Orbit design method for orbiting in a region of an orbit

Abstract

The present application discloses a method for designing an orbit for on-orbit regional cruising, which divides the orbit into four segments, i.e., a low-orbit patrol segment, a first orbit transfer segment, a high-orbit patrol segment and a second orbit transfer segment; the method comprises: allocating operation time for each segment by an optimization algorithm; designing the high-orbit patrol segment and the low-orbit patrol segment under a time allocation scheme; taking fuel consumption as an optimization target, expressing the fuel consumption by total velocity increment, and continuously optimizing the total velocity increment under different time allocation schemes by the optimization algorithm to finally give a locally optimal or globally optimal time allocation scheme. The present application uses a Lambert double-pulse control algorithm to design the orbit transfer segment and uses a genetic algorithm to optimize the orbit, thereby solving the optimal on-orbit regional cruising orbit and having the advantages of less fuel consumption, wider service range and higher robustness.

Description

Technical Field

[0001] This invention relates to the field of space on-orbit servicing and orbit control, specifically to a method for planning and maneuvering control of on-orbit area patrol missions for maintenance spacecraft. Background Technology

[0002] With the advancement of aerospace technology, the number of spacecraft in orbit is constantly increasing, and high-efficiency orbits such as GEO are gradually becoming an important resource. The threat posed by space debris in orbit to high-value satellites has received increasing attention, and the on-orbit monitoring and maintenance of high-value satellites has gradually become a new research hotspot. Therefore, scholars from various countries are actively exploring new on-orbit servicing solutions from different perspectives, including spacecraft design and orbital mission planning. Currently, the main solution to the on-orbit servicing problem is to directly enter orbit from the deployment orbit to approach the target, conduct on-orbit servicing, and then return to the deployment orbit after completing the mission. However, this solution only considers a "one-to-one" model of satellite on-orbit servicing. If on-orbit monitoring and maintenance of multiple spacecraft in the same orbit is required, or space debris cleanup is needed, multiple orbital maneuvers are required, resulting in significant fuel consumption. Summary of the Invention

[0003] The purpose of this invention is to provide an orbit design method for on-orbit area cruising, which deploys a maintenance spacecraft in an orbit adjacent to the target orbit and achieves area cruising within a specific range of the target orbit through maneuver control, thereby providing on-orbit services to satellites within the area.

[0004] To achieve the above objectives, this invention provides a track design method for on-orbit regional cruising. The on-orbit regional cruising track is divided into four segments: a low-orbit patrol segment, an initial track change segment, a high-orbit patrol segment, and a secondary track change segment. The track design method for on-orbit regional cruising includes: allocating the running time of each segment through an optimization algorithm; designing the high-orbit patrol segment and the low-orbit patrol segment under the time allocation scheme; using fuel consumption as the optimization objective, representing fuel consumption with the total speed increment; and continuously optimizing the algorithm based on the total speed increment under different time allocation schemes, ultimately providing a locally optimal or globally optimal time allocation scheme.

[0005] The above-mentioned orbit design method for on-orbit patrol includes: 1) providing inputs, including the number of orbital elements of the target orbit, the range of the perihelion angle E of the target orbit service area, and the maximum time T for one orbit of the maintenance spacecraft; 2) under the constraint of the maximum time T for one orbit of the maintenance spacecraft, using an optimization algorithm to allocate the running time of each segment; let the running time of the low-Earth orbit patrol segment be t1, the running time of the initial orbit change segment be t2, the running time of the high-Earth orbit patrol segment be t3, and the running time of the second orbit change segment be t4; 3) based on the running time t1 of the low-Earth orbit patrol segment and the running time t4 of the high-Earth orbit patrol segment... 3. Design the number of six rails for the low-orbit patrol section and the high-orbit patrol section; 4) Based on the number of six rails for the low-orbit patrol section and the high-orbit patrol section, as well as the running time t2 of the first orbit change section and the running time t4 of the second orbit change section, calculate the speed increment dv1 of the first orbit change section and the speed increment dv2 of the second orbit change section. The total speed increment dv = dv1 + dv2; 5) Return to step 2), use the total speed increment dv as the objective function input, and continuously optimize the time allocation scheme through the optimization algorithm until the termination condition of the optimization algorithm is met, and finally give the local optimal or global optimal time allocation scheme.

