Integrated control method and device for angular momentum unloading and constellation configuration maintenance of deep space satellite

Abstract

The invention provides a deep space satellite angular momentum unloading and constellation configuration maintenance integrated control method and device, and the method comprises the steps: obtaining a whole satellite angular momentum accumulation rule for a constellation satellite Sati through a ground measurement or on-satellite data method; designing a constellation configuration maintenance control strategy of a constellation satellite Sati by adopting a relative motion principle, calculating an angular momentum unloading moment # imgabs0 #, and controlling a pulse direction; determining an optimal unloading thruster combination according to an angular momentum accumulation rule of the constellation satellite Sati, a pulse direction # imgabs1 # maintained by constellation configuration and thruster configuration of the constellation satellite Sati; angular momentum unloading is executed according to the selected thruster; and according to the on-satellite angular momentum accumulation and the flywheel rotating speed, the steps are repeatedly executed, and constellation satellite angular momentum unloading and configuration maintenance integrated control can be completed in the constellation satellite in-orbit operation process. Unnecessary loss can be avoided, and the in-orbit operation time of the satellite is powerfully prolonged.

Description

Technical Field

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

[0002] Satellite systems often adopt on-orbit networking strategies to build specific constellation configurations to achieve specific scientific goals, such as gravity field measurement, high-precision navigation, and emergency communications. On the one hand, in order to ensure the long-term stability of the constellation configuration, prevent the relative position offset between satellites, and ensure the overall performance of the constellation, it is crucial to implement constellation configuration maintenance measures for networking satellites. Taking gravity field measurement satellites as an example, it is necessary to strictly ensure the relative configuration of satellites. On the other hand, in order to ensure the long-term, high-precision and stable operation of the onboard payload, the flywheel in the attitude control mechanism needs to continuously offset the external environmental interference torque. In this process, the flywheel will continue to accumulate angular momentum until it reaches its design limit, that is, the angular momentum saturation state, at which time the flywheel will lose the ability to effectively control the satellite attitude. Therefore, in order to prevent angular momentum saturation and ensure the continuous stability and high-precision control of the satellite attitude, regular and effective unloading of the flywheel angular momentum becomes indispensable.

[0003] Existing angular momentum unloading strategies vary for satellites at different orbital altitudes. For near-Earth satellites, magnetic torquers are the main means of unloading flywheel angular momentum, and angular momentum unloading is achieved by utilizing the interaction between the geomagnetic field and the magnetic torquer. However, for deep space satellites such as lunar relay satellites and high-orbit satellites that are far away from areas with dense magnetic field lines of the Earth, the geomagnetic torque is significantly weakened or almost non-existent, so they cannot rely on geomagnetic torque for angular momentum unloading like medium and low-orbit satellites. For such satellites, thruster jets are generally used to achieve effective control and unloading of flywheel angular momentum. In the process of maintaining the constellation configuration of networking satellites, thrusters are usually used for orbit adjustment and maintenance due to the need to maintain the relative position stability between satellites and the accuracy of orbital parameters.

[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 performing flywheel unloading operations in a certain period of time and focusing on constellation configuration maintenance in another period of time. Through reasonable scheduling and planning, the time-sharing control strategy can ensure that both operations can be fully executed while avoiding conflicts and interference between them. However, this strategy requires a longer mission cycle and higher energy consumption.

[0005] Chinese patent application CN 105373133 A proposes a method for joint control of synchronous orbit electric propulsion position keeping and angular momentum unloading. This method determines the ignition duration and ignition position of each electric thruster and adjusts the thruster direction to achieve angular momentum unloading. However, this method needs to calculate and adjust the thruster direction in each control cycle, and the calculation and control are complex. It is only applicable to satellites carrying adjustable thruster thrust directions, and is difficult to implement in actual engineering.

