A hybrid formation satellite constellation failure reconstruction method after satellite failure

Abstract

The present invention discloses a method for reconstructing a mixed formation satellite constellation after satellite failure, which belongs to the field of aerospace technology. Starting from the perspective of geometric features of constellation configuration, combined with the characteristics of Walker-δ constellation configuration, the present invention analyzes the root satellite of the mixed satellite formation in the Walker-δ constellation before failure, connects the formation nodes through parent-child star constraints and inter-sub-satellite constraints, establishes a formation configuration constraint tree with the root satellite as the root, parent-child star constraints as the edges, and inter-sub-satellite constraints as the connection, and transforms the complex multi-satellite multi-constraint constellation reconstruction problem into a simple constraint tree hierarchical traversal problem; when a satellite fails, the reconstruction of the mixed formation constellation can be achieved under given mission performance indicators and phase adjustment maneuvers, and autonomous on-orbit reconstruction can be achieved for satellite constellations with a small total number of satellites. The present invention is scalable and can solve the failure reconstruction problem for mixed formation constellations with different compositions and different formation constraints. The present invention has the advantage of high reconstruction efficiency.

Description

Technical Field

[0001] The present invention relates to a satellite failure reconstruction method for a mixed formation satellite constellation, and is particularly suitable for solving a constellation reconstruction method when a satellite fails in a satellite constellation composed of different types of satellite formations, and belongs to the field of aerospace technology. Background Art

[0002] A satellite constellation is a satellite system composed of multiple satellites in orbit with a certain temporal and spatial relationship. It has high application value in satellite communications, satellite navigation, earth observation and other fields. After the satellite constellation is deployed in orbit, the satellites in the constellation may lose their function due to space debris collisions, system equipment failures and other reasons, resulting in a gap in the overall performance of the satellite constellation. In order to fully utilize the value of normally operating satellites in the constellation and improve the operating performance of the entire constellation after a satellite fails, the constellation needs to be reconstructed. However, the increase in the number of satellites has brought a huge workload for the configuration maintenance and reconstruction of the satellite constellation. In order to solve the problem of on-orbit operation and maintenance of satellite constellations, efficient and fast configuration maintenance and reconstruction methods are urgently needed.

[0003] Among the satellite constellation reconstruction methods that have been developed, the prior art [1] (Xiang Junhua. Research on Satellite Constellation Configuration Control and Design [D]. National University of Defense Technology, 2007.) considers the situation where there is a failed satellite in the orbital plane. Based on the total propellant consumption, total reconstruction time, and performance repair strength, the propellant and time constraints required for reconstruction control between the orbital planes of the constellation configuration are considered, and an adjacent satellite reconstruction strategy and a uniform phase reconstruction strategy are proposed. The advantage of this method is that it can quickly calculate the constellation reconstruction strategy considering certain constraints. The disadvantage is that it only considers the situation where one satellite fails, and cannot solve the problem of mixed formation constellation reconstruction.

[0004] Prior art [2] (Zhang Yasheng, Zhang Yulin. Research on performance-repairing constellation rapid reconstruction method [J]. Journal of Equipment Command and Technology Academy, 2005, 16 (4): 66-72.) proposed three constellation reconstruction strategies, namely adjacent satellites, uniform phase, and uniform constellation, to address the problem of multiple consecutive satellite failures, taking the maximum invisible time as the performance parameter. It also proposed a constellation rapid reconstruction configuration optimization design method that minimizes the total reconstruction time by combining fuel consumption and reconstruction time. The advantage of this method is that it can solve the problem of multiple consecutive satellite failures and propose an overall constellation optimization design method. The disadvantage is that it is difficult to fully consider the mission constraints and cannot solve the problem of mixed formation constellation reconstruction.

[0005] In the prior art [3] (Ferringer M, Spencer D, Clifton R, et al. Pareto-hypervolumes for the Reconfiguration of Satellite Constellations [C] / / AIAA / AAS Astrodynamics Specialist Conference and Exhibit. 2008: 6611.), multiple reconstruction indicators are proposed as evaluation criteria for reconstruction schemes, and the maneuver model is determined according to the maneuver energy consumption. The reconstruction optimization model is constructed using the NSGA-II algorithm based on the Pareto non-inferiority idea and non-dominated sorting to optimize the reconstruction scheme. The advantage of this method is that it can optimize the satellite constellation more comprehensively, and the reconstruction indicators obtained in the end are relatively excellent. It can handle the reconstruction problem of mixed formation constellations. The disadvantage is that the model construction is complex and the genetic algorithm requires iterative calculation, which makes this method have a large computational pressure in actual operation. Summary of the invention

