Multi-observation satellite approaching target imaging task planning method

Abstract

The invention discloses a multi-observation satellite approaching target imaging task planning method. The method comprises the following steps: S1, inputting target orbit parameters and satellite states; s2, relevant constraint conditions are formulated, and visibility analysis of a target satellite is carried out; s3, the target meeting the constraint condition is a visible target, and an imaging task is carried out; the targets which do not meet the constraint conditions are invisible targets, and observation is carried out by adopting an orbital transfer strategy; s4, when the target satellite is an invisible target, the observation satellites approach the target satellite in a Hough transfer mode, the pulse speeds and the Hough transfer time of the multiple observation satellites are calculated, and a candidate task set is generated; s5, defining a task priority function and calculating fuel consumption; and S6, generating an optimal task sequence in combination with the task priority and the fuel consumption, and outputting an imaging plan. According to the method, visibility analysis and Hough transfer are combined, so that the invisible target observation success rate is increased; meanwhile, the task conflict rate is reduced based on dual optimization of priority and fuel consumption.

Description

Technical Field

[0001] The present invention relates to the field of space information analysis, and particularly to a method for mission planning of multi-observation satellites approaching a target for imaging. Background Art

[0002] With the increasing number of space spacecraft, space surveillance satellites play an important role. Satellites use the optical cameras carried by themselves to observe targets at close range to obtain information such as the health status and fault conditions of target spacecraft, or to evaluate the collision risk caused by debris and failed spacecraft. With the continuous development of technology, more and more new satellites with stronger orbital maneuvering capabilities are put into use, which can better complete the target imaging mission.

[0003] The traditional method has low efficiency in resolving task conflicts, and it is difficult to efficiently adjust the task sequence under the premise of ensuring priority, and it is difficult to handle constraints. Summary of the Invention

[0004] In order to solve the existing problems, the present invention provides a method for mission planning of multi-observation satellites approaching a target for imaging. The specific scheme is as follows: A method for mission planning of multi-observation satellites approaching a target for imaging, comprising the following steps: S1. Input the target orbit parameters and satellite status; S2. Formulate relevant constraint conditions and perform visibility analysis of the target satellite; S3. The targets that meet the constraint conditions are visible targets, and imaging tasks are performed; the targets that do not meet the constraint conditions are invisible targets, and a variable orbit strategy is adopted for observation; S4. When the target satellite is an invisible target, the observation satellite approaches the target satellite in a Hohmann transfer manner, calculates the pulse velocity and Hohmann transfer time of multiple observation satellites, and generates a candidate task set; S5. Define a task priority function and calculate the fuel consumption; S6. Combine the task priority and fuel consumption to generate an optimal task sequence and output an imaging plan.

[0005] Preferably, the constraint conditions in step S2 include: adopting a two-body model and ignoring the earth perturbation; the satellite adopts a Hohmann transfer pulse method for orbit change; the satellite payload is an optical camera, and the optical imaging needs to meet the solar illumination angle constraint >0.

[0006] Preferably, the specific method for the observation satellite to approach the target satellite in a Hohmann transfer manner in step S4 is as follows: S41. The observation satellite changes its orbit from the original operating orbit to the transfer orbit along the transition orbit. The transition orbit is in the same orbital plane as the original operating orbit, and the semi-major axis of the transition orbit is equal to the semi-major axis of the target orbit where the target satellite is located. At this time, the two intersection points of the transition orbit and the target orbit are denoted as A and B. S42. After the observation satellite flies from point A to point B along the transition orbit, it flies along the target orbit to the preset observation point.

[0007] Preferably, the specific steps of calculating the pulse velocity and the Hohmann transfer time of an observation satellite in step S4 include: S41'. According to the Kepler orbit theory, the coordinate positions of points A and B and the time for the observation satellite to reach the two points can be calculated. The time for the observation satellite to start changing its orbit from the original operating orbit to point A is , after entering the transition orbit, the time for flying to point B along the transition orbit is , and the time for changing the orbit from point B to the observation position is denoted as . Then the total time taken by the observation satellite from starting to change its orbit to the observation point on the target orbit is: (1) S42'. The included angle between the observation satellite and the observed satellite is denoted as , and by using the included angle θ and the number of orbits k, through (2) Ensure that the relative position meets the imaging requirements. is the angular velocity parameter of the observation satellite, is the number of orbits; where ; According to Kepler's third law, the Hohmann transfer time is as follows: (3), the Hohmann transfer time of the present invention includes and . According to equation (3),

