A fast and high-precision equivalent mapping method for mass characteristics of onboard satellites

Abstract

The present invention relates to a method for rapid, high-precision equivalent mapping of mass characteristics for a satellite, comprising the following steps: obtaining the mass, center of mass position, and moment of inertia of the satellite under measured operating conditions using a mass characteristic testing device; calculating the mass, center of mass position, and moment of inertia of an initial simplified model; assembling six mass spheres of unit volume in the initial simplified model and distributing them at the six face centers of a rectangular parallelepiped, solving for their density and position parameters, and completing an iterative simplified model equivalent construction; converting components other than the six mass spheres in the iterative simplified model from measured operating conditions to unmeasured operating conditions, and calculating the mass, center of mass position, and moment of inertia of the satellite under the unmeasured operating conditions. The highly simplified equivalent model constructed by the present invention, combined with a weight distribution algorithm for the six face-center mass spheres, achieves high-precision mapping of test values ​​under measured operating conditions, thereby quickly providing accurate mass characteristic parameters for unmeasured operating conditions, effectively reducing the number of ground tests, saving test costs, and improving development efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of spacecraft design, and in particular to a fast and high-precision equivalent mapping method for mass characteristics of a satellite. Background Art

[0002] The satellite's mass characteristic parameters (including mass, center of mass position, and moment of inertia; unless otherwise specified, moment of inertia refers to the moment of inertia about the center of mass axis) are key parameters that influence the accuracy of its attitude control. Therefore, high-precision satellite mass characteristic parameters must be obtained during the development process. For manned satellites, due to their integration requirements for new payloads, their mass characteristics exhibit significant dynamics as the payload configuration changes (such as payload configuration changes and fueling status adjustments). This leads to high test frequency and time pressure, necessitating a method for rapidly acquiring high-precision mass characteristic parameters.

[0003] To obtain mass characteristic parameters under untested conditions, the satellite's mass characteristic parameters under testable conditions (e.g., a locked payload and unfueled tank, hereinafter referred to as the measured condition) are typically calibrated to approximate the measured values ​​using a 3D model. Finally, any discrepancies between the measured and untested components in the model are set to the untested state, thereby calculating the satellite's mass characteristic parameters under the untested condition. To obtain a 3D model equivalent to the measured values, the traditional method involves calibrating a fully detailed 3D model of the satellite (including cables, bolts, thermal control cladding, etc.). This model is highly complex (typically with >10,000 entities), resulting in lengthy mass characteristic calculations, increased computing resources, and significantly increased hardware costs. Furthermore, this traditional method relies on trial-and-error adjustments to material properties (such as density and mass distribution) to approximate the measured values. This approach is not only inefficient but also difficult to maintain stable accuracy. This traditional approach is particularly unsuitable for onboard satellites, and a more efficient solution is urgently needed. Summary of the Invention

[0004] The present invention aims to solve the technical problems in the prior art of low efficiency and difficulty in ensuring stable accuracy of traditional satellite quality characteristic parameter testing methods, and to provide a fast and high-precision equivalent mapping method for the quality characteristics of onboard satellites.

[0005] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0006] A fast and high-precision equivalent mapping method for mass characteristics of an onboard satellite comprises the following steps:

[0007] Step 1: Obtain the mass, center of mass position and moment of inertia of the satellite under actual working conditions through the mass characteristic testing device;

[0008] Step 2: Calculate the mass, center of mass position and moment of inertia of the initial simplified model;

[0009] Step 3: Assemble six mass balls of unit volume in the initial simplified model and distribute them at the six face centers of the cuboid, solve their density and position parameters, and complete the equivalent construction of the iterative simplified model;

[0010] Step 4: Convert all components except the six mass balls in the iterative simplified model from the measured working condition to the unmeasured working condition, and calculate the mass, center of mass position and moment of inertia of the satellite under the unmeasured working condition.

