A precision quantification evaluation method for thermal stability test of large space structure

Abstract

The application provides a precision quantification evaluation method for thermal stability test of a large space structure, comprising the following steps: S1: obtaining a plurality of sets of thermal deformation measurement data of the large space structure in a whole cycle of entering and leaving the earth shadow; S2: constructing a precision evaluation model, including the one-way point measurement precision U SX , SY , SZ of the thermal stability of the large space structure in X, Y and Z directions; and S3: quantitatively evaluating the measurement precision of the sets of thermal deformation measurement data based on the precision evaluation model, and obtaining a result. Through the method, the measurement precision of the thermal stability of the structure in X, Y and Z directions is quantitatively evaluated, so that the dynamic thermal stability deformation (thermal stability of the structure) of the large space structure in the cycle of entering and leaving the earth shadow under the alternating action of transient external heat flow in the on-orbit operation is accurately predicted, and the test time is greatly reduced.

Description

Technical Field

[0001] This invention relates to the construction of an accuracy evaluation model for thermal stability tests of large space structures and the quantitative evaluation of measurement accuracy, and particularly to a method for quantitative evaluation of the accuracy of thermal stability tests of large space structures. Background Technology

[0002] During their on-orbit operation, large space structures constantly experience complex space environments. They heat up rapidly under solar radiation and cool down rapidly when the sun is blocked by the Earth or the spacecraft itself. Entering and exiting the Earth's shadow generates significant temperature differences. These effects cause thermal strain and deformation in the spacecraft structure, and its thermal stability directly impacts the performance of the platform and payloads. Thermal stability measurement experiments for large space structures require multiple high-precision thermal deformation measurements of the large structure at progressively varying heat flow intervals within the spacecraft's entry and exit from the Earth's shadow to obtain dynamic thermal stability deformation (structural thermal stability). Traditional steady-state thermal deformation measurements only require one set of thermal deformation data at a stable temperature to predict the structure's on-orbit form and position accuracy at that temperature. However, thermal stability measurement experiments for large space structures require multiple sets of thermal deformation data under progressively varying heat flow conditions within the spacecraft's entry and exit from the Earth's shadow to predict the structure's on-orbit form and position accuracy throughout the entire cycle of entering and exiting the Earth's shadow. Therefore, measuring the steady-state thermal deformation of large spacecraft structures often requires a long measurement time. Summary of the Invention

[0003] To address the problems existing in the prior art, this invention provides a quantitative evaluation method for the accuracy of thermal stability tests on large space structures. Based on the error distribution of the data set obtained from thermal stability tests on large space structures, an accuracy evaluation model is constructed. This model quantitatively evaluates the measurement accuracy of structural thermal stability in the X, Y, and Z directions, thereby accurately predicting the dynamic thermal stability deformation (structural thermal stability) of large space structures under transient external heat flow alternation during their orbital entry and exit from Earth's shadow period, and significantly reducing test time.

[0004] This invention is achieved using the following technical solution:

[0005] A method for quantitatively evaluating the accuracy of thermal stability tests on large space structures includes the following steps:

[0006] S1: Acquire multiple sets of thermal deformation measurement data for large spatial structures throughout the entire period of entering and exiting the Earth's shadow;

[0007] In the first domestic thermal stability test of a large-scale space structure platform, based on the simulation of transient external heat flow alternation in a vacuum cryogenic environment, a four-camera networked rapid photogrammetry system was adopted under thermal vacuum conditions. This system included a motion fixture system and a centralized control system to support simultaneous shooting by the four cameras. Multi-camera networked parallel automated control was used to acquire and transmit the four-camera photographic data, ensuring minute-level rapid measurement of thermal stability deformation data of the large-scale space structure. Figure 1 As shown.

[0008] S2: Construct an accuracy evaluation model, including the unidirectional point measurement accuracy U of the thermal stability of large space structures in the X, Y, and Z directions. SX U SY U SZ ;

[0009] S3: Quantitatively evaluate the measurement accuracy of the thermal deformation measurement data set based on the accuracy evaluation model, and obtain the results.

