Contract network primary satellite selection method based on task area guard strategy

Abstract

The invention belongs to the technical field of contract network primary satellite selection, and relates to a contract network primary satellite selection method based on a task area guard strategy, which comprises the following steps of: acquiring space state data, platform state data and task state data of all satellites in a constellation in a certain rolling time domain; the invention discloses an adaptive constellation settlement generation method based on minimum hop count constraint, and the method comprises the steps: employing a space density clustering algorithm to generate a constellation settlement set in an adaptive manner according to a set minimum hop count; calculating primary satellites and backup primary satellites of each settlement set by integrating various performances of satellites through a settlement primary satellite selection method based on a task area guard strategy; according to the method, a primary satellite selection strategy is optimized, and the reliability of distributed task planning and the adaptability and robustness of a distributed system are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of coordinated observation planning of distributed satellite systems, and in particular relates to a method for selecting a master satellite of a contract network based on a mission area duty strategy. Background Art

[0002] With the expansion of the constellation scale, centralized task planning algorithms are gradually difficult to apply to the task scheduling management of large-scale distributed constellation systems. Compared with centralized methods, distributed methods have become a hot research topic due to their high reliability, good fault tolerance, reconfigurability, and high computational efficiency. Among them, the contract network mechanism is widely used in the collaborative scheduling problem of distributed satellite systems. As a distributed collaborative method based on multi-agent theory, the contract network mechanism effectively solves the online collaborative scheduling problem of distributed satellites through the three processes of bidding, bidding, and bid evaluation.

[0003] In the current distributed satellite mission planning methods based on contract network protocols, most researchers mainly focus on the bidding, tendering, and bid evaluation processes, such as: Distributed Negotiation Intelligent Mission Planning for Satellites on Orbit for Instant Response [J]. Journal of Space Science, 2024, 44(01): 159-168, Contract Network Algorithm for Distributed Remote Sensing Satellite Task Allocation [J]. Journal of Harbin Engineering University, 2020, 41(07): 1059-1065. There is little research on the selection of the primary satellite in the contract network protocol. In existing research, the selection of the primary satellite of the contract network mainly relies on random selection planning and routing performance priority strategies, such as: Earth Observation Satellite Mission Planning and Scheduling Technology [M]. Beijing: National Defense Industry Press, 2021: 112-120, A New Virtual Satellite Formation Scheme for Deterministic Transmission [J]. Journal of Communications, 2023, 44(10): 137-148. However, the primary satellite selection process should comprehensively consider its computing and communication capabilities, orbital coverage, system reliability and dynamic adjustment capabilities. Random or single selection strategies will lead to unreasonable primary satellite selection, which will have a negative impact on distributed mission planning. By optimizing the primary satellite selection strategy, it is helpful to improve the efficiency and fairness of distributed mission planning and the adaptability and robustness of distributed systems. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a method for selecting a primary satellite for a contract network based on a mission area duty strategy.

[0005] In order to achieve the purpose of the present invention, the present invention is implemented by adopting the following technical solutions.

