Integrated Control Method and Device for Angular Momentum Unloading and Constellation Configuration Maintenance of Deep Space Satellites

Abstract

The present invention provides an integrated control method and device for deep space satellite angular momentum unloading and constellation configuration maintenance, including: for constellation satellite Sat i , obtaining the whole satellite angular momentum accumulation law through ground measurement or on-board data method; designing the constellation configuration maintenance control strategy for constellation satellite Sat i , calculating the angular momentum unloading moment #imgabs0#, and controlling the pulse direction; determining the optimal unloading thruster combination according to the angular momentum accumulation law of constellation satellite Sat i , the pulse direction #imgabs1# of constellation configuration maintenance, and the thruster configuration of constellation satellite Sat i ; performing angular momentum unloading according to the selected thrusters; and repeating the above steps according to the on-board angular momentum accumulation and flywheel speed, so as to complete the integrated control of angular momentum unloading and configuration maintenance of the constellation satellite during the on-orbit operation of the constellation satellite. The present invention can avoid unnecessary losses and effectively extend the on-orbit operation time of the satellite.

Description

Technical Field

[0001] The present invention belongs to the technical field of spacecraft attitude and orbit control, and particularly relates to an integrated control method and device for deep-space satellite angular momentum unloading and constellation configuration maintenance. Background Technique

[0002] Satellite systems often adopt on-orbit networking strategies to construct specific constellation configurations to achieve specific scientific goals, such as gravity field measurement, high-precision navigation, and emergency communication. On the one hand, to ensure the long-term stability of the constellation configuration, prevent relative position offsets between satellites, and guarantee the overall performance of the constellation, it is crucial to implement constellation configuration maintenance measures for the networking satellites. Taking gravity field measurement satellites as an example, the relative configuration of the satellites needs to be strictly ensured. On the other hand, to ensure the long-term and high-precision stable operation of the on-board payloads, the flywheels in the attitude control mechanism need to continuously counteract the external environmental disturbance torques. In this process, the flywheels will continuously accumulate angular momentum until they reach their design limit, i.e., the angular momentum saturation state. At this time, the flywheels will lose their effective control ability over the satellite attitude. Therefore, to prevent angular momentum saturation and ensure the continuous stability and high-precision control of the satellite attitude, it is essential to regularly and effectively unload the flywheel angular momentum.

[0003] Existing angular momentum unloading strategies vary for satellites at different orbital altitudes. For low-Earth orbit satellites, the magnetorquer is the main means of unloading the flywheel angular momentum, which realizes angular momentum unloading by utilizing the interaction between the Earth's magnetic field and the magnetorquer. However, for deep-space satellites such as lunar relay satellites and high-orbit satellites that are far from the dense region of the Earth's magnetic field lines, since the geomagnetic torque is significantly weakened or almost non-existent, they cannot rely on the geomagnetic torque for angular momentum unloading like medium- and low-orbit satellites. For such satellites, thruster jetting is generally used to effectively control and unload the flywheel angular momentum. During the process of constellation configuration maintenance of networking satellites, due to the need to maintain the relative position stability between satellites and the accuracy of orbital parameters, thrusters are usually also used for orbit adjustment and maintenance.

[0004] Since flywheel unloading and constellation configuration maintenance are necessary operations for constellation satellites, existing satellite angular momentum unloading and constellation configuration maintenance schemes generally adopt a time-sharing control strategy, that is, focusing on executing the flywheel unloading operation within a certain time period, and focusing on constellation configuration maintenance within another time period. Through reasonable scheduling and planning, although the time-sharing control strategy can ensure that both operations can be fully executed and avoid conflicts and interferences between them. However, this strategy requires a longer mission cycle and higher energy consumption.

[0005] Chinese Patent Application CN 105373133 A proposes a combined control method for synchronous orbit electric propulsion position keeping and angular momentum unloading. This method adjusts the thrust direction of thrusters to achieve angular momentum unloading by determining the ignition duration and ignition position of each electric thruster. However, this method requires calculating and adjusting the thruster direction in each control cycle, which is complex in calculation and control and is only applicable to satellites carrying thrusters with adjustable thrust directions, making it difficult to implement in actual engineering.

