Optimization and adjustment method for inter-satellite separation near field safety

Abstract

An optimization adjustment method for inter-satellite separation near field safety comprises the steps that firstly, key engineering parameters are identified through fuzzy parameter identification so as to carry out early rigorous control, meanwhile, secondary fuzzy engineering parameters are removed, and initial engineering parameters for carrying out iterative optimization are determined; establishing the initial engineering parameters and the corresponding controlled deviation range in a dynamic simulation model by utilizing a Monte Carlo targeting method, carrying out dynamic simulation calculation of traversal combination by utilizing simulation software, obtaining the worst result of the near-field spacing under all working conditions, and if the safety requirement is not met, carrying out dynamic simulation calculation of traversal combination; and if not, adjusting the nominal value, the deviation and the nearest spacing layout and carrying out the next round of iteration until the requirements are met. According to the method, rapid identification and iterative optimization of the fuzzy engineering parameters are realized, computing resources, time cost and labor cost are saved, and the product development period is shortened.

Description

Technical Field

[0001] The present invention belongs to the field of spacecraft control, and relates to a near-field safety analysis method for inter-satellite separation of multiple spacecraft, and in particular to a near-field safety assessment and control method for inter-satellite separation under multi-fuzzy parameter constraints. Background Art

[0002] The intersatellite separation of multiple spacecraft is generally carried out through a connection and separation mechanism. After the connection device is unlocked, the separation spring provides separation energy to achieve the successful separation of the main satellite and the sub-satellite. During the separation process, if the protruding equipment, cables, multiple layers, etc. of the main satellite and the sub-satellite interfere with or hook each other in motion, it may cause the spacecraft to have an abnormal attitude or even cause the mission to fail. Affected by ground gravity, the multi-body motion of intersatellite separation in a microgravity environment cannot be accurately reproduced in ground tests, and it is impossible to judge the near-field separation safety under extreme conditions. Therefore, conducting near-field safety calculations for intersatellite separation during the mission design phase is a prerequisite for ensuring the success of the mission.

[0003] At present, the near-field safety analysis of intersatellite separation faces the following two major engineering challenges. On the one hand, there are many engineering parameters that may affect near-field safety, and each engineering parameter has a corresponding nominal value and deviation. The previous near-field simulation method only focused on parameter deviations, and the calculation strategy adopted ergodic calculations, which would cause the calculation scale to grow exponentially with the increase in the number of parameters. While paying a huge computational cost, it is impossible to quantitatively evaluate the rationality of the nominal values ​​of the engineering parameters. On the other hand, in the mission design stage, the nominal values ​​and deviations of the above engineering parameters are often vague, and there is a complex coupling effect between the engineering parameters on near-field safety, which makes designers feel powerless when iterating or optimizing design solutions. Summary of the invention

[0004] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art, to provide an intersatellite separation near-field safety optimization adjustment method integrating fuzzy parameter identification and Monte Carlo shooting, to achieve rapid identification and iterative optimization of fuzzy engineering parameters, to save computing resources, time cost and manpower cost, and to shorten the development cycle.

[0005] The technical solution of the present invention is: a method for optimizing and adjusting the near-field safety of inter-satellite separation, the steps are as follows:

[0006] (1) According to the design plan, establish a multi-body dynamics simulation model of multiple spacecraft with inter-satellite separation;

[0007] (2) List all engineering parameters that may affect the near-field safety of intersatellite separation, determine the nominal value and corresponding deviation range of each engineering parameter according to the design scheme, and further determine the minimum distance D of the motion process under the ideal state of the design scheme. min and separation safety expectation Dexp ;

[0008] (3) For all engineering parameters, only a single engineering parameter is selected as an adjustment item each time. While keeping the nominal values ​​of other engineering parameters except the adjustment item unchanged, the adjustment item is set to the extreme values ​​of the deviation in two directions through simulation to obtain the corresponding minimum inter-satellite spacing change. After calculating the minimum inter-satellite spacing change corresponding to all engineering parameters, the minimum inter-satellite spacing changes are sorted according to the numerical values ​​of the minimum inter-satellite spacing changes.