[0010] According to the method of claim 1, the accuracy evaluation model specifically includes:

[0011] The unidirectional position measurement error U of the calibrated reference length in the X, Y, and Z directions within the control field ΔX U ΔY U ΔZ ;

[0012] The unidirectional point location traceability calibration error U of the calibrated reference length in the X, Y, and Z directions within the control field CX U CY U CZ ;

[0013] The unidirectional repeatability measurement error δ of all measurement sampling points (characterization points) in the control field in the X, Y, and Z directions. X δ Y δ Z .

[0014] Furthermore, the accuracy evaluation model is as follows:

[0015]

[0016]

[0017]

[0018] Where ± represents the direction of the measurement accuracy value, and the confidence level k is 1 or 2.

[0019] Furthermore, the confidence level of the accuracy evaluation model is k. In the evaluation of measurement accuracy of industrial testing systems and instruments, k takes the value of 1 or 2; in the benchmark used by national metrology units for the traceability calibration of industrial testing systems and instruments, k takes the value of 3. The confidence level k of the accuracy evaluation model of this invention takes the value of 1 or 2.

[0020] Furthermore, step S3 specifically includes the following steps:

[0021] S3-1: U ΔX U ΔY U ΔZ Quantitative assessment;

[0022] S3-2: U CX U CY U CZ Quantitative assessment;

[0023] S3-3: δ X δ Y δ Z Quantitative assessment.

[0024] Furthermore, step S3-1 specifically includes the following steps:

[0025] S3-1-1: Measurement of the calibration values ​​L of n calibrated reference lengths within the control field. 0i , where i = 1, ..., n;

[0026] S3-1-2: Obtain m measurement values ​​L for n lengths from the thermal stability deformation measurement data during the entire lifecycle of the spacecraft entering and leaving the Earth's shadow. ij Where i = 1, ..., n, j = 1, ..., m;

[0027] S3-1-3: Calculate the absolute value ΔL of the measurement error of the j-th length. ij |, that is:

[0028] |ΔL ij |=|L ij -L 0i |

[0029] S3-1-4: Calculate the position measurement error (U) of the j-th point with the i-th length. Δij ),Right now:

[0030]

[0031] S3-1-5: Calculate the unidirectional point measurement error (U) for the i-th length in the j-th measurement. ΔXij ),Right now:

[0032]

[0033] S3-1-6: Unidirectional point measurement error (U) in deformation measurement data throughout the entire cycle ΔXij U ΔYij U ΔZij )Statistical verification of the distribution characteristics of the set of samples confirmed that the unidirectional point measurement error (U) ΔXij U ΔYij U ΔZij The set follows a normal distribution;

[0034] S3-1-7: Calculate the average value and standard deviation of the sample of all unidirectional point measurement errors, i.e. (S(U ΔXij ), S(U ΔYij ), S(U ΔZij ));

[0035] S3-1-8: Perform an overall sample evaluation of the set of unidirectional point measurement errors for all measurement data sets.

[0036] Furthermore, step S3-1-8 specifically includes:

[0037] When the confidence level k is 1

[0038]

[0039]

[0040]

[0041] When the confidence level k is 2

[0042]

[0043]

[0044]

[0045] Furthermore, step S3-2 specifically includes:

[0046] The traceability calibration error U of n reference lengths already calibrated in the measurement control field C U can then be obtained. CX U CY U CZ for:

[0047] When the confidence level k is 2

[0048]

[0049] Furthermore, step S3-3 specifically includes the following steps:

[0050] S3-3-1: In the thermal stability deformation measurement data during the entire life cycle of the spacecraft entering and leaving the Earth's shadow, obtain n measurement points in the measurement control field, and perform m measurements (X) under the step-by-step transient external heat flow alternation measurement conditions. ij Y ij Z ij ), where i = 1, ..., n, j = 1, ..., m;

