Space-based distributed hierarchical management and control system and method for low-orbit high-density satellite constellation

Abstract

The invention discloses a space-based distributed hierarchical management and control system and method for a low-orbit high-density satellite constellation, and relates to the technical field of spatial information technology and satellite cooperative control. According to the satellite constellation management and control method based on the space-based distributed management and control nodes, on the premise that original hardware equipment and functions of heterogeneous constellations are not added, the interconnection and intercommunication level between heterogeneous resource satellite constellations of different shell layers is improved. The low-orbit high-density satellite constellation is composed of a plurality of low-orbit satellite clusters with heterogeneous resources, and a plurality of task star seats with heterogeneous resources can cooperate together to make up the capability limitation of a single satellite and provide various work services. Inter-satellite communication links exist in the shell layers of the task star base, but communication between the shell layers is mutually independent, and the shell layers are not communicated with other task star shell layers. And the task star seat is a high-density constellation with stable shell structure and uniform distribution. The management and control star seat is composed of a plurality of management and control stars distributed on a plurality of groups of orbits, each management and control star can serve as a space-based distributed management and control node, has the capability of being compatible with the communication mode of the task star seat of each shell layer, and can establish communication with the task stars in a proper communication range. According to the invention, interconnection and interworking and global management of large-scale low-orbit satellite group resources can be realized by deploying a management and control node network.

Description

Technical Field

[0001] The present invention relates to the field of space information technology and satellite collaborative control technology, and specifically to a space-based distributed hierarchical management and control system and method for low-orbit high-density satellite constellations in the field of satellite communication technology. Background Art

[0002] In the field of space applications, satellites, as the primary carriers, can be categorized by their functions into four types: communications satellites, navigation satellites, remote sensing satellites, and satellites used for scientific and technological experiments. With the rapid rise of the commercial space sector and the advancement of large-scale constellation projects, constellations composed of numerous small satellites have emerged. The collaborative operation of multiple satellites not only effectively overcomes the limitations of a single satellite's in-orbit capabilities but also demonstrates significant advantages in satellite communications, environmental monitoring, improved navigation accuracy, and joint observation.

[0003] Countries around the world are currently competing to develop large-scale low-Earth orbit (LEO) satellite networks and actively promoting research in related theories and technologies. With the continuous advancement of satellite technology and communication methods, the number of satellite launches worldwide has exploded. Satellite constellation designs have evolved from early, small-scale configurations consisting of a single orbit and a few to dozens of satellites to high-density, mega-constellation systems encompassing multiple orbital levels and comprising hundreds, thousands, or even tens of thousands of satellites.

[0004] However, despite the rapid expansion of mega-constellations comprised of satellites with diverse payloads (including communications, navigation, and remote sensing), these systems are generally challenged by insufficient interoperability, leading to the dilemma of being "unable to connect, manage, or use." Furthermore, the traditional ground-based, planned, centralized satellite tracking, control, and operations model is no longer able to meet the rapidly increasing volume of satellite data and the rapidly changing information landscape, making it impossible to provide efficient service support to a vast number of users worldwide.

[0005] To address these issues, several hierarchical control node deployment architectures for mega-satellite constellations have been proposed. In this architecture, upper-level control node satellites connect to and collect link status and resource information from lower-level node satellites, performing routing calculations to manage and control all lower-level node satellites within their control area. Lower-level node satellites then complete specific operational tasks, thereby reducing mega-constellation signaling overhead. However, existing hierarchical control systems for mega-satellite constellations lack heterogeneous constellation communication and adaptability, making it difficult to fully realize the collaborative potential of multi-heterogeneous, multi-configuration constellations.

[0006] For example, the invention patent with authorization announcement number CN113328777B, titled "Hierarchical Network Operation and Maintenance and Resource Management System and Method for Mega-Satellite Constellations," addresses the management and control challenges of a single, large-scale low-orbit satellite constellation by deploying local coordination layer controllers on high-orbit or medium-orbit satellites. It also provides an approximate calculation formula for the number of local coordination layer controllers for a low-orbit satellite constellation. However, this method is only applicable to a single low-orbit constellation with a stable configuration and fully interconnected satellite communications within the constellation. For large-scale, heterogeneous constellations with resources that lack communication link establishment capabilities between different layers, the method faces the problem of "not being able to connect."

[0007] Authorization Announcement No. CN112532296B, titled "A Method for Constructing a Large-Scale Satellite Network Based on Elliptical Satellite Coverage," and Authorization Announcement No. CN112532297B, titled "A Method for Constructing a Large-Scale Satellite Network Based on Rectangular Satellite Coverage," respectively proposed methods for deploying control domains based on elliptical and rectangular shapes, achieving full coverage of the control area of ​​large-scale satellite constellations. However, these methods rely on the stability of the constellation system configuration and topological relationships, have strict requirements for the configuration of giant satellite constellations, lack the adaptive capabilities to cope with heterogeneous constellations and emergencies, and cannot adapt to the dynamic changes in the topological relationships between constellations, and still face the problem of "unmanageable".

[0008] The invention patent, entitled "A Spatial Layer Controller Election Algorithm for a Spatial Information Network," with authorization announcement number CN106789293B, employs a layered and regionalized strategy to simplify complex spatial information networks. It also leverages the centralized control philosophy of SDN technology to divide the spatial layer into six regions, selecting appropriate satellites as controller nodes in each region, taking into account periodic changes in satellite topology. However, this method requires all satellite nodes to be equipped with an SDN controller, limiting its compatibility with heterogeneous giant satellite constellations that lack SDN controllers. This technical limitation prevents its use with existing satellite constellations.

[0009] Faced with this situation, in order to fully utilize the advantages of heterogeneous resources of different types of satellites and realize the effective integration and optimal configuration of low-orbit high-density satellite constellations with multiple functions such as communication, navigation, and remote sensing, it is urgent to develop a space-based distributed hierarchical management and control system and its method for low-orbit high-density satellite constellations, so as to realize "cross-layer communication", "global management and control" and "efficient utilization" of low-orbit high-density constellation systems, so as to better adapt to the diversified needs of future aerospace applications. Summary of the Invention

[0010] Technical problems to be solved by the invention:

[0011] In view of the above problems, the present invention proposes a satellite constellation control method based on space-based distributed control nodes. Without increasing the original hardware equipment and functions of the heterogeneous constellation, it improves the level of interconnection and interoperability between satellite constellations with heterogeneous resources in different shells. It can also enhance the robustness and flexibility of the entire constellation system through the adaptive maintenance capability of the control domain, and solve the current problem of satellite constellation systems being "unable to connect, manage, and use".

