Collision warning method and system based on group target tracking and dangerous area stratification

Abstract

The present invention belongs to the field of target collision warning technology. To address the current high collision risk of spacecraft, a collision warning method and system based on group target tracking and dangerous area stratification is provided. The collision warning method based on group target tracking and dangerous area stratification includes calculating the spacecraft's trajectory and dividing the dangerous area; dividing the group targets into several sparse groups based on the similarity of their position information and motion states, and constructing a mesh topology structure of behavioral associations for each sparse group; obtaining the overall motion trajectory of each sparse group; calculating the moment when each sparse group is closest to the spacecraft and simultaneously releasing the behavioral association of the corresponding sparse group, searching for targets within the dangerous area at the corresponding moment, and calculating the collision risk of individual targets in the corresponding sparse group; and comparing with a warning threshold to determine whether to perform orbital avoidance operations. This method can reduce the probability of collision.

Description

Technical Field

[0001] The present invention belongs to the technical field of target collision warning, and in particular relates to a collision warning method and system based on group target tracking and dangerous area stratification. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Current collision probability calculation models are based on the collision probability between a spacecraft and a single target or multiple targets. When a spacecraft encounters a group of targets, the current collision probability calculation model requires separate training for each target's individual behavior, resulting in significant computational overhead. Furthermore, collision probability calculations primarily utilize box and Gaussian models, which employ error ellipsoids to calculate collision probability. This approach ignores the impact of motion on hazardous areas during motion, increasing the likelihood of false alarms and missed alarms, thereby increasing the collision risk of the spacecraft. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a collision warning method and system based on group target tracking and danger zone stratification. The method redistributes the groups at set intervals. When the target group approaches a satellite or spacecraft, the group target behavior association is released, and the collision risk is calculated using a Gaussian probability distribution model and the danger zone stratification principle to reduce the probability of collision.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A first aspect of the present invention provides a collision warning method based on group target tracking and dangerous area stratification.

[0007] In one or more embodiments, a collision warning method based on group target tracking and dangerous area stratification is provided, including:

[0008] The position information and motion status of the spacecraft and the group targets are obtained at set intervals, the trajectory of the spacecraft is calculated, and the danger zone is divided; the motion status includes the motion direction and motion speed;

[0009] According to the location information and similarity of the group targets' motion states, the group targets are divided into several sparse groups, and a mesh topology structure of the behavioral associations of each sparse group is constructed;

[0010] The central target of each mesh topology structure is taken as the main target, and the similarity of the motion state between other targets and the main target is used as the weight. The overall motion state of each sparse group is weightedly calculated to obtain the overall motion trajectory of each sparse group.

[0011] Based on the overall motion trajectory of each sparse group and the trajectory of the spacecraft, the time when each sparse group is closest to the spacecraft is calculated and the behavior association of the corresponding sparse group is simultaneously released. The target in the danger zone at the corresponding time is found and the collision risk of each target in the corresponding sparse group is calculated.

[0012] The collision risk of each individual target in the corresponding sparse group is compared with the warning threshold one by one to determine whether to perform orbit avoidance maneuvers.

[0013] As an implementation method, the process of dividing the group targets into several sparse groups is as follows:

[0014] The group targets are initially divided into several position subclusters according to their positions. Then, according to the similarity of their motion states, each position subcluster is refined into speed subclusters with similar positions and speeds, thus obtaining sparse groups.

[0015] As an implementation method, in the process of constructing a mesh topology structure, whether to connect two targets is determined based on the similarity of their speed directions; if the similarity of the speed directions of the two targets is greater than a preset threshold, the speed directions are judged to be similar and a connecting line is drawn.

[0016] As an implementation method, with the center of mass of the spacecraft as the center, the short axis and long axis of the ellipse are preset to construct three layers of areas from the inside to the outside, namely the high-risk area, the medium-risk area and the low-risk area.

