Method for designing state of self-tandem connection of small high-orbit satellites

Abstract

The present invention provides a method for the self-series design state of small high-orbit satellites, for the self-series design state of a small high-orbit satellite common platform, or for the self-series design state of a deep space exploration spacecraft. The method includes: establishing a fundamental frequency theoretical analysis model based on the series cantilever beam theory and the Rayleigh-Ritz theory; obtaining the preliminary stiffness ratio of the two satellites; assuming that the upper satellite is a pure rigid body, obtaining the first-order fundamental frequency of the lower satellite and the first-order fundamental frequency of the upper satellite based on the preliminary stiffness ratio of the two satellites; combining the inter-satellite stiffness matrix to obtain the first-order fundamental frequency index distribution of the two satellites and the first-order fundamental frequency of the series-connected two satellites. The present invention effectively decomposes the fundamental frequency requirements of the two-satellite assembly into the fundamental frequency requirements of a single satellite, ensuring the technical effects of clear single-satellite design boundaries, reasonable overall design resource allocation, accurate optimization design direction, and a clear fault handling interface. During the satellite development process, the present invention effectively decomposes the indicators through top-level design to achieve optimization and control of the dynamic characteristics of the entire satellite.

Description

Technical Field

[0001] The present invention relates to the field of satellite launch technology, and in particular to a method for designing a self-tandem connection state of a small high-orbit satellite. Background Art

[0002] To reduce launch costs and fully utilize payload capacity, launching two medium-to-large platform satellites in medium-to-high orbits in a tandem configuration is a common method used for international commercial satellite launches. Successful examples of tandem dual-satellite launchers include Ariane's SPELDA (external support structure) and SYLDA (internal support structure), as well as my country's CZ-3A series' external support structure for launching the Beidou navigation satellites. Furthermore, given the significant payload capacity consumed by both the internal and external support structures, the dual-satellite self-tandem launch method has become a popular method for launching deep space exploration spacecraft. All-electric propulsion satellites, such as the Boeing 702SP, also utilize this launch method.

[0003] A tandem dual-satellite system can be considered as a whole to meet the mechanical requirements of the launch process. The most fundamental and critical requirement is the first-order fundamental frequency requirements for both the lateral and longitudinal directions of the dual-satellite system. However, the development of a tandem dual-satellite system presents more challenges than a single-satellite launch. This primarily involves effectively decomposing the fundamental frequency requirements of the dual-satellite system into those of a single satellite, ensuring clear design boundaries for the individual satellites, rational allocation of overall design resources, accurate optimization direction, and a clear interface for troubleshooting. During satellite development, effectively decomposing these indicators through top-level design to optimize and control the dynamic characteristics of the entire satellite has been a pressing technical challenge. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for the self-series design state of small high-orbit satellites, so as to solve the problem that the existing fundamental frequency requirements of a binary satellite combination cannot be effectively decomposed into the fundamental frequency requirements of a single satellite.

[0005] To solve the above technical problems, the present invention provides a method for a self-series design state of a small high-orbit satellite, a self-series design state of a small high-orbit satellite common platform, or a self-series design state of a deep space exploration spacecraft, the method comprising:

[0006] According to the series cantilever beam theory and Rayleigh-Ritz theory, a fundamental frequency theoretical analysis model is established;

[0007] Obtain the initial stiffness ratio of the binary star;

[0008] Assuming that the upper satellite is a pure rigid body, the first-order fundamental frequency of the lower satellite and the first-order fundamental frequency of the upper satellite are obtained according to the preliminary stiffness ratio of the two satellites;

[0009] Combined with the inter-satellite stiffness matrix, the first-order fundamental frequency index distribution of the binary satellites and the first-order fundamental frequency of the tandem binary satellites are obtained.

[0010] Optionally, the method for designing a self-tandem connection state of a small high-orbit satellite further includes:

[0011] The first step includes establishing a fundamental frequency theoretical analysis model using series cantilever beam theory and Rayleigh-Ritz theory under the constraints of the carrier on the fundamental frequency, mass and size envelope.

[0012] Optionally, the method for designing a self-tandem connection state of a small high-orbit satellite further includes:

[0013] The second step includes adjusting the mass ratio of the binary stars and the size ratio of the binary stars to determine the preliminary stiffness ratio of the binary stars.