[0009] (4) According to the numerical sorting of the minimum inter-satellite spacing change, the key engineering parameters are screened out in combination with the minimum inter-satellite spacing change threshold, and the rest are secondary engineering parameters;

[0010] (5) For all engineering parameters, their nominal values ​​are taken, and the corresponding minimum inter-satellite spacing change Δd is obtained by simulation, and it is judged that Δd≤β(D min -D exp ) is established, if established, proceed to the next step, if not, readjust the nominal value of the key engineering parameters or the design scheme until Δd≤β(D min -D exp ) is established and then proceed to the next step, where β is the safety factor;

[0011] (6) For key engineering parameters, select their adjusted nominal values ​​and corresponding deviation ranges. For secondary engineering parameters, select their nominal values ​​as initial parameter settings for Monte Carlo target simulation. By traversing the upper and lower limit combinations of key engineering parameters, the minimum inter-satellite spacing change corresponding to each working condition is obtained, where the maximum value of the minimum inter-satellite spacing change is recorded as Δd max ;

[0012] (7) If Δd max ≤β(D min -D exp ), the design scheme and the nominal values ​​of each engineering parameter and the corresponding deviations meet the near-field safety requirements of intersatellite separation. Otherwise, the deviation ranges are adjusted in sequence according to the key engineering parameters until the adjusted Δd max Satisfies the requirements; if the final Δd max If the requirements are still not met, return to step (5) and readjust the nominal values ​​of key engineering parameters or the design scheme until Δd max Until the requirements are met.

[0013] Furthermore, the ideal state is that the intersatellite separation process only has a linear velocity along the theoretical separation direction.

[0014] Furthermore, the numerical sorting according to the minimum inter-satellite spacing change amount is combined with the minimum inter-satellite spacing change amount threshold to screen out the key engineering parameters, specifically: define the engineering parameter sensitivity S i , When S i When ≥α, the corresponding engineering parameter is the key engineering parameter; 1 , X 2 , X 3 …are all engineering parameters, and α is the given sensitivity threshold.

[0015] Preferably, the value of α is 5%, and the value of the safety factor β is 80%.

[0016] Furthermore, in step (5), the nominal value or design scheme of the key engineering parameters is readjusted by first adjusting the layout scheme to increase D min ; If the layout scheme is limited and the adjusted Δd still does not meet the requirements, the nominal values ​​of the key engineering parameters are adjusted. Specifically, the nominal values ​​are adjusted in order according to the ranking of the key engineering parameters. If Δd still does not meet the requirements after adjusting the nominal value of the first-ranked key engineering parameter, the nominal value of the next-ranked key engineering parameter is adjusted until the adjusted Δd meets the requirements.

[0017] Furthermore, the traversal simulation uses ADAMS software to calculate 2 n working conditions, n is the number of key engineering parameters.

[0018] The advantages of the present invention over the prior art are as follows: the present invention integrates fuzzy parameter identification and Monte Carlo shooting method, solves the intersatellite near-field separation safety optimization problem under the comprehensive effect of multiple fuzzy engineering parameters, firstly performs a single parameter deviation, then adjusts the parameter nominal value accordingly, and finally adjusts the parameter deviation, thereby realizing rapid identification and iterative optimization of fuzzy engineering parameters, saving manpower and material resources and shortening the development cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a flowchart of the method of the present invention;

[0020] Figure 2 A list of all engineering parameters that may affect the near-field safety of intersatellite separation in the embodiments of the present invention;

[0021] Figure 3 Schematic diagram of a multi-body dynamics simulation model of a primary satellite and a secondary satellite in an embodiment of the present invention;

[0022] Figure 4 A list of key engineering parameters identified by deviation sensitivity analysis in an embodiment of the present invention;

[0023] Figure 5 The minimum spacing of the separation process for the rationality analysis of the nominal value in the embodiment of the present invention;

[0024] Figure 6 This is the minimum spacing distribution of all working conditions in the Monte Carlo shooting analysis in the embodiment of the present invention. DETAILED DESCRIPTION