[0006] The above-mentioned orbit design method for cruising in the orbital area includes six orbital elements of the target orbit, namely, semi-major axis a, eccentricity e, right ascension of the ascending node Ω, orbital inclination i, and argument of perigee ω. The range of perigee angles of the target orbit's service area is E1 < E < E2, where E1 and E2 represent the minimum and maximum perigee angles of the service area, respectively.

[0007] The above-mentioned orbit design method for on-orbit area cruising employs a genetic algorithm for optimization.

[0008] The above-mentioned track design method for on-orbit area patrol involves calculating the number of track elements for both the low-orbit and high-orbit patrol sections based on the target track altitude, the near-point angle range of the target track service area, the low-orbit patrol section running time t1, and the high-orbit patrol section running time t3, using track dynamics theory and the influence of track altitude on track angular velocity.

[0009] In the above-mentioned track design method for cruising in the orbital area, in step 4), the Lambert double-pulse control algorithm is used to calculate the velocity increment dv1 of the first track change segment and the velocity increment dv2 of the second track change segment.

[0010] In the above-mentioned orbit design method for on-orbit area cruising, in step 5), the termination condition of the optimization algorithm is preset.

[0011] Compared with the prior art, the beneficial technical effects of the present invention are:

[0012] (1) Larger service range: The on-orbit area patrol track designed in this invention uses a "rectangular" patrol segment to cover a large orbital segment, and the maintenance spacecraft can realize on-orbit monitoring and maintenance of satellites within this range;

[0013] (2) Better fuel consumption: This invention uses the Lambert algorithm to design the track and performs optimization based on the genetic algorithm, which can design a more fuel-efficient track-changing scheme;

[0014] (3) Shorter response time for on-orbit service tasks: The on-orbit area cruise orbit designed in this invention deploys maintenance spacecraft near potential service targets. Therefore, when a mission instruction is received, the corresponding on-orbit monitoring and maintenance tasks can be executed quickly. Attached Figure Description

[0015] The track design method for on-orbit area cruising of the present invention is given by the following embodiments and figures.

[0016] Figure 1 A schematic diagram of the orbital segment for a maintenance spacecraft to cruise in its orbit.

[0017] Figure 2 This is a flowchart of the track design method for on-orbit area cruising according to the present invention.

[0018] Figure 3 This is a flowchart of the track design process in this invention.

[0019] Figure 4 This is a flowchart illustrating the calculation of the change in track speed in this invention.

[0020] Figure 5 This is a schematic diagram of the orbital patrol track of the maintenance spacecraft in the orbital region according to a preferred embodiment of the present invention.

[0021] Figure 6 This is a diagram of the low-orbit patrol section operation in a preferred embodiment of the present invention.

[0022] Figure 7 This is a diagram of the initial track-changing section in a preferred embodiment of the present invention.

[0023] Figure 8 This is an operational diagram of the high-rail patrol section in a preferred embodiment of the present invention.

[0024] Figure 9 This is a diagram of the relative orbit of a spacecraft in a preferred embodiment of the present invention.

[0025] Figure 10 This is a graph showing the speed change during iteration in a preferred embodiment of the present invention. Detailed Implementation

[0026] The following will combine Figures 1-10The track design method for on-orbit area cruising according to the present invention will be described in further detail.

[0027] The orbit design method for on-orbit area cruising of the present invention utilizes the phase difference generated by the orbital altitude difference to enable maintenance spacecraft to cruise within a certain time and a specific orbital area, thereby providing on-orbit monitoring and maintenance services for high-value satellites in the target orbital service area.

[0028] In this invention, the maintenance spacecraft's regional cruise trajectory is divided into four parts: a low-Earth orbit (LEO) patrol segment, an initial orbit change segment, a high-Earth orbit (HEO) patrol segment, and a secondary orbit change segment. The LEO patrol segment utilizes the phase difference generated by the orbital altitude difference to allow the maintenance spacecraft to traverse the target orbit service area, achieving forward patrolling. The initial orbit change segment is the orbit change segment between the maintenance spacecraft's maneuver from the LEO patrol segment to the HEO patrol segment. In the HEO patrol segment, the maintenance spacecraft again utilizes the phase difference generated by the orbital altitude difference to traverse the target orbit service area, achieving backward patrolling. The secondary orbit change segment maneuvers the maintenance spacecraft back to the starting point of the LEO patrol segment. The maintenance spacecraft repeatedly executes the above four trajectory control segments, thereby forming a closed-loop flight trajectory that cruises around the target orbit service area, as shown below. Figure 1 As shown.