[0006] Chinese Patent Application CN 103941749 A proposes a combined control method for east-west position keeping and angular momentum unloading. This method determines the optimal unloading moment to achieve east-west maintenance by comprehensively analyzing the effects of the Earth's non-spherical perturbation, solar radiation pressure, etc. on the satellite orbit and considering the influence of angular momentum unloading on the satellite orbit. However, in this method, the influence of environmental perturbation on the satellite orbit is analyzed, and its conclusion is only applicable to geostationary orbit satellites. At the same time, this method is only applicable to east-west position keeping.

[0007] The journal article "Ma Chuanling, Liu Yong, Chen Ming, et al. Combined Control Method for Mission Orbit Maintenance and Momentum Wheel Unloading of CE-4 Relay Satellite [J]. Journal of Astronautics, 2020, 41(4):9." proposes a combined control method for mission orbit maintenance and momentum wheel unloading. This method qualitatively analyzes the law of satellite angular momentum accumulation and the relationship between the change in angular momentum before and after unloading and the equivalent velocity increment of jet unloading, and offsets the influence of momentum wheel unloading after control through bias control. However, in this paper, the relationship between the equivalent velocity increment of unloading and the unloading angular momentum depends on ground precise orbit determination measurement data and is only applicable to the CE-4 relay satellite, making it difficult to be adopted in the orbit maintenance tasks of other configuration spacecraft. Summary of the Invention

[0008] To solve the above technical problems, the present invention provides an integrated control method and device for angular momentum unloading and constellation configuration maintenance of deep space satellites. By using the geometric relationship between the control torque of angular momentum unloading and the control force of constellation configuration maintenance, an on-board thruster selection strategy for integrated control is formulated, aiming to improve the utilization efficiency of on-board resources and extend the on-orbit life of satellites.

[0009] To achieve the above object, the present invention adopts the following technical solutions:

[0010] An integrated control method for angular momentum unloading and constellation configuration maintenance of deep space satellites, comprising the following steps:

[0011] Step 1: For constellation satellite Sat i , obtain the law of overall satellite angular momentum accumulation through ground measurement or on-board data method;

[0012] Step 2: Design constellation satellite Sat using the relative motion principle iThe constellation configuration maintenance control strategy calculates the angular momentum unloading moment , and controls the pulse direction;

[0013] Step 3: According to the angular momentum accumulation law of the constellation satellite Sat i , the pulse direction for constellation configuration maintenance, and the thruster configuration of the constellation satellite Sat i , determine the optimal unloading thruster combination;

[0014] Step 4: Perform angular momentum unloading according to the selected thrusters;

[0015] Step 5: According to the on-board angular momentum accumulation and flywheel speed, repeat Steps 1 to 4, that is, during the on-orbit operation of the constellation satellite, complete the integrated control of angular momentum unloading and configuration maintenance of the constellation satellite.

[0016] The present invention also provides an integrated control device for angular momentum unloading and constellation configuration maintenance of deep space satellites, including the following modules:

[0017] Measurement module, for the constellation satellite Sat i , obtain the whole-satellite angular momentum accumulation law through ground measurement or on-board data method;

[0018] Calculation module, design the constellation configuration maintenance control strategy of the constellation satellite Sat i , calculate the angular momentum unloading moment , and control the pulse direction;

[0019] Optimal determination module, according to the angular momentum accumulation law of the constellation satellite Sat i , the pulse direction for constellation configuration maintenance, and the thruster configuration of the constellation satellite Sat i , determine the optimal unloading thruster combination;

[0020] Execution module, perform angular momentum unloading according to the selected thrusters;

[0021] Control module, according to the on-board angular momentum accumulation and flywheel speed, repeat the functions of the above modules, that is, during the on-orbit operation of the constellation satellite, complete the integrated control of angular momentum unloading and configuration maintenance of the constellation satellite.

[0022] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, it implements the steps of the above-mentioned integrated control method for angular momentum unloading and constellation configuration maintenance of deep space satellites.

[0023] The present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned integrated control method for deep-space satellite angular momentum unloading and constellation configuration maintenance are realized.