[0006] The technical problem to be solved by the method for failure reconstruction of a mixed formation satellite constellation after satellite failure disclosed in the present invention is: starting from the perspective of geometric features of the constellation configuration, combined with the characteristics of the Walker-δ constellation configuration, the reconstruction of the mixed formation constellation can be achieved under given mission performance indicators and phase adjustment maneuvers when a satellite fails, and autonomous in-orbit reconstruction can be achieved for satellite constellations with a small total number of satellites. The present invention can not only solve the constellation reconstruction problem under the problem of single satellite failure, but also solve the constellation reconstruction problem when multiple satellites fail. At the same time, the present invention is scalable and can solve the failure reconstruction problem for mixed formation constellations with different compositions and different formation constraints. The present invention has the advantage of high reconstruction efficiency.

[0007] The objective of the present invention is achieved through the following technical solutions:

[0008] The present invention discloses a method for reconstructing a satellite constellation after a hybrid formation fails. The root satellite of the hybrid satellite formation in the Walker-δ constellation before the failure is analyzed, and the formation nodes are connected through the parent-child satellite constraint and the inter-sub-satellite constraint. A formation configuration constraint tree is established with the root satellite as the root, the parent-child satellite constraint as the edge, and the inter-sub-satellite constraint as the connection. The satellite failure data is read to determine whether each root satellite fails. The reconstruction phase adjustment amount of the failed root satellite is determined by the satellite phase uniform distribution and optimization method within the plane. The reconstruction phase adjustment amount of the sub-satellite in the current layer of the constraint tree that is only subject to the parent-child satellite constraint is determined by the geometric relationship in the parent-child satellite constraint. It is determined whether the current layer number of the constraint tree is equal to the total number of layers of the constraint tree. The reconstruction phase adjustment amount of the sub-satellite in the current layer of the constraint tree is determined by the geometric relationship in the inter-sub-satellite constraint. It is determined whether the current layer number of the constraint tree is equal to the total number of layers of the constraint tree. According to the satellite phase adjustment maneuver mode, the reconstruction method of all satellites is determined by the reconstruction phase adjustment amount of all satellites in the constellation. The reconstruction methods of all satellites are combined to obtain the mixed formation satellite constellation failure reconstruction method after a satellite failure, that is, the mixed formation satellite constellation failure reconstruction after a satellite failure is realized.

[0009] The present invention discloses a hybrid formation satellite constellation failure reconstruction method after a satellite fails, comprising the following steps:

[0010] Step 1: Analyze the root satellite of the hybrid satellite formation in the Walker-δ constellation before failure, and use the parent-child satellite constraint θ and the child satellite constraint Connect the formation nodes, with the root satellite as the root, the parent-child satellite constraint θ as the edge, and the child satellite constraint Build a formation configuration constraint tree for the connection.

[0011] Consider only the hybrid satellite formation located at a node in the Walker-δ constellation before failure, and define the root satellite as a satellite in the formation that exists independently without relying on any constraints. The constraints between satellites in the formation are simplified or converted into two categories: parent-child satellite constraints θ and child-child constraints Define the parent-child satellite constraint θ as the constraint between different types of satellites in the mixed satellite formation, and define the constraint between child satellites is the constraint between satellites of the same type. To reduce the complexity of the constraint tree, if there are multiple constrained satellites, the multiple constrained satellites are placed as far away from the root satellite as possible.

[0012] Take the root satellite as the root of the constraint tree, take the parent-child satellite constraint θ as the edge of the constraint tree, establish the formation configuration constraint tree, and use the child satellite constraint The related nodes are connected. The total number of layers of the constraint tree is defined as Ξ. Thus, the complex multi-star multi-constraint constellation reconstruction problem is transformed into a simple constraint tree hierarchical traversal problem, reducing the complexity of the reconstruction method.

[0013] Preferably, the parent-satellite and child-satellite constraint θ includes the heading phase constraint, lateral distance constraint, circumferential angular velocity constraint, and line-of-sight angle constraint between the communication satellite and the observation satellite, and the child-satellite inter-constraint includes the minimum phase angle constraint between the slave satellites in the fly-around formation and the constraints between the satellites in the serial formation.

[0014] Step 2: Read the satellite failure data, determine whether each root satellite has failed, and execute Step 3 or Step 4 according to the judgment result.