[0006] Chinese patent application CN 103941749 A proposes a joint control method for east-west position keeping and angular momentum unloading. This method comprehensively analyzes the impact of the earth's non-spherical perturbations, solar light pressure, etc. on the satellite orbit, and considers the impact of angular momentum unloading on the satellite orbit to determine the optimal unloading time to achieve east-west maintenance. However, this method analyzes the impact of environmental perturbations on the satellite orbit, and its conclusions are 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. Joint control method for mission orbit maintenance and momentum wheel unloading for CE-4 relay satellite [J]. Acta Astronautics, 2020, 41(4):9." proposed a joint control method for mission orbit maintenance and momentum wheel unloading. This method qualitatively analyzes the relationship between the satellite angular momentum accumulation law and the change in angular momentum before and after unloading and the equivalent velocity increment of jet unloading, and offsets the influence of the momentum wheel unloading after control through bias control. However, the relationship between the unloading equivalent velocity increment and the unloading angular momentum in this paper depends on the ground-based precise orbit determination measurement data, which is only applicable to the CE-4 relay satellite and is difficult to be used in orbit maintenance missions of other configuration spacecraft. Summary of the invention

[0008] In order 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. Through the geometric relationship between the vectors of angular momentum unloading control torque and constellation configuration maintenance control force, an integrated control on-board thruster selection strategy is formulated, aiming to improve the efficiency of on-board resource utilization and extend the on-orbit life of the satellite.

[0009] In order to achieve the above object, the present invention adopts the following technical solution:

[0010] An integrated control method for deep space satellite angular momentum unloading and constellation configuration maintenance comprises the following steps:

[0011] 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;

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

[0013] 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 thruster configuration, determine the optimal unloading thruster combination;

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

[0015] 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.

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

[0017] 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;

[0018] 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;

[0019] 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;

[0020] an execution module for executing angular momentum unloading according to the selected thrusters;

[0021] 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.

[0022] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of the above-mentioned integrated control method for deep space satellite angular momentum unloading and constellation configuration maintenance are implemented.

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

[0024] Beneficial effects:

[0025] For deep space constellation satellites such as lunar relay satellites and high-orbit satellites that cannot use magnetic torquers 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, flywheel angular momentum unloading and satellite constellation configuration maintenance are organically combined to achieve efficient coordination. In the past, satellites frequently turned thrusters on and off to maintain angular momentum balance and constellation configuration stability. This not only causes the precious fuel resources to be consumed quickly, but also makes it difficult to replenish space fuel, which undoubtedly increases resource pressure; it also accelerates the wear and aging of components due to frequent mechanical movements, shortening the satellite's on-orbit life. After adopting the method of the present invention, the number of thruster startups and shutdowns is greatly reduced, and the on-board fuel can be used efficiently and cost-effectively to avoid unnecessary losses, effectively extending the satellite's on-orbit operation time. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the body coordinate system and the VVLH coordinate system;

[0027] Figure 2 A flow chart of an 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 This is a schematic diagram of the installation of the flywheel on the star;

[0029] Figure 4 This is a schematic diagram of the thruster installation position;

[0030] Figure 5 This is a schematic diagram of the changing trend of the relative distance between the two stars during the time-sharing strategy;

[0031] Figure 6 Schematic diagram of the changing trend of the relative distance between the two satellites during integrated control. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with 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 intended 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] like Figure 2As shown, the integrated control method for deep space satellite angular momentum unloading and constellation configuration maintenance according to the embodiment of the present invention comprises the following steps:

[0034] Step 1: For the constellation satellite Sat i , the accumulation law of angular momentum of the whole satellite is obtained through ground measurement, satellite data and other methods:

[0035] ;

[0036] 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; represents time. Assume that the maximum threshold of satellite i’s whole-star angular momentum is From the current moment At the beginning, according to the law of accumulation of angular momentum of the whole star, when Satellite i performs unloading at time . Determine the angular momentum unloading time at this time According to the formula for accumulating the angular momentum of the entire star, the next unloading time can be determined.

[0037] 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, including:

[0038] Step 2.1: If the target satellite Sat exists in the constellation c , then according to step 2.3, establish the satellite i relative to the target satellite Sat c Otherwise, proceed to step 2.2.

[0039] Step 2.2: Assume that there is a virtual satellite that is orbiting in a nominal orbit that meets the requirements. Take 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 .