[0008] S43'. Based on step S42', equation (2) can be changed as follows: (4) In the formula represents the original operating orbit height of the observation satellite, represents the transition orbit height, represents the distance from the observation point to the earth's center, is the gravitational constant of the earth; after giving the parameter k, and the velocity increment of each pulse can be calculated. To sum up, the above process is expressed as: (5) is the velocity increment of the pulse, T is the time from when the observation satellite starts to change its orbit until it reaches the observation point, and x 1 is the initial orbital elements of the observation imaging satellite, and x 2 is the initial orbital elements of the observed satellite; according to the initial orbital elements of the satellite, the velocity increment when the observation satellite changes its orbit can be calculated through the above formula (5) and the total time T; Formula (5) describes the velocity increment required for the satellite to move from the initial orbit to the target orbit and the functional relationship between the transfer time T and the initial orbital elements of the two satellites; the derivation process of formula (5) is as follows: First, the six orbital elements of the satellite's initial orbit are given, which are: a - semi-major axis, e - eccentricity, i - inclination, Ω - right ascension of the ascending node, ω—— argument of perigee, M - mean anomaly; For two satellites, their initial orbital elements are x1 = (a1, e1, i1, Ω1, ω 1 、 M1) and x2 = (a2, e2, i2, Ω2, ω 2 、 M2); According to the basic orbital elements of the satellite, the initial orbital radius r = a(1 - e) / (1 + ecosM). Since the Hohmann transfer requires the initial and target orbits to be circular orbits, the eccentricities e1 and e2 are both 0, and the transfer orbit is an elliptical orbit, so r0 = a1, r2 = a2, , substitute r0, r1, r2 into formula (3) respectively to calculate T1 and T2, and substitute them into formulas (7) and (8) to calculate , , thus obtaining the total time T and the total velocity increment .

[0009] Preferably, step S5 specifically includes the following steps: S51, define the priority of the observation task to describe the situation of the target imaging observation task, as follows: (6) is the velocity increment of the pulse, T is the time from when the observation satellite starts to change its orbit until it reaches the observation point, m and n are weight parameters, and m + n = 1. According to the results of multiple experiments and the task requirements, m is taken as 0.4 and n is taken as 0.6. Calculate the priority according to formula (6) and take the minimum value; S52, calculate the fuel consumption of each pulse: The velocity increment of the first acceleration (near the perigee) , where ; (7) Second acceleration (at the periapsis) velocity increment , where ; (8) ΔV = ΔV1 + ΔV2. According to the Tsiolkovsky formula, the velocity increment is directly related to the fuel consumption. The greater the velocity change, the greater the fuel consumption and the more fuel is consumed by the spacecraft. Therefore, it is used to represent the fuel consumption; represents the standard gravitational constant, represents the transfer orbit altitude, represents the distance from the observation point to the center of the earth, and h represents the altitude of the transfer orbit.

[0010] Preferably, step S6 is specifically: by calculating the priority and fuel consumption of the above observation tasks, the smaller the value of formula (6), the higher the priority, and then calculating the minimum fuel consumption to plan the observation satellite imaging task.

[0011] The present invention also discloses a computer-readable storage medium with a computer program stored thereon. After the computer program runs, it executes the method described in any one of the above.

[0012] The present invention also discloses a computer system, including a processor and a storage medium. The storage medium stores a computer program, and the processor reads and runs the computer program from the storage medium to execute the method described in any one of the above.

[0013] The beneficial effects of the present invention are as follows: The present invention is applicable to scenarios such as high-orbit debris monitoring and failure spacecraft status assessment; by combining visibility analysis with Hohmann transfer, it improves the observation success rate of invisible targets; at the same time, the present invention is based on the dual optimization of priority and fuel consumption, reducing the task conflict rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0015] Figure 1 It is a schematic diagram of the orbital operation and orbital transfer of the observation satellite and the target satellite of the present invention.

[0016] Figure 2 It is a flowchart of the method of the present invention.

[0017] The reference numerals are as follows: 1. Observation satellite; 2. Target satellite; 3. Original operating orbit of the observation satellite; 4. Transfer orbit; 5. Transition orbit; 6. Operating orbit of the target satellite. Detailed implementation manner

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0019] Aiming at the complex operating orbit plane and large visibility differences of target satellites in the approach imaging of multiple observation satellites, a method integrating visibility analysis, orbit maneuvering, and mission planning models is provided to achieve efficient and accurate imaging. The observation satellite uses the optical camera carried by itself to observe the target at close range to obtain information such as the health status and fault conditions of the target satellite, or to evaluate the collision risks caused by debris and failed spacecraft.