[0051] S3-3-2: Using the three-dimensional coordinates of the n measurement points in the first measurement as a reference, and taking all measurement points in the measurement control field of the thermal stability deformation measurement data set as common points, perform coordinate system transformation to obtain the measurement error (ΔX) of the j-th measurement of the i-th measurement point relative to the three-dimensional coordinates of the n measurement points in the X, Y, and Z directions in the first measurement. ij ΔY ij ΔZ ij There are a total of m-1 sets of measurement errors;

[0052] In this process, all measurement points (n measurement points) on a large spatial structure are measured m times. Then, using the three-dimensional coordinates of the n measurement points from the first measurement as a reference, the three-dimensional coordinates of the remaining n measurement points from the m-1 measurements are transformed into the same coordinate system.

[0053] S3-3-3: Calculate the measurement error (ΔX) of the three-dimensional point coordinates of group m-1. ij ΔY ij ΔZ ij The RMS value of ), that is:

[0054] δ 1X =RMS(ΔX) ij )

[0055] δ 1Y =RMS(ΔY) ij )

[0056] δ 1Z =RMS(ΔZ) ij )

[0057] S3-3-4: Based on steps S3-3-1 to S3-3-3, obtain (δ) 1X δ 1Y δ 1Z ), (δ 2X δ 2Y δ 2Z )……(δ (m-1)X δ (m-1)Y δ (m-1)Z );

[0058] S3-3-5: Deformation measurement data over the entire cycle (δ) (m-1)X δ (m-1)Y δ(m-1)Z )Statistical verification of the distribution characteristics of the set of samples, which was verified (δ (m-1)X δ (m-1)Y δ (m-1)Z The set follows a normal distribution;

[0059] S3-3-6: Calculate the average value and standard deviation of the set of RMS values ​​of the coordinate measurement errors of all three-dimensional points of the measurement control field in the deformation measurement data throughout the entire cycle, i.e. (S(δ iX ), S(δ iY ), S(δ iZ ));

[0060] S3-3-7: The set of RMS values ​​of the measurement error of the three-dimensional point coordinates of the measurement control field in all measurement data is used for overall sample evaluation.

[0061] Furthermore, step S3-3-7 specifically includes:

[0062] When the confidence level k is 1

[0063]

[0064]

[0065]

[0066] When the confidence level k is 2

[0067]

[0068]

[0069]

[0070] The beneficial effects of this invention are:

[0071] The method of this invention aims to obtain the quantitative accuracy of test data on thermal stability deformation of large space structures caused by periodic alternating external heat flow in a simulated space environment on the ground, and to predict the dynamic thermal stability deformation (structural thermal stability) of large space structures during on-orbit operation. This ensures that the on-orbit form and position accuracy and thermal design of large space structures meet design and usage requirements. Based on the error distribution of the data set obtained from the thermal stability test of large space structures, an accuracy evaluation model is constructed to quantitatively evaluate the measurement accuracy of structural thermal stability in the X, Y, and Z directions. This accurately predicts the dynamic thermal stability deformation (structural thermal stability) of large space structures under the transient alternating external heat flow during the entry and exit of Earth's shadow period during on-orbit operation, and greatly reduces the test time. Attached Figure Description

[0072] Figure 1 A schematic diagram of a four-camera network splicing measurement system for dynamic thermal stability deformation testing under vacuum and low temperature conditions;

[0073] Figure 2 A schematic diagram showing the layout of sampling points (characterization points) and reference lengths (reference scales) for measuring a large space structure specimen;

[0074] Figure 3 A schematic diagram showing the layout of coding points and marker points for the measurement control field;

[0075] Figure 4 A schematic diagram illustrating the intersection of four-camera measurement grid stations for optimal measurement.