[0024] Beneficial effects:

[0025] For deep-space constellation satellites such as lunar relay satellites and high-orbit satellites that cannot use magnetic torque actuators for angular momentum unloading, the present invention proposes an integrated control method and device for angular momentum unloading and constellation configuration maintenance. Through the integrated control of flywheel angular momentum unloading and satellite constellation configuration maintenance, the flywheel angular momentum unloading and satellite constellation configuration maintenance are organically combined to achieve efficient coordination. In the past, in order to maintain angular momentum balance and constellation configuration stability, thrusters were frequently turned on and off. This not only rapidly consumed precious fuel resources, and it is difficult to replenish space fuel, undoubtedly increasing the resource pressure; but also due to frequent mechanical actions, the wear and aging of components were accelerated, shortening the on-orbit life of the satellite. After adopting the method of the present invention, the number of thruster on-off operations is greatly reduced, and the on-board fuel can be efficiently utilized in a thrifty manner, avoiding unnecessary losses, and effectively extending the on-orbit operation time of the satellite. Description of the drawings

[0026] Figure 1 Schematic diagrams of the body coordinate system and the VVLH coordinate system;

[0027] Figure 2 Flowchart of the integrated control method for deep-space satellite angular momentum unloading and constellation configuration maintenance according to an embodiment of the present invention;

[0028] Figure 3 Schematic diagram of the on-board flywheel installation;

[0029] Figure 4 Schematic diagram of the thruster installation position;

[0030] Figure 5 Schematic diagram of the change trend of the relative distance between two satellites during the time-sharing strategy;

[0031] Figure 6 Schematic diagram of the change trend of the relative distance between two satellites during integrated control. Detailed implementation manners

[0032] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0033] As Figure 2As shown in the figure, the integrated control method for deep space satellite angular momentum unloading and constellation configuration maintenance in the embodiments of the present invention includes the following steps:

[0034] Step 1: For the constellation satellite Sat i , obtain the overall satellite angular momentum accumulation law through methods such as ground measurement and on-board data:

[0035] ;

[0036] Among them, represents the overall satellite angular momentum of satellite i; represents the angular momentum accumulation function of satellite i obtained through on-board measurement and ground observation; represents time. Assume that the maximum threshold of the overall satellite angular momentum of satellite i is . Starting from the current moment , according to the overall satellite angular momentum accumulation law, when , satellite i performs unloading. Determine the angular momentum unloading moment at this time. According to the overall satellite angular momentum accumulation formula, the next unloading moment can be judged.

[0037] Step 2: Design the constellation configuration maintenance control strategy for the constellation satellite Sat i , calculate the angular momentum unloading moment , and control the pulse direction, including:

[0038] Step 2.1: If there is a target satellite Sat c in the constellation, then according to Step 2.3, establish the relative motion equation of satellite i with respect to the target satellite Sat c . Otherwise, go to Step 2.2.

[0039] Step 2.2: Assume that there is a virtual satellite running on a nominal orbit that meets the requirements. Use the virtual satellite as the target satellite Sat c , and establish the relative motion equation of satellite i with respect to the target satellite Sat c .

[0040] Step 2.3: Establish the target satellite VVLH coordinate system. The definition of the VVLH coordinate system is shown in Figure 1 .

[0041] Figure 1 Among them, the body coordinate system is: the origin is located at the satellite's center of mass, points along the longitudinal axis of the spacecraft assembly towards the head of the spacecraft as positive, is perpendicular to and points to the line in the first quadrant of the longitudinal symmetry plane of the spacecraft, axis and and constitute a right - hand coordinate system.

[0042] The VVLH coordinate system (Vehicle Velocity Local Horizontal coordinate system) is defined as follows: The origin is located at the satellite's center of mass, points in the direction from the satellite's center of mass to the center of mass of the central celestial body, points along the negative normal direction of the orbital plane, points along the flight direction, and together with , constitute a right - hand coordinate system.

[0043] For the relative motion relationship between the constellation satellite Sat i and the target satellite Sat c , that is, the T - H equation:

[0044] ;

[0045] where is the orbital angular velocity of the target satellite; are the control accelerations acting on the satellite Sati respectively; respectively represent the difference in the perturbation accelerations acting on the satellite Sat i and the target satellite Sat c ; x, y, z respectively represent the three - axis positions of the satellite Sat i in the VVLH coordinate system of the target satellite Sat c .