[0006] A method for selecting a primary satellite of a contract network based on a mission area duty strategy comprises the following steps: S1. Acquire the space status data, platform status data and mission status data of m satellites from a distributed satellite constellation within a rolling time domain window; wherein: The space state data is the ECEF space position velocity of satellite i ,in are the xyz three-axis positions of satellite i in the ECEF system, are the xyz three-axis velocities of satellite i in the ECEF system; The platform status data is the satellite health of satellite i , remaining power , Remaining memory , remaining bandwidth , recorded as ; The mission status data is the mission completion rate of satellite i ; S2: construct a space state data set based on the space state data, platform state data and task state data obtained in step S1. , platform status data collection , Task status data collection ; In constructing the spatial state data set At the same time, the initial number of cluster midpoints N is set, and the minimum number of hops M between satellites in the settlement is set; the platform status data set Includes platform number collection ; S3, according to the number of cluster midpoints N from the spatial state data set Randomly select N coordinate points as the initial cluster center set , the initial cluster center set Input the spatial density clustering algorithm, and set the number of iterations iter and the iteration accuracy error to perform iterative calculations to obtain the settlement set. ; S4. Define the constrained conditions for establishing a link for each satellite according to the geometric visible constraint, inter-satellite distance constraint and relative angular velocity constraint that affect the visibility between satellites. The constrained conditions for establishing a link are: geometric visible constraint = inter-satellite distance constraint = relative angular velocity constraint = 1, that is, , make a link judgment for each satellite in the settlement, let i=1; S5. Constructing the settlement based on graph theory Satellite Undirected connected graph ,in is the set of vertices of the connected graph, is the edge set of the connected graph, Represents vertex v jTo the vertex v k The edge of S6: A connectivity matrix defined according to the link building constraint conditions in step S4 and the undirected connectivity graph G in step S5. , through the settlements i All satellites in the network are connected to determine the connectivity and construct the connectivity matrix W i , that is, settlements i Routing table; S7. Use the Dijkstra algorithm and repeatedly use the iterative formula: ; After iterative calculation, the minimum hop count matrix mt is obtained i , the minimum hop count matrix mt i The expression is: ; In the formula, From the vertex To the top The minimum number of hops; According to the link building judgment results of each satellite in the settlement S, let i=1, and iterate and calculate the minimum hop count matrix set of the settlement ; If the largest element in MT is less than the set minimum hop count M, that is , then output the settlement set S, otherwise N=N+1, and return to step S3; S8, respectively obtain the space state data set from steps S2 and S3 , platform status data collection , task status data set and cluster set S, and input the ECEF coordinates of the mission area ; S9, Settlements i Contains platform number collection ,csp i,j For settlements i The number of the jth satellite in the i The spatial coordinates of the center point are marked as , satellite csp i,j and settlement center Distance dp j , there are settlements i Center distance matrix ; S10, based on the virtual topology strategy, the movement cycle between satellites is divided into a series of equally spaced time slices to construct a satellite network snapshot, and then the satellite routing performance index is calculated, the satellite platform performance index is calculated based on the satellite platform data set, and the satellite mission performance index is calculated based on the satellite mission data set; the satellite routing performance index includes the satellite average routing delay, satellite routing delay difference, average node degree and node degree jitter; the satellite platform performance index includes satellite health, remaining power, remaining memory, and remaining bandwidth; the satellite mission performance index is the mission accumulation rate; wherein: The matrix of the average routing delay is: ; Where TS is the minimum delay matrix between satellites, is an m*1 matrix of all 1s; The matrix of the routing delay difference is: ; The matrix of the average node degree is: ; The matrix of the node degree jitter is: ; In the formula, It means taking the maximum value for each row of MW. It means taking the minimum value for each row of MW; The matrix of satellite health is: ; The matrix of the remaining power is: ; The matrix of the remaining memory is: ; The matrix of the remaining bandwidth is: ; The matrix of the task accumulation rate is: ; S11, construct an indicator matrix according to the satellite routing performance indicators, satellite platform performance indicators and satellite mission performance indicators in step S10 , for settlements i ,Will Substituting into the entropy weight method, the settlement s is calculated i The main satellite efficiency matrix of each satellite in ,right Sort in descending order, and the performance value of the first performance ranking is recorded as , the corresponding satellite number is recorded as , the second most efficient value is , the corresponding satellite number is recorded as , and according to the mission area duty strategy Select the main star ms i and backup main star bs i ;in: The mission area guarding strategy is based on the known effectiveness matrix and satellite number matrix The mission area guard strategy is: a. If Located in the mission area Tg, If it is outside the mission area Tg, the main star ms i = , backup main star bs i = ; b. If Located outside the mission area Tg, is within the task area Tg, and , then the main star ms i = , backup main star bs i = ; c. If Located outside the mission area Tg, is within the task area Tg, and , then the main star ms i = , backup main star bs i = ; d. If and Both are located outside the mission area Tg, then the main star ms i = , backup main star bs i = ; S12, let i = 1, and iterate and calculate the primary star set based on step S11 and backup primary star set .

[0007] As a preferred embodiment of the present invention, the distributed satellite constellation is composed of satellites with different functional payloads and different orbits; wherein: the functional payloads include optical remote sensing payloads, SAR payloads, and electronic reconnaissance payloads; and the orbit distribution covers low orbit, medium orbit, and synchronous orbit.

[0008] As a preferred solution of the present invention, the task scheduling of the distributed satellite constellation adopts an event-triggered hybrid scheduling framework to carry out task scheduling for satellite resources in different rolling time domains in stages.

[0009] As a preferred solution of the present invention, the geometric visibility constraint requires that there is no earth obstruction between satellites, and when any satellite is not in the atmosphere, it means that the satellites are geometrically visible. If the satellites are geometrically visible, then =1; The inter-satellite distance constraint requires that the spatial distance between satellites is less than or equal to the maximum transmission distance. If the inter-satellite distance constraint is satisfied between satellites, the calculation ; The relative angular velocity constraint requires that the relative movement between satellites does not exceed the antenna capture and tracking capability of any satellite. If the relative angular velocity constraint is satisfied between the satellites, ran=1.

[0010] As a preferred embodiment of the present invention, the settlement s i The construction process of the routing table: Settlements i Included Satellites, built based on graph theory Undirected connected graph ,in is the set of vertices of the connected graph, is the edge set of the connected graph, Represents vertex v j To the vertex v k The edge of Based on the link building constraints defined in step S4, the connectivity matrix of the undirected connected graph G Defined as: ; Through the settlements i All satellites in the network are connected to determine the connectivity and build a connectivity matrix W i , that is, settlements i The routing table.