[0012] The technical solution adopted by the present invention to solve the above technical problems is:

[0013] A space-based distributed hierarchical management and control system for low-orbit, high-density satellite constellations. The low-orbit, high-density satellite constellations are composed of multiple groups of low-orbit satellite clusters with heterogeneous resources, including multiple mission satellite constellations with heterogeneous resources and a management and control satellite constellation with constellation management capabilities. The multiple mission satellite constellations with heterogeneous resources include communication satellite constellations, navigation satellite constellations, remote sensing satellite constellations, etc., which can work together to make up for the capability limitations of a single satellite and provide various operational services. There are inter-satellite communication links within the shell of the mission star constellation, but the communications between the shells are independent of each other and are not connected to other mission star shells. The mission star constellation is a high-density constellation with a stable shell configuration and uniform distribution. The management and control satellite constellation is composed of multiple management and control satellites distributed on multiple groups of orbits. Each management and control satellite can serve as a space-based distributed management and control node and has the ability to be compatible with the communication methods of the mission star constellations in each shell, and can establish communication with mission satellites within a suitable communication range.

[0014] The space-based distributed hierarchical control system for low-orbit high-density satellite constellations is composed of several control domains and inter-domain communication links.

[0015] The control domain can be regarded as a distributed control unit of the space-based distributed hierarchical control system. Overall, the space-based distributed hierarchical control system is a collection of all control domains and inter-domain communication links.

[0016] Each control domain consists of the following components: 1. A control satellite, serving as the domain's information processing center and responsible for coordinating activities within the domain; 2. Intra-domain mission satellites, including at least one gateway satellite and zero or more common mission satellites; and 3. Intra-domain intersatellite links, connecting the various satellite nodes within the domain. There is no duplication between control satellites and intra-domain mission satellites in different control domains. The collection of all control domains ensures complete coverage of the low-orbit, high-density satellite constellation.

[0017] Furthermore, within a specific control domain, the communication path between the control satellite and the entry satellite is one hop, meaning there is a direct communication link between the two. Other mission satellites within the domain must connect to the entry satellite via the intra-domain communication link to achieve communication with the control satellite.

[0018] Inter-domain communication links exist between adjacent control domains. Adjacent control domains specifically refer to adjacent control domains that are reachable within a single hop on the communication topology, rather than physically adjacent control domains. Inter-domain communication links take two forms: direct communication between control satellites in adjacent control domains; and intercommunication between mission satellites within adjacent control domains. These inter-domain communication links enable distributed control of the mega-constellation system.

[0019] According to the space-based distributed hierarchical control system, the following technical solutions can also be obtained based on the same inventive concept:

[0020] A space-based distributed hierarchical control method, the specific process is as follows:

[0021] Step 1: The control satellite loads a pre-calculated and stored database. The database includes the following data: A1: Control satellite constellation orbital configuration, A2: Orbital row data for all control satellites, A3: Control satellite inter-satellite communication topology, A4: Control satellite control beam coverage field parameters, B1: Constellation shell and orbital configuration of each mission satellite, B2: Orbital row data for each mission satellite, B3: Inter-satellite communication topology for each shell mission satellite, B4: Payload functions and payload operating parameters for each mission satellite.

[0022] Step 2: The control satellite obtains information about itself and adjacent control satellites, including A1: control satellite constellation orbit configuration, A2: orbital row data of all control satellites, and A3: inter-control satellite communication topology relationship, obtains adjacent control satellite numbers, establishes inter-domain communication links with adjacent control satellites on the communication topology network, and completes time synchronization.

[0023] Step 3: The control star calculates the priority queue of entry star selection indicators for itself and the adjacent control stars. The calculation process is as follows: the first step, according to B1: the constellation shell and orbital configuration of each mission star, the mission star constellation shell is processed in turn, and the shell data corresponding to the two-row orbital data of each mission star is retrieved; the second step, the two-row data is solved to obtain the six elements of the satellite orbit, including the semi-major axis, eccentricity, orbital inclination, pericenter angle, ascending node longitude and true anomaly, and then the orbit recursion calculation method is used to calculate the position coordinates and velocity vectors of all mission stars in the constellation shell in the geocentric inertial system; the third step, the six elements of the control star orbit are obtained by the same method. And calculate the position coordinates and velocity vector of the control satellite in the geocentric inertial system; the fourth step is to screen the mission satellites in the shell: first, the calculated satellite position coordinates are combined with the control beam coverage field parameters of the control satellite to exclude mission satellites outside the maximum communication half-angle coverage area of ​​the control satellite; secondly, according to the six numbers of satellite orbits, exclude mission satellites that have a certain range of right ascension difference from the ascending node of the control satellite. The purpose of this processing is to make the remaining optional mission satellites have a longer entry satellite communication time window; then, calculate the entry star selection index l of the control satellite i for each mission satellite j i,j ,(j∈{1,2,3,L,n}, n is the number of remaining task stars after screening, and n≥0, l i,j It can measure the movement relationship between the control star i and the entry star j and the sustainable communication time, l i,j The larger the value, the farther the control star i is from the entry star j, and the shorter the communication time will be. The fifth step is to determine whether the selected entry star exists. If the selected entry star does not exist, this step is not processed and the seventh step is directly entered. If the selected entry star exists, the sixth step is entered. The sixth step is to determine whether the control star itself or the adjacent entry star meets the conditions for switching, using a shell-by-shell method. If the control star itself and the adjacent entry star do not meet the conditions for switching, the entry star selection index l is set. i,j Set to 0; if there is a situation that meets the switching conditions in the shell itself or the adjacent entrance star, no processing is done; Step 7, all l calculated in each shell i,j They are arranged in order from small to large, and then form the entry star selection index priority queue L i .