[0029] The terms "low orbit" and "high orbit" are relative to the target orbit. The target orbit service area is the area where maintenance spacecraft are monitored and maintained in orbit. It is a segment of the target orbit. Low orbit is below the target orbit, and high orbit is above the target orbit.

[0030] The present invention provides a track design method for on-orbit area cruising, which allocates the running time of each segment through an optimization algorithm; designs high-orbit patrol segments and low-orbit patrol segments under the time allocation scheme; takes fuel consumption as the optimization objective and uses the total speed increment to approximate the fuel consumption; the optimization algorithm continuously optimizes according to the total speed increment under different time allocation schemes, and finally gives a locally optimal or globally optimal time allocation scheme.

[0031] Figure 2 The diagram shows a flowchart of the track design method for on-orbit area cruising according to the present invention.

[0032] See Figure 2 The orbit design method for on-orbit area cruising of the present invention includes:

[0033] 1) Provide inputs, including the number of orbital elements of the target orbit, the range of the perihelion angle E of the target orbit service area, and the maximum time T for the maintenance spacecraft to complete one orbit;

[0034] The six orbital elements of the target orbit include the semi-major axis a, eccentricity e, right ascension of the ascending node Ω, orbital inclination i, and argument of perigee ω. The range of perigee angles in the service area of ​​the target orbit is E1 < E < E2, where E1 and E2 represent the minimum and maximum perigee angles of the service area, respectively.

[0035] 2) Under the constraint of the longest time for a maintenance spacecraft to complete one orbit, use an optimization algorithm to allocate the running time for each segment. That is, under the constraint of the longest time for a maintenance spacecraft to complete one orbit, use an optimization algorithm to give a time allocation scheme for each segment.

[0036] Let the running time of the low-orbit patrol section be t1, the running time of the initial track change section be t2, the running time of the high-orbit patrol section be t3, and the running time of the second track change section be t4. Let t1, t2, t3, and t4 satisfy the constraint t1+t2+t3+t4≤T;

[0037] Preferably, the optimization algorithm uses a genetic algorithm;

[0038] 3) Design the number of six tracks for the low-orbit patrol section and the high-orbit patrol section based on the low-orbit patrol section running time t1 and the high-orbit patrol section running time t3;

[0039] Based on the target orbital altitude, the near-point angle range of the target orbital service area, the low-orbit patrol segment running time t1, and the high-orbit patrol segment running time t3, the number of six track members for the low-orbit and high-orbit patrol segments is calculated using the theory of orbital dynamics and the influence of orbital altitude on orbital angular velocity.

[0040] like Figure 3 Taking the low-orbit patrol section as an example, the specific calculation process for the number of six track members is as follows:

[0041] For a given semi-major axis a of the target orbit, the average angular velocity n traveling on the target orbit is:

[0042]

[0043] In the formula, μ is the gravitational parameter, μ = GM, and for Earth, μ = 3.682 × 10⁻⁶. 5 ;

[0044] Therefore, after a given low-orbit patrol segment travel time t1, the difference in the angle m between the mean apogee and the mean perigee that any point on the target orbit can rotate through is:

[0045] m = nt1 (2)

[0046] The relationship between the angle difference m at the near point and the angle E at the far point is as follows:

[0047] m=E-Ecos(E) (3)

[0048] Given the target orbit eccentricity e and the difference in approximate angle m, the difference in approximate angle e2 of the point can be obtained from equation (4).

[0049] e2=m+(ee 3 / 8)sin(m)+e 2 sin(2m) / 2+(3 / 8)e 3 sin(3m) (4)

[0050] Given that the designated patrol range for the anomalous angle of the mission is e1 = f2 - f1, where f1 represents the minimum anomalous angle of the patrol area and f2 represents the maximum anomalous angle of the patrol area, the anomalous angle E1 traversed by the maintenance spacecraft during the mission time can be obtained as follows:

[0051] E1 = e2 + e1 (5)

[0052] The expected mean apogee angle difference m2 of the maintenance spacecraft can then be obtained by solving equation (6).

[0053] m2=E1-E1cos(E1) (6)

[0054] Then we can know that the expected mean angular velocity n2 of the maintenance spacecraft is...