[0076] Figure 5 This is a schematic diagram illustrating the predicted thermal stability of a large space structure's periodic entry and exit from the Earth's shadow structure during its on-orbit operation. Detailed Implementation

[0077] To make the technical solutions and advantages of the present invention clearer, the technical solutions of the embodiments of the present invention will be fully described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0078] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0079] 4.1 Methods for Obtaining Measurement Data of Dynamic Thermal Stability Deformation (Structural Thermal Stability)

[0080] In the first domestic thermal stability test of a large-scale space structure platform, based on the simulation of transient external heat flow alternation in a vacuum cryogenic environment, a four-camera networked rapid photogrammetry system was adopted under thermal vacuum conditions. This system included a motion fixture system and a centralized control system to support simultaneous shooting by the four cameras. Multi-camera networked parallel automated control was used to acquire and transmit the four-camera photographic data, ensuring minute-level rapid measurement of thermal stability deformation data of the large-scale space structure. Figure 1 As shown.

[0081] The above four-camera network stitching measurement system acquires multiple sets of thermal deformation measurement data for a large space structure throughout its entire shadow transition period. Then, an accuracy evaluation model is constructed, and a measurement accuracy quantification evaluation process is used to obtain the measurement accuracy of these thermal deformation measurement data sets. For example, when a large space structure is orbiting the Earth, its shadow transition period is 124 minutes. During the thermal stability test, one set of three-dimensional morphology (three-dimensional coordinate values ​​of measurement sampling points (characterization points)) of the large space structure is acquired every 2 minutes, resulting in 62 sets of three-dimensional morphology (three-dimensional coordinate values ​​of measurement sampling points (characterization points)) of the large space structure acquired throughout its entire shadow transition period. Then, through the accuracy evaluation model construction (Chapter 4.2) and measurement accuracy quantification evaluation method (Chapter 4.3) of the main content of this invention, the overall measurement accuracy of the set of three-dimensional coordinate values ​​of the 62 sets of measurement sampling points (characterization points) (thermal stability measurement data of the large space structure) is evaluated to determine whether it meets the measurement accuracy requirement of better than 20 μm (see Chapter 5, "Specific Implementation Examples").

[0082] 4.2 Accuracy Evaluation Model for Structural Thermal Stability Measurement Data

[0083] Based on the measurement acquisition scheme and sources of measurement error in the thermal stability test of large space structures, it can be seen that the unidirectional point measurement accuracy (U0) of the thermal stability of large space structures in the X, Y, and Z directions is limited. SX U SY U SZ It contains three parts:

[0084] 1) In the full-cycle deformation measurement data, the unidirectional point measurement error (U) of the calibrated reference length (reference scale) in the X, Y, and Z directions within the measurement control field. ΔX U ΔY U ΔZ );

[0085] 2) The unidirectional point location traceability calibration error (U) of the calibrated reference length in the X, Y, and Z directions within the measurement control field. CX U CY U CZ );

[0086] 3) Unidirectional repeatability measurement error (δ) of all measurement sampling points (characterization points) in the X, Y, and Z directions within the measurement control field. X δ Y δ Z ).

[0087] The accuracy evaluation of thermal stability test measurement is the unidirectional point measurement accuracy (U) in the X, Y, and Z directions. SX U SY U SZ Its measurement accuracy is characterized in the following form:

[0088]

[0089]

[0090]

[0091] Where ± represents the direction of the measurement accuracy value; k is the confidence level of the test data. In the evaluation of measurement accuracy of general industrial testing systems and instruments, k is 1 or 2; in the benchmark for the traceability calibration of industrial testing systems and instruments by national metrology units, k is 3. The confidence level k of the accuracy evaluation model described in this invention is 1 or 2.