[0011] As a preferred solution of the present invention, the satellite routing performance index is given by a minimum delay matrix between satellites; wherein: the calculation process of the minimum delay matrix includes the following steps: S61. Construct an undirected connected graph of all m satellites in the constellation based on graph theory , and calculate the distance l between satellite j and satellite k in the constellation j,k , then the inter-satellite distance matrix ; S62: Based on the link building constraints defined in step S4, a connectivity matrix of the undirected connected graph G is constructed. and delay matrix , and Defined as: , Where c is the speed of light; S63. Calculate the minimum delay matrix between satellites using the Dijkstra algorithm, expressed as: ; In the formula, From the vertex To the top Minimum delay.

[0012] Beneficial effects of the present invention: 1. The present invention proposes an adaptive constellation cluster generation method based on minimum hop count constraint, which adaptively generates constellation clusters using a spatial density clustering algorithm according to the set minimum hop count; 2. The present invention proposes a settlement master satellite selection process based on the mission area duty strategy, which comprehensively considers the performance of various satellites and dynamically selects the master satellite and the backup master satellite through the mission area duty strategy. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is the contract network master satellite selection process based on the mission area duty strategy in the present invention; Figure 2 This is the adaptive constellation cluster generation process based on the minimum hop count constraint in the present invention; Figure 3 This is the settlement master star selection process based on the mission area guard strategy in the present invention. DETAILED DESCRIPTION

[0014] The present invention is further described in conjunction with the embodiments and the accompanying drawings.

[0015] As Example 1 of the present invention, the total constellation size is set to 72, including 48 low-orbit optical remote sensing satellites and 24 low-orbit SAR satellites, and the rolling time domain window length is set to 20 minutes. Figures 1 to 3 As shown, a method for selecting a primary satellite of a contract network based on a mission area duty strategy includes the following steps: S1. Acquire space status data, platform status data and mission status data of 48 satellites from the distributed satellite constellation in the first rolling time domain window; wherein: The space state data is the ECEF space position velocity of satellite i ,in are the xyz three-axis positions of satellite i in the ECEF system, are the xyz three-axis velocities of satellite i in the ECEF system; The platform status data is the satellite health of satellite i , remaining power , Remaining memory , remaining bandwidth , recorded as ; The mission status data is the mission completion rate of satellite i ; S2: construct a space state data set based on the space state data, platform state data and task state data obtained in step S1. , platform status data collection , Task status data collection ; In constructing the spatial state data set At the same time, the initial number of cluster midpoints is set to 5, and the minimum number of hops between satellites in the settlement is set to 3; the platform status data set Includes platform number collection ; S3, according to the number of cluster midpoints 5 from the spatial state data set Randomly select 5 coordinate points as the initial cluster center set , the initial cluster center set Input the spatial density clustering algorithm, set the number of iterations iter=100 and the iteration accuracy error=0.001 for iterative calculation, and obtain the settlement set ; S4. Define the constrained conditions for establishing a link for each satellite according to the geometric visible constraint, inter-satellite distance constraint and relative angular velocity constraint that affect the visibility between satellites. The constrained conditions for establishing a link are: geometric visible constraint = inter-satellite distance constraint = relative angular velocity constraint = 1, that is, , make a link judgment for each satellite in the settlement, let i=1; S5. Constructing the settlement based on graph theory Satellite Undirected connected graph ,in is the set of vertices of the connected graph, is the edge set of the connected graph, Represents vertex v j To the vertex v k The edge of S6: A connectivity matrix defined according to the link building constraint conditions in step S4 and the undirected connectivity graph G in step S5. , through the settlements i All satellites in the network are connected to determine the connectivity and construct the connectivity matrix W i , that is, settlements i Routing table; S7. Use the Dijkstra algorithm and repeatedly use the iterative formula: ; After iterative calculation, the minimum hop count matrix mt is obtained i , the minimum hop count matrix mt i The expression is: ; In the formula, From the vertex To the top The minimum number of hops; According to the link building judgment results of each satellite in the settlement S, let i=1, and iterate and calculate the minimum hop count matrix set of the settlement ; If the largest element in MT is less than the set minimum hop count 3, that is , then output the settlement set S, otherwise N=N+1, and return to step S3; S8, respectively obtain the space state data set from steps S2 and S3 , platform status data collection , task status data set and cluster set S, and input the ECEF coordinates of the mission area ; S9, Settlements i Contains platform number collection ,csp i,j For settlements i The number of the jth satellite in the i The spatial coordinates of the center point are marked as , satellite csp i,j and settlement center Distance dp j , there are settlements i Center distance matrix ; S10, based on the virtual topology strategy, the movement cycle between satellites is divided into a series of equally spaced time slices to construct a satellite network snapshot, and then the satellite routing performance index is calculated, the satellite platform performance index is calculated based on the satellite platform data set, and the satellite mission performance index is calculated based on the satellite mission data set; the satellite routing performance index includes the satellite average routing delay, satellite routing delay difference, average node degree and node degree jitter; the satellite platform performance index includes satellite health, remaining power, remaining memory, and remaining bandwidth; the satellite mission performance index is the mission accumulation rate; wherein: The matrix of the average routing delay is: ; Where TS is the minimum delay matrix between satellites, is an m*1 matrix of all 1s; The matrix of the routing delay difference is: ; The matrix of the average node degree is: ; The matrix of the node degree jitter is: ; In the formula, It means taking the maximum value for each row of MW. It means taking the minimum value for each row of MW; The matrix of satellite health is: ; The matrix of the remaining power is: ; The matrix of the remaining memory is: ; The matrix of the remaining bandwidth is: ; The matrix of the task accumulation rate is: ; S11, construct an indicator matrix according to the satellite routing performance indicators, satellite platform performance indicators and satellite mission performance indicators in step S10 , for settlements i ,Will Substituting into the entropy weight method, the settlement s is calculated i The main satellite efficiency matrix of each satellite in ,right Sort in descending order, and the performance value of the first performance ranking is recorded as , the corresponding satellite number is recorded as , the second most efficient value is , the corresponding satellite number is recorded as , and according to the mission area duty strategy Select the main star ms i and backup main star bs i ;in: The mission area guarding strategy is based on the known effectiveness matrix and satellite number matrix The mission area guard strategy is: a. If Located in the mission area Tg, If it is outside the mission area Tg, the main star msi = , backup main star bs i = ; b. If Located outside the mission area Tg, is within the task area Tg, and , then the main star ms i = , backup main star bs i = ; c. If Located outside the mission area Tg, is within the task area Tg, and , then the main star ms i = , backup main star bs i = ; d. If and Both are located outside the mission area Tg, then the main star ms i = , backup main star bs i = ; S12, let i = 1, and iterate and calculate the primary star set based on step S11 and backup primary star set .