[0017] As an implementation method, the high-risk zone is a circular area with a radius equal to the sum of the equivalent radius of the spacecraft and the equivalent radius of the space debris. In the high-risk zone, the risk coefficient is 1, and the distance between the center of mass of the spacecraft and the space debris is less than the safety radius, and a collision is bound to occur.

[0018] As an embodiment, the medium-risk area and the low-risk area are parts of elliptical surfaces having structures similar to the two-dimensional projection of the error ellipsoid; the risk coefficient decreases exponentially: , where x and y are the horizontal and vertical coordinates of the coordinate system, and a and b are the warning distance thresholds determined by the relative speed error between the spacecraft and the space target.

[0019] As an implementation method, in the medium-risk zone and the low-risk zone, the closest distance of the two-dimensional projection of the space debris position error ellipsoid in the intersection plane to the center of the coordinate system is regarded as r, and the probability distribution within the overlapping range of the projection and the danger range is calculated. The final collision probability is obtained by multiplying the danger coefficient by the probability size of the overlapping range.

[0020] A second aspect of the present invention provides a collision warning system based on group target tracking and dangerous area stratification.

[0021] In one or more embodiments, a collision warning system based on group target tracking and hazard zone stratification includes:

[0022] A spacecraft trajectory determination module is used to obtain the position information and motion status of the spacecraft and group targets at set intervals, calculate the spacecraft's trajectory, and divide the danger zone; the motion status includes motion direction and motion speed;

[0023] The group target division module is used to divide the group targets into several sparse groups according to their location information and the similarity of their motion states, and to construct a mesh topology structure of the behavior associations of each sparse group;

[0024] The sparse group trajectory determination module is used to calculate the overall motion state of each sparse group by taking the central target of each mesh topology structure as the main target and the similarity of the motion state between other targets and the main target as weights, and obtain the overall motion trajectory of each sparse group;

[0025] The collision risk calculation module is used to calculate the time when each sparse group is closest to the spacecraft based on the overall motion trajectory of each sparse group and the spacecraft's trajectory, and simultaneously disassociate the behavior of the corresponding sparse group, find the target in the danger zone at the corresponding time, and calculate the collision risk of each target in the corresponding sparse group;

[0026] The trajectory avoidance execution judgment module is used to compare the collision risk of each individual target in the corresponding sparse group with the warning threshold one by one to determine whether to execute the trajectory avoidance operation.

[0027] A third aspect of the present invention provides a computer-readable storage medium.

[0028] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the collision warning method based on group target tracking and dangerous area stratification as described above.

[0029] A fourth aspect of the present invention provides an electronic device.

[0030] An electronic device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the steps of the collision warning method based on group target tracking and dangerous area stratification as described above are implemented.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] When a collision between a spacecraft and a group of targets is involved, the present invention divides the group of targets to obtain a sparse result, thereby reducing repeated training of targets with similar motion states; by constructing a mesh topology structure of group target behavior association, a dense group of targets is divided into sparse groups, and the central target of the group is used as the main target. The weighted motion state of the group targets is calculated and used as the overall motion state of the group targets, thereby saving time for monitoring multiple targets; and the groups are redivided at regular intervals. When the target group approaches a satellite or spacecraft, the group target behavior association is released, the collision risk is calculated, and the probability of collision is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0034] Figure 1 1 is a flow chart of a collision warning method based on group target tracking and dangerous area stratification according to an embodiment of the present invention;

[0035] Figure 2 It is a process of converting a group target into a sparse group in an embodiment of the present invention;

[0036] Figure 3 2 is a schematic structural diagram of a collision warning system based on group target tracking and dangerous area stratification according to an embodiment of the present invention;

[0037] Figure 4 This is a schematic diagram of collision risk in a dangerous area according to an embodiment of the present invention;

[0038] Figure 5 is a schematic diagram of an intersection reference system according to an embodiment of the present invention;