[0020] The present invention considers that the target to be observed is located on different orbit planes. First, visibility analysis is calculated for the target. For visible targets that meet the constraint conditions, imaging tasks are performed. For targets that do not meet the constraints and are invisible, a variable orbit strategy is adopted for observation. The following gives the specific orbit maneuvering strategy and the mathematical model of the approach observation mission planning for the target. Specifically, as Figure 2 , a method for mission planning of multiple observation satellites approaching a target for imaging includes the following steps: S1. Input the parameters of the operating orbit 6 of the target satellite and the satellite status.

[0021] S2. Formulate relevant constraint conditions and perform visibility analysis on the target satellite 2. The constraint conditions include: adopting a two-body model and ignoring the earth's perturbation; the observation satellite uses the Hohmann transfer pulse method for orbit change; the payload of the observation satellite is an optical camera, and the optical imaging needs to meet the solar illumination angle constraint >0.

[0022] S3. Targets that meet the constraint conditions are visible targets, and imaging tasks are performed; targets that do not meet the constraint conditions are invisible targets, and a variable orbit strategy is adopted for observation.

[0023] S4. When the target satellite 2 is an invisible target, the observation satellite 1 uses the Hohmann transfer method to approach the target satellite 2, calculates the pulse velocities and Hohmann transfer times of multiple observation satellites, and generates a candidate mission set.

[0024] Among them, the specific method for the observation satellite 1 to approach the target satellite 2 using the Hohmann transfer method is as follows: S41. The observation satellite 1 changes its orbit from the original operating orbit 3 along the transfer orbit 4 to the transition orbit 5. The transition orbit 5 is in the same orbital plane as the original operating orbit 3, and the semi-major axis of the transition orbit 5 is equal to the semi-major axis of the target satellite operating orbit 6 where the target satellite 2 is located. At this time, the two intersection points of the transition orbit 5 and the target satellite operating orbit 6 are denoted as A and B. S42. After the observation satellite 1 flies from point A to point B along the transition orbit 5, it flies along the target satellite operating orbit 6 to the preset observation point.

[0025] Taking the calculation of one observation satellite as an example, the specific steps for calculating the pulse velocity and Hohmann transfer time of one observation satellite include: S41'. According to Kepler's orbit theory, the coordinate positions of points A and B and the time for the observation satellite 1 to reach these two points can be calculated. The time for the observation satellite 1 to start changing its orbit from the original operating orbit 3 to point A is , after entering the transition orbit 5, the time for flying to point B along the transition orbit 5 is , and the time for changing the orbit from point B to the observation position is denoted as . Then the total time taken for the observation satellite 1 to start changing its orbit to the observation point on the target satellite operating orbit 6 is: (1) S42'. The angle between the observation satellite 1 and the observed satellite, i.e., the target satellite 2, is denoted as , and by using the angle θ and the number of laps k, through (2) Ensure that the relative position meets the imaging requirements. is the angular velocity parameter of the observation satellite 1, is the number of laps; where ; According to Kepler's third law, the Hohmann transfer time is as follows: (3), The Hohmann transfer time of the present invention includes and . According to equation (3),

[0026] ; S43'. Based on step S42', equation (2) can be changed as follows: (4) In the formula represents the height of the original operating orbit of the observation satellite, represents the height of the transition orbit 5, represents the distance from the observation point to the earth's center, is the earth's gravitational constant; after giving the parameter k, And the velocity increment of each pulse. In summary, the above process is expressed as: (5) is the velocity increment of the pulse, T is the time from when the observation satellite 1 starts to change its orbit until the observation point, and x 1 is the initial orbital elements of the observation imaging satellite, and x 2 is the initial orbital elements of the observed satellite 1; according to the initial orbital elements of the satellite, the velocity increment at the time of orbit change of the observation satellite can be calculated through the above formula (5) and the total time T; Formula (5) describes the velocity increment required for the satellite to move from the initial orbit to the target orbit and the functional relationship between the transfer time T and the initial orbital elements of the two satellites; the derivation process of formula (5) is as follows: First, the six orbital elements of the satellite's initial orbit are given, which are: a - semi-major axis, e - eccentricity, i - inclination, Ω - right ascension of the ascending node, ω—— argument of perigee, M - mean anomaly; For the two satellites, their initial orbital elements are respectively x1 = (a1, e1, i1, Ω1, ω 1 、 M1) and x2 = (a2, e2, i2, Ω2, ω 2 、 M2); According to the basic orbital elements of the satellite, the initial orbital radius r = a(1 - e) / (1 + ecosM). Since the Hohmann transfer requires the initial and target orbits to be circular orbits, the eccentricities e1 and e2 are both 0, and the transfer orbit is an elliptical orbit, so r0 = a1 and r2 = a2, , substitute r0, r1, r2, and then substitute them into formula (3) to calculate T1 and T2, and substitute them into (7) and (8) to calculate , , thus obtaining the total time T and the total velocity increment ;