[0025] Aiming at the fuzzy characteristics of engineering parameters in the design stage, the present invention combines fuzzy parameter identification and Monte Carlo shooting method. First, through the fuzzy parameter identification method, the key engineering parameters are identified in the design stage in order to carry out preliminary tightening control, and at the same time, the minor fuzzy engineering parameters are eliminated to determine the initial engineering parameters for iterative optimization. Then, using the Monte Carlo shooting method, the initial engineering parameters and their corresponding deviation ranges after control are established in the dynamic simulation model, and the simulation software is used to carry out dynamic simulation calculations of traversal combinations to obtain the worst results of near-field spacing under all working conditions. If the safety requirements are not met, the nominal value, deviation and nearest spacing layout are adjusted and the next round of iteration is carried out.

[0026] The calculation process is attached. Figure 1 , the specific method is as follows:

[0027] (1) To establish a multi-body dynamics simulation model of multiple spacecraft (such as the main satellite and satellite), it is necessary to ensure that the mass characteristics of the spacecraft, the main modal frequencies of large flexible components (such as antennas and solar panels), the force and position of the separation spring, the force and position of the separation plug, and the layout of equipment near the inter-satellite separation surface (especially the equipment with the minimum spacing) are consistent with the design or implementation status.

[0028] (2) List all fuzzy engineering parameters that may affect near-field safety.

[0029] Determine the nominal value and corresponding deviation range of each engineering parameter according to the preliminary design plan Determine the minimum distance D of the ideal analytical motion process for the initial design solution min and separation safety expectation D exp (For example, D exp =20mm means that the minimum spacing in the near field of the separation process is not less than 20mm). Here, the ideal motion, i.e., the intersatellite separation process, only has a linear velocity along the theoretical separation direction.

[0030] Among them, there are m engineering parameters, and their nominal values ​​are X 1 ,X 2 ,...,X m , the superscript + sign indicates a positive deviation, a 1 ,b 1 ,c 1,... is the maximum allowable deviation value. Similarly, the subscript - indicates a negative deviation. 2 ,b 2 ,c 2 ,...is the maximum allowable deviation value. The above parameters are preliminarily set according to the spacecraft design and process capabilities.

[0031] (3) Identify key engineering parameters.

[0032] Select a single engineering parameter (such as X 1 ), while keeping the nominal values ​​of other engineering parameters unchanged, the positive and negative deviations of this single engineering parameter (such as +a 1 ,-a 2 ), and carry out the extreme deflection simulation calculation in the multi-body dynamics simulation software to obtain the minimum inter-satellite spacing change after the engineering parameter deflection (such as Δd X1 ). According to the above operation, the positive and negative deviations of all engineering parameters are calculated in turn to obtain the minimum inter-satellite spacing change Δd after the deviation of each engineering parameter. i ,i=X 1 ,X 2 ,X 3 ,...and sort their numerical values.

[0033] Define the engineering parameter sensitivity as When S i When α is greater than or equal to α (α is a given sensitivity threshold, and the recommended value is 5%), it is considered that this engineering parameter has a significant impact on the safety of near-field separation and is listed as a key engineering parameter (A 1 A 2 A 3 …)[n×1](sorted by the corresponding sensitivity values ​​from large to small). i <α, it is considered that this engineering parameter has an order of magnitude difference compared with the comprehensive influence of other engineering parameters and is listed as a secondary engineering parameter (B 1 B 2 B 3 …)[(mn)×1](sorted by the corresponding sensitivity values ​​from large to small). That is, the number of key engineering parameters is n, and the number of secondary engineering parameters is mn.

[0034] (4) Reasonable analysis of nominal values ​​of engineering parameters: All engineering parameters are set according to their nominal values ​​(H 1 H 2 H 3 …)[m×1], the minimum inter-satellite distance change Δd is calculated using multi-body dynamics simulation software. If Δd>β(D min -D exp)(β is the safety factor, the recommended value is 80%), then the nominal value and deviation of the engineering parameters of the design solution need to be adjusted.