[0015] Let the current layer number ξ of the constraint tree established in Step 1 be 1. Read and traverse the satellite failure data of the satellite constellation, and combine the constraint tree established in Step 1 to filter the failure information of the root satellites. If there is a root satellite failure in the constellation, execute Step 3; if there is no root satellite failure in the constellation, let ξ = 2 and execute Step 4.

[0016] Step 3: Determine the reconstruction phase adjustment amount of the failed root satellite through the in-plane satellite phase distribution and optimization method.

[0017] Since the root satellites are independent of each other, and the phase of the root satellites can determine the overall phase of the satellite formation, and at the same time to improve the uniformity of the overall performance of the Walker-δ constellation, the root satellites are reconstructed by using the in-plane phase distribution method. Taking the positions of the root satellites as the reference positions for the corresponding groups of satellite formations, the basic parameters of the Walker-δ constellation can all be determined through the properties of the Walker-δ constellation. The basic parameters of the Walker-δ constellation are the total number of formation groups T in the constellation, the number of constellation orbital planes P, the phase parameter F, the semi-major axis of the orbit a, the orbital inclination i, the right ascension of the ascending node Ω of the reference position of the first group of satellites in the first orbital plane at the reference time 1 and the phase angle u 1,1 . Define the number of formation groups S = T / P in the current orbital plane. Define that there are m root satellites with formation failure in the jth orbital plane, m < S, and arrange the group numbers of the groups containing the failed root satellites in ascending order as k 1 , k 2 ,..., k m . The reconstruction phase adjustment amount of the kth root satellite in the jth orbital plane is expressed as

[0018]

[0019] where is the in-plane phase adjustment amount of the root satellite of the formation with the smallest number in the jth orbital plane that has not failed, j ∈ [1, P], k ∈ [1, S], k ≠ k i . l is the group number of the formation with the smallest number that has not failed in the jth orbital plane, and q is the failure group serial number of the first group of failed formations with a group number greater than l in the jth orbital plane, expressed as

[0020] l=min{l|l≠k i ,i∈[1,m],i∈N,l∈[1,S]}

[0021] q=min{q|k q >l,q∈[1,m]}

[0022] Taking the phase adjustment amount as a constraint, the phase adjustment optimization problem is solved by the optimization method to obtain the optimal solution under the given performance index of the task. If the task does not have a given performance indicator, Set to 0.

[0023] Traverse all orbital planes with failed root satellites to obtain the reconstruction adjustment of all root satellites. Let ξ=2.

[0024] Preferably, the performance indicators of the phase adjustment optimization problem include minimum fuel saving, minimum revisit interval, and maximum coverage.

[0025] Step 4: Determine the reconstruction phase adjustment amount of the sub-satellite in the constraint tree layer ξ that is only constrained by the parent-child constraint θ through the geometric relationship in the parent-child constraint θ.

[0026] For the sub-satellite in the ξth layer of the constraint tree, the set of allowable phase adjustment values ​​of the kth sub-satellite on the jth orbital plane under the parent-child constraint θ is determined according to the geometric relationship in the parent-child constraint θ: According to the performance indicators given by the task, in the collection The reconstruction phase adjustment of each satellite constrained only by the parent-child satellite constraint θ is solved separately.

[0027] Preferably, the performance indicators include the most fuel efficient, the smallest revisit interval, and the largest coverage.

[0028] Step 5: Determine whether the current layer number of the constraint tree is equal to the total number of layers of the constraint tree, and execute step 4 or step 6 according to the judgment result.

[0029] Compare the current layer number ξ of the constraint tree with the total number of layers Ξ of the constraint tree. If ξ<Ξ, set ξ=ξ+1 and execute step 4; if ξ=Ξ, set ξ=2 and execute step 6.

[0030] Step 6: Constraints between satellites The geometric relationship in is used to determine the reconstruction phase adjustment amount of the ξ-th layer sub-satellite in the constraint tree.

[0031] For the sub-satellites in the ξth layer of the constraint tree, according to the inter-satellite constraints The geometric relationship in the j-th orbital plane determines the constraints between the sub-satellites. The set of allowed phase adjustments under According to the performance indicators given by the task, the set obtained in step 4 With Collection The intersection of The constraints between the sub-stars are solved separately Constrained reconstruction phase adjustment of each satellite

[0032] Preferably, the performance indicators include the most fuel efficient, the smallest revisit interval, and the largest coverage.

[0033] Step 7: Determine whether the current layer number of the constraint tree is equal to the total number of layers of the constraint tree, and execute step 6 or step 8 according to the judgment result.