[0024] Step 4: The control star selects the index priority queue L based on its own and the adjacent control star’s entry star obtained by step 3. i , initially select the front entry star of itself and the entry star of the adjacent control star in the queue. If there is a conflict, select new preliminary entry stars in the priority queue in sequence until the conflict is resolved or there is no entry star to be selected; finally, under the condition of no repeated selection, select an entry star for the current control star in each task star shell layer.

[0025] Step 5: Based on the distribution of the control star itself and the adjacent entry stars, combined with the shell configuration, the candidate domain of the mission star is calculated. The specific process is as follows: for the high-density uniform constellation configuration shell, the adjacent entry stars corresponding to the adjacent control stars are mapped on the mission star shell topology communication network. The line connecting the mapped adjacent entry stars is used as the boundary of the feasible domain, and the circumscribed polygonal area formed by connecting the end of the feasible domain boundary is used as the candidate domain M of the mission star.

[0026] Step 6: The control satellite calculates the link establishment index matrix T within the candidate domain M. It shares this index with adjacent control satellites via intersatellite links and receives the link establishment index matrix T sent by adjacent control satellites. For high-density uniform constellation configuration shells, the elements of T are composed of the link establishment coefficient T. This coefficient T measures the difficulty of establishing a communication link between satellites: for the gateway satellite itself, the link establishment coefficient is 0. For two communication links with the same total number of hops, the smaller the link establishment coefficient is, the smaller the number of inter-orbital communication hops involved. For two communication links with the same number of on-orbit and inter-orbit hops involved, the smaller the link establishment coefficient is, the more stable the relative position and orientation between the mission satellites involved in the inter-orbit communication.

[0027] Step 7: After receiving the link index matrix T for each shell calculated by all adjacent control satellites, the control satellite compares it with its own link index T. If an element in its own link index matrix T is less than the corresponding value in the T matrices of all adjacent control satellites, the mission satellite corresponding to that element is preliminarily selected as a candidate for the domain; otherwise, no action is taken. This step enables adaptive control domain partitioning based on the link index matrix T. After the partitioning is complete, information about events such as satellite failures, communication topology changes, and new satellites entering orbit is obtained based on intersatellite communication links and updated to the database. The process then returns to step 1 and repeats for the next round of control domain partitioning.

[0028] By running the above steps on each control satellite in a distributed manner, a cross-shell inter-constellation communication network can be established, thereby realizing hierarchical management of the low-orbit, high-density satellite constellation network, and having adaptive maintenance capabilities to maintain system availability in events such as satellite failures, communication topology changes, and new satellites entering orbit.

[0029] The present invention has the following beneficial technical effects:

[0030] The present invention provides a constellation control method based on space-based distributed control nodes. Without adding to the existing hardware and functionality of heterogeneous mission constellations, the method enhances the interconnectivity between satellite constellations with heterogeneous resources in different shells by leveraging the control constellation's "communication bridge" function. Furthermore, based on distributed space-based control nodes, the method enables global, hierarchical control of giant, heterogeneous constellations. The control system also possesses a degree of adaptive capability, enabling dynamic maintenance of the giant constellation system in the event of satellite failures, changes in communication topology, and the entry of new satellites into orbit. This enhances the robustness and flexibility of the entire constellation system, resolving the current challenges of constellations being "unable to connect, manage, or operate." By deploying a network of control nodes, the present invention enables interconnectivity and global management of large-scale low-orbit satellite cluster resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention can be better understood by referring to the description given below in conjunction with the accompanying drawings, which together with the following detailed description are included in this specification and form a part of this specification, and are used to further illustrate the preferred embodiments of the present invention and explain the principles and advantages of the present invention.

[0032] Figure 1 This is an architecture diagram of a space-based distributed hierarchical control system for low-orbit high-density satellite constellations in an embodiment of the present invention;

[0033] Figure 2 This is a configuration diagram of a control star constellation system in an embodiment of the present invention;

[0034] Figure 3 This is a flow chart of the space-based distributed hierarchical control method in an embodiment of the present invention;

[0035] Figure 4 This is a schematic diagram of the communication link between the control satellite and the entry satellite in an embodiment of the present invention;

[0036] Figure 5 Schematic diagram of the projection of the position velocity vectors of the control satellite and the mission satellite on the surface of the earth in an embodiment of the present invention;

[0037] Figure 6 Schematic diagram of the process of selecting the boundary of the feasible region and the task stars within the region in an embodiment of the present invention. DETAILED DESCRIPTION

[0038] To help those skilled in the art better understand the present invention, exemplary embodiments or examples of the present invention are described below with reference to the accompanying drawings. Obviously, the described embodiments or examples are only some of the embodiments or examples of the present invention, and not all of them. All other embodiments or examples derived by those skilled in the art based on the embodiments or examples of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0039] To achieve efficient management and optimal resource allocation for low-orbit, high-density satellite constellations, this paper proposes a specific implementation plan based on a space-based distributed hierarchical control and management system. This solution deploys a constellation of control satellites capable of communicating with all the mission satellites in each shell, creating a network system consisting of multiple distributed control domains. Each control domain contains at least one control satellite, serving as an information processing center node, responsible for coordinating activities within the domain and establishing inter-domain communication links with adjacent control domains to ensure cross-domain information exchange. A control satellite consists of computing, communication, and storage units. Each control satellite not only monitors and adjusts the status and resource allocation of all mission satellites within its control area in real time, but also automatically adjusts the network topology based on environmental changes, thereby enhancing the flexibility, robustness, and responsiveness of the mega-constellation system. Through this distributed architecture, the present invention aims to address the existing challenges of "unable to connect, manage, or utilize" and achieve efficient interconnection and autonomous management of low-orbit, high-density satellite constellations.

[0040] Combine Figure 1-6 A specific embodiment of the present invention is given, and a schematic diagram of a low-orbit high-density satellite constellation is shown as follows: Figure 1 As shown, it includes three different shells, namely the management star shell, the mission star shell a and the mission star shell b.

