Autonomous decision-making method for multi-load space platform system considering plume avoidance

Abstract

This invention provides an autonomous decision-making method for a multi-payload space platform system that considers plume avoidance. Taking into account the uniform distribution of payloads within the space platform and the uncertainty of the ignition direction after payload release, the method effectively avoids collisions / interference with the space platform, such as a maneuvering aircraft, after payload release by optimizing the release selection. This method is particularly suitable for the rapid release of multiple payloads carried by a space platform.

Description

Technical Field

[0001] This invention belongs to the field of complex multi-payload satellite technology, and in particular relates to an autonomous decision-making method for multi-payload space platform systems that takes into account plume avoidance. Background Technology

[0002] Rapid payload release in space is a widely used spaceflight mission. In practice, considering the varying mission scenarios where space platforms carry multiple payloads, the maneuvering direction of the released payload has significant uncertainty. To ensure safe avoidance between the released payload and the space platform, three traditional modes are used: 1) Performing pre-release attitude maneuvers based on the direction of the individual payload's release thrust plume to ensure flight safety after release. This places excessive demands on the space platform's attitude maneuvering capabilities, is too costly, and is practically impossible in current spacecraft; 2) If the space platform does not perform pre-release attitude prediction for any released payload, the payload must undergo a collision and interference threat assessment with the space platform after release and perform avoidance maneuvers. This places high demands on the payload and significantly impacts its rendezvous time efficiency with highly time-sensitive targets; 3) Delaying the maneuvering time after the payload separates from the space platform, and implementing maneuvers only after establishing a sufficient safety distance. This mode limits the payload's timeliness, and the space platform system cannot meet the needs of certain time-sensitive missions. Summary of the Invention

[0003] To address the aforementioned issues, this invention provides an autonomous decision-making method for multi-payload space platform systems that considers plume avoidance. By optimizing the selection of release pods, it enables mutual safe avoidance between the payload and the space platform after release.

[0004] An autonomous decision-making method for a multi-payload space platform system considering plume avoidance includes the following steps:

[0005] Obtain the safe distance ΔL relative to the space platform that the payloads in each compartment can generate after release. m Each cabin has a preset avoidance angle, m = 1, 2, ..., N, where N represents the total number of cabins;

[0006] According to ΔL m The load in the corresponding cabin is released according to the set threshold value, where if there is a corresponding ΔL for the cabin... m If the value exceeds the set threshold, release ΔL. m The maximum value corresponds to the load in the compartment, if all ΔL m If none of the values ​​exceed a set threshold, the load in the compartment corresponding to the maximum avoidance angle will be released. The set threshold is the envelope dimension L of the space platform. b The sum of the distance ΔL between the maximum allowable load plume of the space platform and the space platform.

[0007] Furthermore, the avoidance angle θ corresponding to each cabin m The default method is:

[0008]

[0009]

[0010] in, This represents the motion direction vector of the m-th compartment relative to the space platform when the load in the m-th compartment is released in the initial state. Δv represents the pre-set ignition vector direction after load release, Δv represents the load release velocity relative to the space platform, and Δt represents the running time of the load after release relative to the initial release time.

[0011] Furthermore, the safe distance ΔL that the payload can generate relative to the space platform after release. m The calculation method is as follows:

[0012]

[0013] Furthermore, the lower limit Δt of the running time Δt after load release relative to the initial release time. min The method for determining it is as follows:

[0014]

[0015] Where, θ admin，max The cone angle of the conical region is the maximum allowable safe avoidance after load release, and θ admin，max The calculation method is as follows:

[0016]

[0017] Where, φ max This represents the attitude maneuvering angle of the space platform before load release.

[0018] Furthermore, before releasing the load in the compartment corresponding to the maximum avoidance angle, the preset attitude of the space platform needs to be adjusted. The adjustment method is as follows:

[0019]

[0020]

[0021] Where Δφ represents the magnitude of the attitude maneuver angle that the space platform needs to preset. This represents the motion direction vector of the k-th compartment relative to the space platform when the payload in the currently released compartment is released, where k is the compartment number corresponding to the maximum avoidance angle. This indicates the ignition vector direction after the pre-set load release. θ represents the direction of the rotation axis vector when the space platform performs attitude maneuvers. admin，max The cone angle of the cone-shaped region is the maximum permissible safe avoidance after load release.

[0022] Beneficial effects:

[0023] 1. This invention provides an autonomous decision-making method for a multi-payload space platform system that considers plume avoidance. Taking into account the uniform distribution of payloads within the space platform and the uncertainty of the ignition direction after payload release, the method effectively avoids collisions / interference with the space platform, such as a maneuvering aircraft, after payload release by optimizing the release selection. This method is particularly suitable for the rapid release of multiple payloads carried by a space platform.