[0046] In addition, ;

[0047] where is the semi - major axis of the orbit, is the orbital eccentricity, is the true anomaly, is the mean angular velocity; represents the distance of the target satellite from the central celestial body; is the gravitational constant of the central celestial body.

[0048] Step 2.4: The control of the orbital direction mainly lies in the control of the orbital inclination and the right ascension of the ascending node. This control only requires the application of a normal control force, that is, the normal part of the T - H equation:

[0049] ;

[0050] where represents the generalized control acceleration, Denote the normal control acceleration. The control method of the present invention will not be specifically discussed herein. In the present invention, PD control is adopted: , where denotes the normal control proportional gain coefficient, denotes the normal control derivative gain coefficient.

[0051] The in-plane phase control of the orbit adopts along-track control, i.e.: , where denotes the along-track control proportional gain coefficient, denotes the along-track control derivative gain coefficient.

[0052] Step 2.5: Calculate the pulse direction to be controlled for maintaining the constellation configuration according to the relative motion position relationship .

[0053] ;

[0054] where denotes the coordinate transformation matrix from the VVLH coordinate system to the body coordinate system, denotes the control acceleration; denotes the calculation of Euclidean norm.

[0055] Step 3: Determine the optimal unloading thruster combination according to the angular momentum accumulation law of the constellation satellite Sat i , the pulse direction for maintaining the constellation configuration, and the thruster configuration of the constellation satellite Sat i , including:

[0056] Step 3.1: Assume that the constellation satellite Sat i has the 1st to Nth thrusters, and establish the thruster installation position matrix , the thrust vector matrix :

[0057] ;

[0058] ;

[0059] where denotes the installation position of the jth thruster (j = 1~N) in this system; respectively denote the thrust vector directions of the jth thruster (j = 1~N) in this system.

[0060] Step 3.2: Establish a mixed integer programming mathematical model:

[0061] ;

[0062] where Represents the set of the on / off states of thrusters. If the j-th thruster is turned on, then , otherwise take 0, represents the N-dimensional real vector space; represents the angle between the thrust direction and the control pulse; arccos(A,B) is the arccosine function to calculate the angle between vectors A and B; represents the summation function; represents the matrix cross product;

[0063] The optimization variables are: , and the optimization variables are the thruster numbers from 1 to N and the unloading time t. If thruster j is selected, then , otherwise .

[0064] The optimization objective is: , that is, to minimize the angle between the thrust direction and the control pulse direction;

[0065] The constraints are:

[0066] (1) , that is, the number of selectable thrusters is less than or equal to 3;

[0067] (2) , that is, the thrust moment direction is consistent with the direction of the angular momentum to be unloaded;

[0068] (3) , that is, the unloading time t is between and the angular momentum unloading time ;

[0069] Step 3.3: Use the genetic algorithm to optimize the above mixed integer programming problem to obtain the optimal thruster combination.

[0070] Step 4: Perform angular momentum unloading according to the selected thrusters.

[0071] Step 5: According to the angular momentum accumulation on the satellite and the flywheel speed, repeat Steps 1 to 4, and the integrated control of angular momentum unloading and configuration maintenance of the constellation satellite can be completed during the on-orbit operation of the constellation satellite.

[0072] Example:

[0073] The constellation configuration is assumed to be the formation flight of two co-orbital large elliptical orbits around the moon, and it is required that the relative distance between the two is always within 500 km. Satellites A and B are the master and slave satellites to each other. During the on-orbit operation of the satellite, the attitude is always maintained in the mode of the solar wing facing the sun and the antenna facing the moon to ensure the on-board energy and lunar observation. The satellite attitude control mechanism uses a 3-normal + 1-inclined flywheel group, and the flywheel installation layout is as Figure 3 shown. The thruster layout is asFigure 4 As shown, the installation positions of the thrusters are shown in Table 1. Among them, Figure 3 in the flywheel, a layout of 3 vertical and 1 inclined installation is adopted, and the angle between the inclined flywheel S and each satellite main axis is 54.735°; Figure 4 in which 1N is the thrust of the attitude control engine and 5N is the thrust of the orbit control engine.