[0041] The control satellite constellation in the embodiment of the present invention adopts the Walker-Delta configuration, which can be expressed in the form of α:NS / NP / F, where α is the orbital inclination (°), NS is the total number of satellites, NP is the number of orbital planes, and F is the phase factor. Under this configuration, each orbital plane is evenly distributed along the equator and adopts a 2π distribution, that is, the ascending node right ascension (RAAN) of all orbital planes is equally spaced in the range of [0,2π], and the ascending node right ascension difference of adjacent orbital planes is ΔΩ=2π / NP. Specifically, it can be expressed as 83.6:36 / 6 / 3, with an orbital altitude of 8000km. Each control satellite can be used as a space-based distributed control node, equipped with currently applied point-controllable point beam butterfly antenna payloads, phased array antenna payloads, 5G antenna payloads, and laser communication payloads. These control satellites have the ability to be compatible with the communication methods of each shell mission star constellation, and can establish communications with the heterogeneous mission satellite terminals with suitable communication distances and communication pointing angles. Inside the control star shell, the specific communication relationship is as follows: Figure 2 As shown, adjacent satellites in the same orbital plane establish inter-satellite links on the same orbit, and satellites in different orbital planes establish inter-satellite links on different orbits. Figure 2 In this specific example, control satellite 0 will establish co-orbital inter-satellite links with control satellites 1 and 4, and inter-orbital inter-satellite links with control satellites 2 and 6. Due to the differences in the inter-orbital inter-satellite link connection methods, the inter-satellite links are configured in an X-shape, that is, the phase differences between the satellites connected by all inter-orbital inter-satellite links are the same, forming a stable 2D-Torus communication topology network.

[0042] Both mission shells a and b are high-density constellations with stable, evenly distributed configurations. Like the control satellites, they employ the Walker-Delta configuration: Mission shell a can be represented as 70:720 / 36 / 1, orbiting at an altitude of 450 km. Mission shell b can be represented as 97.87:720 / 36 / 1, orbiting at an altitude of 627 km, in a sun-synchronous orbit. Within these two shells, adjacent satellites within the same orbital plane within the same shell establish intra-orbital inter-satellite links, while satellites in different orbital planes establish inter-orbital inter-satellite links. Due to the different inter-orbital inter-satellite link connection methods, the inter-satellite links are configured in an X-shape, meaning that all satellites connected by the inter-orbital links have the same phase difference, forming a stable 2D-Torus communication topology.

[0043] In a specific embodiment of the present invention, a space-based distributed hierarchical control system for a low-orbit high-density satellite constellation is provided. Figure 1As shown, it is composed of several control domains and inter-domain communication links. The control domain can be regarded as a distributed control unit of the space-based distributed hierarchical control system. On the whole, the space-based distributed hierarchical control system is a collection of all control domains and inter-domain communication links. Each control domain is composed of the following components: 1. The control satellite, which serves as the information processing center node of the control domain and is responsible for coordinating activities within the domain; 2. The intra-domain mission satellite, including at least one entry satellite and zero or more ordinary mission satellites; 3. The intra-domain inter-satellite link, which is used to connect the various satellite nodes in the domain. There is no duplication between the control satellites and intra-domain mission satellites of different control domains. The collection of all control domains can achieve complete coverage of the low-orbit high-density satellite constellation.

[0044] In addition, in a specific control domain, the communication path between the control satellite and the entry satellite is one hop, that is, there is a direct communication link between the two. Other mission satellites in the domain need to be transferred to the entry satellite through the intra-domain communication link to achieve communication with the control satellite. The inter-domain communication link exists between adjacent control domains. The adjacent control domains specifically refer to adjacent control domains that are reachable in one hop on the communication topology network, rather than control domains that are close in physical space. Inter-domain communication links include two forms: one is in the form of direct communication between control satellites in adjacent control domains; the other is in the form of mutual communication between mission satellites within adjacent control domains. Through this inter-domain communication link, distributed control of the giant constellation system is achieved.

[0045] like Figure 3 As shown in FIG. 1 , a space-based distributed hierarchical control method is used in this embodiment. The specific operation process of each control satellite is as follows:

[0046] Step S1: The control satellite loads a pre-calculated database into the storage unit. The database includes the following data: A1: Control satellite constellation orbital configuration, A2: Orbital row data for all control satellites, A3: Control satellite inter-satellite communication topology, A4: Control satellite control beam coverage field parameters, B1: Constellation shells and orbital configurations for each mission satellite, B2: Orbital row data for each mission satellite, B3: Inter-satellite communication topology for each shell mission satellite, and B4: Payload functions and payload operating parameters for each mission satellite.

[0047] Step S2: The calculation unit of the control satellite obtains the adjacent control satellite numbers according to the control satellite constellation orbit configuration A1, the orbital two-row number data of all control satellites A2 and the communication topology relationship between control satellites A3 in the storage unit. Figure 2 In the specific example, the control satellites adjacent to control satellite 0 are numbered 1 to 6. The communication unit then establishes an inter-domain communication link with the adjacent control satellites to complete time synchronization, with the goal of synchronizing the control domain division time t within the computing units of each control satellite.

[0048] Step S3: The calculation unit of the control star performs the following calculations: first, the control star's own entry star selection index priority queue L0 is calculated, and then the adjacent control stars' entry star selection index priority queues L1, L2, ..., L6 are calculated in sequence. The entry star selection index priority queue L corresponding to the control star i is i The calculation process is as follows, (i∈{0,1,2,L,6}, represents the number of itself and the adjacent control star):

[0049] The specific process of S3 is as follows:

[0050] The first step is to process the constellation shells a, b, and c of each mission star in B1 in sequence according to their orbital configurations, and retrieve the corresponding shell data from the orbital two-line data of each mission star in B2.

[0051] The second step is to solve the two-line data to obtain the six satellite orbit parameters: semi-major axis, eccentricity, orbit inclination, periapsis argument, ascending node longitude and true anomaly. Then, orbit recursion calculation methods such as the SGP4 calculation method are used to calculate the position coordinates and velocity vectors of all mission satellites in the constellation shell at time t in the geocentric inertial system.

