle between the normal of the key payload surface and the reverse direction of the observation line of sight, and the attitude angle is the magnitude of the angle between the normal of the key payload surface of the evading spacecraft and the reverse direction of the sun's rays. Furthermore, the factors affecting observability include: relative distance d, solar angle θ s , line-of-sight angle θ v , and attitude angle θ a . Among them, the relative distance affects the imaging quality of the imaging sensor, the solar angle determines whether the observed spacecraft is visible, the line-of-sight angle determines whether the key payload surface is visible to the observing spacecraft, and the attitude angle determines whether the key payload surface of the evasion is irradiated by sunlight.

[0057] Among the above influencing factors, the angles related to the attitude of the evading spacecraft are the line-of-sight angle θ v and the attitude angle θ a . Therefore, in this typical scenario, the observability can be divided into two categories according to whether it contains the attitude information of the evading spacecraft: overall observability and key payload surface observability. Among them, overall observability means that the observation satellite has the conditions for imaging the entire observed spacecraft, while key surface observability means that the observation satellite has the conditions for imaging the key payload surface of the observed spacecraft. In the research of attitude avoidance strategies, if not specifically specified, the observability is the key surface observability. The judgment conditions for the two types of observability are as follows:

[0058] Table 1 Comparison of observability judgment conditions

[0059]

[0060] In this embodiment, the observability judgment condition is set based on the observability of the key load surface. That is, as can be seen from Table 1, the observability judgment condition includes: the equivalent distance between the target party and the avoidance party is less than the preset minimum observation distance, the solar angle is less than the preset maximum observable solar angle, the line-of-sight angle is less than the preset maximum line-of-sight angle, and the attitude angle is less than the preset maximum attitude angle.

[0061] Furthermore, in this method, the preset minimum observation distance is set to 100 km, the preset maximum observable solar angle is 120°, and the preset maximum line-of-sight angle and the preset maximum attitude angle are 90°.

[0062] In this embodiment, when describing the attitude of the spacecraft, the Euler angle description method, the quaternion description method, or other attitude description methods can be used, all of which are within the protection scope of this method.

[0063] Specifically, the Euler angle is an intuitive description method that uses three angles to represent the attitude of the spacecraft. These angles are the yaw angle of rotation around the Z axis, the pitch angle of rotation around the Y axis, and the roll angle of rotation around the X axis.

[0064] The direction cosine matrix (DCM) can be constructed from the Euler angles, and its formula is as follows:

[0065] DCM = R z (ψ)·R y (θ)·R x (φ)(1)

[0066] In formula (1), R x (φ), R y (θ) and R z (ψ) are the rotation matrices around the X, Y, and Z axes respectively, and their specific forms are:

[0067]

[0068]

[0069]

[0070] Specifically, the quaternion is a method to avoid gimbal lock. It consists of a real part and three imaginary parts, and is expressed as:

[0071] q = [q w ,q x ,q y ,q z T (5)

[0072] The relationship between the quaternion and the DCM is as follows: ​

[0073]

[0074] Preferably, the quaternion description method is adopted to process and obtain the observable time period data set.

[0075] In step S110, during the calculation of the observable time period, it is first necessary to clarify the orbit and attitude information of the avoiding party within the preset time period (obtained in step S100), so as to perform calculations in combination with the trajectory of the observing spacecraft.

[0076] According to the two-body motion equation, it can be obtained that:

[0077]

[0078] In formula (7), r and v respectively represent the position and velocity vectors of the spacecraft in the inertial coordinate system (such as J2000).