[0024] 2. This invention provides an autonomous decision-making method for a multi-load space platform system that considers plume avoidance. It determines the available release bays based on the ignition vector direction of the release load and the attitude of the space platform, and provides the avoidance angle θ corresponding to each bay. m Safety distance ΔL m And the minimum permissible ignition time Δt to meet safety avoidance requirements min The method for determining this provides effective guidance for how space platforms can quickly release multiple loads they carry.

[0025] 3. This invention provides an autonomous decision-making method for a multi-payload space platform system that considers plume avoidance, when all cabins do not satisfy ΔL. m >ΔL+L b At that time, that is, the safe distance ΔL that the load can generate relative to the space platform after release. m When the distance ΔL between the load plume and the space platform is less than the maximum allowable load plume distance ΔL, only the load in the compartment corresponding to the maximum avoidance angle can be released. At this time, there is still a risk of mutual interference between the load and the space platform. Therefore, before releasing the load in the compartment corresponding to the maximum avoidance angle, the present invention adjusts the preset attitude of the space platform according to the set rules, which can effectively avoid the collision / interference problem between the load and the space platform after release, and ensure that the load can be released quickly and safely. Attached Figure Description

[0026] Figure 1 A flowchart of an autonomous decision-making method for a multi-payload space platform system considering plume avoidance is provided for this invention;

[0027] Figure 2 Schematic diagram of four uniformly distributed loads;

[0028] Figure 3 This is a schematic diagram of five uniformly distributed loads. Detailed Implementation

[0029] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0030] This invention relates to a multi-payload space platform, which carries multiple payloads embedded within it. After the payloads are released in orbit, the propulsion system needs to be activated to complete the corresponding tasks. The space platform optimizes the payload release location based on the payload's flight plan after release, ensuring mutual safety between the space platform and the payloads without requiring specific avoidance measures for collisions and thrust plume interference.

[0031] Specifically, such as Figure 1 As shown, an autonomous decision-making method for a multi-payload space platform system considering plume avoidance includes the following steps:

[0032] S1: Obtain the safe distance ΔL relative to the space platform that the payloads in each compartment inside the space platform can generate after release. m Each cabin class corresponds to a preset avoidance angle, m = 1, 2, ..., N, where N represents the total number of cabins; for example... Figure 2 and Figure 3 The diagram shows the layout of multiple loads evenly distributed inside the space platform, which can be defined as load 1, load 2, and load N. It should be noted that the ignition of the loads after release will cause disturbance and heat flow impact on the space platform, so a certain safe avoidance distance must be maintained between them.

[0033] It should be noted that the safe avoidance zone after load release can be characterized by a conical region with the release position vector of each load chamber as the axis and the corresponding half-cone angle θ. The safe avoidance zone is defined by θ. admin This indicates that the initial operating attitude of the space platform is known, and the ignition attitude direction of the released payload after release is known.

[0034] Furthermore, the avoidance angle θ corresponding to each cabin m The default method is:

[0035]

[0036]

[0037] Among them, the avoidance angle θ m This represents the avoidance angle corresponding to the vector direction of the m-th compartment relative to the space platform when releasing the load, under the pre-known release load ignition vector direction. This represents the motion direction vector of the m-th compartment relative to the space platform when the load in the m-th compartment is released in the initial state. It can be represented in the corresponding coordinate system according to the actual mission requirements. The vector direction is determined by the layout of the space platform and the flight attitude. This parameter can be obtained from the attitude measurement unit of a traditional aircraft. The ignition vector direction after payload release is pre-defined and can be represented in the corresponding coordinate system according to actual mission requirements. This parameter is determined by the flight mission after payload release and is obtained from the payload control unit. Δv represents the release velocity of the payload relative to the space platform, which is determined by the design state of the space platform and is used as an input parameter in this invention. Δt represents the running time of the payload relative to the initial release time, which is determined by the space platform and the release mission and is used as an input parameter in this invention. The lower limit of the running time Δt is Δt. min That is, the minimum permissible ignition time Δt to meet the safety avoidance requirements. min The method for determining it is as follows:

[0038]

[0039] Where, θ admin，max Let be the cone angle of the maximum allowable safe avoidance cone region after load release, which is also the optimal decision angle that the maximum safe avoidance region satisfies based on attitude maneuverability. Its calculation method is as follows:

[0040]

[0041] Where, φ max The attitude maneuvering angle of the space platform before load release is used to characterize the attitude maneuvering capability of the space platform before load release.