[0074] Assume that the lower bound of satellite unloading is 0.003 Nms and the upper bound is 0.5 Nms. When the absolute value of the difference between the angular momentum of a certain axis and the whole satellite unloading center (default is 0) exceeds the upper bound of unloading (0.5 Nms), the whole satellite judges to start unloading. When unloading until the absolute value of the difference between the angular momentum of the three axes and the whole satellite unloading center (default is 0) is less than the lower bound of unloading (0.003 Nms), the unloading stops. The satellite attitude is mainly affected by the solar radiation torque, mainly generating angular momentum accumulation on the Y axis, and its unloading period is about 16h.

[0075] Table 1 Installation positions of thrusters (body coordinate system)

[0076]

[0077] The installation point is the coordinate of the thruster axis at the bottom plate installation point; the installation angle is the angle between the thruster axis and the three axes of the mechanical coordinate system (the nozzle facing outward is the positive direction).

[0078] The on-orbit positions and velocities of satellite A and satellite B measured at 06:26:45.5666 on April 3, 2024, Beijing time (J2000 coordinate system) are shown in Table 2.

[0079] Table 2

[0080]

[0081] Due to the initial position and velocity deviations, the relative distance between the two satellites changes continuously with time. Figure 5 shows the change trend of the relative distance between the two satellites. From Figure 6 it can be seen that at 17:39:45.5666 on April 6, 2024, Beijing time, the relative distance between the two satellites reaches about 400 km, and constellation configuration maintenance needs to be implemented. That is, Figure 6 represents the change of the relative distance between the two satellites.

[0082] Adopt the integrated control method of angular momentum unloading and constellation configuration maintenance in the present invention, optimize the thruster combination, perform angular momentum unloading, and analyze the influence of this method on constellation configuration maintenance and energy consumption. The specific steps are as follows:

[0083] Step 1: Determine the cumulative law of satellite angular momentum. For satellites A and B, their attitudes are mainly affected by the solar radiation torque, which mainly causes angular momentum accumulation about the Y-axis, and its unloading period is about 16 h.

[0084] Step 2: Since satellites A and B are master and slave satellites to each other, at this time, taking satellite B as the target satellite, establish the relative kinematic equation of satellite A relative to satellite B.

[0085] As known from the previous discussion, the control is in the x-axis direction of the VVLH coordinate system. Since the satellite attitude always maintains a stable pointing to the ground, the coordinate transformation matrix from the VVLH coordinate system to the body coordinate system is the identity matrix, and the direction of the control pulse in this system is: [1; 0; 0].

[0086] Step 3: Establish the installation position matrix and thrust vector matrix according to the thruster layout of satellite A:

[0087] ;

[0088] ;

[0089] According to the thruster installation position matrix and the thrust vector matrix, combined with the control pulse direction and angular momentum direction obtained above, establish a mixed-integer optimization mathematical model;

[0090] Use the genetic algorithm to optimize the mixed-integer programming problem to obtain the optimal thruster combinations T1 and T2 and the unloading moment .

[0091] Step 4: Perform angular momentum unloading according to the selected thrusters. After calculation, the generated torque for unloading is: [0; -0.2511; 0] Nm. Therefore, the on-time for unloading: . The generated control force for unloading is 1.9319 N, and the corresponding generated velocity pulse is about: 0.0378 m / s.

[0092] Step 5: Repeat Step 1 to Step 4. According to the optimization results, satellites A and B perform angular momentum unloading and simulate the relative position change. The results are as Figure 6 shown.

[0093] It can be seen that the period for maintaining the constellation configuration is postponed by about 1 day, and the configuration maintenance period is extended by about 25%. Thus, it can be known that the integrated control strategy for angular momentum unloading and constellation configuration maintenance proposed by the present invention can reduce the frequency of constellation configuration maintenance and improve the utilization efficiency of on-board resources.

[0094] The present invention also provides an integrated control device for angular momentum unloading and constellation configuration maintenance of deep space satellites, including the following modules:

[0095] Measurement module, for constellation satellite Sati , obtain the overall satellite angular momentum accumulation law through ground measurement or on-orbit data methods;

[0096] Calculation module, design the constellation configuration maintenance control strategy of constellation satellite Sat i using the relative motion principle, calculate the angular momentum unloading moment , and control the pulse direction;

[0097] Optimal determination module, according to the constellation satellite Sat i angular momentum accumulation law, the pulse direction of constellation configuration maintenance and the thruster configuration of constellation satellite Sat i , determine the optimal unloading thruster combination;

[0098] Execution module, perform angular momentum unloading according to the selected thruster;

[0099] Control module, according to the on-orbit angular momentum accumulation and flywheel speed, repeatedly execute the functions of the above modules, that is, during the on-orbit operation of the constellation satellite, complete the integrated control of angular momentum unloading and configuration maintenance of the constellation satellite.