[0052] The third step is to obtain the six orbital numbers of the control satellite using the same method, and calculate the position coordinates and velocity vector of the control satellite i in the geocentric inertial system at time t;

[0053] The fourth step is to screen the mission stars in the shell: First, Figure 4 As shown in the figure, according to the satellite position coordinates calculated in the second and third steps, combined with the control beam coverage field parameters of the A4 control star, the mission satellites outside the maximum communication half-angle coverage area of ​​the control star i are excluded; secondly, according to the six satellite orbit numbers calculated in the second and third steps, the mission satellites with a right ascension difference of ±30° from the ascending node of the control star i are excluded. The purpose of this processing is to make the remaining optional mission satellites have a longer entry satellite communication time window; then, the entry star selection index l of the control star i for each mission star j is calculated. i,j ,(j∈{1,2,3,L,n},n is the number of remaining task stars after screening, and n≥0). i,j The calculation process is as follows Figure 5 As shown, the position velocity vectors of the remaining mission satellites and the position velocity vector of the control satellite i are projected onto the surface of the earth. The projection calculation process is as follows: the position vector r of the control satellite i is i =(x,y,z), velocity vector v i =(v x ,v y ,v z ), taking the radius of the earth R as an example, calculate the distance from the current position to the center of the earth Normalize the position vector and multiply it by the radius of the earth R to get the position vector projection of the subsatellite point of the control satellite i and the velocity vector projection of the subsatellite point Based on the above principle, the projection vector r of the subsatellite point position of mission star j can be obtained by the same calculation j ′, velocity vector projection v j ′; Finally, calculate the relative position vector projection Δr i,j ′=r i ′-r j ′, relative velocity vector projection Δv i,j ′=v j ′-v i ′, so the entry star selects the indicator Its physical meaning is Figure 5 As shown in the figure, it represents the vector angle (unit: °) between the relative position vector projection and the relative velocity vector projection, which can measure the communication time that can be maintained between the control satellite i and the entry satellite j. i,j When the angle is greater than 90°, the entry satellite i will be far away from the control satellite j, and there is a risk that the entry satellite i will leave the communication range of the control satellite j;

[0054] Step 5: Determine whether the selected entry star already exists. If the selected entry star does not exist, this step is not processed and the process goes directly to step 7. If the selected entry star exists, the process goes to step 6.

[0055] Step 6: Determine whether the star itself or the adjacent entry star meets the conditions to be switched, using a shell-by-shell method. If the shell itself and the adjacent entry star do not meet the conditions to be switched, the entry star selection index l i,j Set to 0; if there are situations in the shell itself or in the adjacent entry stars that meet the conditions for switching, no processing is done; the purpose of the judgment and screening here is to keep the task star division in the domain relatively stable when the entry star does not change, so as to maximize the maintenance time of a single control domain and reduce the giant constellation signaling overhead caused by frequent switching of the control domain. The specific judgment method for whether the current entry star meets the conditions for switching is as follows: First, make judgment 1: judge the position of the current entry star relative to the control star. If the current entry star is in the optimal communication range, it means that the communication is stable and still has a long communication window, and the conditions for switching are not met, and the judgment is completed; if the current entry star is between the optimal communication range and the maximum communication range, it means that the communication is not stable enough, and then make judgment 2: the entry star selection index l i,j Judgment: If l i,j If it is large, it means that the trajectory of the current entry star will be far away from the current control star, the communication stability will be further deteriorated, and the communication window will be maintained for a short time. The switching conditions are met and the judgment is completed. i,j Set to 0; if l i,jIf the value is smaller, it means that the trajectory of the current entry star will be close to the current control star or maintain a stable distance. The communication stability will be improved, and the maintainable communication window time will be longer. The switching conditions are not met, and the judgment is completed.

[0056] Step 7: All l calculated in each shell i,j They are arranged in order from small to large. Taking shell a as an example, l i,j,a for all l in shell a i,j A collection arranged in ascending order, l i,j,b Similarly. Then form the entry star selection index priority queue L i ={l i,j,a ,l i,j,b}.

[0057] Step S4: The calculation unit of the control star performs the following calculations: First, the control star's own entry star selection index priority queue L0 is read in the order of shells a and b, and the task star corresponding to the first index in the shell queue is used as the primary entry star; secondly, the adjacent control star's entry star selection index priority queues L1, L2, ..., L6 are read in the order of shells a and b, and the task star corresponding to the first index in the shell queue is used as the adjacent control star's primary entry star; then, it is determined whether its own primary entry star conflicts with the adjacent control star's primary entry star. If so, the primary entry star with the larger entry star selection index remains unchanged, and the smaller one selects a new primary entry star in the priority queue in sequence until the conflict is resolved or there is no entry star to be selected; finally, an entry star is selected for the current control star in each task star shell under the condition that there is no repeated selection.

[0058] Step S5: The calculation unit of the control star calculates the task star candidate domain M based on the distribution of the entry stars corresponding to itself and the adjacent control stars, combined with the shell configuration. The specific process is as follows: For the high-density uniform constellation configuration shell a and shell b, as shown Figure 6 As shown, according to Figure 2 The positions of the adjacent entry stars corresponding to the adjacent control stars 1 to 6 in the mission star shell topology communication network are taken as the feasible region boundary, and the circumscribed hexagonal area formed by connecting the feasible region boundaries end to end is taken as the mission star candidate region M;

[0059] Step S6: The calculation unit of the control star calculates the link establishment index matrix T in different shell layer candidate domains M in turn, and then shares the link establishment index matrix T in different shell layer candidate domains M with adjacent control stars through the communication unit, and receives the link establishment index matrix T sent by the adjacent control star.

[0060] like Figure 6 As shown, the specific process of S6 is as follows:

[0061] In the first step, based on the inter-satellite communication topology relationship B3 of each shell mission star in the storage unit, the mission stars and the entry star within the boundary of the feasible domain are mapped to their positions on the 2D-Torus communication topology network. Then, the shortest number of hops required to connect the mission stars in each domain to the entry star is calculated, including the shortest hop number k for on-orbit communication and the shortest hop number m for off-orbit communication.