[0011] In the above technical solution, step one is specifically as follows:

[0012] Determine the working coordinate system for satellite quality characteristic testing , define the coordinate system as the global coordinate system WCS1, based on the global coordinate system WCS1, the mass of the satellite under the measured working condition is obtained by the mass characteristic test device , the center of mass position is , the moment of inertia is , where the units of mass, center of mass position, and moment of inertia are 、 and .

[0013] In the above technical solution, step 2 is specifically as follows:

[0014] Create an initial simplified model, which only contains the components in the measured working condition that are inconsistent with the unmeasured working condition. Based on the global coordinate system WCS1, the mass of the initial simplified model is calculated as and the center of mass position is ; Create a centroid reference coordinate system , the origin of the coordinate system is , coordinate axis and quality characteristic test working coordinate system The coordinate axes are kept consistent, and the center of mass reference coordinate system is defined as the global coordinate system WCS2 (that is, the global coordinate system is switched from WCS1 to WCS2). Based on the global coordinate system WCS2, the moment of inertia of the initial simplified model around each coordinate axis of the global coordinate system WCS2 is calculated as follows: .

[0015] In the above technical solution, step three is specifically as follows:

[0016] Switch the global coordinate system from WCS2 to WCS1 and create a cuboid whose six face normals are ± 0.05 with respect to the global coordinate system WCS1. 、± 、± The axis direction is consistent, and a volume of The density and position parameters of the cubic meter mass ball are determined in sequence based on the global coordinate system WCS1, so that the mass characteristic parameters (mass, center of mass position and moment of inertia) of the iterative simplified model are equivalent to the corresponding parameters under the actual satellite working conditions.

[0017] In the above technical solution, step four is specifically as follows:

[0018] The components except the six mass balls in the iterative simplified model are converted from the measured working condition to the unmeasured working condition. Based on the global coordinate system WCS1, the mass of the satellite under the unmeasured working condition is finally obtained by calculation: , the center of mass position is And the moment of inertia is .

[0019] In the above technical solution, in step 3:

[0020] The mass of each mass ball , which is calculated as follows:

[0021] ;

[0022] Ball density , the unit is .

[0023] In the above technical solution, in step 3:

[0024] Based on the global coordinate system WCS1, the center position of the cuboid The calculation formula is as follows:

[0025] ; ; .

[0026] In the above technical solution, in step 3:

[0027] Based on the global coordinate system WCS1, 、 、 The distance between the center of the axial mass ball and the centroid of the cuboid 、 、 The calculation formula is as follows:

[0028] ;

[0029] ;

[0030] ;

[0031] in, is the mass of the ball.

[0032] In the above technical solution, in step 3:

[0033] Based on the density and position parameters of the mass ball, the equivalent construction of the iterative simplified model is completed. Taking the global coordinate system WCS1 as the benchmark, the mass of the iterative simplified model is calculated as , the center of mass position is And the moment of inertia is .

[0034] The present invention has the following beneficial effects:

[0035] The present invention's rapid, high-precision equivalent mapping method for satellite-mounted mass characteristics constructs a highly simplified equivalent model by evenly distributing small mass spheres at the six face centers of a rectangular parallelepiped, replacing the traditional complex, fully detailed model (typically with >10,000 entities). Specifically, the model, excluding components that differ between measured and unmeasured conditions, is simplified to a small mass sphere model containing only six entities. This significantly reduces model complexity, enabling computations to be performed on a standard computer, eliminating the need for high-performance workstations. This significantly improves computational efficiency and significantly reduces hardware requirements.