[0100] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, it implements the steps of the above-mentioned integrated control method for deep space satellite angular momentum unloading and constellation configuration maintenance.

[0101] The present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the steps of the above-mentioned integrated control method for deep space satellite angular momentum unloading and constellation configuration maintenance.

[0102] Those skilled in the art should understand that the embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories, CD-ROMs, optical memories, etc.) containing computer-usable program codes. The solutions in the embodiments of the present invention can be implemented in various computer languages, for example, object-oriented programming languages such as Java and interpreted scripting languages such as JavaScript.

[0103] The present invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each flow and / or block of the flowchart illustrations and / or block diagrams, and combinations of flows and / or blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions executed by the processor of the computer or other programmable data processing apparatus create means for implementing the functions specified in the flow Figure 1 one or more flows and / or blocks Figure 1 one or more blocks.

[0104] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means that implement the functions specified in the flow Figure 1 one or more flows and / or blocks Figure 1 one or more blocks.

[0105] These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, such that the instructions executed on the computer or other programmable apparatus provide steps for implementing the functions specified in the flow Figure 1 one or more flows and / or blocks Figure 1 one or more blocks.

[0106] Although the preferred embodiments of the present invention have been described, additional changes and modifications can be made by those skilled in the art once they learn of the basic inventive concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0107] It is apparent that those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. An integrated control method for deep space satellite angular momentum unloading and constellation configuration maintenance, characterized in that: The steps include: Step 1: For the constellation satellite Sat i , the accumulation law of angular momentum of the whole satellite is obtained through ground measurement or on-board data method; Step 2: Design the constellation satellite Sat using the principle of relative motion i The constellation configuration maintenance control strategy calculates the angular momentum unloading moment , control the pulse direction; Step 3: According to the constellation satellite Sat i Angular momentum accumulation law, pulse direction maintained by constellation configuration And the constellation satellite Sat i The thruster configuration of the system is used to determine the optimal unloaded thruster combination, including: Step 3.1: Assume that the constellation satellite Sat i With the 1st to Nth thrusters, establish the thruster installation position matrix , thrust vector matrix : ； ； in, Indicates the installation position of the jth thruster in this system, j=1~N; They represent the thrust vector directions of the j-th thruster in this system, Step 3.2: Establish a mixed integer programming mathematical model: ； in, represents the set of thruster on / off states. If the jth thruster is on, then ,otherwise Take 0, represents N-dimensional real vector space; Indicates the angle between the thrust direction and the control pulse; arccos(A,B) is the inverse cosine function, which calculates the angle between vectors A and B; represents the sum function; represents matrix cross product; The optimization variables are: , the optimization variables are thruster numbers 1 to N and unloading time t. If thruster j is selected, then ,otherwise ; The optimization goal is: , that is, to minimize the angle between the thrust direction and the control pulse direction; The constraints are: (1) , that is, the number of thrusters to be selected is less than or equal to 3; (2) , that is, the direction of the thrust torque is consistent with the direction of the angular momentum to be unloaded; (3) , that is, the unloading time t is and the angular momentum unloading moment between; Step 3.3: Use genetic algorithm to optimize the above mixed integer programming problem to obtain the optimal thruster combination; Step 4: Perform angular momentum unloading according to the selected thruster; Step 5: Repeat steps 1 to 4 according to the accumulated angular momentum on the satellite and the flywheel speed, that is, complete the integrated control of angular momentum unloading and configuration maintenance of the constellation satellite during the on-orbit operation of the constellation satellite.