[0034] Compare the current layer number ξ of the constraint tree with the total number of layers Ξ of the constraint tree. If ξ<Ξ, set ξ=ξ+1 and execute step 6; if ξ=Ξ, execute step 8.

[0035] Step eight: According to the satellite phase adjustment maneuver mode, the reconstruction method of all satellites is determined through the reconstruction phase adjustment amount of all satellites in the constellation, and the reconstruction methods of all satellites are combined to obtain the mixed formation satellite constellation failure reconstruction method after a satellite failure, that is, to realize the mixed formation satellite constellation failure reconstruction after a satellite failure.

[0036] According to the phase adjustment maneuver given by the task, the reconstructed phase adjustment amount of the root satellite obtained in step 3 is The reconstructed phase adjustment of each sub-satellite obtained in step 4 is only constrained by the parent-child satellite constraint θ The intersatellite constraints obtained in step 6 Constrained reconstruction phase adjustment of each satellite Determine the reconstruction method of the kth satellite on the jth orbital plane of the ξth layer in the constraint tree, that is, the reconstruction method of all satellites in the constellation. Combine the reconstruction methods of all satellites to obtain the reconstruction method of the hybrid formation satellite Walker-δ constellation after satellite failure, that is, to achieve the reconstruction of the hybrid formation satellite constellation after satellite failure.

[0037] Step 9: The reconstruction result of the mixed formation satellite constellation after satellite failure obtained in step 8 is annotated to all satellites in the described Walker-δ constellation, and each satellite performs a reconstruction maneuver according to a corresponding reconstruction method to achieve the reconstruction of the described Walker-δ constellation of mixed formation satellites with satellite failure, so that the described constellation can restore the normal function before the satellite failure to the greatest extent.

[0038] Beneficial effects:

[0039] 1. The present invention discloses a hybrid satellite formation configuration constraint tree construction method, which adopts the constraints between the root satellite, the parent-child satellite constraints and the sub-satellite constraints between the satellite nodes in the formation, thereby converting the complex multi-satellite multi-constraint constellation reconstruction problem into a simple constraint tree hierarchical traversal problem, reducing the complexity of the reconstruction method, and making the hybrid formation constellation reconstruction problem possible.

[0040] 2. The present invention discloses a method for generating a hybrid formation satellite constellation failure reconstruction strategy. It simplifies complex constraints by using a constraint tree, converts all configuration constraints into two major categories of constraints for processing, greatly reduces the number of calculation branches and judgment layers in the reconstruction strategy generation process, and improves the algorithm's computational performance and reconstruction efficiency.

[0041] 3. The existing satellite constellation failure reconstruction strategy generation method has low computational efficiency when solving the complex constrained multi-satellite formation satellite constellation reconstruction problem, and even cannot provide effective results. The satellite constellation failure reconstruction strategy generation method disclosed in the present invention can effectively solve the constellation reconstruction strategy generation problem of multi-constrained formation and multi-satellite failure while considering the optimization performance by analyzing the constraints in each branch and each level in the constraint tree.

[0042] 4. The present invention discloses a mixed formation satellite constellation failure reconstruction method after satellite failure. By grading and classifying inter-satellite constraints, it can adapt to given mission performance indicators and phase adjustment maneuvers, and can process satellite constellations of different compositions, different numbers, and different formation constraints. The reconstruction strategy generation efficiency is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 A three-dimensional schematic diagram of a constellation in an example of the present invention;

[0044] Figure 2 It is a schematic diagram of a constraint tree in an example of the present invention;

[0045] Figure 3 The present invention discloses a flow chart of a mixed formation satellite constellation failure reconstruction method after a satellite fails. DETAILED DESCRIPTION

[0046] In order to better illustrate the purpose and advantages of the present invention, the invention is further described below with reference to the accompanying drawings and examples.

[0047] like Figure 1 As shown, in this example, the semi-major axis a of the Walker-δ12 / 3 / 1 constellation orbit 0The orbital altitude is 7000km, the orbital inclination is 55°, the reference ascending node and phase are both 0°, and the formation is a serial formation composed of three types of satellites: α, β, and γ. The number of satellites in the three types is 1, 1, and 3 respectively. Among them, only α can carry out high-power ground communication, β depends on α, and γ depends on α or β. The standard inter-satellite communication distance of the three types of satellites is 100km. The failed satellites are α in the second formation in the first orbital plane, β in the third formation in the second orbital plane, and the second γ in the fourth formation in the third orbital plane. The reconstruction allowed time T = 24 hours, and the reconstruction is carried out using the double-pulse phase modulation method, and fuel consumption is given priority.