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

[0041] Figure 1 In the body coordinate system, the origin is Located at the satellite's centroid, The direction along the vertical axis of the spacecraft assembly pointing to the head of the spacecraft is positive. Perpendicular to The I quadrant line pointing to the longitudinal symmetry plane of the spacecraft, Axis and and A right-handed coordinate system is formed.

[0042] The VVLH coordinate system (Vehicle Velocity Local Horizontal coordinate system) is: 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, , A right-handed coordinate system is formed.

[0043] Constellation SatelliteSat i With the target satellite Sat c The relative motion relationship between them is the TH equation:

[0044] ;

[0045] 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 The three-axis position in the VVLH coordinate system.

[0046] also, ; in, is the semi-major axis of the orbit, is the orbital eccentricity, is the true anomaly angle, is the average angular velocity; Indicates the distance of the target satellite relative to the central celestial body; is the gravitational constant of the central body.

[0047] Step 2.4: The control of orbital direction mainly lies in the control of orbital inclination and right ascension of ascending node. This control only requires applying normal control force, that is, the normal part of TH equation:

[0048] ;

[0049] in, represents the generalized control acceleration, Indicates normal control acceleration. The present invention does not discuss the control method in detail, and PD control is adopted in the present invention: ,in, represents the normal control proportional gain coefficient, Represents the normal control derivative gain coefficient.

[0050] 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 trace control differential gain coefficient.

[0051] Step 2.5: Calculate the pulse direction to maintain the constellation configuration to be controlled based on the relative motion position relationship .

[0052] ;

[0053] 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 .

[0054] 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:

[0055] 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 :

[0056] ;

[0057] ;

[0058] in, Indicates the installation position of the jth thruster (j=1~N) in this system; They respectively represent the thrust vector directions of the jth thruster (j=1~N) in this system.

[0059] 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;

[0060] The optimization variables are: , the optimization variables are thruster numbers 1 to N and unloading time t. If thruster j is selected, then ,otherwise .

[0061] The optimization goal is: , that is, to minimize the angle between the thrust direction and the control pulse direction;

[0062] 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;

[0063] Step 3.3: Use genetic algorithm to optimize the above mixed integer programming problem and obtain the optimal thruster combination.

[0064] Step 4: Perform angular momentum unloading according to the selected thruster.

[0065] Step 5: Repeat steps 1 to 4 according to the accumulated angular momentum on the satellite and the flywheel speed, 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.

[0066] Example:

[0067] The constellation configuration assumes a formation flight of two satellites in the same orbital plane around the moon in a large elliptical orbit. The two satellites are required to always maintain a relative distance of 500km, with satellite A and satellite B acting as the master and slave of each other. During the satellite's in-orbit operation, the attitude of the satellite always maintains the solar panel facing the sun and the antenna facing the moon to ensure on-board energy and observation of the moon. The satellite attitude control mechanism adopts a 3-positive + 1 oblique flywheel assembly, and the flywheel installation layout is as follows: Figure 3 The thruster layout is shown in Figure 4 As shown, the thruster installation position is shown in Table 1. Among them, Figure 3 The middle flywheel adopts a 3-normal-mounted 1-oblique-mounted layout, and the angle between the oblique-mounted flywheel S and each satellite main axis is 54.735°; Figure 4Here, 1N is the thrust of the attitude control engine, and 5N is the thrust of the orbit control engine.

[0068] Assuming that the lower limit of satellite unloading is 0.003Nms and the upper limit of unloading is 0.5Nms, when the absolute value of the difference between the angular momentum of a certain axis and the unloading center of the whole satellite (default is 0) exceeds the upper limit of unloading (0.5Nms), the whole satellite judges to start unloading. When the absolute value of the difference between the angular momentum of the three axes and the unloading center of the whole satellite (default is 0) is less than the lower limit of unloading (0.003Nms), unloading stops. The satellite attitude is mainly affected by the pressure torque of sunlight, which mainly produces angular momentum accumulation on the Y axis, and its unloading period is about 16h.

[0069] Table 1 Thruster installation position (body coordinate system)

[0070] The installation point is the coordinate of the thruster axis at the base plate installation point; the installation angle is the angle between the thruster axis and the three axes of the mechanical coordinate system (the nozzle is facing outwards as the positive direction).