[0014] Optionally, the method for designing a self-tandem connection state of a small high-orbit satellite further includes:

[0015] The third step includes calculating the first-order fundamental frequency requirement of the lower satellite by considering the mass characteristics of the upper satellite and not considering the stiffness of the upper satellite, and estimating the first-order fundamental frequency requirement of the upper satellite according to the preliminary stiffness ratio of the dual satellites.

[0016] Optionally, the method for designing a self-tandem connection state of a small high-orbit satellite further includes:

[0017] The fourth step includes establishing an inter-satellite point connection finite element model, calculating and obtaining an equivalent stiffness matrix of the inter-satellite point connection finite element model, and substituting the equivalent stiffness matrix into the dual-satellite finite element model to obtain a calculated value of the self-series first-order fundamental frequency.

[0018] Optionally, the method for designing a self-tandem connection state of a small high-orbit satellite further includes:

[0019] Compare the calculated value of the first-order fundamental frequency of the self-tandem system with the transport requirements. If the transport requirements are not met, repeat steps 2 to 4. If the transport requirements are met, the self-tandem binary satellite fundamental frequency decomposition is completed.

[0020] Optionally, in the method for designing a self-tandem connection state of small high-orbit satellites, the stiffness ratio, mass ratio, and size ratio between the two satellites are determined in two stages, including:

[0021] Taking the second step as the first stage, the mass ratio and size ratio between the two satellites are used to improve the first-order fundamental frequency of the binary series connection, so as to preliminarily determine the stiffness ratio parameters;

[0022] Taking the fourth step as the second stage, after verifying that the stiffness ratio is reasonable and meets the carrier's requirements for the first-order fundamental frequency of the self-series binary star, fine-tuning is carried out with the goal of optimizing the mass ratio and size ratio of the binary star to optimize the mass and size envelope of the entire star.

[0023] Optionally, in the method for designing a self-tandem connection state of a small high-orbit satellite, determining the first-order fundamental frequency index of the dual satellites is implemented in two stages, including:

[0024] Taking the third step as the first stage, the preliminary first-order fundamental frequency of the lower satellite is obtained based on the pure rigid body assumption of the upper satellite, and the preliminary first-order fundamental frequency of the upper satellite is obtained by preliminarily determining the stiffness ratio parameter;

[0025] Taking the fourth step as the second stage, after the binary satellites are designed according to the preliminary first-order fundamental frequency and the finite element model is established, the inter-satellite connection stiffness matrix is ​​introduced to establish the binary satellite self-series finite element model. Under the premise of meeting the carrier's requirements for the first-order fundamental frequency of the self-series binary satellites, the first-order fundamental frequency of the binary satellites can be fine-tuned to obtain the first-order fundamental frequency index of the binary satellites.

[0026] In the method for the self-series design state of small high-orbit satellites provided by the present invention, a fundamental frequency theoretical analysis model is established based on the series cantilever beam theory and the Rayleigh-Ritz theory; the preliminary stiffness ratio of the two satellites is obtained; assuming that the upper satellite is a pure rigid body, the first-order fundamental frequency of the lower satellite and the first-order fundamental frequency of the upper satellite are obtained based on the preliminary stiffness ratio of the two satellites; combined with the inter-satellite stiffness matrix, the first-order fundamental frequency index distribution of the two satellites and the first-order fundamental frequency of the series-connected two satellites are obtained, effectively decomposing the fundamental frequency requirements of the two-satellite combination into the fundamental frequency requirements of a single satellite, ensuring the technical effects of clear single-satellite design boundaries, reasonable overall design resource allocation, accurate optimization design direction, and a clear fault handling interface. During the satellite development process, the present invention effectively decomposes the indicators through top-level design to achieve optimization and control of the dynamic characteristics of the entire satellite.

[0027] The method for the self-series connection design state of small high-orbit satellites disclosed in the present invention is applicable to the self-series connection design state of small high-orbit satellite public platforms, and is also applicable to the self-series connection design state of deep space exploration spacecraft. It has strong engineering applicability, can effectively reduce the risk of repeated self-series connection dual-satellite designs, improve the satellite carrying ratio, and reduce the time cost of satellite development. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of a method for self-tandem design of small high-orbit satellites according to an embodiment of the present invention. DETAILED DESCRIPTION

[0029] The following describes in further detail the method for self-tandem design of small high-orbit satellites proposed by the present invention, in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description and claims. It should be noted that the drawings are highly simplified and not to exact scale, and are intended solely to facilitate and clarify the purpose of illustrating the embodiments of the present invention.