[0079] At the initial moment of the mission, the position and velocity vectors of the observing party and the avoiding party are respectively denoted as r i0 , r e0 , v i0 , v e0 , where the subscript i represents the observing party and the subscript e represents the avoiding party. Solving the initial value problem according to formula (7), the r i (t), r e (t), v i (t), v e (t) after time t can be obtained. The position of the sun in the inertial coordinate system is respectively r s . Therefore, the line-of-sight vector, the solar ray vector, and the key payload surface normal vector are respectively

[0080] r sgt = r e - r i (8)

[0081] r sun = r e - r s (9)

[0082] r atd = Φ BE r k (10)

[0083] In formula (10), Φ BE is the rotation matrix from the body coordinate system of the avoiding party to the inertial coordinate system, and this matrix can be obtained from the spacecraft attitude quaternion and formula (6), r k is the unit vector of the normal of the key payload surface of the avoiding party spacecraft in its own system.

[0084] Further, the judgment thresholds of each observation element set above, that is, the relative distance d is less than 100 km, the solar angle θ s is less than 120°, the line-of-sight angle θ v and the attitude angle θ a is less than 90°. Only when the observation elements meet the above constraints can the observation conditions for the key load surface be satisfied.

[0085] Therefore, the influencing factors of observability can be expressed by formula (11), where the <> symbol represents the included angle between two vectors. By comparing the results of each formula in formula (11) with the judgment threshold, the judgment result at each moment can be obtained. It should be noted that when the spacecraft attitude maneuvers, formula (10) needs to be re-expressed to calculate the new judgment result.

[0086]

[0087] The calculated observable time period is denoted as [(t 10 , t 11 ), (t 20 , t 21 ), …, (t n0 , t n1 )], which means that there are n discontinuous observable time periods within the simulation time period.

[0088] After calculating the observable time period, attitude maneuvers need to be performed to avoid observing the target side, so that the observable time within the simulation time period is as short as possible. In this embodiment, the relative position change relationship of the double stars will be obtained by predicting their trajectories first, and then the desired attitude will be calculated according to different constraint conditions. Then, the attitude planning method will be applied to obtain the complete attitude maneuver curve.

[0089] In step S120, when planning the attitude of the observable time period by using the quaternion spherical linear interpolation method, attitude planning is performed respectively under the sun avoidance strategy and the target avoidance strategy. According to the two avoidance strategies, the attitude planning results are obtained. When a relatively gentle attitude maneuver curve is required, the sun avoidance is selected, but when an emergency avoidance is required, the attitude planning result of the target avoidance strategy is selected.

[0090] In this embodiment, the attitude of the avoiding spacecraft at the initial moment can be expressed as q0 = [q w0 , q x0 , q y0 , q z0 . Without applying external force control, its attitude remains unchanged in the inertial space. To calculate the desired attitude for avoidance, the sun avoidance strategy and the target avoidance strategy are proposed.

[0091] Specifically, the solar avoidance strategy is directional solar avoidance, that is, when there is an observation spacecraft, by adjusting the attitude quaternion of the avoidance spacecraft, the key payload surface is always facing away from the sun during the original observable period, so that it cannot be observed. The corresponding avoidance constraint is:

[0092] 1. The direction of the positive normal of the +X plane always satisfies the solar orientation during the observable period, that is, the +X plane faces away from the sun.

[0093] 2. At the end of the simulation, return to the initial posture, that is, the +X plane points back to the center of the earth, the +Y plane points back to the direction of the orbital speed, and the +Z direction is given by the right-hand rule.

[0094] Specifically, the target avoidance strategy is to avoid the target in a directional manner, that is, by adjusting the attitude quaternion of the avoidance spacecraft, the key payload surface is always facing away from the target during the original observable period, thus forming unfavorable observation conditions. The corresponding avoidance constraint is:

[0095] 1. The positive normal direction of the +X plane always satisfies the target orientation during the observable period, that is, the +X plane faces away from the target.

[0096] 2. At the end of the simulation, return to the initial posture, that is, the +X plane points back to the center of the earth, the +Y plane points back to the direction of the orbital speed, and the +Z direction is given by the right-hand rule.

[0097] Furthermore, under the constraints of the above two avoidance strategies, the quaternion spherical linear interpolation method is used to solve the avoidance observation posture during the observable period.