[0048] like Figure 3 As shown, the present embodiment discloses a hybrid formation satellite constellation failure reconstruction method after a satellite failure, and the specific implementation method is as follows:

[0049] Step 1: Analyze the root satellite of the hybrid satellite formation in the Walker-δ constellation before failure, and use the parent-child satellite constraint θ and the child satellite constraint Connect the formation nodes, with the root satellite as the root, the parent-child satellite constraint θ as the edge, and the child satellite constraint Build a formation configuration constraint tree for the connection.

[0050] In this example, the root satellite is defined as star α, and the parent-child star constraint θ between star α and star β is αβ The β star is located 100 km behind the α star, and the parent-child star constraint θ between the α star and the γ star is αγ When γ is in front of α, γ is 100 km behind α, and the parent-child star constraint θ between β and γ is βγ When the γ star is in front of the β star, the γ star is 100 km behind the β star, and the inter-satellite constraints between the γ stars are When there is a γ star in front of the γ star, the distance between the γ stars is 100km.

[0051] According to the constraint θ αβ ,θ αγ ,θ βγ , Construct the constraint tree, the result is as follows Figure 2 As shown, θ αβ ,θ αγ ,θ βγ is a solid line with an arrow, It is a long dashed line, constraining the total number of tree layers to be Ξ=3.

[0052] Step 2: Read satellite failure data to determine whether each satellite is failed, and execute step 3 or step 4 based on the judgment result.

[0053] The current layer number of the constraint tree established in step 1 is set to ξ = 1. In this example, the fourth root satellite of the first orbital plane of the constellation fails, so step 3 is executed.

[0054] Step 3: Determine the reconstructed phase adjustment amount of the failed root satellite through the in-plane satellite phase uniform distribution and optimization method.

[0055] The reconstructed phase adjustment amount of the remaining root satellites in the first orbital plane is

[0056]

[0057] The total speed increment and time consumed by double pulse phase modulation are

[0058]

[0059]

[0060] Where: μ = 398600km3 / s2 is the gravitational constant, N is the number of turns required for phase adjustment, △u is the phase adjustment amount, and One to one correspondence.

[0061] Construct the following optimization problem and solve it

[0062] Minimize

[0063]

[0064] Subject to

[0065] △t≤T

[0066] The solution is to save fuel and time, and the phase adjustment of the first satellite in the first orbital plane is Then the phase adjustment of other satellites on the first orbital plane can be obtained

[0067]

[0068]

[0069] The rootless satellites in other orbital planes are invalid and do not need to be calculated. Let ξ=2.

[0070] Step 4: Determine the reconstruction phase adjustment amount of the sub-satellite in the constraint tree layer ξ that is only constrained by the parent-child constraint θ through the geometric relationship in the parent-child constraint θ.

[0071] Consider the parent-child satellite constraint of the first orbital plane sub-satellite β in the second level of the constraint tree. For a β satellite with a normally functioning α satellite in the formation, since the α satellite still exists, its function is not affected and it can be reconstructed together with the α satellite in the formation, that is,

[0072]

[0073]

[0074]

[0075] For a β-star whose α-star fails in a formation, if it wants to restore normal function, it needs to be placed behind other α-stars or behind β-stars with α-stars. In order to save fuel consumption, the two nearest available positions can be selected for reconstruction. In this example, the two nearest available positions of the second formation β-star are 100km behind the first formation β-star after reconstruction and 100km behind the third formation β-star after reconstruction. After calculation and comparison, it can be obtained That is, 100 km behind the β star of the third formation after reconstruction.

[0076] Considering the parent-child satellite constraint of the second orbital plane sub-satellite β in the second layer of the constraint tree, since the current valid β satellites are all located behind the valid α satellites, reconstructing the β satellite will not change the constellation performance and will cause additional fuel consumption, which does not need to be calculated.

[0077] The other orbital sub-satellites β in the second layer are not affected by satellite failure and do not need to be calculated.

[0078] Step 5: Determine whether the current layer number of the constraint tree is equal to the total number of layers of the constraint tree, and execute step 4 or step 6 according to the judgment result.

[0079] The current level number ξ=2 of the constraint tree is less than the total level number Ξ=3 of the constraint tree, so let ξ=ξ+1 and execute step 4.