[0039] Figure 6 This is a diagram of the intersection plane danger level division according to an embodiment of the present invention;

[0040] Figure 7 is the original intersection plane schematic (relative velocity is perpendicular to the paper);

[0041] Figure 8 2 is a diagram showing changes in risk factors according to an embodiment of the present invention. DETAILED DESCRIPTION

[0042] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0043] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0044] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0045] Figure 1 FIG is a flow chart of a collision warning method based on group target tracking and dangerous area stratification in an embodiment of the present invention. Figure 1 The collision warning method based on group target tracking and dangerous area stratification in this embodiment may include:

[0046] S101, obtaining the position information and motion status of the spacecraft and the group targets at set intervals, calculating the trajectory of the spacecraft and dividing the danger zone; the motion status includes motion direction and motion speed.

[0047] It should be noted here that the group targets may be meteorite clusters, or other celestial bodies and their surrounding celestial bodies.

[0048] In this step, the position information and motion status of the spacecraft and the group targets can be obtained from the aerospace database through authorized synchronization.

[0049] Specifically, with the center of mass of the spacecraft as the center, the short axis and long axis of the ellipse are preset to construct three layers of areas from the inside to the outside, namely the high-risk area, the medium-risk area and the low-risk area, such as Figure 6 and Figure 7 shown.

[0050] S102 , dividing the group of targets into a number of sparse groups according to the position information and similarity of the motion states of the group of targets, and constructing a mesh topology structure of the behavior associations of the sparse groups.

[0051] In step S102, Figure 2 As shown in , the process of dividing the group targets into several sparse groups is:

[0052] The group targets are initially divided into several position subclusters according to their positions. Then, according to the similarity of their motion states, each position subcluster is refined into speed subclusters with similar positions and speeds, thus obtaining sparse groups.

[0053] For example, the K-Means clustering algorithm is used to initially divide the group targets into several location subclusters.

[0054] The K-Means clustering algorithm works by minimizing the distance between the target point in the cluster and the cluster center. Its objective function is:

[0055] ;

[0056] is the objective function (sum of squared errors within clusters);

[0057] is the number of clusters;

[0058] It is A cluster contains all the points belonging to the cluster;

[0059] is the coordinate (position) of the target point;

[0060] It is The center of a cluster.

[0061] The K-Means clustering algorithm iteratively optimizes this objective function by first assigning each point to the nearest cluster center and then updating the cluster centers until convergence.

[0062] When constructing the mesh topology, the decision to connect two targets is based on the similarity in their speed directions. If the speed similarity between two targets exceeds a preset threshold (e.g., 0.8), the targets are considered similar and a connecting line is drawn. This ensures that targets are only connected when the speed similarity is high, further enhancing the visualization of the clustering.

[0063] S103 , taking the central target of each mesh topology structure as the main target and the similarity of the motion states of other targets to the main target as weights, weightedly calculate the overall motion state of each sparse group to obtain the overall motion trajectory of each sparse group.

[0064] In each mesh topology, the similarity of the motion states between other targets and the main target can be represented by cosine similarity.

[0065] The cosine similarity formula is as follows:

[0066] ;

[0067] in, represents cosine similarity;

[0068] and are the velocity vectors of the two targets;

[0069] is the dot product of two velocity vectors;

[0070] and They are velocity vectors and The mold length.

[0071] The normalized velocity vector has unit length and simplifies to:

[0072] ;

[0073] The above formula calculates the similarity between two velocity vectors, and the value is The closer the value is to 1, the more similar the two velocity vectors are.

[0074] S104, based on the overall motion trajectory of each sparse group and the operating trajectory of the spacecraft, calculate the moment when each sparse group is closest to the spacecraft and simultaneously release the behavioral association of the corresponding sparse group, find the target in the danger zone at the corresponding moment, and calculate the collision risk of a single target in the corresponding sparse group.