[0098] Spherical linear interpolation is a linear interpolation operation of quaternions, which is mainly used to smoothly interpolate between two quaternions representing rotations.

[0099] Specifically, let the time corresponding to posture p be t1, the time corresponding to posture q be t2, and the posture quaternion corresponding to t′ be r, which is the posture quaternion to be calculated. Therefore, the proportional coefficient t satisfies:

[0100]

[0101] Note that the angle between quaternions p and q is θ, the angle between p and r is tθ, and the angle between q and r is (1-t)θ. The expression for r can be written according to the interpolation formula:

[0102] r(t)=a(t)p+b(t)q (12)

[0103] Also available:

[0104] cosθ=p·q cos(tθ)=p·r cos[(1-t)θ]=q·r

[0105] Next, multiplying both sides of Equation (12) by p simultaneously gives:

[0106]

[0107] Multiplying both sides of Equation (12) by q simultaneously gives:

[0108]

[0109] Combining Equation (13) and Equation (14) gives:

[0110]

[0111] So there is:

[0112]

[0113] In this embodiment, when planning the attitude of the observable period under the qualitative avoidance constraint by using the quaternion spherical linear interpolation method: if the result of the quaternion dot product is negative, then any one of the two quaternions is negated to ensure that the rotation is the shortest path. If the angle θ between quaternions p and q causes sinθ→0, and at this time the angle θ is very small, then there will be a problem with the division in Equation (16). To avoid this problem, when the angle θ is very small, linear interpolation is used instead, and solving Equation (16) degenerates to:

[0114] Slerp(p, q, t) = (1 - t)·p + t·q.

[0115] In this paper, the effectiveness of the method in this paper is also proved by simulation experiment data.

[0116] In the simulation experiment, it is implemented in the Python language. The simulation start epoch is 00:00:00 on December 1, 2022, UTC time. The simulation duration is 2 days, and the simulation step size is 1 minute. The reference orbit describing the relative motion is selected as the orbit with the same orbital parameters as the avoiding party at the initial moment, as Figure 4 shown, which is a schematic diagram of the relative motion trajectory scene of the avoiding party and the target party. The minimum observation distance is set to 100 km. The initial orbital parameters and attitude parameters of the scene are shown in Table 2 and Table 3.

[0117] Table 2. Initial orbital parameters

[0118]

[0119] Table 3. Initial attitude quaternion of the observing spacecraft

[0120]

[0121] According to the quaternion parameter settings, it is found that the initial attitude of the evader has its +X plane always pointing to the center of the Earth, the +Y plane pointing to the direction of the orbital velocity, and the +Z direction given by the right-hand rule. The +X plane is set as the key payload plane. According to the above analysis, the relative distance, solar angle, line-of-sight angle, and attitude angle are calculated respectively. The change curves during the simulation period are shown as Figure 5 and Figure 6 shown below. Figure 7 Shows the change of the attitude quaternion of the evader satellite before attitude maneuver evasion. According to Figure 6 and Figure 7 the information shown above and comprehensive analysis of each threshold, the visibility judgment result shown as Figure 8 can be obtained. The visibility period is from the 808th minute to the 1110th minute.

[0122] Furthermore, the experimental results of sun-pointing evasion are given. Figure 9 The change of the attitude quaternion of the evader after evasion is given. Figure 10 The following shows the angle changes after evasion.

[0123] The visibility judgment is shown as Figure 11 below. It can be seen that after sun-pointing, the target does not have a window to observe the evader during the simulation period.

[0124] Furthermore, the experimental results of target-pointing evasion are given. Figure 12 The change of the attitude quaternion of the evader after target-pointing evasion is given. Figure 13 The following shows the angle changes after target-pointing evasion.

[0125] The visibility judgment is shown as Figure 14 below. It can be found that after target-pointing, the target does not have a window to observe the evader during the simulation period.