[0092] 4.3 Quantitative Evaluation Method for the Accuracy of Structural Thermal Stability Measurement Data

[0093] 4.3.1 Reference Length (Reference Scale) Unidirectional Point Measurement Error (U) ΔX U ΔY U ΔZ Quantitative assessment

[0094] 1) Measure the calibration value L of the n reference lengths that have been calibrated in the control field. 0i ,(i=1,…,n);

[0095] 2) From the thermal stability deformation measurement data of the spacecraft during its entire lifecycle of entering and leaving the Earth's shadow, obtain m measurement values ​​L for n lengths. ij , (i=1,…,n, j=1,…,m);

[0096] 3) Calculate the absolute value of the measurement error |ΔL| for the j-th measurement of the i-th length. ij |, that is:

[0097] |ΔL ij |=|L ij -L 0i |

[0098] 4) Calculate the position measurement error (U) of the j-th point with length i. Δij ),Right now:

[0099]

[0100] 5) Calculate the unidirectional position measurement error (U) of the i-th length in the j-th measurement. ΔXij ),Right now:

[0101]

[0102] 6) Unidirectional point measurement error (U) in deformation measurement data throughout the entire cycle ΔXij U ΔYij U ΔZij)Statistical verification of the distribution characteristics of the set of samples confirmed that the unidirectional point measurement error (U) ΔXij U ΔYij U ΔZij The set follows a normal distribution;

[0103] 7) Calculate the average and standard deviation of the set of errors for all unidirectional point measurements, i.e. (S(U ΔXij ), S(U ΔYij ), S(U ΔZij ));

[0104] 8) Evaluate the overall sample of the unidirectional point measurement error set of all measurement data sets, i.e.:

[0105] or

[0106]

[0107] 9) Based on the evaluation method in step 8), U can be obtained. ΔY U ΔZ :

[0108] or

[0109]

[0110] or

[0111]

[0112] 4.3.2 Reference Length (Reference Scale) Unidirectional Traceability Calibration Error (U) CX U CY U CZ Quantitative assessment

[0113] According to the calibration certificate for the reference length issued by the National Institute of Metrology, the traceability calibration error U of the n reference lengths calibrated within the measurement control field is... C U can then be obtained. CX U CY U CZ for:

[0114]

[0115] 4.3.3 Measurement control field unidirectional repeatability measurement error (δ) X δ Y δ Z Quantitative assessment

[0116] 1) In the thermal stability deformation measurement data during the entire life cycle of the spacecraft entering and leaving the Earth's shadow, obtain n measurement points in the measurement control field, and perform m measurements (X) under the step-by-step transient external heat flux alternation measurement conditions. ij Y ij Z ij ), (i=1,…,n, j=1,…,m);

[0117] 2) Using the three-dimensional coordinates of the first set of n measurement points as the reference, and taking all measurement points in the measurement control field of the thermal stability deformation measurement data set as common points, perform coordinate system transformation to obtain the measurement error (ΔX) of the j-th measurement of the i-th measurement point relative to the three-dimensional coordinates of the first set of n measurement points in the X, Y, and Z directions. ij ΔY ij ΔZ ij There are a total of m-1 sets of measurement errors;

[0118] 3) Calculate the measurement error (ΔX) of the three-dimensional point coordinates of group m-1. ij ΔY ij ΔZ ij The RMS value of ), that is:

[0119] δ 1X =RMS(ΔX) ij )

[0120] δ 1Y =RMS(ΔY) ij )

[0121] δ 1Z =RMS(ΔZ) ij )

[0122] 4) Based on steps 1) to 3), obtain (δ) 1X δ 1Y δ 1Z ), (δ 2X δ 2Y δ 2Z )……(δ (m-1)X δ (m-1)Y δ (m-1)Z );

[0123] 5) In the deformation measurement data over the entire cycle (δ) (m-1)X δ (m-1)Y δ (m-1)Z )Statistical verification of the distribution characteristics of the set of samples, which was verified (δ (m-1)X δ (m-1)Y δ (m-1)Z The set follows a normal distribution;

[0124] 6) Calculate the average value and standard deviation of the set of RMS values ​​of the coordinate measurement errors of all three-dimensional points in the deformation measurement data of the entire cycle, i.e. (S(δiX), S(δiY), S(δiZ))

[0125] 7) The set of RMS values ​​of the measurement error of the three-dimensional point coordinates of the measurement control field in all measurement data is used for overall sample evaluation, that is:

[0126] or

[0127]

[0128] 8) Based on the evaluation method in step 7), δ can be obtained. Y δ Z :

[0129] or

[0130]

[0131] or

[0132]

[0133] To better illustrate the purpose and advantages of this invention, the following calculation examples further explain the invention. An example of the thermal stability test and data processing of a large space structure (measurement control field envelope size Φ5m) under simulated space conditions, as well as the quantitative evaluation process for measurement accuracy, is shown below.