[0016] As Example 2 of the present invention, the total constellation size is expanded to 102 satellites, including 48 low-orbit optical remote sensing satellites, 2 synchronous optical remote sensing satellites, 24 low-orbit SAR satellites, and 28 electronic reconnaissance satellites, and the rolling time domain window length is set to 10 minutes, such as Figures 1 to 3 As shown, a method for selecting a primary satellite of a contract network based on a mission area duty strategy includes the following steps: S1. Acquire space status data, platform status data and mission status data of 28 satellites from the distributed satellite constellation in the first rolling time domain window; wherein: The space state data is the ECEF space position velocity of satellite i ,in are the xyz three-axis positions of satellite i in the ECEF system, are the xyz three-axis velocities of satellite i in the ECEF system; The platform status data is the satellite health of satellite i , remaining power , Remaining memory , remaining bandwidth , recorded as ; The mission status data is the mission completion rate of satellite i ; S2: construct a space state data set based on the space state data, platform state data and task state data obtained in step S1. , platform status data collection , Task status data collection ; In constructing the spatial state data set At the same time, the initial number of cluster midpoints is set to 8, and the minimum number of hops between satellites in the settlement is set to 3; the platform status data set Includes platform number collection ; S3, according to the number of cluster midpoints 8 from the spatial state data set Randomly select 8 coordinate points as the initial cluster center set , the initial cluster center set Input the spatial density clustering algorithm, set the number of iterations iter=100 and the iteration accuracy error=0.001 for iterative calculation, and obtain the settlement set ; S4. Define the constrained conditions for establishing a link for each satellite according to the geometric visible constraint, inter-satellite distance constraint and relative angular velocity constraint that affect the visibility between satellites. The constrained conditions for establishing a link are: geometric visible constraint = inter-satellite distance constraint = relative angular velocity constraint = 1, that is, , make a link judgment for each satellite in the settlement, let i=1; S5. Constructing the settlement based on graph theory Satellite Undirected connected graph ,in is the set of vertices of the connected graph, is the edge set of the connected graph, Represents vertex v j To the vertex v k The edge of S6: A connectivity matrix defined according to the link building constraint conditions in step S4 and the undirected connectivity graph G in step S5. , through the settlements i All satellites in the network are connected to determine the connectivity and construct the connectivity matrix W i , that is, settlements i Routing table; S7. Use the Dijkstra algorithm and repeatedly use the iterative formula: ; After iterative calculation, the minimum hop count matrix mt is obtained i, the minimum hop count matrix mt i The expression is: ; In the formula, From the vertex To the top The minimum number of hops; According to the link building judgment results of each satellite in the settlement S, let i=1, and iterate and calculate the minimum hop count matrix set of the settlement ; If the largest element in MT is less than the set minimum hop count 3, that is , then output the settlement set S, otherwise N=N+1, and return to step S3; S8, respectively obtain the space state data set from steps S2 and S3 , platform status data collection , task status data set and cluster set S, and input the ECEF coordinates of the mission area ; S9, Settlements i Contains platform number collection ,csp i,j For settlements i The number of the jth satellite in the i The spatial coordinates of the center point are marked as , satellite csp i,j and settlement center Distance dp j , there are settlements i Center distance matrix ; S10, based on the virtual topology strategy, the movement cycle between satellites is divided into a series of equally spaced time slices to construct a satellite network snapshot, and then the satellite routing performance index is calculated, the satellite platform performance index is calculated based on the satellite platform data set, and the satellite mission performance index is calculated based on the satellite mission data set; the satellite routing performance index includes the satellite average routing delay, satellite routing delay difference, average node degree and node degree jitter; the satellite platform performance index includes satellite health, remaining power, remaining memory, and remaining bandwidth; the satellite mission performance index is the mission accumulation rate; wherein: The matrix of the average routing delay is: ; Where TS is the minimum delay matrix between satellites, is an m*1 matrix of all 1s; The matrix of the routing delay difference is: ; The matrix of the average node degree is: ; The matrix of the node degree jitter is: ; In the formula, It means taking the maximum value for each row of MW. It means taking the minimum value for each row of MW; The matrix of satellite health is: ; The matrix of the remaining power is: ; The matrix of the remaining memory is: ; The matrix of the remaining bandwidth is: ; The matrix of the task accumulation rate is: ; S11, construct an indicator matrix according to the satellite routing performance indicators, satellite platform performance indicators and satellite mission performance indicators in step S10 , for settlements i ,Will Substituting into the entropy weight method, the settlement s is calculated i The main satellite efficiency matrix of each satellite in ,right Sort in descending order, and the performance value of the first performance ranking is recorded as , the corresponding satellite number is recorded as , the second most efficient value is , the corresponding satellite number is recorded as , and according to the mission area duty strategy Select the main star ms i and backup main star bs i ;in: The mission area guarding strategy is based on the known effectiveness matrix and satellite number matrix The mission area guard strategy is: a. If Located in the mission area Tg, If it is outside the mission area Tg, the main star ms i = , backup main star bs i = ; b. If Located outside the mission area Tg, is within the task area Tg, and , then the main star ms i = , backup main star bs i = ; c. If Located outside the mission area Tg, is within the task area Tg, and , then the main star ms i = , backup main star bs i = ; d. If and Both are located outside the mission area Tg, then the main star ms i = , backup main star bs i = ; S12, let i = 1, and iterate and calculate the primary star set based on step S11 and backup primary star set .