[0080] Step 4: Determine the reconstruction phase adjustment amount of the sub-satellite in the constraint tree layer ξ that is only constrained by the parent-child constraint θ through the geometric relationship in the parent-child constraint θ.

[0081] Consider the parent-child satellite constraint of the first child satellite γ in the first orbital plane of the third level of the constraint tree. For the γ satellite with a normally functioning α satellite in the formation, since the α satellite still exists, the β satellite is not affected, and its function is also not affected, and it can be reconstructed together with the α satellite in the formation, that is,

[0082]

[0083]

[0084] For the γ star in group 3, since a β star is added here, the phase of the γ star needs to be moved accordingly to avoid collision, that is,

[0085]

[0086] For the three γ satellites whose α satellites have failed in the formation, if they want to restore normal functions, they need to be placed behind other α satellites or behind β satellites with α satellites. In order to save fuel consumption, the two nearest available positions can be selected for reconstruction. In this example, the two nearest available positions of the γ satellite of the second formation are 100km behind the last satellite of the first formation after reconstruction and 100km behind the last satellite of the third formation after reconstruction. After calculation and comparison, we can get

[0087]

[0088] That is, after the last star of the third formation after reconstruction.

[0089] Considering the parent-child satellite constraint of the first child satellite γ on the second orbital plane of the third layer of the constraint tree, since the β satellite of the third formation fails and has no reconstruction, it is necessary to move the γ satellite behind the α satellite to ensure inter-satellite communication, that is,

[0090]

[0091] The other groups in the track surface are not affected by the failure and do not need to be calculated.

[0092] The first gamma star in other orbital planes is not affected by the failure and does not need to be calculated.

[0093] Step 5: Determine whether the current layer number of the constraint tree is equal to the total number of layers of the constraint tree, and execute step 4 or step 6 according to the judgment result.

[0094] The current level number ξ=3 of the constraint tree is not less than the total level number Ξ=3 of the constraint tree, so let ξ=2 and execute step 6.

[0095] Step 6: Constraints between satellites The geometric relationship in is used to determine the reconstruction phase adjustment amount of the ξ-th layer sub-satellite in the constraint tree.

[0096] The second-layer sub-satellites have no inter-satellite constraints and do not need to be processed.

[0097] Step 7: Determine whether the current layer number of the constraint tree is equal to the total number of layers of the constraint tree, and execute step 6 or step 8 according to the judgment result.

[0098] The current level number ξ=2 of the constraint tree is less than the total level number Ξ=3 of the constraint tree, so let ξ=ξ+1 and execute step 6.

[0099] Step 6: Constraints between satellites The geometric relationship in is used to determine the reconstruction phase adjustment amount of the ξ-th layer sub-satellite in the constraint tree.

[0100] Consider the inter-satellite constraints of the γ satellites in the first and second orbital planes of the third level of the constraint tree. If there is no γ satellite failure in the formation and the first γ satellite has been reconstructed, it can be reconstructed together with the γ satellites in the formation, that is,

[0101]

[0102]

[0103]

[0104]

[0105]

[0106]

[0107] Considering the inter-satellite constraint of the 3rd orbital plane sub-satellite γ in the 3rd layer of the constraint tree, since the 2nd γ satellite of the 4th formation fails, the 3rd γ satellite needs to be moved behind the 1st γ satellite to ensure inter-satellite communication, that is,

[0108]

[0109] Other gamma stars are not affected by the failure and do not need to be calculated.

[0110] Step 7: Determine whether the current layer number of the constraint tree is equal to the total number of layers of the constraint tree, and execute step 6 or step 8 according to the judgment result.

[0111] The current layer number ξ=3 of the constraint tree is not less than the total number of layers Ξ=3 of the constraint tree, so step eight is executed.

[0112] Step eight: According to the satellite phase adjustment maneuver mode, the reconstruction method of all satellites is determined through the reconstruction phase adjustment amount of all satellites in the constellation, and the reconstruction methods of all satellites are combined to obtain the mixed formation satellite constellation failure reconstruction method after a satellite failure, that is, to realize the mixed formation satellite constellation failure reconstruction after a satellite failure.

[0113] Based on the dual-pulse phase modulation method, the reconstruction strategy of all satellites is calculated. Ignoring the satellites that do not participate in the reconstruction, the final results are shown in Table 1.

[0114] Table 1. Satellite constellation failure reconstruction strategy for mixed formation

[0115]

[0116] Step 9: The reconstruction result of the mixed formation satellite constellation after satellite failure obtained in step 8 is annotated to all satellites in the described Walker-δ constellation, and each satellite performs a reconstruction maneuver according to a corresponding reconstruction method to achieve the reconstruction of the described Walker-δ constellation of mixed formation satellites with satellite failure, so that the described constellation can restore the normal function before the satellite failure to the greatest extent.