[0134] 5.1 Layout of Measurement Sampling Points (Characteristic Points) and Measurement Control Field

[0135] The specific layout of the sampling points (characterization points), reference scale, and measurement control field for a large space structure specimen is as follows:

[0136] 1) The layout of measurement sampling points (characterization points) and reference scales at 10 installation points of a large spatial structure specimen is as follows: Figure 2 As shown. Measurement markers are set up in the front-end installation areas (1), (2), ..., (10). In addition, there are 4 reference rulers, each with 3 pre-calibrated reference lengths (reference rulers). S i -S i+3 SS i -SS i+3 SSS i -SSS i+3 SSSS i -SSSS i+3 (i = 1….3).

[0137] 2) Based on the camera station shooting distance and intersection angle of the photogrammetry system, the measurement control field coding points and marker points are laid out around a large spatial structure specimen, such as... Figure 3 As shown.

[0138] 3) A four-camera networked rapid photogrammetry system for vacuum and cryogenic environments. During measurement in a vacuum and cryogenic environment, it employs partitioned subnetting and combined stitching measurements to quickly acquire the three-dimensional coordinates of a single measurement point set, thereby achieving high-precision transient thermal deformation measurement capabilities, such as... Figure 4 As shown.

[0139] 5.2 Quantitative Evaluation Process and Results of Measurement Accuracy of Thermal Stability Deformation Measurement Test System

[0140] 1) Unidirectional point measurement error of the reference length (reference scale) in the X, Y, and Z directions (U ΔX U ΔY U ΔZ Evaluation results

[0141] Table 1. Measurement error of unidirectional point of reference length (U) ΔX U ΔY U ΔZ Data processing (unit: mm)

[0142]

[0143] Based on the unidirectional point measurement error (U) in the three directions of the reference length X, Y, and Z. ΔX U ΔY U ΔZ The evaluation method shows that:

[0144] Table 2. Measurement error of unidirectional point of reference length (U) ΔX U ΔY U ΔZ Evaluation results (unit: mm)

[0145]

[0146] 2) One-way traceability calibration error of reference length (reference scale) (U) CX U CY U CZ Evaluation results

[0147] According to the calibration certificate for the reference length issued by the National Institute of Metrology, the traceability calibration error U of the n reference lengths calibrated within the measurement control field is... C =15um, then U can be obtained. CX U CY U CZ for:

[0148]

[0149] 3) Measurement control field unidirectional repeatability measurement error (δ) X δ Y δ Z Evaluation results

[0150] The measurement control field measurement points for acquiring 62 sets of measurement data for each sub-condition were used as the reference to calculate the repeatability error, resulting in 61 sets of repeatability RMS error values.

[0151] Table 3 Measurement control field unidirectional repeatability measurement error (δ) X δ Y δ Z Data processing (unit: mm)

[0152]

[0153] Based on the unidirectional repeatability measurement error (δ) of the measurement control field X δ Y δ Z According to the data evaluation method:

[0154] Table 4 Measurement control field unidirectional repeatability measurement error (δ) X δ Y δ Z Evaluation results (unit: mm)

[0155]

[0156]

[0157] 4) Based on the above measurement accuracy characterization and evaluation methods, and the measurement data set of the entire test link and test conditions at room temperature and pressure, vacuum and low temperature, the measurement accuracy of the thermal stability deformation measurement test system is evaluated, that is, the unidirectional point measurement accuracy (U) of thermal stability deformation measurement under different confidence levels (k=1, k=2). SX U SY U SZ ).