[0035] According to the principle of starting with the easy and then the difficult, the engineering adjustment strategy is as follows: ① Make appropriate adjustments to the layout plan to increase D min ; If the layout scheme is limited and the adjusted Δd still does not meet the requirements, consider adjusting the nominal value of the design; ② Sort the key engineering parameters (sort from large to small according to the corresponding sensitivity values), and adjust the nominal values ​​of the parameters in turn. If Δd still does not meet the requirements after adjusting the nominal value of the first-ranked key engineering parameter, then adjust the nominal value of the next key engineering parameter until the adjusted Δd meets the requirements.

[0036] After the nominal value or layout scheme is adjusted, re-perform sensitivity analysis to determine the ranking of key engineering parameters of the new scheme (sort from large to small according to the corresponding sensitivity values).

[0037] (5) Monte Carlo calculation of key engineering parameter deviations.

[0038] It is assumed that the deviation range of key engineering parameters after adjustment is set in this Minor engineering parameters only use nominal values ​​(B 1 B 2 B 3 …)[(mn)×1], as the initial parameter setting for Monte Carlo target shooting simulation.

[0039] ADAMS software is used to perform traversal simulation calculations on the upper and lower limit combinations of key engineering parameters, which requires a total of 2 n Working conditions, obtain the minimum inter-satellite spacing change Δd corresponding to each working condition j ,j=1,...,2 n , and its maximum value is recorded as Δd max .

[0040] (6) If Δd max >β(D min -D exp ), the deviation range of key engineering parameters shall be adjusted in sequence according to their ranking. The adjustment shall be within the capabilities of design, process and operation. If the deviation range of the first key engineering parameter is adjusted, Δd max If the requirement is still not met, adjust the deviation range of the next key engineering parameter until the adjusted Δd max Satisfy the requirement, that is, Δd max ≤β(D min -D exp ).

[0041] If the final Δd maxIf the requirements are still not met, return to step (4) and adjust the layout plan or nominal value until Δd max Until the requirements are met.

[0042] Example

[0043] (1) The multi-body dynamics simulation model of the primary and secondary satellites was established using ADAMS software. Figure 3 .

[0044] (2) List all fuzzy engineering parameters that may affect near-field safety: (see Appendix Figure 2 , the number of parameters m = 21). The minimum distance of the ideal motion process of inter-satellite separation is D min =25mm, the expected value of separation safety is D exp =10mm.

[0045] (3) Sensitivity analysis of engineering parameter deviation: Keeping the nominal values ​​of other engineering parameters unchanged, the extreme tensile simulation calculation of the positive and negative deviations of a single engineering parameter was carried out in ADAMS software to determine n = 8 key engineering parameters, and the rest were minor engineering parameters (see Appendix Figure 4 ).

[0046] (4) Reasonable analysis of nominal values ​​of engineering parameters: All engineering parameters are set according to their nominal values. The simulation calculation results show that the change in the minimum distance between satellites is Δd = 3.5 mm (see Appendix Figure 5 ), satisfying Δd≤80%(D min -D exp )=12mm, no need to adjust the nominal values ​​and layout of key engineering parameters.

[0047] (5) Monte Carlo calculation of key engineering parameter deviations: The key engineering parameters are set with deviation ranges, and the secondary engineering parameters only use nominal values ​​as the initial parameter settings for Monte Carlo target shooting simulation. ADAMS software is used to perform traversal simulation calculations on the upper and lower limit combinations of key engineering parameters, and a total of 2 n = 256 working conditions, the maximum change of the minimum spacing under all working conditions is Δd max =5.6mm(see attached Figure 6 ), satisfying Δd max ≤80%(D min -D exp)=12mm, that is, the near-field safety of intersatellite separation for this mission meets the requirements. Therefore, according to the current layout plan and the control of separation-related engineering parameters, the near-field safety of intersatellite separation can be guaranteed. It should be pointed out that fuzzy parameter identification can quickly determine the engineering parameters that need to be adjusted first in the iterative plan, which is a feature that the previous Monte Carlo method does not have; secondly, when faced with calculation conditions with more engineering parameters, the previous Monte Carlo method requires huge computing resources and computing time, which is not conducive to solution iteration.