[0042] In addition, the safe distance ΔL relative to the space platform that the load can generate after release m The calculation method is as follows:

[0043]

[0044] S2: According to ΔL m The load in the corresponding cabin is released according to the set threshold value, where if there is a corresponding ΔL for the cabin... m If the value exceeds the set threshold, release ΔL. m The maximum value corresponds to the load in the compartment, if all ΔL m If none of the values ​​exceed a set threshold, the load in the compartment corresponding to the maximum avoidance angle will be released. The set threshold is the envelope dimension L of the space platform. b The sum of the distance ΔL between the maximum allowable load plume of the space platform and the space platform (L) b +ΔL).

[0045] In other words, there are two scenarios regarding the safety and optimal selection of release berths.

[0046] Scenario 1: There are cabins that satisfy ΔL m >ΔL+L b The preferred release compartment is determined by the following formula:

[0047] flag = k, where ΔL k =max(ΔL1,ΔL2,…,ΔL) N )

[0048] Here, flag represents the preferred cabin identifier, which is pre-numbered 1, 2, ..., N, where k is ΔL. m The maximum value corresponds to the cabin number.

[0049] Scenario 2: If none of the cabins meet ΔL m >ΔL+L b The preferred release compartment is determined by the following formula:

[0050] flag = k, where θ k =max(θ1,θ2,...,θ) N )

[0051] Here, flag represents the preferred cabin identifier, which is pre-numbered 1, 2, ..., N, and k is the cabin number corresponding to the maximum avoidance angle.

[0052] It should be noted that if none of the cabins meet ΔL m When the value is greater than ΔL, after selecting the compartment to be released, it is also necessary to determine the pre-set attitude of the space platform before the load is released, based on the preferred compartment and the avoidance angle of the maneuvering ignition of the released load. In other words, before releasing the load in the compartment corresponding to the maximum avoidance angle, the pre-set attitude of the space platform needs to be adjusted. The adjustment method is as follows:

[0053]

[0054]

[0055] Where Δφ represents the magnitude of the attitude maneuver angle that the space platform needs to preset. This represents the motion direction vector of the k-th compartment relative to the space platform when the payload in the currently released compartment is released, where k is the compartment number corresponding to the maximum avoidance angle. This indicates the ignition vector direction after the pre-set load release. θ represents the direction of the rotation axis vector when the space platform performs attitude maneuvers. admin，max The cone angle of the cone-shaped region is the maximum permissible safe avoidance after load release.

[0056] The following example uses a space platform carrying five payloads evenly distributed to analyze the optimal selection of payload release compartments under typical conditions using the method of this invention. The relevant parameters for the example are as follows: the allowable safe size of the payload plume on the space platform is 10m; the envelope size of the space platform body is 10m; the relative speed of the payloads after release is 4m / s; and the attitude maneuverability angle of the platform before payload release is 10°.

[0057] The release unit vector of each module during the release of the space platform is represented in this system as:

[0058] numerical values Release Capsule 1 Release Unit Vector (0,1,0) Release pod 2 release unit vector (-0.95,0.31,0) Release Capsule 3 Release Unit Vector (-0.59,-0.81,0) Release pod 4 release unit vector (0.59,-0.81,0) Release Capsule 5 Release Unit Vector (0.95,0.31,0)

[0059] Example 1: The unit vector of the attitude direction during a load release attitude maneuver is represented in the space platform constitutive framework as:

[0060] numerical values Release load 1 attitude maneuver vector (0.82,0.57,0.09)

[0061] Step 1: Calculate the maximum permissible safe avoidance area for separation that meets the requirements of optimal decision-making and attitude maneuvering:

[0062] N is set to 5, and φ max =10° Substitute We can obtain:

[0063] θ admin，max =82°

[0064] Step 2: Quantitative analysis of the minimum ignition time that can be safely avoided under the conditions of the mission:

[0065] θ admin，max Substituting 82° into the safety avoidance angle θ admin，max The plume safety protection dimension ΔL of the space platform and the spacecraft body dimension L b The relative velocity Δv after load release and the minimum allowable ignition time Δt after release. min Relationship We can obtain:

[0066] Δt min =5.05s

[0067] Step 3: Determine the available release bays based on the ignition vector direction of the released load and the attitude of the space platform. Based on the analysis results of Step 2, the post-release load maneuver time Δt is selected as 6s.

[0068] The safety calculation results of releasing load 1 relative to each compartment are shown in the table below:

[0069]

[0070]

[0071] Given flag = k, where ΔL k =max(ΔL1,ΔL2,…,ΔL) N As can be seen, using compartment 4 to release the load meets the safety avoidance requirements.