[0126] In the above spacecraft attitude planning method for evasion observation tasks, by analyzing the scene elements affecting observability, a calculation method for the observable period and a spherical interpolation method for quaternions are further proposed. At the same time, by setting two evasion strategies of sun-pointing evasion and target-pointing evasion, it is verified that the proposed method can achieve smooth changes in the attitude of the evading spacecraft and can achieve the evasion task objectives. Furthermore, in this paper, experiments are also carried out under the constraint conditions of sun-pointing evasion and target-pointing evasion. The experimental results show that this method is effective for generating spacecraft attitude evasion strategies.

[0127] It should be understood that although Figure 1The steps in the flowchart are shown in sequence according to the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 1 at least a part of the steps in Figure 1 may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed alternately or in turn with at least a part of other steps or sub-steps or stages of other steps.

[0128] In one embodiment, as Figure 15 shown, a spacecraft attitude planning device for avoiding observation tasks is provided, including: a situation information acquisition module 200, an observable period acquisition module 210, and an avoidance attitude planning module 220, where:

[0129] The situation information acquisition module 200 is configured to acquire the orbit information and attitude information of its own side within a preset period, as well as the motion trajectory of the target side;

[0130] The observable period acquisition module 210 is configured to process the motion trajectory of the target side, as well as the orbit information and attitude information of its own side under the observable condition judgment, to obtain an observable period data set in which the own side is observed within a preset period. The observable period data set includes a plurality of discontinuous observable period data;

[0131] The avoidance attitude planning module 220 is configured to plan the attitude of the observable period under the qualitative avoidance constraint by using the quaternion spherical linear interpolation method based on the observable period data set, so as to avoid the observation of the target method.

[0132] For the specific limitations on the spacecraft attitude planning device for avoiding observation tasks, reference can be made to the limitations on the spacecraft attitude planning method for avoiding observation tasks in the above text, which will not be elaborated here. Each module in the above-mentioned spacecraft attitude planning device for avoiding observation tasks can be implemented in whole or in part by software, hardware, and their combination. The above-mentioned modules can be embedded in the processor of the computer device in hardware form or be independent of it, or can be stored in the memory of the computer device in software form, so that the processor can call and execute the operations corresponding to the above-mentioned modules.

[0133] In one embodiment, a computer device is provided. The computer device can be a terminal, and its internal structure diagram can be as Figure 16As shown. The computer device includes a processor, a memory, a network interface, a display screen, and an input device connected via a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The network interface of the computer device is used to communicate with an external terminal via a network connection. When the computer program is executed by the processor, it implements a method for spacecraft attitude planning for avoiding observation tasks. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen. The input device of the computer device can be a touch layer covering the display screen, or a button, a trackball, or a touchpad provided on the housing of the computer device, or an external keyboard, touchpad, or mouse, etc.

[0134] Those skilled in the art can understand that Figure 16 the structure shown in is only a block diagram of some structures related to the solution of this application, and does not constitute a limitation on the computer device to which the solution of this application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements.

[0135] In one embodiment, a computer device is provided, including a memory and a processor. A computer program is stored in the memory. When the processor executes the computer program, the following steps are implemented:

[0136] Obtain the orbital information and attitude information of one's own side within a preset time period, as well as the motion trajectory of the target side;

[0137] Under the condition of observability judgment, process according to the motion trajectory of the target method and the orbital information and attitude information of one's own side to obtain an observable time period data set of one's own side being observed within a preset time period. The observable time period data set includes a plurality of discontinuous observable time period data;

[0138] Based on the observable time period data set, use the quaternion spherical linear interpolation method to plan the attitude during the observable time period under the qualitative avoidance constraint to achieve avoidance of the observation of the target method.