[0017] As Example 3 of the present invention, the total constellation size is expanded to 202 satellites, including 96 low-orbit optical remote sensing satellites, 2 synchronous optical remote sensing satellites, 48 ​​low-orbit SAR satellites, and 56 electronic reconnaissance satellites, and the rolling time domain window length is set to 5 minutes; Figures 1 to 3 As shown in the figure, a method for selecting a primary satellite of a contract network based on a mission area duty strategy includes the following steps: S1. Acquire space status data, platform status data and mission status data of 56 satellites from the distributed satellite constellation in the first rolling time domain window; wherein: The space state data is the ECEF space position velocity of satellite i ,in are the xyz three-axis positions of satellite i in the ECEF system, are the xyz three-axis velocities of satellite i in the ECEF system; The platform status data is the satellite health of satellite i , remaining power , Remaining memory , remaining bandwidth , recorded as ; The mission status data is the mission completion rate of satellite i ; S2: construct a space state data set based on the space state data, platform state data and task state data obtained in step S1. , platform status data collection , Task status data collection ; In constructing the spatial state data set At the same time, the initial number of cluster midpoints is set to 6, and the minimum number of hops between satellites in the settlement is set to 4; the platform status data set Includes platform number collection ; S3, according to the number of cluster midpoints 6 from the spatial state data set Randomly select 6 coordinate points as the initial cluster center set , the initial cluster center set Input the spatial density clustering algorithm, set the number of iterations iter=100 and the iteration accuracy error=0.001 for iterative calculation, and obtain the settlement set ; S4. Define the constrained conditions for establishing a link for each satellite according to the geometric visible constraint, inter-satellite distance constraint and relative angular velocity constraint that affect the visibility between satellites. The constrained conditions for establishing a link are: geometric visible constraint = inter-satellite distance constraint = relative angular velocity constraint = 1, that is, , make a link judgment for each satellite in the settlement, let i=1; S5. Constructing the settlement based on graph theory Satellite Undirected connected graph ,in is the set of vertices of the connected graph, is the edge set of the connected graph, Represents vertex v j To the vertex v k The edge of S6: A connectivity matrix defined according to the link building constraint conditions in step S4 and the undirected connectivity graph G in step S5. , through the settlements i All satellites in the network are connected to determine the connectivity and construct the connectivity matrix W i , that is, settlements i Routing table; S7. Use the Dijkstra algorithm and repeatedly use the iterative formula: ; After iterative calculation, the minimum hop count matrix mt is obtained i , the minimum hop count matrix mt i The expression is: ; In the formula, From the vertex To the top The minimum number of hops; According to the link building judgment results of each satellite in the settlement S, let i=1, and iterate and calculate the minimum hop count matrix set of the settlement ; If the largest element in MT is less than the set minimum hop count of 4, that is , then output the settlement set S, otherwise N=N+1, and return to step S3; S8, respectively obtain the space state data set from steps S2 and S3 , platform status data collection , task status data set and cluster set S, and input the ECEF coordinates of the mission area ; S9, Settlements i Contains platform number collection ,csp i,j For settlements i The number of the jth satellite in the i The spatial coordinates of the center point are marked as , satellite csp i,j and settlement center Distance dp j , there are settlements i Center distance matrix ; S10, based on the virtual topology strategy, the movement cycle between satellites is divided into a series of equally spaced time slices to construct a satellite network snapshot, and then the satellite routing performance index is calculated, the satellite platform performance index is calculated based on the satellite platform data set, and the satellite mission performance index is calculated based on the satellite mission data set; the satellite routing performance index includes the satellite average routing delay, satellite routing delay difference, average node degree and node degree jitter; the satellite platform performance index includes satellite health, remaining power, remaining memory, and remaining bandwidth; the satellite mission performance index is the mission accumulation rate; wherein: The matrix of the average routing delay is: ; Where TS is the minimum delay matrix between satellites, is an m*1 matrix of all 1s; The matrix of the routing delay difference is: ; The matrix of the average node degree is: ; The matrix of the node degree jitter is: ; In the formula, It means taking the maximum value for each row of MW. It means taking the minimum value for each row of MW; The matrix of satellite health is: ; The matrix of the remaining power is: ; The matrix of the remaining memory is: ; The matrix of the remaining bandwidth is: ; The matrix of the task accumulation rate is: ; S11, construct an indicator matrix according to the satellite routing performance indicators, satellite platform performance indicators and satellite mission performance indicators in step S10 , for settlements i ,Will Substituting into the entropy weight method, the settlement s is calculated i The main satellite efficiency matrix of each satellite in ,right Sort in descending order, and the performance value of the first performance ranking is recorded as , the corresponding satellite number is recorded as , the second most efficient value is , the corresponding satellite number is recorded as , and according to the mission area duty strategy Select the main star ms i and backup main star bs i ;in: The mission area guarding strategy is based on the known effectiveness matrix and satellite number matrix The mission area guard strategy is: a. If Located in the mission area Tg, If it is outside the mission area Tg, the main star ms i = , backup main star bs i = ; b. If Located outside the mission area Tg, is within the task area Tg, and , then the main star ms i = , backup main star bs i = ; c. If Located outside the mission area Tg, is within the task area Tg, and , then the main star ms i = , backup main star bs i = ; d. If and Both are located outside the mission area Tg, then the main star ms i = , backup main star bs i = ; S12, let i = 1, and iterate and calculate the primary star set based on step S11 and backup primary star set .