[0075] Specifically, behavioral disassociation involves reconsidering sparse groups as separate entities. If the original sparse grouping of targets no longer meets current requirements over time and their behavior is no longer considered similar, behavioral disassociation is performed to update the sparse groups and ensure the accuracy of behavioral association. Disassociation occurs when the sparse group and the spacecraft are closest, allowing for the focus on all targets, determining collision probabilities and reducing the likelihood of false alarms and missed alerts.

[0076] In this embodiment, the high-risk zone is a circular area with a radius equal to the sum of the equivalent radius of the spacecraft and the equivalent radius of the space debris. In the high-risk zone, the risk factor is 1. If the distance between the center of mass of the spacecraft and the space debris is less than the safety radius, a collision is certain to occur.

[0077] The medium-risk area and the low-risk area are parts of elliptical surfaces that are similar in structure to the two-dimensional projection of the error ellipsoid. Figure 8 As shown, the risk factor decreases exponentially: , where x and y are the horizontal and vertical coordinates of the coordinate system, and a and b are the warning distance thresholds determined by the relative speed error between the spacecraft and the space target. For example, in an ideal state, the relative speed of the spacecraft and the space target is perpendicular to the paper, but in actual applications, there will be a certain error in the calculation of the speed of the spacecraft and the space target. If the speed error of the space target in the intersection plane is regarded as the ideal value (0, 0), the spacecraft speed error is regarded as , then the relative speed error between the two is The larger the speed error, the higher the distance threshold for warning. The simple calculation method is: , Dangerous areas of different degrees have different k values, so the values ​​of a and b are different, forming multiple elliptical boundaries. The specific k value needs to be verified through examples.

[0078] In the moderate danger zone and the low danger zone, the closest distance from the two-dimensional projection of the space debris position error ellipsoid in the intersection plane to the center of the coordinate system is regarded as r, the probability distribution within the overlapping range of the projection and the danger range is calculated, and the final collision probability is obtained by multiplying the danger coefficient by the probability size of the overlapping range.

[0079] During specific implementation, the probability distribution within the overlapping range between the projection and the danger range can be calculated using an existing algorithm, such as a Monte Carlo algorithm.

[0080] S105, comparing the collision risk of each individual target in the corresponding sparse group with the warning threshold one by one to determine whether to perform a trajectory avoidance operation, such as Figure 4-Figure 5 shown.

[0081] The warning threshold here can be set based on historical data and experience. For example, the collision probability threshold of the International Space Station (ISS) is set at 10 -4 The warning threshold can also be divided according to different risk levels. For example, red warning (collision probability> 10 -4 ), emergency avoidance is required; yellow warning (collision probability 10 -5 ~10 -4 ), need to pay attention and possibly avoid; green warning (collision probability <10 -5 ), considered safe.

[0082] based on Figure 2 Table 1 shows the number of points requiring attention determined by the collision warning method based on group target tracking and dangerous area stratification according to an embodiment of the present invention.

[0083] Table 1 The number of points that need to be considered;

[0084]

[0085] This method divides a group of targets into smaller groups, resulting in a sparser result. This reduces repeated training for targets with similar motion states, and allows the overall motion state of the group to be defined by simply obtaining simple relationships within the sparse group. Furthermore, when a spacecraft approaches a group of targets, the behavioral associations between the targets are disassociated, and the trajectory of satellites within the risk range is accurately tracked and predicted, reducing collision risk.