[0030] In addition, unless otherwise stated, features in different embodiments of the present invention may be combined with each other. For example, a feature in the second embodiment may be substituted for a corresponding feature in the first embodiment having the same or similar function, and the resulting embodiment will also fall within the scope of disclosure or description of this application.

[0031] The core idea of ​​the present invention is to provide a method for the self-tandem design state of small high-orbit satellites to solve the existing problem that the fundamental frequency requirements of a binary satellite combination cannot be effectively decomposed into the fundamental frequency requirements of a single satellite.

[0032] To achieve the above-mentioned concept, the present invention provides a method for the self-series design state of small high-orbit satellites, comprising: establishing a fundamental frequency theoretical analysis model based on the series cantilever beam theory and the Rayleigh-Ritz theory; obtaining a preliminary stiffness ratio of the two satellites; assuming that the upper satellite is a pure rigid body, obtaining the first-order fundamental frequency of the lower satellite and the first-order fundamental frequency of the upper satellite based on the preliminary stiffness ratio of the two satellites; and obtaining the first-order fundamental frequency index distribution of the two satellites and the first-order fundamental frequency of the series-connected two satellites in combination with the inter-satellite stiffness matrix.

[0033] This embodiment provides a method for designing the state of a self-series connection of small high-orbit satellites, including: establishing a fundamental frequency theoretical analysis model based on the series cantilever beam theory and the Rayleigh-Ritz theory; obtaining a preliminary stiffness ratio of two satellites; assuming that the upper satellite is a pure rigid body, obtaining the first-order fundamental frequency of the lower satellite and the first-order fundamental frequency of the upper satellite based on the preliminary stiffness ratio of the two satellites; and obtaining a first-order fundamental frequency index allocation of the two satellites and the first-order fundamental frequency of the series connection of the two satellites in combination with the inter-satellite stiffness matrix.

[0034] In one embodiment of the present invention, the method for the self-serial design state of a small high-orbit satellite also includes: performing the first step, which includes establishing a fundamental frequency theoretical analysis model using the serial cantilever beam theory and the Rayleigh-Ritz theory under the constraints of the carrier on the fundamental frequency, mass and size envelope.

[0035] In one embodiment of the present invention, the method for the self-serial design state of small high-orbit satellites further includes: performing a second step, which includes adjusting the mass ratio and size ratio of the binary stars to determine the initial stiffness ratio of the binary stars.

[0036] In one embodiment of the present invention, the method for the self-serial design state of a small high-orbit satellite further includes: performing a third step, wherein the third step includes calculating the first-order fundamental frequency requirement of the lower satellite while considering the mass characteristics of the upper satellite and not considering the stiffness of the upper satellite, and estimating the first-order fundamental frequency requirement of the upper satellite based on the preliminary stiffness ratio of the dual satellites.

[0037] In one embodiment of the present invention, the method for the self-series connection design state of a small high-orbit satellite further includes: performing a fourth step, wherein the fourth step includes establishing an inter-satellite point connection finite element model, calculating and obtaining an equivalent stiffness matrix of the inter-satellite point connection finite element model, and substituting the equivalent stiffness matrix into the dual-satellite finite element model to obtain a calculated value of the first-order fundamental frequency of the self-series connection.

[0038] In one embodiment of the present invention, the method for the self-series connection design state of a small high-orbit satellite further includes: comparing the calculated value of the self-series first-order fundamental frequency with the carrying requirements. If the carrying requirements are not met, repeating the second to fourth steps; if the carrying requirements are met, completing the self-series dual-satellite fundamental frequency decomposition.

[0039] In one embodiment of the present invention, in the method for the self-series connection design state of small high-orbit satellites, the stiffness ratio, mass ratio, and size ratio between the two satellites are determined in two stages, including: the second step is the first stage, and the mass ratio and size ratio between the two satellites are used to improve the first-order fundamental frequency of the two satellites in series, thereby preliminarily determining the stiffness ratio parameters; the fourth step is the second stage, and after verifying that the stiffness ratio is reasonable and meets the carrier's requirements for the first-order fundamental frequency of the self-series two satellites, fine-tuning is performed with the goal of optimizing the mass ratio and size ratio of the two satellites to optimize the mass and size envelope of the entire satellite.