[0036] The six-sided center mass ball weight distribution algorithm replaces the traditional manual trial and error method of adjusting the material properties of the fully detailed model, greatly shortening the model parameter debugging time and improving modeling efficiency; at the same time, the equivalent mapping error of mass, center of mass position and moment of inertia can be controlled within 0.001%, thereby quickly and accurately calculating the mass characteristic parameters under untested working conditions, effectively reducing the number of ground tests, saving test costs and improving development efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] Figure 1 Flowchart of the method for accurately calculating the quality characteristic parameters of unmeasured working conditions by using the satellite quality characteristic parameters of measured working conditions;

[0039] Figure 2 Schematic diagram of the coordinate system for satellite quality characteristics testing;

[0040] Figure 3 A schematic diagram of the satellite model with full details (including cables, bolts, thermal control coating, etc.);

[0041] Figure 4 This is a schematic diagram of the payload and unfueled tank state in the locked state under the actual measured working conditions of the satellite;

[0042] Figure 5 This is a schematic diagram of evenly arranging mass balls at the six face centers of a rectangular parallelepiped;

[0043] Figure 6 Schematic diagram of the payload, unfueled tank, and six-mass sphere in the locked state under the actual satellite operating conditions;

[0044] Figure 7 Schematic diagram of the satellite's payload, fuel-filled tank, and six-mass sphere in its deployed state under untested operating conditions.

[0045] The reference numerals in the figures indicate:

[0046] The working coordinate system for quality characteristic testing, The center of mass reference coordinate system is shown in Figure 1. 1-structure, 2-cable, 3-bolt, 4-light shield and thermal control cover, 5-load in locked state, 6-tank without fuel, 7-mass ball, 8-cuboid, 9-load in deployed state, 10-tank with full fuel. DETAILED DESCRIPTION

[0047] The inventive concept of the present invention is:

[0048] The present invention provides a fast and high-precision equivalent mapping method for the mass characteristics (including mass, center of mass position and moment of inertia) of onboard satellites. The core of the method is to construct a highly simplified equivalent model by evenly arranging mass balls at the six centers of a rectangular parallelepiped, thereby significantly improving computational efficiency and greatly reducing hardware requirements. By adopting a weight distribution algorithm for the six-center mass balls, high-precision equivalent mapping of the satellite's measured working conditions mass characteristic parameters is achieved, and the error can be controlled within 0.001%, thereby quickly providing accurate mass characteristic parameters for unmeasured working conditions. The method is particularly suitable for quickly obtaining high-precision quality characteristic parameter requirements during the satellite assembly and testing phase, effectively reducing the number of ground tests, thereby saving test costs and improving development efficiency.

[0049] In summary, the method of the present invention can significantly improve the computing efficiency while ensuring accuracy and reduce the dependence on high-performance computing resources, in order to solve the difficulty of obtaining quality characteristic parameters caused by changes in the configuration of the satellite payload (such as changes in the payload shape, adjustments to the fuel filling status, etc.).

[0050] The rapid and high-precision equivalent mapping method for mass characteristics of a satellite carried by the present invention comprises the following steps:

[0051] Step 1: Determine the satellite quality characteristics test working coordinate system , define the coordinate system as the global coordinate system WCS1, based on the global coordinate system WCS1, the mass of the satellite under the actual working condition of the satellite (the payload is locked and the tank is not filled with fuel) is obtained through the mass characteristic test device. , the center of mass position is , the moment of inertia is , where the units of mass, center of mass position, and moment of inertia are 、 and .

[0052] Step 2: Create an initial simplified model in the 3D software. This initial simplified model only includes the components in the measured working condition that are inconsistent with the unmeasured working condition (in this embodiment, it includes the load and the tank, where the load is locked and the tank is not filled with fuel). Based on the global coordinate system WCS1, the mass of the initial simplified model is calculated as and the center of mass position is ; Create a centroid reference coordinate system , the origin of the coordinate system is , coordinate axis and quality characteristic test working coordinate system The coordinate axes are kept consistent, and the center of mass reference coordinate system is defined as the global coordinate system WCS2 (that is, the global coordinate system is switched from WCS1 to WCS2). Based on the global coordinate system WCS2, the moment of inertia of the initial simplified model around each coordinate axis of the global coordinate system WCS2 is calculated as follows: .