[0086] Figure 3This is a schematic diagram of the structure of a collision warning system based on group target tracking and dangerous area stratification in an embodiment of the present invention. Figure 1 The collision warning method based on group target tracking and dangerous area stratification corresponds to Figure 3 As shown, the collision warning system based on group target tracking and dangerous area stratification in this embodiment may include:

[0087] The spacecraft trajectory determination module 301 is used to obtain the position information and motion status of the spacecraft and the group of targets at set intervals, calculate the spacecraft's trajectory and divide the dangerous area; the motion status includes the motion direction and motion speed;

[0088] A group target division module 302 is used to divide the group targets into a number of sparse groups according to the location information and similarity of the movement states of the group targets, and to construct a mesh topology structure of the behavior association of each sparse group;

[0089] The sparse group trajectory determination module 303 is used to calculate the overall motion state of each sparse group by taking the central target of each mesh topology structure as the main target and the similarity of the motion state between other targets and the main target as weights, thereby obtaining the overall motion trajectory of each sparse group;

[0090] The collision risk calculation module 304 is used to calculate the time when each sparse group is closest to the spacecraft based on the overall motion trajectory of each sparse group and the spacecraft's trajectory, and simultaneously disassociate the behavior of the corresponding sparse group, find the target in the danger zone at the corresponding time, and calculate the collision risk of each target in the corresponding sparse group;

[0091] The trajectory avoidance execution judgment module 305 is used to compare the collision risk of each individual target in the corresponding sparse group with the warning threshold one by one to determine whether to execute the trajectory avoidance operation.

[0092] It should be noted here that, Figure 3 The various modules in the collision warning system based on group target tracking and dangerous area stratification are Figure 1 The various steps in the collision warning method based on group target tracking and dangerous area stratification correspond one to one, and the specific implementation process is the same and will not be repeated here.

[0093] Electronic devices include a central processing unit (CPU), which can perform various actions and processes according to programs stored in read-only memory (ROM) or programs loaded from storage into random access memory (RAM). RAM also stores various programs and data required for system operation. The CPU, ROM, and RAM are connected to each other via a bus. Input / output (I / O) interfaces are also connected to the bus.

[0094] The following components are connected to the I / O interface: an input section including a keyboard and mouse; an output section including cathode ray tubes (CRTs), liquid crystal displays (LCDs), and speakers; a storage section including a hard disk; and a communication section including network interface cards such as local area network (LAN) cards and modems. The communication section performs communication processing via a network such as the Internet. A drive is also connected to the I / O interface as needed. Removable media such as magnetic disks, optical disks, magneto-optical disks, and semiconductor memories are installed in the drive as needed, allowing computer programs read from these media to be installed in the storage section as needed.

[0095] When the central processing unit in the electronic device of this embodiment executes the program, the following is achieved: Figure 1 The steps in the collision warning method based on group target tracking and dangerous area stratification are shown.

[0096] In particular, according to an embodiment of the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present application includes a computer program product, which includes a computer program carried on a computer readable medium, the computer program including a computer program for executing Figure 1 In such an embodiment, the computer program can be downloaded and installed from a network via the communication portion and / or installed from a removable medium. When the computer program is executed by the central processing unit, the various functions defined in the apparatus of the present application are performed.

[0097] in, Figure 1 The computer program instructions corresponding to the method shown can also be stored in a computer readable memory that can guide a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0098] Those skilled in the art will appreciate that all or part of the processes in the above-described method embodiments can be implemented by instructing the relevant hardware through a computer program. The program can be stored in a computer-readable storage medium, and when executed, the program can include the processes in the above-described method embodiments. The storage medium can be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM).

[0099] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A collision warning method based on group target tracking and dangerous area stratification, characterized in that: include: The position information and motion status of the spacecraft and the group targets are obtained at set intervals, the trajectory of the spacecraft is calculated, and the danger zone is divided; the motion status includes the motion direction and motion speed; According to the location information and similarity of the group targets' motion states, the group targets are divided into several sparse groups, and a mesh topology structure of the behavioral associations of each sparse group is constructed; The central target of each mesh topology structure is taken as the main target, and the similarity of the motion state between other targets and the main target is used as the weight. The overall motion state of each sparse group is weightedly calculated to obtain the overall motion trajectory of each sparse group. Based on the overall motion trajectory of each sparse group and the trajectory of the spacecraft, the time when each sparse group is closest to the spacecraft is calculated and the behavior association of the corresponding sparse group is simultaneously released. The target in the danger zone at the corresponding time is found and the collision risk of each target in the corresponding sparse group is calculated. The collision risk of each individual target in the corresponding sparse group is compared with the warning threshold one by one to determine whether to perform orbit avoidance maneuvers.