2. The integrated control method for deep space satellite angular momentum unloading and constellation configuration maintenance according to claim 1, characterized in that: In step 1, the accumulation law of the angular momentum of the whole star is: ； in, represents the whole satellite angular momentum of satellite i; represents the angular momentum accumulation function of satellite i obtained through on-board measurements and ground observations; Indicates time; From the current moment At the beginning, the next angular momentum unloading time is estimated according to the angular momentum accumulation law of the whole star .

3. The integrated control method for deep space satellite angular momentum unloading and constellation configuration maintenance according to claim 1, characterized in that: The step 2 comprises: Step 2.1: If the target satellite Sat exists in the constellation c , then establish the satellite i relative to the target satellite Sat c The relative motion equations of .

4. The integrated control method for deep space satellite angular momentum unloading and constellation configuration maintenance according to claim 3, characterized in that: The step 2 also includes, if there is no target satellite Sat in the constellation, c , then proceed to step 2.2: Step 2.2: Assume that there is a virtual satellite that operates in a nominal orbit that meets the requirements; use the virtual satellite as the target satellite Sat c , establish the satellite i relative to the target satellite Sat c The relative motion equations of .

5. The integrated control method for deep space satellite angular momentum unloading and constellation configuration maintenance according to claim 3, characterized in that: The step 2 also includes: Step 2.3: Establish the target satellite VVLH coordinate system: Origin Located at the satellite's centroid, Along the satellite's mass center to the center of mass of the central celestial body, Along the negative normal of the track surface, Along the flight direction, , Construct a right-handed coordinate system; Building a constellation of satellitesSat i With the target satellite Sat c The relative motion relationship between them is the TH equation: ； in, is the target satellite orbital angular velocity; are the control accelerations of satellite Sati respectively; Represents satellite Sat i With the target satellite Sat c The difference in perturbation acceleration; x, y, z represent the satellite Sat i On the target satellite Sat c Three-axis position in the VVLH coordinate system; also, ; in, is the semi-major axis of the orbit, is the orbital eccentricity, f is the true anomaly, and n is the mean angular velocity; Indicates the distance of the target satellite relative to the central celestial body; is the gravitational constant of the central body.

6. The integrated control method for deep space satellite angular momentum unloading and constellation configuration maintenance according to claim 5, characterized in that: The step 2 also includes: Step 2.4: Control the orbital direction according to the orbital inclination and the right ascension of the ascending node. This control only applies the normal control force, that is, the normal part of the TH equation: ； in, represents the generalized control acceleration, represents the normal control acceleration, dy represents the difference of perturbation acceleration; Take PD control: ,in, represents the normal control proportional gain coefficient, represents the normal control differential gain coefficient; The phase control in the orbital plane adopts the control along the track, that is: ,in represents the proportional gain coefficient of the tracking control, represents the differential gain coefficient of the tracking control; Step 2.5: Calculate the pulse direction to maintain the constellation configuration to be controlled based on the relative motion position relationship : ； in, Represents the coordinate transformation matrix from the VVLH coordinate system to the body coordinate system, Indicates control acceleration; Indicates seeking The Euclidean norm of .

7. An integrated control device for deep space satellite angular momentum unloading and constellation configuration maintenance that implements the integrated control method for deep space satellite angular momentum unloading and constellation configuration maintenance as described in claim 1, characterized in that: Includes the following modules: Measurement module, for constellation satellites Sat i , the accumulation law of angular momentum of the whole satellite is obtained through ground measurement or on-board data method; Computing module, using the principle of relative motion to design constellation satellites Sat i The constellation configuration maintenance control strategy calculates the angular momentum unloading moment , control the pulse direction; The optimal determination module is based on the constellation satellite Sat i Angular momentum accumulation law, pulse direction maintained by constellation configuration And the constellation satellite Sat i thruster configuration, determine the optimal unloading thruster combination; an execution module for executing angular momentum unloading according to the selected thrusters; The control module repeatedly executes the functions of the above modules according to the accumulated angular momentum on the satellite and the speed of the flywheel, that is, it completes the integrated control of the angular momentum unloading and configuration maintenance of the constellation satellite during the on-orbit operation of the constellation satellite.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps of the integrated control method for deep space satellite angular momentum unloading and constellation configuration maintenance as described in any one of claims 1-6 are implemented.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the integrated control method for deep space satellite angular momentum unloading and constellation configuration maintenance as described in any one of claims 1-6 are implemented.

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