[0071] The on-orbit position velocities (J2000 coordinate system) of satellite A and satellite B obtained by orbit determination at 2024-04-03 06:26:45.5666 Beijing time are shown in Table 2.

[0072] Table 2

[0073] Due to the initial position and velocity deviations, the relative distance between the two stars changes over time. Figure 5 It shows the changing trend of the relative distance between the two stars. Figure 6 It can be seen that at 2024-04-06-17:39:45.5666 Beijing time, the relative distance between the two satellites reached about 400km, and the constellation configuration needs to be maintained. Figure 6 Indicates the change in the relative distance between two satellites.

[0074] The integrated control method of angular momentum unloading and constellation configuration maintenance in the present invention is adopted to optimize the thruster combination, perform angular momentum unloading, and analyze the influence of the method on constellation configuration maintenance and energy consumption. The specific steps are as follows:

[0075] Step 1: Determine the satellite angular momentum accumulation rule. The attitude of satellite A and satellite B is mainly affected by the solar pressure moment, which mainly produces angular momentum accumulation on the Y axis, and its unloading period is about 16h.

[0076] Step 2: Since satellites A and B are master and slave to each other, satellite B is taken as the target satellite and the relative kinematic equation of satellite A relative to satellite B is established.

[0077] As discussed previously, the x-axis direction of the VVLH coordinate system is controlled. 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 unit matrix, and the control pulse direction in this system is: [1;0;0].

[0078] Step 3: Establish the installation position matrix and thrust vector matrix according to the thruster layout of satellite A:

[0079] ;

[0080] ;

[0081] According to the thruster installation position matrix and thrust vector matrix, combined with the control pulse direction and angular momentum direction obtained above, a mixed integer optimization mathematical model is established;

[0082] Genetic algorithm is used to optimize the mixed integer programming problem and obtain the optimal thruster combination T1 and T2 and unloading time. .

[0083] Step 4: Perform angular momentum unloading according to the selected thruster. After calculation, the torque generated by unloading is: [0;-0.2511;0]Nm. Therefore, the unloading startup time is: The control force generated by unloading is 1.9319N, and the corresponding speed pulse is about 0.0378m / s.

[0084] Step 5: Repeat steps 1 to 4, and perform angular momentum unloading on satellite A and satellite B according to the optimization results, and simulate the relative position change. The results are as follows: Figure 6 shown.

[0085] It can be seen that the constellation configuration maintenance period is delayed by about 1 day, and the configuration maintenance period is extended by about 25%. It can be seen that the integrated control strategy of angular momentum unloading and constellation configuration maintenance proposed in the present invention can reduce the frequency of constellation configuration maintenance and improve the efficiency of on-board resource utilization.

[0086] The present invention also provides an integrated control device for deep space satellite angular momentum unloading and constellation configuration maintenance, comprising the following modules:

[0087] 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;

[0088] 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;

[0089] 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;

[0090] an execution module for executing angular momentum unloading according to the selected thrusters;

[0091] 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.

[0092] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of the above-mentioned integrated control method for deep space satellite angular momentum unloading and constellation configuration maintenance are implemented.

[0093] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-mentioned integrated control method for deep space satellite angular momentum unloading and constellation configuration maintenance.

[0094] It should be understood by those skilled in the art that the embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes. The solutions in the embodiments of the present invention may be implemented in various computer languages, for example, object-oriented programming language Java and interpreted scripting language JavaScript, etc.

[0095] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0096] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0097] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0098] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0099] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, 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 thruster configuration, determine the optimal unloading 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 according to step 2.3, establish the satellite i relative to the target satellite Sat c The relative motion equation of ; otherwise, proceed to step 2.

2.

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: 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, is the true anomaly angle, is the average 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, represents the difference in 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. The integrated control method for deep space satellite angular momentum unloading and constellation configuration maintenance according to claim 1, characterized in that: The step 3 comprises: 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 and obtain the optimal thruster combination.

8. An integrated control device for deep space satellite angular momentum unloading and constellation configuration maintenance, 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.

9. 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 one of claims 1-7 are implemented.

10. 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 1-7 are implemented.

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