[0018] As Example 4 of the present invention, the distributed satellite constellation is composed of satellites with multiple functional payloads and different orbits; wherein: the functional payloads include optical remote sensing payloads, SAR payloads, and electronic reconnaissance payloads; and the orbital distribution covers low orbit, medium orbit, and synchronous orbit.

[0019] As Embodiment 5 of the present invention, the task scheduling of the distributed satellite constellation adopts an event-triggered hybrid scheduling framework to carry out task scheduling for satellite resources in different rolling time domains in stages.

[0020] As embodiment 6 of the present invention, the geometric visibility constraint requires that there is no earth occlusion between satellites, and when any satellite is not in the atmosphere, it means that the satellites are geometrically visible. If the satellites are geometrically visible, then =1; The inter-satellite distance constraint requires that the spatial distance between satellites is less than or equal to the maximum transmission distance. If the inter-satellite distance constraint is satisfied between satellites, the calculation ; The relative angular velocity constraint requires that the relative movement between satellites does not exceed the antenna capture and tracking capability of any satellite. If the relative angular velocity constraint is satisfied between the satellites, ran=1.

[0021] As Example 7 of the present invention, the settlement s i The construction process of the routing table: Settlements i Included Satellites, built based on graph theory Undirected connected graph ,in is the set of vertices of the connected graph, is the edge set of the connected graph, Represents vertex v j To the vertex v k The edge of Based on the link building constraints defined in step S4, the connectivity matrix of the undirected connected graph G Defined as: ; Through the settlements i All satellites in the network are connected to determine the connectivity and build a connectivity matrix W i , that is, settlements i The routing table.