[0055]

[0056] Finally, the expected radius a2 of the low-orbit patrol segment can be solved according to equation (8).

[0057]

[0058] The calculation process for the six track members in the high-rail patrol section is the same as above;

[0059] 4) Based on the number of six tracks in the low-orbit patrol section and the high-orbit patrol section, as well as the running time t2 of the first track change section and the running time t4 of the second track change section, calculate the speed increment dv1 of the first track change section and the speed increment dv2 of the second track change section. The total speed increment dv = dv1 + dv2.

[0060] Once the start and end points of the low-orbit patrol section and the high-orbit patrol section are known, the Lambert double-pulse control algorithm can be used to calculate the speed increment required for orbit change.

[0061] 5) Return to step 2), use the total speed increment dv as the objective function input, and continuously optimize the time allocation scheme through the optimization algorithm until the termination condition of the optimization algorithm is met, and finally give the local optimal or global optimal time allocation scheme.

[0062] The termination conditions for the optimization algorithm are preset.

[0063] The orbit design method for on-orbit regional cruising of the present invention uses the Lambert double-pulse control algorithm to design the orbit change track and the genetic algorithm to optimize the track, thus solving for the optimal on-orbit regional cruising track. It has the advantages of less fuel consumption, wider service range, and higher robustness.

[0064] The track design method for on-orbit area cruising of the present invention will now be described in detail with reference to specific embodiments.

[0065] 1) Provide inputs, as shown in Table 1;

[0066] Table 1 Input Parameters

[0067]

[0068] 2) Under the constraint of the longest time T for the maintenance spacecraft to complete one orbit, the genetic algorithm is used to allocate the running time t1 for the low-orbit patrol segment, the running time t2 for the initial orbit change segment, the running time t3 for the high-orbit patrol segment, and the running time t4 for the second orbit change segment; and the total velocity increment dv calculated in step 4) is used as the objective function input to continuously optimize the time allocation of each segment. The final optimized time allocation scheme is t1 = 406400s, t2 = 5000s, t3 = 447600s, and t4 = 5000s.

[0069] In this embodiment, the objective function output is designed as follows:

[0070] 3) Based on the running time t1 of the low-orbit patrol section and the running time t3 of the high-orbit patrol section, design the number of six tracks for the low-orbit patrol section and the high-orbit patrol section. Except for the semi-major axis of the track, the rest are the same as the target track. The semi-major axis of the low-orbit patrol section is a1 = 40585.8KM, and the semi-major axis of the high-orbit patrol section is a2 = 43737.4KM.

[0071] 4) Based on the number of six tracks in the low-orbit patrol section and the high-orbit patrol section, the running time of the first track change section t2 = 5000s, and the running time of the second track change section t4 = 5000s, the speed increment dv1 of the first track change section and the speed increment dv2 of the second track change section are calculated using the Lambert double-pulse control algorithm, and dv = 2.36558KM / s is obtained.

[0072] The final output results are shown in Table 2.

[0073] Table 2 Output Results

[0074]

[0075] A complete orbital trajectory of the maintenance spacecraft in the J2000 coordinate system is shown below. Figure 5Among them, the double-lined segment is the low-gauge patrol segment, the solid line segment is the initial track change segment, the dotted-lined segment is the high-gauge patrol segment, and the dashed line segment is the second track change segment. Figure 6 The image shows the orbital path of a maintenance spacecraft during its low-Earth orbit patrol phase. By operating in an orbit below the target orbit, the maintenance spacecraft can provide on-orbit servicing for the target satellite while also gaining a leading phase to prepare for on-orbit servicing of other satellites. Figure 7 This is the initial orbit change phase for maintenance spacecraft. After the maintenance spacecraft has traversed the service area in the low Earth orbit patrol phase, it needs to return to the service area, thus requiring a maneuvering orbit change. Figure 8 The diagram shows the high-orbit patrol segment. When the maintenance spacecraft operates in an orbit slightly higher than the target orbit, its phase gradually lags behind, allowing it to continue providing on-orbit service to the target orbit service area. Simultaneously, the flight trajectory of the entire cruise orbit in the target orbit coordinate system can be obtained, see... Figure 9 In this diagram, the double-dash segment represents the low-orbit patrol segment, the solid line segment represents the initial orbit change segment, the dotted-dash segment represents the high-orbit patrol segment, and the dashed line segment represents the second orbit change segment. Furthermore, a velocity change graph can be obtained during the iteration process, which proves that the final iteration result is the optimal velocity change method. The horizontal axis of the graph represents the iteration number, and the vertical axis represents the velocity change during that iteration. See [link to graph]. Figure 10 ;

[0076] This allows for the completion of a track design process that is simple, fast, requires few input conditions, can be adjusted according to task requirements, and provides intuitive and visual output results.