[0158] Table 5. Accuracy of the thermal stability deformation measurement system with confidence level k=1 (unit: mm)

[0159]

[0160] Table 6. Accuracy of the thermal stability deformation measurement system with confidence level k=2 (unit: mm)

[0161]

[0162]

[0163] 5.3 Thermal stability prediction of a large space structure's periodic entry and exit from Earth's shadow structure during on-orbit operation

[0164] Large space structure platforms, due to their large size and complex interfaces, are susceptible to changes in thermal stability under transient external heat flows in the space environment, thus affecting the working state and performance of optical payloads. Therefore, it is necessary to conduct thermal stability deformation measurements on the ground, using the space structure platform's load adapter interface points as measurement characterization points. The accuracy of the thermal stability deformation measurement test system was quantitatively evaluated, ensuring the accuracy and reliability of the measurement data. This allows for precise prediction of the structural thermal stability of the space structure platform during its periodic entry and exit from Earth's shadow during on-orbit operation. Figure 5 As shown.

[0165] Application Prospects

[0166] In the evaluation of measurement data from the first domestic thermal stability test of a large space structure platform, the conformity of the thermal stability design indicators of the structure platform was successfully verified. It provided key data interpretation support in the development of spacecraft models and has significant innovative and practical value.

[0167] The model for evaluating the accuracy of thermal stability tests of large space structures and the method for quantitatively assessing measurement accuracy have been successfully applied to the first domestic thermal stability test of a large space structure platform at the whole-vehicle level. By comparing the results with the simulation analysis of structural thermal stability, the thermal stability design indicators of the prototype platform were verified, and good evaluation results were obtained. This ensured the accuracy and reliability of thermal stability test data for large-size, high-precision spacecraft structures, provided key experimental data support for the thermal stability design of spacecraft platform structures and loads, provided engineering basis for further optimization and improvement of its structural design, and laid a solid foundation for the high-quality and high-efficiency development of subsequent spacecraft model development processes.

[0168] During the development and verification of a large-scale space structure platform, the effectiveness of this technology in characterizing and predicting the dynamic thermal stability deformation (structural thermal stability) of large-scale space structures during on-orbit operation was fully verified, providing an effective quantitative evaluation method for the design specifications compliance and on-orbit performance prediction of large-scale space structures. Simultaneously, this technology can also be used for measurement, testing, verification, and evaluation during the development of large-scale space structures carried by space-based information equipment such as satellite optical observation, remote sensing, and global communications, including products such as antenna reflectors, optical structures, support arms, and trusses. It provides crucial experimental verification data support for achieving high-precision, high-resolution, and high-throughput payload performance indicators, as well as high-reliability, long-life, and stable on-orbit operation, demonstrating significant application value and promising prospects for widespread adoption.

[0169] In the description of this specification, references to terms such as "an embodiment" and "example" refer to specific features, structures, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms are not necessarily intended to refer to corresponding embodiments or examples in a suitable manner.

[0170] It must be pointed out that the above description of the embodiments is not intended to limit the invention but only to help understand the core idea of ​​the invention. For those skilled in the art, any improvements to the invention and equivalent alternatives made to the invention without departing from the principle of the invention are also within the scope of protection of the claims of the invention.