[0022] As an eighth embodiment of the present invention, the satellite routing performance indicator is given by a minimum delay matrix between satellites; wherein: the calculation process of the minimum delay matrix comprises the following steps: S61. Construct an undirected connected graph of all m satellites in the constellation based on graph theory , and calculate the distance l between satellite j and satellite k in the constellation j,k , then the inter-satellite distance matrix ; S62: Based on the link building constraints defined in step S4, a connectivity matrix of the undirected connected graph G is constructed. and delay matrix , and Defined as: , Where c is the speed of light; S63. Calculate the minimum delay matrix between satellites using the Dijkstra algorithm, expressed as: ; In the formula, From the vertex To the top Minimum delay.

[0023] During the experiment, the low-orbit optical remote sensing satellite, low-orbit SAR satellite, and electronic reconnaissance satellite are all walker constellations in sun-synchronous circular orbits, with orbital altitudes of 520km, 600km, and 700km respectively. The initial health of the satellite is a random value between [0.7, 0.98] that conforms to the normal distribution, and the percentages of the remaining power, remaining memory, and remaining bandwidth matrices are random values ​​between [0.82, 0.96] that conform to the normal distribution. In Example 1, Example 2 and Example 3, the master satellite selection method based on the minimum hop priority is adopted, and the average failure probability of the master satellite of the distributed space-based system in the rolling time domain is 32.9%, 60.9% and 60.6% respectively, and the average failure probability calculated by the method of this patent is 28.8%, 56.1% and 57.2% respectively; in the case of a single master satellite failure, the coordination efficiency of the distributed space-based system under the traditional master satellite selection method is reduced by 12.1%, 15.5% and 17.4% respectively, and the coordination efficiency of the distributed space-based system under the master satellite selection method based on the mission area duty strategy is reduced by 4.2%, 8.2% and 9.2%. The master satellite selection method of the distributed space-based system in the present invention effectively improves the reliability and robustness of the distributed space-based system.

Claims

1. A method for selecting a primary satellite for a contract network based on a mission area duty strategy, characterized in that: The steps include: S1. Acquire the space status data, platform status data and mission status data of m satellites from a distributed satellite constellation within a rolling time domain window; wherein: The space state data is the ECEF space position velocity of satellite i ,in are the xyz three-axis positions of satellite i in the ECEF system, are the xyz three-axis velocities of satellite i in the ECEF system; The platform status data is the satellite health of satellite i , remaining power , Remaining memory , remaining bandwidth , recorded as ; The mission status data is the mission completion rate of satellite i ; S2: construct a space state data set based on the space state data, platform state data and task state data obtained in step S1. , platform status data collection , Task status data collection ; In constructing the spatial state data set At the same time, the initial number of cluster midpoints N is set, and the minimum number of hops M between satellites in the settlement is set; the platform status data set Includes platform number collection ; S3, according to the number of cluster midpoints N from the spatial state data set Randomly select N coordinate points as the initial cluster center set , the initial cluster center set Input the spatial density clustering algorithm, and set the number of iterations iter and the iteration accuracy error to perform iterative calculations to obtain the settlement set. ; S4. Define the constrained conditions for establishing a link for each satellite according to the geometric visible constraint, inter-satellite distance constraint and relative angular velocity constraint that affect the visibility between satellites. The constrained conditions for establishing a link are: geometric visible constraint = inter-satellite distance constraint = relative angular velocity constraint = 1, that is, , make a link judgment for each satellite in the settlement, let i=1; S5. Constructing the settlement based on graph theory Satellite Undirected connected graph ,in is the set of vertices of the connected graph, is the edge set of the connected graph, Represents vertex v j To the vertex v k The edge of S6: A connectivity matrix defined according to the link building constraint conditions in step S4 and the undirected connectivity graph G in step S5. , through the settlements i All satellites in the network are connected to determine the connectivity and construct the connectivity matrix W i , that is, settlements i Routing table; S7. Use the Dijkstra algorithm and repeatedly use the iterative formula: ； After iterative calculation, the minimum hop count matrix mt is obtained i , the minimum hop count matrix mt i The expression is: ； In the formula, From the vertex To the top The minimum number of hops; According to the link building judgment results of each satellite in the settlement S, let i=1, and iterate and calculate the minimum hop count matrix set of the settlement ; If the largest element in MT is less than the set minimum hop count M, that is , then output the settlement set S, otherwise N=N+1, and return to step S3; S8, respectively obtain the space state data set from steps S2 and S3 , platform status data collection , task status data set and cluster set S, and input the ECEF coordinates of the mission area ; S9, Settlements i Contains platform number collection ,csp i,j For settlements i The number of the jth satellite in the i The spatial coordinates of the center point are marked as , satellite csp i,j and settlement center Distance dp j , there are settlements i Center distance matrix ; S10, based on the virtual topology strategy, the movement cycle between satellites is divided into a series of equally spaced time slices to construct a satellite network snapshot, and then the satellite routing performance index is calculated, the satellite platform performance index is calculated based on the satellite platform data set, and the satellite mission performance index is calculated based on the satellite mission data set; the satellite routing performance index includes the satellite average routing delay, satellite routing delay difference, average node degree and node degree jitter; the satellite platform performance index includes satellite health, remaining power, remaining memory, and remaining bandwidth; the satellite mission performance index is the mission accumulation rate; wherein: The matrix of the average routing delay is: ； Where TS is the minimum delay matrix between satellites, is an m*1 matrix of all 1s; The matrix of the routing delay difference is: ； The matrix of the average node degree is: ； The matrix of the node degree jitter is: ； In the formula, It means taking the maximum value for each row of MW. It means taking the minimum value for each row of MW; The matrix of satellite health is: ； The matrix of the remaining power is: ； The matrix of the remaining memory is: ； The matrix of the remaining bandwidth is: ； The matrix of the task accumulation rate is: ； S11, construct an indicator matrix according to the satellite routing performance indicators, satellite platform performance indicators and satellite mission performance indicators in step S10 , for settlements i ,Will Substituting into the entropy weight method, the settlement s is calculated i The main satellite efficiency matrix of each satellite in ,right Sort in descending order, and the performance value of the first performance ranking is recorded as , the corresponding satellite number is recorded as , the second most efficient value is , the corresponding satellite number is recorded as , and according to the mission area duty strategy Select the main star ms i and backup main star bs i ;in: The mission area guarding strategy is based on the known effectiveness matrix and satellite number matrix The mission area guard strategy is: a. If Located in the mission area Tg, If it is outside the mission area Tg, the main star ms i = , backup main star bs i = ; b. If Located outside the mission area Tg, is within the task area Tg, and , then the main star ms i = , backup main star bs i = ; c. If Located outside the mission area Tg, is within the task area Tg, and , then the main star ms i = , backup main star bs i = ; d. If and Both are located outside the mission area Tg, then the main star ms i = , backup main star bs i = ; S12, let i = 1, and iterate and calculate the primary star set based on step S11 and backup primary star set .