[0040] In one embodiment of the present invention, in the method for the self-series connection design state of small high-orbit satellites, the determination of the first-order fundamental frequency index of the dual satellites is implemented in two stages, including: the third step is the first stage, the preliminary first-order fundamental frequency of the lower satellite is obtained based on the pure rigid body assumption of the upper satellite, and the preliminary first-order fundamental frequency of the upper satellite is obtained with the initial stiffness ratio parameter; the fourth step is the second stage, after the dual satellites are designed according to the preliminary first-order fundamental frequency and a finite element model is established, the inter-satellite connection stiffness matrix is ​​introduced to establish a dual-satellite self-series connection finite element model, and the first-order fundamental frequency index of the dual satellite is obtained by fine-tuning the first-order fundamental frequency of the dual satellites while meeting the carrier's requirements for the self-series dual satellite first-order fundamental frequency.

[0041] In the method for the self-series design state of small high-orbit satellites provided by the present invention, a fundamental frequency theoretical analysis model is established based on the series cantilever beam theory and the Rayleigh-Ritz theory; the preliminary stiffness ratio of the two satellites is obtained; assuming that the upper satellite is a pure rigid body, the first-order fundamental frequency of the lower satellite and the first-order fundamental frequency of the upper satellite are obtained based on the preliminary stiffness ratio of the two satellites; combined with the inter-satellite stiffness matrix, the first-order fundamental frequency index distribution of the two satellites and the first-order fundamental frequency of the series-connected two satellites are obtained, effectively decomposing the fundamental frequency requirements of the two-satellite combination into the fundamental frequency requirements of a single satellite, ensuring the technical effects of clear single-satellite design boundaries, reasonable overall design resource allocation, accurate optimization design direction, and a clear fault handling interface. During the satellite development process, the present invention effectively decomposes the indicators through top-level design to achieve optimization and control of the dynamic characteristics of the entire satellite.

[0042] The method for the self-series connection design state of small high-orbit satellites disclosed in the present invention is applicable to the self-series connection design state of small high-orbit satellite public platforms, and is also applicable to the self-series connection design state of deep space exploration spacecraft. It has strong engineering applicability, can effectively reduce the risk of repeated self-series connection dual-satellite designs, improve the satellite carrying ratio, and reduce the time cost of satellite development.

[0043] The method for the self-series connection design state of small high-orbit satellites provided by the present invention is aimed at small geostationary orbit satellites that use a small high-orbit satellite public platform. The mass requirement for the self-series connection of the two satellites is no more than 5400 kg, the first-order fundamental frequency requirement for the self-series connection of the two satellites is no less than 10 Hz, and the longitudinal dimension envelope requirement is no more than 4.8 meters.

[0044] Combined with the preliminary design of the binary satellite, under the constraints of the carrier on the fundamental frequency, mass and size envelope, the estimated values ​​of the equivalent parameters are used as the design input of the series cantilever beam. The series cantilever beam theory and the Rayleigh-Ritz theory are used to establish a fundamental frequency theoretical analysis model, thereby calculating the first-order fundamental frequency of the system, that is, the characteristics of the first-order fundamental frequency of the series cantilever beam as it changes with the stiffness ratio, mass ratio and size ratio of the series beam.

[0045] The mass ratio and size ratio between the two satellites are used to improve the first-order fundamental frequency of the binary star series connection. Part of the mass of the intersatellite segment is allocated to the two satellites. The mass ratio and size ratio between the two satellites are initially set to 1.25 and 1 respectively. Considering the error of 15%, the stiffness ratio parameter is initially set to 1.6.

[0046] Under the constraint that the first-order lateral fundamental frequency of the self-series binary satellite is not less than 10 Hz, the preliminary first-order fundamental frequency of the lower satellite is obtained to be 46 Hz based on the pure rigid body assumption of the upper satellite, and the preliminary first-order fundamental frequency of the upper satellite is obtained to be 29 Hz based on the initial stiffness ratio parameter.