[0027] S5. Define the task priority function and calculate the fuel consumption. Specifically, it includes the following steps: S51. Define the priority of the observation task to describe the situation of the target imaging observation task, as follows: (6) is the velocity increment of the pulse, T is the time from when the observation satellite 1 starts to change its orbit until the observation point, m and n are weight parameters, and m + n = 1. According to the results of multiple experiments and task requirements, m is taken as 0.4 and n is taken as 0.6. Calculate the priority according to formula (6) and take the minimum value; S52. Calculate the fuel consumption per pulse: Velocity increment of the first acceleration (periapsis) , where ; (7) Velocity increment of the second acceleration (periapsis) , where ; (8) ΔV = ΔV1 + ΔV2. According to the Tsiolkovsky formula, the velocity increment is directly related to the fuel consumption. The greater the velocity change, the greater the fuel consumption, and the more fuel is consumed by the spacecraft. Therefore, this is used to represent the fuel consumption. Represents the standard gravitational constant, Represents the altitude of transfer orbit 5, Represents the distance from the observation point to the center of the earth, and h represents the altitude of transfer orbit 4.

[0028] S6. Combine the mission priority and fuel consumption to generate an optimal mission sequence and output the imaging plan.

[0029] Specifically: By calculating the priority and fuel consumption of the above observation tasks, the smaller the value of formula (6), the higher the priority, and then calculate the minimum fuel consumption to plan the imaging mission of the observation satellite.

[0030] This article addresses the problem of imaging mission planning for maneuvering satellites to regional targets. First, relevant constraints are given; then the target visibility is calculated, and a satellite orbit transfer strategy is given for invisible targets; finally, a close-proximity imaging mission planning for imaging-type space targets is given. The present invention is applicable to scenarios such as high-orbit debris monitoring and failure spacecraft status assessment; by combining visibility analysis and Hohmann transfer, the observation success rate of invisible targets is improved; at the same time, the present invention is based on the dual optimization of priority and fuel consumption to reduce the mission conflict rate.

[0031] The present invention also discloses a computer-readable storage medium and a computer system. The medium stores a computer program. After the computer program runs, it executes the method described in any one of the above. A computer system includes a processor and a storage medium. The storage medium stores a computer program, and the processor reads and runs the computer program from the storage medium to execute the method described in any one of the above.

[0032] In one or more exemplary embodiments, the described functionality may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software as a computer program product, the functions may be stored on or transmitted via a computer-readable medium as one or more instructions or code. The computer-readable medium includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. The storage media may be any available media that can be accessed by a computer. By way of example and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a web site, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium.

[0033] The foregoing description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0034] Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for planning a multi-observation satellite approaching target imaging mission, characterized in that: The following steps are involved: S1. Input target orbit parameters and satellite status; S2. Formulate relevant constraints and conduct visibility analysis of the target satellite; S3: Targets that meet the constraints are visible targets and perform imaging tasks; targets that do not meet the constraints are invisible targets and are observed using a change-orbit strategy; S4. When the target satellite is an invisible target, the observation satellite approaches the target satellite using the Hohmann transfer method, calculates the pulse speed and Hohmann transfer time of multiple observation satellites, and generates a candidate task set; S5. Define task priority function and calculate fuel consumption; S6. Combine task priorities and fuel consumption to generate the optimal task sequence and output the imaging plan.

2. The method according to claim 1, characterized in that The constraints in step S2 include: using a two-body model and ignoring earth perturbations; the satellite uses the Hohmann transfer pulse method to change orbit; the satellite payload is an optical camera, and the optical imaging must meet the solar illumination angle constraint >

0.

3. The method according to claim 1, characterized in that The specific method of the observation satellite in step S4 approaching the target satellite using the Hohmann transfer method is as follows: S41, the observation satellite changes its orbit from the original orbit along the transfer orbit to the transition orbit, wherein the transition orbit is on the same orbital plane as the original orbit, and the semi-major axis of the transition orbit is equal to the semi-major axis of the target orbit where the target satellite is located; At this time, the two intersection points of the transition orbit and the target orbit are recorded as A and B; S42. After the observation satellite flies from point A to point B along the transition orbit, it flies to the preset observation point along the target orbit.