2. The method for selecting a primary satellite for a contract network based on a mission area duty strategy according to claim 1, characterized in that: The distributed satellite constellation is composed of satellites with different functional payloads and different orbits; wherein: the functional payloads include optical remote sensing payloads, SAR payloads, and electronic reconnaissance payloads; and the orbit distribution covers low orbit, medium orbit, and synchronous orbit.

3. The method for selecting a primary satellite for a contract network based on a mission area duty strategy according to claim 2 is characterized in that: The task scheduling of the distributed satellite constellation adopts an event-triggered hybrid scheduling framework to carry out task scheduling for satellite resources in different rolling time domains in stages.

4. The method for selecting a primary satellite for a contract network based on a mission area duty strategy according to claim 1, characterized in that: The geometric visibility constraint requires that there is no earth occlusion between satellites and that any satellite is not in the atmosphere, indicating that the satellites are geometrically visible. If the satellites are geometrically visible, then =1; The inter-satellite distance constraint requires that the spatial distance between satellites is less than or equal to the maximum transmission distance. If the inter-satellite distance constraint is satisfied between satellites, the calculation ; The relative angular velocity constraint requires that the relative movement between satellites does not exceed the antenna capture and tracking capability of any satellite. If the relative angular velocity constraint is satisfied between the satellites, ran=1.

5. The method for selecting a primary satellite for a contract network based on a mission area duty strategy according to claim 1, characterized in that: The settlements i The construction process of the routing table: Settlements i Included Satellites, built based on graph theory Undirected connected graph ,in is the set of vertices of the connected graph, is the edge set of the connected graph, Represents vertex v j To the vertex v k The edge of Based on the link building constraints defined in step S4, the connectivity matrix of the undirected connected graph G Defined as: ； Through the settlements i All satellites in the network are connected to determine the connectivity and build a connectivity matrix W i , that is, settlements i The routing table.

6. The method for selecting a primary satellite for a contract network based on a mission area duty strategy according to claim 1, characterized in that: The satellite routing performance index is given by the minimum delay matrix between satellites; wherein: the calculation process of the minimum delay matrix includes the following steps: S61. Construct an undirected connected graph of all m satellites in the constellation based on graph theory , and calculate the distance l between satellite j and satellite k in the constellation j,k , then the inter-satellite distance matrix ; S62: Based on the link building constraints defined in step S4, a connectivity matrix of the undirected connected graph G is constructed. and delay matrix , and Defined as: ， Where c is the speed of light; S63. Calculate the minimum delay matrix between satellites using the Dijkstra algorithm, expressed as: ； In the formula, From the vertex To the top Minimum delay.

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