Claims

1. A method for precision quantification and evaluation of thermal stability tests of large space structures, characterized by, The method comprises the following steps: S1: obtaining a plurality of sets of thermal deformation measurement data of a large space structure in a whole cycle of entering and exiting the earth's shadow; In the large space structure platform thermal stability test, on the basis of realizing the simulation of space transient external heat flow alternation in a vacuum low-temperature environment, a four-camera network rapid photography measurement system in a thermal vacuum environment is adopted, a motion tool system and a centralized control system supporting the synchronous shooting of the four cameras are configured, and a multi-camera station network parallel automatic control means is adopted to realize the acquisition and transmission of the four-camera photography data, so as to fully guarantee the minute-level rapid measurement of the thermal stability deformation data of the large space structure; S2: Constructing precision evaluation model, including single-direction point measurement precision of large space structure thermal stability in X, Y, Z three directions ; The precision evaluation model specifically comprises: Control the single direction point position measurement error of the calibrated reference length in X, Y, Z three directions in the field ; Control the single direction point position traceable calibration error of the calibrated reference length in X, Y, Z three directions in the field ; Control the single-directional repeatability measurement error of all measurement sampling points in the field in X, Y, Z three directions ; The one-way point measurement accuracy is calculated by the following formula: Wherein, ± represents the direction of the measurement precision value, and the confidence k is 1 or 2; S3: quantitatively evaluating the measurement precision of the thermal deformation measurement data set based on the precision evaluation model, and obtaining a result.

2. The method of claim 1, wherein, Step S3 specifically comprises the following steps: S3-1: quantitative assessment; S3-2: quantitative assessment; S3-3: Quantitative assessment.

3. The method of claim 2, wherein, Step S3-1 specifically comprises the following steps: S3-1-1: measuring the calibrated values of the n reference lengths calibrated in the control field wherein, = 1,..., ; S3-1-2: In the thermal stability deformation measurement data of the spacecraft in and out of the earth shadow full cycle, obtain each m times of measurement values of n lengths wherein, = 1, …, , = 1, …, ; S3-1-3: Obtain the absolute value of the i-th length of the j-th measurement error i.e. S3-1-4: Obtain the point location measurement error of the ith length and the jth time (e ), that is: S3-1-5: Obtain the single-direction point location measurement error of the i-th length and the j-th time (S3-1-5) ), that is: S3-1-6: One-way point measurement error in deformation measurement data in the whole cycle ) The statistical verification of the distribution characteristics of the set sample verified that the one-way point measurement error ) conforms to the normal distribution; S3-1-7: Obtain the average value and standard deviation of all one-way point location measurement error set samples, i.e., (S3-1-6) ), ( ); S3-1-8: overall sample evaluation of the one-way point measurement error set of all measurement data sets.

4. The method of claim 3, wherein, Step S3-1-8 is specifically: When the confidence k is 1, When the confidence k is 2, 。 5. The method of claim 2, wherein, Step S3-2 is specifically: Measuring the traceability calibration error of n reference lengths calibrated in a control field i.e. one can obtain : When the confidence k is 2, .

6. The method of claim 2, wherein, Step S3-3 specifically comprises the following steps: S3-3-1: In the thermal stability deformation measurement data of the spacecraft in and out of the earth shadow full cycle, obtain the measurement control field n measurement points, and m measurement values under the step-by-step transient external heat flow alternating measurement working condition wherein, ; S3-3-2: taking the three-dimensional coordinates of the n measuring points in the first measurement as the reference, taking all the measuring points of the measurement control field of the thermal steady deformation measurement data set as the common points, performing coordinate system conversion, obtaining the measurement error of the m-1 times measurement of the n measuring points in the X, Y, Z three directions relative to the three-dimensional coordinates of the n measuring points in the first measurement , a total of m-1 groups of measurement errors . ​ S3-3-3: Obtain the RMS value of the three-dimensional point coordinate measurement error (σ ) of the m-1 groups, that is: S3-3-4: According to steps S3-3-1 to S3-3-3, obtain ; S3-3-5: Deformation measurement data throughout the entire cycle ( )Statistical verification of the distribution characteristics of the set of samples, which has been verified ( The set follows a normal distribution; S3-3-6: obtain the average value and the standard deviation of all the measurement error RMS value set samples of the three-dimensional point coordinate measurement error of all the measurement control fields in the whole period of deformation measurement data, that is, , ; S3-3-7: overall sample evaluation of the measurement control field three-dimensional point coordinate measurement error RMS value set in all measurement data.

7. The method of claim 6, wherein, Step S3-3-7 is specifically: When the confidence k is 1, When the confidence k is 2, 。

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