[0072] Example 2: The unit vector of the attitude direction during a load release attitude maneuver is represented in the space platform constitutive framework as:

[0073] numerical values Release load 2 attitude maneuver vector (0.14,0.99,0)

[0074] Steps 1 and 2 are the same as the above implementation example.

[0075] Step 3: Determine the available release bays based on the ignition vector direction of the released load and the attitude of the space platform. Based on the analysis results of Step 2, the post-release load maneuver time Δt is selected as 6s.

[0076] The safety calculation results of releasing load 2 relative to each compartment are shown in the table below:

[0077] Ignition avoidance angle / ° Ignition safety distance / m Capsule 1 releases load 2 <![CDATA[θ1=8.05]]> <![CDATA[L1=3.36]]> Capsule 2 release load 2 <![CDATA[θ2=79.98]]> <![CDATA[L2=23.63]]> Capsule 3 releases load 2 <![CDATA[θ3=28.02]]> <![CDATA[L3=11.27]]> Capsule 4 releases load 2 <![CDATA[θ4=44.12]]> <![CDATA[L4=16.71]]> Capsule 5 releases load 2 <![CDATA[θ5=63.88]]> <![CDATA[L5=21.55]]>

[0078] Given flag = k, where θ k =max(θ1,θ2,...,θ) N As can be seen, the need to avoid using cabin 2 for release is relatively small.

[0079] Step 4: Research on pre-set evasion maneuver strategies.

[0080] The preset attitude angle for cabin 2 is 2.02°.

[0081] Preset attitude maneuvering roll direction The projection of our system on the space platform is (0,0,-0.98).

[0082] Therefore, this invention provides a method for quantitative analysis of plume avoidance areas for multi-load space platforms and an optimization method for selecting safe avoidance release cabins based on the direction of thrust after release. Considering the uniform distribution of loads inside space maneuvering vehicles, the collision / interference problem between loads and the space platform after release can be effectively avoided through optimized selection of load release. This method can be used for the rapid release of multiple loads carried by a space platform.

[0083] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A method for autonomous decision making of a multi-payload space platform system considering plume avoidance, characterized in that, The method comprises the following steps: The safe distance ΔL of the load in each cabin of the space platform relative to the space platform after release m , and each cabin corresponds to a preset avoidance angle, m = 1, 2, …, N, N represents the total number of cabins According to ΔL m The load in the corresponding compartment is released based on the value of the set threshold, where if there is a corresponding ΔL for the compartment... m If the value exceeds the set threshold, release ΔL. m The maximum value corresponds to the load in the compartment, if all ΔL m If none of the values ​​exceed a set threshold, the load in the compartment corresponding to the maximum avoidance angle will be released. The set threshold is the envelope dimension L of the space platform. b The sum of the distance ΔL between the maximum allowable load plume and the space platform.

2. The autonomous decision-making method for a multi-payload space platform system considering plume avoidance according to claim 1, wherein, The avoidance angle θ corresponding to each cabin m The preset method is: in, This represents the motion direction vector of the m-th compartment relative to the space platform when the load in the m-th compartment is released in the initial state. Δv represents the pre-set ignition vector direction after load release, Δv represents the load release velocity relative to the space platform, and Δt represents the running time of the load after release relative to the initial release time.

3. The autonomous decision-making method for a multi-payload space platform system considering plume avoidance according to claim 2, wherein, The safe distance ΔL that the load can generate relative to the space platform after release m The calculation method is as follows:

4. The autonomous decision making method for multi-payload space platform system considering plume avoidance of claim 2, wherein, Lower limit Δt of the running time Δt with respect to the initial release time point after the load release min The determination method is that: Where, θ admin，max The cone angle of the conical region is the maximum allowable safe avoidance after load release, and θ admin，max The calculation method is as follows: where φ max is the attitude maneuver angle of the space platform before the payload release.

5. A method for autonomous decision making for a multi-payload space platform system considering plume avoidance according to any one of claims 1 to 4, characterized in that, Before releasing the load in the cabin corresponding to the maximum value of the avoidance angle, the preset posture of the space platform needs to be adjusted, and the adjustment method is: Where Δφ represents the magnitude of the attitude maneuver angle that the space platform needs to preset. This represents the motion direction vector of the k-th compartment relative to the space platform when the payload in the currently released compartment is released, where k is the compartment number corresponding to the maximum avoidance angle. This indicates the ignition vector direction after the pre-set load release. θ represents the direction of the rotation axis vector when the space platform performs attitude maneuvers. admin，max The cone angle of the cone-shaped region is the maximum permissible safe avoidance after load release.

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