[0053] Step 3: Switch the global coordinate system from WCS2 to WCS1, and create a cuboid whose six face normals are ± 、± 、± The axis direction is consistent, and a volume of The density and position parameters of the cubic meter mass balls are determined in sequence based on the global coordinate system WCS1, so that the mass characteristic parameters (mass, center of mass position and moment of inertia) of the iterative simplified model (initial simplified model + six mass balls) are equivalent to the corresponding parameters under the actual measured working conditions of the satellite.

[0054] The mass of each ball The calculation formula is as follows:

[0055]

[0056] Ball density , the unit is ;

[0057] Based on the global coordinate system WCS1, the position of the cuboid's centroid (the overall center of mass of the six mass balls) The calculation formula is as follows:

[0058]

[0059]

[0060] .

[0061] Based on the global coordinate system WCS1, 、 、 The distance between the center of the axial mass ball and the centroid of the cuboid 、 、 The calculation formula is as follows:

[0062]

[0063]

[0064]

[0065] Based on the density and position parameters of the mass balls, the equivalent construction of the iterative simplified model (initial simplified model + six mass balls) is completed. Taking the global coordinate system WCS1 as the benchmark, the mass of the iterative simplified model is calculated as , the center of mass position is And the moment of inertia is .

[0066] Step 4: Convert all components except the six mass balls in the iterative simplified model from the measured working condition to the unmeasured working condition. Based on the global coordinate system WCS1, the mass of the satellite under the unmeasured working condition is finally obtained by calculation: , the center of mass position is And the moment of inertia is .

[0067] The present invention will be further described below with reference to the accompanying drawings and examples.

[0068] See also Figure 1-7 The present invention provides a fast and high-precision equivalent mapping method for mass characteristics (including mass, center of mass position and moment of inertia) of a satellite. This method uses a highly simplified equivalent model constructed by evenly arranging mass balls at the six center points of a rectangular parallelepiped. This method, combined with a weight distribution algorithm for the six center mass balls, achieves high-precision equivalent mapping of mass characteristic parameters under measured satellite operating conditions, thereby quickly providing accurate mass characteristic parameters for unmeasured satellite operating conditions. Figure 1 The specific steps are as follows:

[0069] Step 1: Obtain the mass, center of mass position, and moment of inertia of the satellite under actual operating conditions (e.g., when movable parts are locked and the tank is unfueled) using a mass characteristic test device. This specifically includes the following steps:

[0070] Determine the working coordinate system for satellite quality characteristic testing , define the coordinate system as the global coordinate system WCS1, the origin of the coordinate system In the satellite-rocket docking plane, at the geometric center of the four satellite leg end faces; The axis is in the satellite-rocket docking plane and points to the optical camera; The axis is perpendicular to the satellite-rocket docking plane and points to the direction of the satellite's in-orbit flight; The axis is in the satellite-rocket docking plane and is determined by the right-hand rule, such as Figure 2 As shown; Based on the global coordinate system WCS1, the quality of the satellite under the actual working condition is obtained through the mass characteristic test device is 68.7942 , center of mass position for , moment of inertia for The measured working conditions include structural parts 1, cables 2, bolts 3, sunshade and thermal control cover 4, load in locked state 5, and unfilled tank 6. Figure 3 As shown, the number of entities contained in the corresponding satellite full-detail model is 12152;

[0071] Step 2: Calculate the mass, center of mass position, and moment of inertia of the initial simplified model (containing only the moving parts in the locked state and no fuel in the tank). This includes the following steps:

[0072] An initial simplified model is created in a 3D software. The initial simplified model only includes components that are inconsistent with the unmeasured working conditions in the measured working conditions. In this embodiment, the components include a load 5 in a locked state and a tank 6 without fuel, as shown in FIG. As shown, the initial simplified model contains 239 entities; based on the global coordinate system WCS1, the mass of the initial simplified model is calculated is 9.3264 , center of mass position for ; Create a centroid reference coordinate system , the origin of the coordinate system is the center of mass position, that is , coordinate axis and quality characteristic test working coordinate system Keep the coordinate axes consistent, define the center of mass reference coordinate system as the global coordinate system WCS2 (that is, the global coordinate system is switched from WCS1 to WCS2), and calculate the moment of inertia of the initial simplified model around the coordinate axes of the global coordinate system WCS2. for ;

[0073] Step 3: Assemble six mass balls of unit volume in the initial simplified model and distribute them at the six face centers of the cuboid, solve their density and position parameters, and complete the equivalent construction of the iterative simplified model; specifically, the following steps are included:

[0074] Switch the global coordinate system from WCS2 to WCS1 and create a cuboid 8, whose six face normals are ± 、± 、± Axially, a volume of The mass of the cubic ball is 7, as Figure 5 As shown; Based on the global coordinate system WCS1, the density and position parameters of the mass balls 7 are determined in sequence, so that the mass characteristic parameters (mass, center of mass position and moment of inertia) of the iterative simplified model (initial simplified model + six mass balls 7) are equivalently matched with the corresponding parameters under the actual working conditions of the satellite. The iterative simplified model contains 245 entities;

[0075] The mass of each ball 7 The calculation formula is as follows:

[0076]

[0077] The calculated value is 9.9113 ;

[0078] density , the calculated value is 9.9113 ;

[0079] Based on the global coordinate system WCS1, the position of the centroid of the cuboid 8 (the overall center of mass of the six mass balls 7) The calculation formula is as follows;

[0080]

[0081]

[0082] .

[0083] The calculated value is ;

[0084] Based on the global coordinate system WCS1, 、 、 The distance between the center of the axial mass ball 7 and the centroid of the cuboid 8 、 、 The calculation formula is as follows:

[0085]

[0086]

[0087]

[0088] The calculated value is ;

[0089] Based on the density and position parameters of the mass balls 7, the equivalent construction of the iterative simplified model (initial simplified model + six mass balls 7) is completed, as shown in Figure 6 As shown. Taking the global coordinate system WCS1 as the benchmark, the quality of the iterative simplified model is calculated is 68.7942 , center of mass position for and moment of inertia for , compared with the measured values ​​of the corresponding parameters under the actual working conditions, the deviations of mass, center of mass position and moment of inertia are all less than 0.001%;

[0090] Step 4: Transform all components except the six mass balls 7 in the iterative simplified model from the measured working condition to the unmeasured working condition (change in the shape of the moving parts, change in the fuel filling amount in the tank), and calculate the mass, center of mass position and moment of inertia of the satellite under the unmeasured working condition;

[0091] The components except the six mass balls 7 in the iterative simplified model are converted from the measured working condition to the unmeasured working condition. In this embodiment, the load and tank components are converted from the locked state load 5 and the unfilled tank 6 to the deployed state load 9 and the fully filled tank 10. Figure 7 As shown, based on the global coordinate system WCS1, the mass of the satellite under the unmeasured working condition is finally obtained by calculation 71.6942 , including 2.9kg of fuel in the tank, center of mass position for and moment of inertia for .

[0092] The rapid and high-precision equivalent mapping method for mass characteristics of satellites in this invention is universal and can meet the requirements of rapid and high-precision equivalent mapping and prediction of mass characteristic parameters of different satellites such as remote sensing, communication, and navigation. For working conditions with higher mass characteristic test accuracy, the volume of the mass ball is set to 0.1mm. 3 , 0.01mm 3 or 0.001mm 3 Even smaller, thereby reducing the influence of the mass ball shape on the moment of inertia calculation and improving the mapping accuracy.

[0093] The contents not described in detail in the specification of the present invention belong to the technology generally recognized by those skilled in the art.