[0062] The second step is to define the inter-orbit communication correction coefficient C to correct the negative impact of inter-orbit communication on the stability of the communication link relative to the same-orbit communication. For shells a and b, the relative positions between adjacent mission satellites in the same orbit can remain stable, so the inter-satellite links in the same orbit can maintain long-term stability; while the relative positions of mission satellites in adjacent orbits will continue to change during their orbits around the earth, so the stability of inter-orbit communication is weaker than that of the same-orbit communication. Taking into account that the range of distance variation between adjacent satellites in a high-density constellation is relatively small, while the relative position direction changes are more significant, the present invention defines the inter-orbit communication correction coefficient C = 1-e ω ,in The physical meaning is the angular velocity of the relative position change of mission satellite 1 and mission satellite 2 in the inter-orbit communication, r1=(x1,y1,z1), r2=(x2,y2,z2) are the position coordinates of mission satellite 1 and mission satellite 2 in the geocentric inertial coordinate system, v1=(v x1 ,v y1 ,v z1 ),v2=(v x2 ,v y2 ,v z2 ) is the velocity vector of mission satellite 1 and mission satellite 2 in the geocentric inertial coordinate system. C = 1-e -ω The purpose of the form is to make the inter-orbit communication correction coefficient C∈[0,1) when ω∈[0,+∞).

[0063] The third step is to calculate the link coefficient T of the entry star relative to the task star in each domain. Where k is the shortest hop number for intra-orbit communication, m is the shortest hop number for inter-orbit communication, and n j is the total number of communication paths that meet the shortest path requirement on the topological network when performing the jth off-track communication, C i is the inter-orbit communication correction coefficient for the i-th communication path in the shortest path above, the calculation method of which is given in step 2. The link establishment coefficient T here measures the difficulty of establishing a communication link between satellites: for the gateway satellite itself, its link establishment coefficient is 0; for two communication links with the same total number of hops, the smaller the link establishment coefficient is, the smaller the number of inter-orbit communication hops included is; for two communication links with the same number of on-orbit and inter-orbit hops is, the smaller the link establishment coefficient is, the more stable the relative position and direction between the mission satellites in the inter-orbit communication are.

[0064] The fourth step is to obtain the chain index matrix T corresponding to the shell layer candidate domain M, T = (t ij )m×n, Where m, n are the number of rows and columns of the 2D topological network, t ij The element in the i-th row and j-th column of the link-building indicator matrix T, Task ij is the node with coordinate value (i, j) of the mission star in the 2D topological network space, T ij Task ij The node chaining coefficient, M is the candidate domain of the shell.

[0065] The fifth step is to connect the link index matrix T of shell a and shell b through the communication unit. Figure 2 The adjacent control stars 1 to 6 shown share and receive the link establishment index matrix T sent by the adjacent control stars 1 to 6.

[0066] Step S7: After the communication unit receives the link index matrix T calculated for each shell layer from all adjacent control satellites, it compares it with its own link index T. If an element in its own link index matrix T is less than the corresponding value in the T matrices of all adjacent control satellites, the mission satellite corresponding to that element is preliminarily determined as a satellite within the candidate domain; otherwise, no processing is performed. This step enables adaptive control domain partitioning based on the link index matrix T. After the partitioning is completed, event information such as satellite failures, communication topology changes, and new satellites entering orbit is obtained based on the intersatellite communication links and updated to the database. The system then returns to step 1 and repeats the next round of control domain partitioning.

[0067] By running the above steps on each control satellite in a distributed manner, a cross-shell inter-constellation communication network can be established, thereby realizing hierarchical management of the low-orbit, high-density satellite constellation network, and having adaptive maintenance capabilities to maintain system availability in events such as satellite failures, communication topology changes, and new satellites entering orbit.

[0068] It has been verified that the method proposed in the present invention solves the technical problem proposed in the present invention, and the method described in the present invention has been verified to fully achieve the technical effect claimed in the present invention.

[0069] The space-based distributed hierarchical control method for low-orbit high-density satellite constellations proposed in the present invention is the underlying technical core of the present invention.

[0070] The computer program of the system (software) developed by the present invention is stored on a computer-readable storage medium. The computer program is configured to implement the steps of the aforementioned space-based distributed hierarchical control method for a low-orbit, high-density satellite constellation when invoked by a processor. This materializes the present invention on a carrier, becoming a computer program product.

[0071] A space-based distributed hierarchical management and control device for low-orbit, high-density satellite constellations, the device comprising at least one processor and a memory communicatively connected to the at least one processor, wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the above-mentioned space-based distributed hierarchical management and control method for low-orbit, high-density satellite constellations, thereby realizing interconnection and global management of large-scale low-orbit star cluster resources.

[0072] Various implementations of the systems and techniques described herein can be realized in digital electronic circuit systems, integrated circuit systems, dedicated ASICs (application specific integrated circuits), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system that includes at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0073] The computer programs (also referred to as programs, software, software applications, or code) of the present invention include machine instructions for a programmable processor and can be implemented using high-level procedural and / or object-oriented programming languages, and / or assembly / machine languages. As used herein, the terms "machine-readable medium" and "computer-readable medium" refer to any computer program product, device, and / or means (e.g., a magnetic disk, optical disk, memory, programmable logic device (PLD)) for providing machine instructions and / or data to a programmable processor, including machine-readable media that receive machine instructions as machine-readable signals. The term "machine-readable signal" refers to any signal for providing machine instructions and / or data to a programmable processor.

[0074] It should be understood that the various forms of the above-described processes may be used, and steps may be reordered, added, or deleted. For example, the steps described in this application may be performed in parallel, sequentially, or in a different order. As long as the desired results of the technical solutions disclosed in this application can be achieved, they are all within the scope of protection of the present invention.

Claims

1. A space-based distributed hierarchical control and management system for low-orbit, high-density satellite constellations, wherein the low-orbit, high-density satellite constellations are composed of multiple groups of low-orbit satellite clusters with heterogeneous resources, including multiple mission satellite constellations with heterogeneous resources and a control satellite constellation with constellation control capabilities; the multiple mission satellite constellations with heterogeneous resources include communication satellite constellations, navigation satellite constellations, and remote sensing satellite constellations, which can work together to make up for the capability limitations of a single satellite and provide various operational services; there are inter-satellite communication links within the shells of the mission star constellation, but the communications between the shells are independent of each other and are not connected to other mission star shells; the mission star constellation is a high-density constellation with a stable shell configuration and uniform distribution; the control star constellation is composed of multiple control satellites distributed on multiple groups of orbits, each of which can serve as a space-based distributed control and management node and has the ability to be compatible with the communication methods of the mission star constellations in each shell, and can establish communication with mission satellites within a suitable communication range; It is characterized in that The space-based distributed hierarchical control system for low-orbit high-density satellite constellations is composed of several control domains and inter-domain communication links; The control domain can be regarded as a distributed control unit of the space-based distributed hierarchical control system. Overall, the space-based distributed hierarchical control system is the collection of all control domains and inter-domain communication links. Each control domain includes the following components: The control star, as the information processing center node of the control domain, is responsible for coordinating activities within the domain; In-domain mission stars include at least one entry star and zero or more ordinary mission stars; Intra-domain inter-satellite links, used to connect various satellite nodes within the domain; There is no duplication between the control satellites of different control domains and the mission satellites within the domains; the collection of all control domains can achieve complete coverage of the low-orbit high-density satellite constellation.