[0048] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A method for optimizing and adjusting near-field safety of inter-satellite separation, characterized in that: (1) According to the design plan, establish a multi-body dynamics simulation model of multiple spacecraft with inter-satellite separation; (2) List all engineering parameters that may affect the near-field safety of intersatellite separation, determine the nominal value and corresponding deviation range of each engineering parameter according to the design scheme, and further determine the minimum distance D of the motion process under the ideal state of the design scheme. min and separation safety expectation D exp ; (3) For all engineering parameters, only a single engineering parameter is selected as an adjustment item each time. While keeping the nominal values ​​of other engineering parameters except the adjustment item unchanged, the adjustment item is set to the extreme values ​​of the deviation in two directions through simulation to obtain the corresponding minimum inter-satellite spacing change. After calculating the minimum inter-satellite spacing change corresponding to all engineering parameters, the minimum inter-satellite spacing changes are sorted according to the numerical values ​​of the minimum inter-satellite spacing changes. (4) According to the numerical sorting of the minimum inter-satellite spacing change, the key engineering parameters are screened out in combination with the minimum inter-satellite spacing change threshold, and the rest are secondary engineering parameters; (5) For all engineering parameters, their nominal values ​​are taken, and the corresponding minimum inter-satellite spacing change Δd is obtained by simulation, and it is judged that Δd≤β(D min -D exp ) is established, if established, proceed to the next step, if not, readjust the nominal value of the key engineering parameters or the design scheme until Δd≤β(D min -D exp ) is established and then proceed to the next step, where β is the safety factor; (6) For key engineering parameters, select their adjusted nominal values ​​and corresponding deviation ranges. For secondary engineering parameters, select their nominal values ​​as initial parameter settings for Monte Carlo target simulation. By traversing the upper and lower limit combinations of key engineering parameters, the minimum inter-satellite spacing change corresponding to each working condition is obtained, where the maximum value of the minimum inter-satellite spacing change is recorded as Δd max ; (7) If Δd max ≤β(D min -D exp ), the design scheme and the nominal values ​​of each engineering parameter and the corresponding deviations meet the near-field safety requirements of intersatellite separation. Otherwise, the deviation ranges are adjusted in sequence according to the key engineering parameters until the adjusted Δd max Satisfies the requirements; if the final Δd max If the requirements are still not met, return to step (5) and readjust the nominal values ​​of key engineering parameters or the design scheme until Δd max Until the requirements are met.

2. The method for optimizing and adjusting near-field safety of inter-satellite separation according to claim 1, characterized in that: The ideal state is that the intersatellite separation process only has a linear velocity along the theoretical separation direction.

3. The method for optimizing and adjusting near-field safety of inter-satellite separation according to claim 1 is characterized in that: The above-mentioned numerical sorting based on the minimum inter-satellite spacing change amount and the minimum inter-satellite spacing change amount threshold are combined to screen out the key engineering parameters, specifically: define the engineering parameter sensitivity S i , When S i When ≥α, the corresponding engineering parameter is the key engineering parameter; X1, X2, X3… are all engineering parameters, and α is the given sensitivity threshold.

4. The method for optimizing and adjusting near-field safety of inter-satellite separation according to claim 3 is characterized in that: The value of α is 5%.

5. The method for optimizing and adjusting near-field safety of inter-satellite separation according to claim 1 is characterized by: The safety factor β is set to 80%.

6. The method for optimizing and adjusting near-field safety of inter-satellite separation according to claim 1 is characterized by: In the step (5), the nominal value or design scheme of the key engineering parameters is readjusted. The adjustment method is as follows: first, the layout scheme is adjusted to increase D min ; If the layout scheme is limited and the adjusted Δd still does not meet the requirements, the nominal values ​​of the key engineering parameters are adjusted. Specifically, the nominal values ​​are adjusted in order according to the ranking of the key engineering parameters. If Δd still does not meet the requirements after adjusting the nominal value of the first-ranked key engineering parameter, the nominal value of the next-ranked key engineering parameter is adjusted until the adjusted Δd meets the requirements.

7. The method for optimizing and adjusting near-field safety of inter-satellite separation according to claim 1 is characterized by: The traversal simulation uses ADAMS software to calculate 2 n working conditions, n is the number of key engineering parameters.

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