4. The method according to claim 3, characterized in that: The specific steps of calculating the pulse velocity and Hohmann transfer time of an observation satellite in step S4 include: S41', According to Kepler's orbit theory, we can calculate the coordinates of points A and B and the time it takes for the observation satellite to reach the two points; the time it takes for the observation satellite to change its orbit from the original orbit to point A is After entering the transition orbit, the time it takes to fly to point B in the transition orbit is , and then change the track from point B to the observation position. The time is recorded as , then the total time taken by the observation satellite from the beginning of orbit change to the target orbit observation point is: （1） S42', the angle between the observing satellite and the observed satellite, i.e. the target satellite, is recorded as , using the angle θ and the number of turns k, by (2) Ensure that the relative position meets the imaging requirements, is the observed satellite angular velocity parameter, is the number of rounds; among them, ; According to Kepler's third law, the Hohmann transfer time is given by: (3) The Hohmann transfer time of the present invention includes and , according to formula (3), ; S43', based on step S42', formula (2) can be changed as follows: （4） In the formula Indicates the original orbital altitude of the observed satellite. represents the transition orbit altitude, represents the distance from the observation point to the center of the earth, is the gravitational constant; given the parameter k, we can calculate And the speed increment of each pulse, in summary, the above process can be expressed as: (5) is the velocity increment of the pulse, T is the time taken by the observation satellite from the beginning of orbit change to the observation point, x1 is the initial root number of the observation imaging satellite, and x2 is the initial root number of the observed satellite. According to the initial root number of the satellite, the velocity increment of the observation satellite when changing orbit can be calculated by the above formula (5): and the total time T; Formula (5) describes the velocity increment required for the satellite to move from the initial orbit to the target orbit: The functional relationship between the transfer time T and the initial orbital elements of the two satellites; the derivation process of formula (5) is as follows: First, the six numbers of the satellite's initial test orbit are given: a - semi-major axis, e - eccentricity, i - inclination, Ω - right ascension of the ascending node, ω—— Argument of perigee, M – mean anomaly; For two satellites, their initial orbital elements are x1 = (a1, e1, i1, Ω1, ω 1 、 M1) and x2 = (a2, e2, i2, Ω2, ω 2 、 M2); According to the basic elements of the satellite, the initial orbit radius r = a(1-e) / (1+ecosM), and the Hohmann transfer requires that the initial and target orbits are circular orbits, so the eccentricities e1 and e2 are both 0, and the transfer orbit is an elliptical orbit, so r0 = a1, r2 = a2, , then substitute r0, r1, r2 into (3) to calculate T1, T2, and substitute into (7) and (8) to calculate , , thus obtaining the total time T and the total velocity increment .

5. The method according to claim 4, characterized in that Step S5 specifically includes the following steps: S51, define the priority of the observation task to describe the target imaging observation task situation, as follows: （6） is the velocity increment of the pulse, T is the time taken by the observation satellite from the beginning of orbit change to the observation point, m and n are weight parameters, and m+n=1. According to multiple experimental results and mission requirements, m is taken as 0.4 and n is taken as 0.

6. The priority is calculated according to formula (6) and the minimum value is taken; S52, calculate the fuel consumption of each pulse: The first acceleration velocity increment at periapsis ,in ; (7) The second acceleration velocity increment at periapsis ,in ; (8) ΔV=ΔV1+ΔV2. According to the Tsiolkovsky formula, the speed increment is directly related to the fuel consumption. The greater the speed change, the greater the fuel consumption, and the more fuel the spacecraft carries is consumed. Therefore, this is used to express the fuel consumption. represents the standard gravitational constant, represents the transition orbit altitude, represents the distance from the observation point to the center of the earth, and h represents the height of the transfer orbit.

6. The method according to claim 5, characterized in that Step S6 specifically includes: by calculating the priority and fuel consumption of the above observation tasks, the smaller the value of formula (6), the higher the priority, and then calculating the minimum fuel consumption to plan the observation satellite imaging task.

7. A computer-readable storage medium, characterized in that: A computer program is stored on the medium, and after the computer program is run, the method according to any one of claims 1 to 6 is executed.

8. A computer system, characterized in that: The method comprises a processor and a storage medium, wherein a computer program is stored in the storage medium, and the processor reads and runs the computer program from the storage medium to execute the method as claimed in any one of claims 1 to 6.

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