2. The space-based distributed hierarchical management and control system for low-orbit high-density satellite constellations according to claim 1 is characterized in that: In a specific control domain, the communication path between the control satellite and the entry satellite is one hop, that is, there is a direct communication link between the two; other task satellites in the domain need to be transferred to the entry satellite through the domain communication link to achieve communication with the control satellite; The inter-domain communication links exist between adjacent control domains. The adjacent control domains specifically refer to adjacent control domains that are reachable within one hop on the communication topology network, rather than control domains that are physically close. Inter-domain communication links include two forms: one is the direct communication between control satellites in adjacent control domains; the other is the communication between mission satellites within adjacent control domains. Through this inter-domain communication link, distributed control of the giant constellation system can be achieved.

3. A space-based distributed hierarchical control method for low-orbit high-density satellite constellations, characterized by: The method comprises: Step 1: The control star loads the pre-calculated and stored database; Step 2: The control satellite obtains information about itself and its neighboring control satellites, establishes inter-domain communication links with neighboring control satellites on the communication topology network, and completes time synchronization. Step 3: The control star calculates the priority queue of its own entry star selection index and that of its adjacent control stars; Step 4: The control star selects the index priority queue based on its own and the adjacent control star's entry star calculated in step 3. Step 5: Based on the distribution of the control star itself and the adjacent entry stars and the shell configuration, calculate the candidate domain for the mission star; Step 6: The control satellite calculates the link establishment index matrix T in the selected domain M, shares the link establishment index T in the selected domain M with the adjacent control satellite through the inter-satellite link, and receives the link establishment index matrix T sent by the adjacent control satellite; Step 7: After receiving the link index T matrix of each shell layer calculated by all adjacent control stars, the control star compares it with its own link index T to realize the adaptive division function of the control domain based on the link index T matrix.

4. The space-based distributed hierarchical management and control method for low-orbit high-density satellite constellations according to claim 1 is characterized in that: The specific implementation process of the method is: Step 1. The control satellite loads the pre-calculated and stored database: the database includes the following data: A1: control satellite constellation orbit configuration, A2: orbital row data of all control satellites, A3: control inter-satellite communication topology, A4: control beam coverage field parameters of the control satellite, B1: each mission star constellation shell and orbit configuration, B2: orbital row data of each mission star, B3: inter-satellite communication topology of each shell mission star, B4: payload function and payload operating parameters of each mission star; Step 2: The control satellite obtains information about itself and its neighboring control satellites, including A1: orbital configuration of the control satellite constellation, A2: orbital row data of all control satellites, and A3: communication topology relationship between control satellites. It obtains the numbers of neighboring control satellites, establishes inter-domain communication links with neighboring control satellites on the communication topology network, and completes time synchronization. Step 3: The control star calculates the priority queue of its own entry star selection index and that of its adjacent control stars. The calculation process is as follows: The first step is to process the constellation shells of each mission star in turn according to B1: the constellation shells and orbital configurations of each mission star, and retrieve the corresponding shell data in B2: the orbital two-line data of each mission star; The second step is to solve the two-line data to obtain the six elements of the satellite orbit: semi-major axis, eccentricity, orbit inclination, periapsis argument, ascending node longitude and true anomaly. Then, the orbit recursion calculation method is used to calculate the position coordinates and velocity vectors of all mission satellites in the constellation shell in the geocentric inertial system. The third step is to obtain the six orbital numbers of the control satellite using the same method, and calculate the position coordinates and velocity vector of the control satellite in the geocentric inertial system; The fourth step is to screen the mission satellites in the shell: first, the calculated satellite position coordinates are combined with the control beam coverage field parameters of the control star to exclude mission satellites outside the maximum communication half-angle coverage area of ​​the control star; second, based on the six satellite orbit numbers, mission satellites with a certain range of right ascension difference from the control star ascending node are excluded. The purpose of this processing is to make the remaining optional mission satellites have a longer entry satellite communication time window; then, the entry star selection index l of the control star i for each mission star j is calculated. i,j ,(j∈{1,2,3,L,n}, n is the number of remaining task stars after screening, and n≥0, l i,j It can measure the movement relationship between the control star i and the entry star j and the sustainable communication time, l i,j The larger the value, the farther away the control star i is from the entry star j, and the communication time will be shortened. Step 5: Determine whether the selected entry star already exists. If the selected entry star does not exist, this step is not processed and the process goes directly to step 7. If the selected entry star exists, the process goes to step 6. Step 6: Determine whether the star itself or the adjacent entry star meets the conditions to be switched, using a shell-by-shell method. If the shell itself and the adjacent entry star do not meet the conditions to be switched, the entry star selection index l i,j Set to 0; If there is a situation in the shell itself or in the adjacent entry star that meets the conditions for switching, no processing will be done; Step 7: All l calculated in each shell i,j They are arranged in order from small to large, and then form the entry star selection index priority queue L i ; Step 4: The control star selects the entry star priority queue L based on the entry star of itself and the adjacent control star calculated in step 3. i , initially select the entry star at the front of the queue and the entry star of the adjacent control star. If there is a conflict, select new preliminary entry stars in the priority queue in sequence until the conflict is resolved or there is no entry star to be selected; finally, under the condition of no repeated selection, select an entry star for the current control star in each task star shell layer; Step 5: Based on the distribution of the control star itself and the adjacent entry stars, and in combination with the shell configuration, calculate the candidate domain of the mission star. The specific process is as follows: for the high-density uniform constellation configuration shell, the adjacent entry stars corresponding to the adjacent control stars are mapped onto the mission star shell topology communication network. The line connecting the mapped adjacent entry stars is used as the boundary of the feasible domain, and the circumscribed polygonal area formed by connecting the feasible domain boundary end to end is used as the candidate domain M of the mission star. Step 6. The control satellite calculates the link establishment index matrix T within the candidate domain M, shares the link establishment index T within the candidate domain M with the adjacent control satellite through the inter-satellite link, and receives the link establishment index matrix T sent by the adjacent control satellite. For the high-density uniform constellation configuration shell: the elements of T are composed of the link establishment coefficient T. The link establishment coefficient T can measure the difficulty of establishing a communication link between satellites: for the entry satellite itself, its link establishment coefficient is 0; for two communication links with the same total number of hops, the smaller the number of inter-orbit communication hops included, the smaller the link establishment coefficient; for two communication links with the same number of on-orbit hops and inter-orbit hops, the more stable the relative position and direction between the mission satellites in the inter-orbit communication, the smaller the link establishment coefficient. Step 7: After receiving the link index matrix T of each shell layer calculated by all adjacent control stars, the control star compares it with its own link index T; if an element in its own link index matrix T is smaller than the corresponding value in the T matrices of all adjacent control stars, the task star corresponding to the element is preliminarily determined as a star in the candidate domain; Otherwise, no action is taken. This step enables adaptive control domain partitioning based on the link-building indicator matrix T. After the partitioning is complete, information about events such as satellite failures, communication topology changes, and new satellites entering orbit is collected based on the intersatellite communication links and updated to the database. The process then returns to step 1 and repeats for the next round of control domain partitioning. The above steps are run separately on each control satellite in a distributed manner to establish a cross-shell inter-constellation communication network, thereby realizing hierarchical management of the low-orbit high-density satellite constellation network.