[0139] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by the processor, the following steps are implemented:

[0140] Obtain the orbital information and attitude information of one's own side within a preset time period, as well as the motion trajectory of the target side;

[0141] Under the observability judgment condition, process according to the motion trajectory of the target method, as well as the orbital information and attitude information of one's own side, to obtain an observable period data set of one's own side obtained by observation within a preset time period, and the observable period data set includes a plurality of discontinuous observable period data;

[0142] Based on the observable period data set, use the quaternion spherical linear interpolation method to plan the attitude of the observable period under the qualitative avoidance constraint, so as to avoid the observation of the target method.

[0143] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, storage, database, or other medium used in the various embodiments provided in the present application can include non-volatile and / or volatile memories. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0144] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0145] The above-described embodiments only represent several implementation manners of the present application. Their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A spacecraft attitude planning method for avoiding observation tasks, characterized in that The method is applied to the scenario of avoiding observation tasks. In this scenario, there is a target party and an avoiding party. The target party is a non - cooperative target spacecraft for implementing observation, and the avoiding party is the observed spacecraft. The method is implemented in the avoiding party and includes: Obtain the orbital information and attitude information of one's own side within a preset time period, as well as the motion trajectory of the target party; Under the condition of observability judgment, process according to the motion trajectory of the target method and the orbital information and attitude information of one's own side to obtain an observable time - period data set of one's own side being observed within a preset time period. The observable time - period data set includes multiple discontinuous observable time - period data; Based on the observable time - period data set, use the quaternion spherical linear interpolation method to plan the attitude during the observable time period under qualitative avoidance constraints to achieve avoidance of the observation by the target method.

2. The spacecraft attitude planning method according to claim 1, wherein The observability judgment condition is set based on the observability of the key payload surface; The observability judgment condition includes: the relative distance between the target party and the avoiding party is less than a preset minimum observation distance, the solar angle is less than a preset maximum observable solar angle, the line - of - sight angle is less than a preset maximum line - of - sight angle, and the attitude angle is less than a preset maximum attitude angle.

3. The spacecraft attitude planning method according to claim 2, wherein, The preset minimum observation distance is 100 km; The preset maximum observable solar angle is 120°; The preset maximum line - of - sight angle and the preset maximum attitude angle are 90°.

4. The spacecraft attitude planning method according to claim 3, characterized in that According to the motion trajectory of the target method and the orbital information and attitude information of one's own side, use the quaternion description method to process to obtain the observable time - period data set.

5. The spacecraft attitude planning method according to claim 4, characterized in that, When using the quaternion spherical linear interpolation method to plan the attitude during the observable time period, perform attitude planning under the sun - avoidance strategy and the target - avoidance strategy respectively; For the attitude planning results obtained under the two avoidance strategies, according to a preset selection rule, select one of the attitude planning results to achieve avoidance of observation.

6. The spacecraft attitude planning method according to claim 5, wherein, When using the quaternion spherical linear interpolation method to plan the attitude during the observable time period under qualitative avoidance constraints: If the result of the quaternion dot - product is negative, then take the inverse of any one of the two quaternions; If the angle θ between quaternions p and q causes sinθ→0, then use linear interpolation instead, and the solution equation degenerates to Slerp(p, q, t)=(1 - t)·p + t·q.

7. A spacecraft attitude planning device for avoiding observation tasks, characterized in that The device includes: A situation information acquisition module, used to obtain the orbital information and attitude information of one's own side within a preset time period, as well as the motion trajectory of the target party; An observable time - period acquisition module, used to process according to the motion trajectory of the target method and the orbital information and attitude information of one's own side under the condition of observability judgment to obtain an observable time - period data set of one's own side being observed within a preset time period. The observable time - period data set includes multiple discontinuous observable time - period data; An avoidance attitude planning module, used to plan the attitude during the observable time period based on the observable time - period data set, using the quaternion spherical linear interpolation method under qualitative avoidance constraints to achieve avoidance of the observation by the target method.

8. A computer device, comprising a memory and a processor, the memory storing a computer program, characterized in that, When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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