Claims

1. A method for designing a track for in-orbit area cruising, characterized in that, The on-orbit patrol track is divided into four segments: the low-orbit patrol segment, the initial orbit change segment, the high-orbit patrol segment, and the secondary orbit change segment. The on-orbit patrol track design method includes: allocating the running time of each segment through an optimization algorithm; designing the high-orbit patrol segment and the low-orbit patrol segment under the time allocation scheme; taking fuel consumption as the optimization objective, using the total speed increment to represent fuel consumption, and continuously optimizing the algorithm according to the total speed increment under different time allocation schemes, ultimately providing a locally optimal or globally optimal time allocation scheme. The track design method includes: 1) Provide input, including the number of six orbital elements of the target orbit and the perimeter angle of the target orbit's service area. Range and longest time for a maintenance spacecraft to complete one orbit ; 2) Under the constraint of the longest time for a maintenance spacecraft to complete one orbit, use an optimization algorithm to allocate the running time for each segment; Assume the low-orbit patrol segment's operating time is The initial track change section operation time is The high-speed rail patrol section's operating time is The running time of the second track change section is ; 3) Based on the operating time of the low-orbit patrol section and the operating time of the high-orbit patrol section The design specifies the number of six tracks for both the low-orbit and high-orbit patrol sections. 4) Based on the number of six rails in the low-gauge patrol section and the high-gauge patrol section, and the initial track change operation time. Second track change section running time Calculate the speed increment during the initial track change segment. Speed ​​increments in the second track change segment Total speed increment ; 5) Return to step 2), incrementing the total speed. As input to the objective function, the time allocation scheme is continuously optimized by the optimization algorithm until the termination condition of the optimization algorithm is met, and finally a local or global optimal time allocation scheme is given. The target orbit has six orbital elements, including the semi-major axis. eccentricity Right ascension of ascending node Track inclination and perigee argument The target orbit service area is within the range of the nearest point angle. ,in These represent the minimum and maximum angles of proximity within the service area, respectively. Based on the target orbit altitude, the near-point angle range of the target orbit service area, and the operating time of the low-orbit patrol segment. and the operating time of the high-orbit patrol section Using the theory of orbital dynamics, the number of six track members in the low-orbit and high-orbit patrol sections is calculated by examining the influence of track altitude on track angular velocity. The specific calculation process for the six orbital elements is as follows: For a given target orbit semi-major axis The average angular velocity of the target orbit have （1） In the formula, These are gravitational parameters; So, given the operating time of the low-orbit patrol segment Then, the difference in the angle of approach that any point on the target orbit can rotate through on the orbit. for （2） Among them, the angle difference of the near point Angle with near point The relationship between them is （3） Known target orbital eccentricity , mean near point angle difference Then, the difference in the near-point angle through which the point has turned can be obtained from equation (4). （4） The patrol range of the near-point angle specified by the task is also known. ,in, Indicates the minimum approximation angle of the parade area. This represents the maximum anomalous angle within the cruise area, and gives the anomalous angle that the maintenance spacecraft rotates through during the mission. for （5） The expected mean aperimeter angle difference of the maintenance spacecraft can then be obtained by solving equation (6). （6） Then we can know the expected mean angular velocity of the maintenance spacecraft. have （7） Finally, the expected radius of the low-orbit patrol segment can be calculated using equation (8). （8） The calculation process for the number of six track members in the high-rail patrol section is the same as above.

2. The track design method for on-orbit area cruising as described in claim 1, characterized in that, The optimization algorithm uses a genetic algorithm.

3. The track design method for on-orbit area cruising as described in claim 1, characterized in that, In step 4), the Lambert two-pulse control algorithm is used to calculate the velocity increment of the initial track change segment. Speed ​​increments in the second track change segment .

4. The track design method for on-orbit area cruising as described in claim 1, characterized in that, In step 5), the termination condition of the optimization algorithm is preset.

5. The track design method for on-orbit area cruising as described in claim 1, characterized in that, In step 5), the objective function is designed as follows: .

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