2. The collision warning method based on group target tracking and dangerous area stratification according to claim 1, characterized in that: The process of dividing the group targets into several sparse groups is: The group targets are initially divided into several position subclusters according to their positions. Then, according to the similarity of their motion states, each position subcluster is refined into speed subclusters with similar positions and speeds, thus obtaining sparse groups.

3. The collision warning method based on group target tracking and dangerous area stratification according to claim 1, characterized in that: In the process of building a mesh topology structure, whether to connect two targets is determined based on the similarity of their speed directions. If the similarity of the speed directions of two targets is greater than a preset threshold, the speed directions are judged to be similar and a connecting line is drawn.

4. The collision warning method based on group target tracking and dangerous area stratification according to claim 1, characterized in that: With the spacecraft's center of mass as the center, the short and long axes of the ellipse are preset to construct three layers of areas from the inside to the outside, namely the high-risk area, the medium-risk area, and the low-risk area.

5. The collision warning method based on group target tracking and dangerous area stratification according to claim 4, characterized in that: The high-risk zone is a circular area with the sum of the equivalent radius of the spacecraft and the equivalent radius of the space debris as the radius; in the high-risk zone, the risk coefficient of the high-risk zone is 1, and the distance between the center of mass of the spacecraft and the space debris is less than the safety radius, and a collision is bound to occur.

6. The collision warning method based on group target tracking and dangerous area stratification according to claim 4, characterized in that: The medium-risk area and the low-risk area are parts of elliptical surfaces with similar structures to the two-dimensional projection of the error ellipsoid; the risk coefficient decreases exponentially: , where x and y are the horizontal and vertical coordinates of the coordinate system, and a and b are the warning distance thresholds determined by the relative speed error between the spacecraft and the space target.

7. The collision warning method based on group target tracking and dangerous area stratification according to claim 6, characterized in that: In the moderate danger zone and the low danger zone, the closest distance from the two-dimensional projection of the space debris position error ellipsoid in the intersection plane to the center of the coordinate system is regarded as r, the probability distribution within the overlapping range of the projection and the danger range is calculated, and the final collision probability is obtained by multiplying the danger coefficient by the probability size of the overlapping range.

8. A collision warning system based on group target tracking and dangerous area stratification, characterized in that: include: A spacecraft trajectory determination module is used to obtain the position information and motion status of the spacecraft and group targets at set intervals, calculate the spacecraft's trajectory, and divide the danger zone; the motion status includes motion direction and motion speed; The group target division module is used to divide the group targets into several sparse groups according to their location information and the similarity of their motion states, and to construct a mesh topology structure of the behavior associations of each sparse group; The sparse group trajectory determination module is used to calculate the overall motion state of each sparse group by taking the central target of each mesh topology structure as the main target and the similarity of the motion state between other targets and the main target as weights, and obtain the overall motion trajectory of each sparse group; The collision risk calculation module is used to calculate the time when each sparse group is closest to the spacecraft based on the overall motion trajectory of each sparse group and the spacecraft's trajectory, and simultaneously disassociate the behavior of the corresponding sparse group, find the target in the danger zone at the corresponding time, and calculate the collision risk of each target in the corresponding sparse group; The trajectory avoidance execution judgment module is used to compare the collision risk of each individual target in the corresponding sparse group with the warning threshold one by one to determine whether to execute the trajectory avoidance operation.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the collision warning method based on group target tracking and dangerous area stratification as described in any one of claims 1 to 7 are implemented.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the steps of the collision warning method based on group target tracking and dangerous area stratification according to any one of claims 1 to 7 are implemented.

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