[0117] The specific description above further illustrates the purpose, technical solutions and beneficial effects of the invention in detail. It should be understood that the above is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A hybrid formation satellite constellation failure reconstruction method after satellite failure, Features: The following steps are included: Step 1: Analyze the root satellite of the hybrid satellite formation in the Walker-δ constellation before failure, and use the parent-child satellite constraint θ and the child satellite constraint Connect the formation nodes, with the root satellite as the root, the parent-child satellite constraint θ as the edge, and the child satellite constraint Establish formation configuration constraint tree for connection; The implementation method of step one is: Only consider the hybrid satellite formation of a certain node within the Walker-δ constellation before failure. Define the root satellite as a satellite that exists independently in the formation without relying on any constraints. Simplify or transform the constraints between the satellites in the formation into two categories: the parent-child satellite constraint θ and the inter-child satellite constraint. Define the parent-child satellite constraint θ as the constraint between different types of satellites in the hybrid satellite formation, and define the inter-child satellite constraint. As the constraint between satellites of the same type; to reduce the complexity of the constraint tree, if there are multi-constrained satellites, place the multi-constrained satellites as far away from the root satellite as possible. Take the root satellite as the root of the constraint tree, take the parent-child satellite constraint θ as the edge of the constraint tree, establish the formation configuration constraint tree, and use the child satellite constraint Connect the related nodes; define the total number of layers of the constraint tree to be Ξ; thereby transforming the complex multi-star multi-constraint constellation reconstruction problem into a simple constraint tree hierarchical traversal problem, reducing the complexity of the reconstruction method; Step 2: Read satellite failure data to determine whether each satellite is failed, and execute step 3 or step 4 according to the determination result; Step 3: Determine the reconstructed phase adjustment amount of the failed root satellite through the satellite phase uniform distribution and optimization method within the plane; Step 4: Determine the reconstruction phase adjustment amount of the sub-satellite that is only constrained by the parent-child star constraint θ in the constraint tree layer ξ through the geometric relationship in the parent-child star constraint θ; Step 5: Determine whether the current layer number of the constraint tree is equal to the total number of layers of the constraint tree, and execute step 4 or step 6 according to the determination result; Step 6: Constraints between satellites The geometric relationship in the constraint tree is used to determine the reconstruction phase adjustment amount of the sub-satellite in the ξth layer; Step 7: Determine whether the current layer number of the constraint tree is equal to the total number of layers of the constraint tree, and execute step 6 or step 8 according to the determination result; Step eight: According to the satellite phase adjustment maneuver mode, the reconstruction method of all satellites is determined through the reconstruction phase adjustment amount of all satellites in the constellation, and the reconstruction methods of all satellites are combined to obtain the mixed formation satellite constellation failure reconstruction method after a satellite failure, that is, to realize the mixed formation satellite constellation failure reconstruction after a satellite failure.

2. The method for reconfiguring a satellite constellation after a mixed formation fails according to claim 1, Features: The method further includes step nine, in which the result of reconstruction of the mixed formation satellite constellation after satellite failure obtained in step eight is uploaded to all satellites in the described Walker-δ constellation, and each satellite performs reconstruction maneuvers according to a corresponding reconstruction method to achieve the reconstruction of the mixed formation satellite Walker-δ constellation after satellite failure, so that the described constellation can restore the normal function before the satellite failure to the greatest extent.

3. The method for reconfiguring a satellite constellation after a mixed formation fails according to claim 2, Features: The implementation method of step 2 is: Let the current level number of the constraint tree established in step 1 be ξ=1; Read and traverse the satellite failure data of the satellite constellation, and filter the failure information of the root satellite in combination with the constraint tree established in step 1; If a root satellite in the constellation fails, execute step three; if no root satellite in the constellation fails, set ξ=2 and execute step four.