[0094] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A fast and high-precision equivalent mapping method for mass characteristics of onboard satellites, characterized by: The following steps are involved: Step 1: Obtain the mass, center of mass position and moment of inertia of the satellite under actual working conditions through the mass characteristic testing device; Step 2: Calculate the mass, center of mass position and moment of inertia of the initial simplified model; Create an initial simplified model, which only contains the components in the measured working condition that are inconsistent with the unmeasured working condition. Based on the global coordinate system WCS1, the mass of the initial simplified model is calculated as and the center of mass position is ; Create a centroid datum coordinate system , the origin of the coordinate system is , coordinate axis and quality characteristic test working coordinate system The coordinate axes are kept consistent, and the center of mass reference coordinate system is defined as the global coordinate system WCS2. Based on the global coordinate system WCS2, the moment of inertia of the initial simplified model around each coordinate axis of the global coordinate system WCS2 is calculated as follows: ; Step 3: Assemble six mass balls of unit volume in the initial simplified model and distribute them at the six face centers of the cuboid, solve the density and position parameters of the mass balls, and complete the equivalent construction of the iterative simplified model; Step 4: Convert all components except the six mass balls in the iterative simplified model from the measured working condition to the unmeasured working condition, and calculate the mass, center of mass position and moment of inertia of the satellite under the unmeasured working condition.

2. The method for rapid and high-precision equivalent mapping of mass characteristics for onboard satellites according to claim 1, characterized in that: Step 1 is as follows: Determine the working coordinate system for satellite quality characteristic testing , define the coordinate system as the global coordinate system WCS1, based on the global coordinate system WCS1, the mass of the satellite under the measured working condition is obtained by the mass characteristic test device , the center of mass position is , the moment of inertia is , where the units of mass, center of mass position, and moment of inertia are 、 and .

3. The method for rapid and high-precision equivalent mapping of mass characteristics for onboard satellites according to claim 2, characterized in that: Step three is as follows: Switch the global coordinate system from WCS2 to WCS1 and create a cuboid whose six face normals are ± 0.05 with respect to the global coordinate system WCS1. 、± 、± The axis direction is consistent, and a volume of The density and position parameters of the cubic meter mass ball are determined in sequence based on the global coordinate system WCS1, so that the mass characteristic parameters of the iterative simplified model and the corresponding parameters under the actual satellite working conditions are equivalently matched.

4. The method for rapid and high-precision equivalent mapping of mass characteristics for onboard satellites according to claim 2, characterized in that: Step 4 is as follows: The components except the six mass balls in the iterative simplified model are converted from the measured working condition to the unmeasured working condition. Based on the global coordinate system WCS1, the mass of the satellite under the unmeasured working condition is finally obtained by calculation: , the center of mass position is And the moment of inertia is .

5. The method for rapid and high-precision equivalent mapping of mass characteristics for onboard satellites according to claim 3, characterized in that: In step three: The mass of each mass ball , which is calculated as follows: ； Ball density , the unit is .

6. The method for rapid and high-precision equivalent mapping of mass characteristics for onboard satellites according to claim 3, characterized in that: In step three: Based on the global coordinate system WCS1, the center position of the cuboid The calculation formula is as follows: ； ； 。 7. The method for rapid and high-precision equivalent mapping of mass characteristics for onboard satellites according to claim 6, characterized in that: In step three: Based on the global coordinate system WCS1, 、 、 The distance between the center of the axial mass ball and the centroid of the cuboid 、 、 The calculation formula is as follows: ； ； ； in, is the mass of the ball.

8. The method for rapid and high-precision equivalent mapping of mass characteristics for onboard satellites according to claim 3, 5, 6 or 7, characterized in that: In step three: Based on the density and position parameters of the mass ball, the equivalent construction of the iterative simplified model is completed. Taking the global coordinate system WCS1 as the reference, the mass of the iterative simplified model is calculated as , the center of mass position is And the moment of inertia is .

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