[0047] The dual satellites were designed and modeled using 46Hz and 29Hz as their first-order fundamental frequencies, respectively. A finite element model of the intersatellite point-to-point connection was established and analyzed to obtain the intersatellite connection stiffness matrix. This stiffness matrix was then incorporated into the finite element model of the dual satellite self-tandem connection. While meeting the carrier's first-order fundamental frequency requirements for the self-tandem connection, the finite element model was used to optimize the mass and size envelope of the entire satellite by optimizing the dual satellite mass ratio and size ratio.

[0048] In summary, the above embodiments describe in detail different configurations of methods for the self-tandem design of small high-orbit satellites. Of course, the present invention includes, but is not limited to, the configurations listed in the above embodiments. Any variations based on the configurations provided in the above embodiments fall within the scope of protection of the present invention. Those skilled in the art can draw inferences from the above embodiments.

[0049] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0050] The above description is only a description of the preferred embodiments of the present invention and does not limit the scope of the present invention. Any changes and modifications made by ordinary technicians in the field of the present invention based on the above disclosure shall fall within the scope of protection of the claims.

Claims

1. A method for designing a self-tandem connection state of a small high-orbit satellite, characterized in that: The method is used for a self-series design state of a small high-orbit satellite common platform, or for a self-series design state of a deep space exploration spacecraft, and includes: Step 1: Based on the series cantilever beam theory and Rayleigh-Ritz theory, a fundamental frequency theoretical analysis model is established; Step 2: Obtain the initial stiffness ratio of the binary star; Step 3: Assuming the upper satellite is a pure rigid body, the first-order fundamental frequency of the lower satellite and the first-order fundamental frequency of the upper satellite are obtained according to the preliminary stiffness ratio of the two satellites. This includes taking into account the mass characteristics of the upper satellite and ignoring the stiffness of the upper satellite, calculating the first-order fundamental frequency requirement of the lower satellite, and estimating the first-order fundamental frequency requirement of the upper satellite based on the preliminary stiffness ratio of the two satellites. Step 4: Combine the intersatellite stiffness matrix to obtain the first-order fundamental frequency index distribution of the two satellites and the first-order fundamental frequency of the series-connected two satellites. This involves establishing a finite element model of intersatellite point connections, calculating the equivalent stiffness matrix of the intersatellite point connection finite element model, and substituting the equivalent stiffness matrix into the two-satellite finite element model to obtain the calculated value of the self-series first-order fundamental frequency. Taking the third step as the first stage, the preliminary first-order fundamental frequency of the lower satellite is obtained based on the pure rigid body assumption of the upper satellite, and the preliminary first-order fundamental frequency of the upper satellite is obtained by preliminarily determining the stiffness ratio parameter; The fourth step is the second phase. After the dual satellites are designed according to the preliminary first-order fundamental frequency and a finite element model is established, the intersatellite connection stiffness matrix is ​​introduced to establish a finite element model of the dual satellite self-series connection. While meeting the carrier's requirements for the first-order fundamental frequency of the self-series dual satellites, the first-order fundamental frequency of the dual satellites is fine-tuned to obtain the first-order fundamental frequency index of the dual satellites. The method further comprises: Performing a first step, the first step comprising establishing a fundamental frequency theoretical analysis model using a series cantilever beam theory and a Rayleigh-Ritz theory under the constraints of the carrier on the fundamental frequency, mass and size envelope; The method further comprises: Compare the calculated value of the first-order fundamental frequency of the self-tandem system with the transport requirements. If the transport requirements are not met, repeat steps 2 to 4. If the transport requirements are met, the self-tandem binary satellite fundamental frequency decomposition is completed.

2. The method for designing a self-tandem connection state of a small high-orbit satellite according to claim 1, wherein: Also includes: The second step includes adjusting the mass ratio of the binary stars and the size ratio of the binary stars to determine the preliminary stiffness ratio of the binary stars.

3. The method for designing a self-tandem connection state of a small high-orbit satellite according to claim 1, wherein: The stiffness ratio, mass ratio, and size ratio between the two stars are determined in two stages, including: Taking the second step as the first stage, the mass ratio and size ratio between the two satellites are used to improve the first-order fundamental frequency of the binary series connection, so as to preliminarily determine the stiffness ratio parameters; Taking the fourth step as the second stage, after verifying that the stiffness ratio is reasonable and meets the carrier's requirements for the first-order fundamental frequency of the self-series binary star, fine-tuning is carried out with the goal of optimizing the mass ratio and size ratio of the binary star to optimize the mass and size envelope of the entire star.

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