5. The space-based distributed hierarchical management and control method for low-orbit high-density satellite constellations according to claim 4 is characterized in that: Regarding the screening of the mission stars in the shell as described in step 3, Entry star selection indicator l i,j The calculation process is: project the position velocity vectors of the remaining mission satellites and the position velocity vector of the control satellite i onto the surface of the earth. The projection calculation process is as follows: take the position vector r of the control satellite i as i =(x,y,z), velocity vector v i =(v x ,v y ,v z ), let the radius of the earth be R, calculate the distance from the current position to the center of the earth Normalize the position vector and multiply it by the radius of the earth R to get the position vector projection of the subsatellite point of the control satellite i and the velocity vector projection of the subsatellite point Based on the above principle, the projection vector r of the subsatellite point position of mission star j can be obtained by the same calculation j ′, velocity vector projection v j ′; Finally, calculate the relative position vector projection Δr i,j ′=r i ′-r j ′, relative velocity vector projection Δv i,j ′=v j ′-v i ′, so the entry star selects the indicator It is used to represent the vector angle between the relative position vector projection and the relative velocity vector projection, and to measure the communication time that can be maintained between the control satellite i and the entry satellite j. i,j When the angle is greater than 90°, the entry star i will be far away from the control star j, and there is a risk that the entry star i will leave the communication range of the control star j.

6. The space-based distributed hierarchical management and control method for low-orbit high-density satellite constellations according to claim 5 is characterized in that: The specific process of step 6 is as follows: The first step is to map the mission stars and entry stars within the feasible region boundary to their positions on the 2D-Torus communication topology network based on the inter-satellite communication topology relationship B3 of each shell mission star in the storage unit. Then, the shortest number of hops required for each mission star in the region to connect to the entry star is calculated, including the shortest hop number k for on-orbit communication and the shortest hop number m for off-orbit communication. The second step is to define the inter-orbit communication correction coefficient C to correct the negative impact of inter-orbit communication on the stability of the communication link compared to intra-orbit communication. Define the inter-orbit communication correction coefficient C = 1-e ω ,in The physical meaning is the angular velocity of the relative position change of mission satellite 1 and mission satellite 2 in the inter-orbit communication, r1=(x1,y1,z1), r2=(x2,y2,z2) are the position coordinates of mission satellite 1 and mission satellite 2 in the geocentric inertial coordinate system, v1=(v x1 ,v y1 ,v z1 ),v2=(v x2 ,v y2 ,v z2 ) is the velocity vector of mission satellite 1 and mission satellite 2 in the geocentric inertial coordinate system; C = 1-e -ω The purpose of the form is to make the inter-orbit communication correction coefficient C∈[0,1] when ω∈[0,+∞); The third step is to calculate the link coefficient T of the entry star relative to the task star in each domain. Where k is the shortest hop number for intra-orbit communication, m is the shortest hop number for inter-orbit communication, and n j is the total number of communication paths that meet the shortest path requirement on the topological network when performing the jth off-track communication, C i is the inter-orbit communication correction coefficient of the i-th communication path in the above shortest path; The fourth step is to obtain the chain index matrix T corresponding to the shell layer candidate domain M, T = (t ij )m×n, Where m, n are the number of rows and columns of the 2D topological network, t ij The element in the i-th row and j-th column of the link-building indicator matrix T, Task ij is the node with coordinate value (i, j) of the mission star in the 2D topological network space, T ij Task ij The node chain building coefficient, M is the candidate domain of the shell; Step 5: Share the link index matrix T of shell a and shell b with the adjacent control satellite through the communication unit, and receive the link index matrix T sent by the adjacent control satellite; Step S7: After the communication unit receives the link index matrix T of each shell layer calculated by all adjacent control satellites, the calculation unit compares it with its own link index T; if an element in its own link index matrix T is smaller than the corresponding value in the T matrices of all adjacent control satellites, the task satellite corresponding to the element is preliminarily determined as a satellite in the candidate domain; Otherwise, no processing is done; Realize the adaptive division function of the control domain based on the chain building index T matrix; After the division is completed, information on events such as satellite failures, communication topology changes, and new satellites entering orbit is obtained based on the inter-satellite communication links, updated to the database, and the next round of control domain division is repeated.

7. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and the computer program is configured to implement the steps of the space-based distributed hierarchical control method for low-orbit high-density satellite constellations described in any one of claims 3-4 when called by a processor.

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