4. The method for reconfiguring a satellite constellation after a mixed formation fails according to claim 3, Features: The implementation method of step three is: Since the root satellites are independent of each other and the phase of the root satellite can determine the overall phase of the satellite formation, in order to improve the uniformity of the overall performance of the Walker-δ constellation, the root satellite is reconstructed by using the phase uniform distribution method in the orbital plane; the position of the root satellite is used as the reference position corresponding to each group of satellite formations, and the basic parameters of the Walker-δ constellation can be determined by the properties of the Walker-δ constellation, namely, the total number of formations in the constellation T, the number of constellation orbital planes P, the phase parameter F, the orbital semi-major axis a, the orbital inclination i, and the right ascension Ω of the ascending node of the reference position of the first group of satellites in the first orbital plane at the reference time 1 and phase angle u 1,1 ; Define the number of formation groups in the current orbital plane S = T / P, define that the root satellites of the m formations in the j-th orbital plane are invalid, m < S, and arrange the group numbers containing the invalid root satellites from small to large as k 1 ,k 2 ,...,k m , the reconstructed phase adjustment of the kth root satellite in the jth orbital plane is expressed as in is the in-plane phase adjustment of the j-th orbital plane with the smallest number of the non-failed formation root satellite, j∈[1,P], k∈[1,S], k≠k i , l is the smallest number of the non-failed formation group in the j-th orbital plane, q is the failure group number of the first failure formation group with a group number greater than l in the j-th orbital plane, expressed as, l=min{l|l≠k λ ,λ∈[1,m],λ∈N,l∈[1,S]} q=min{q|k q >l,q∈[1,m]} Taking the phase adjustment amount as a constraint, the phase adjustment optimization problem is solved by the optimization method to obtain the optimal solution under the given performance index of the task. If the task does not have a given performance indicator, Set to 0; Traverse all orbital planes with failed root satellites to obtain the reconstruction adjustment values ​​of all root satellites; let ξ = 2.

5. The method for reconfiguring a satellite constellation after a mixed formation fails according to claim 4, Features: Step 4 is implemented as follows: For the subsatellites in the ξ-th layer of the constraint tree, according to the geometric relationship in the parent-satellite and child-satellite constraint θ, determine the set of allowable phase adjustment amounts of the k-th subsatellite in the j-th orbital plane under the parent-satellite and child-satellite constraint θ Based on the performance indicators given by the mission, in the set respectively solve the reconstruction phase adjustment amounts of each subsatellite that is only constrained by the parent-satellite and child-satellite constraint θ 6. A hybrid formation satellite constellation failure reconstruction method after a satellite failure as claimed in claim 5, Features: Step 5 is implemented as follows: Compare the current level number ξ of the constraint tree with the total level number Ξ of the constraint tree. If ξ<Ξ, set ξ=ξ+1 and execute step 4. If ξ=Ξ, set ξ=2 and execute step 6. The implementation method of step six is: For the sub-satellites in the ξth layer of the constraint tree, according to the inter-satellite constraints The geometric relationship in the j-th orbital plane determines the constraints between the sub-satellites. The set of allowed phase adjustments under According to the performance indicators given by the task, the set obtained in step 4 With Collection The intersection of The constraints between the sub-stars are solved separately Constrained reconstruction phase adjustment of each satellite The implementation method of step seven is: Compare the current level number ξ of the constraint tree with the total level number Ξ of the constraint tree. If ξ<Ξ, set ξ=ξ+1 and execute step 6; if ξ=Ξ, execute step 8; 7. A method for reconfiguring a satellite constellation after a mixed formation fails according to claim 6, Features: The implementation method of step eight is: According to the phase adjustment maneuver given by the task, the reconstructed phase adjustment amount of the root satellite obtained in step 3 is The reconstructed phase adjustment of each sub-satellite obtained in step 4 is only constrained by the parent-child satellite constraint θ The intersatellite constraints obtained in step 6 Constrained reconstruction phase adjustment of each satellite Determine the reconstruction method of the kth satellite on the jth orbital plane of the ξth layer in the constraint tree, that is, the reconstruction method of all satellites in the constellation; combine the reconstruction methods of all satellites to obtain the reconstruction method of the Walker-δ constellation of mixed formation satellites after a satellite failure, that is, realize the failure reconstruction of the mixed formation satellite constellation after a satellite failure.

8. A method for reconfiguring a satellite constellation after a mixed formation fails as claimed in claim 7, Features: The parent-child satellite constraint θ includes the heading phase constraint, lateral distance constraint, orbiting angular velocity constraint, and line of sight angle constraint between the communication satellite and the observation satellite. Including the minimum phase angle constraints between the slave satellites in the flyby formation and the constraints between the satellites in the serial formation.

9. The method for reconfiguring a satellite constellation after a mixed formation fails according to claim 7, Features: The performance indicators of the phase adjustment optimization problem include the most fuel-efficient, the smallest revisit interval, and the largest coverage rate.

Images