Reliability testing method of spacecraft mechanical products based on digital simulation

Abstract

The present invention discloses a reliability testing method for spacecraft mechanical products based on digital simulation. The testing method includes: obtaining the mission and functional requirements of the spacecraft mechanical products, and then constructing a digital simulation model and determining the nominal working conditions; performing nominal working condition physical experiments and nominal working condition simulation analysis based on the digital simulation model, and then quantitatively verifying the accuracy of the model based on the obtained performance data and simulation analysis results; if the verification is passed, then obtaining the full working condition based on the possible working conditions when the spacecraft mechanical products are actually working; performing full working condition simulation analysis and obtaining simulation analysis results, thereby comprehensively evaluating the reliability of the spacecraft mechanical products. This testing method can realize the quantitative evaluation of the digital simulation model through a limited number of nominal working condition physical experiments with an easy-to-simulate working environment, combined with large sample data obtained through digital simulation, thereby obtaining the full working condition reliability evaluation results of the spacecraft mechanical products.

Description

Technical Field

[0001] The present invention relates to the field of spacecraft technology, and in particular to a reliability testing method for spacecraft mechanical products based on digital simulation. Background Art

[0002] With the rapid development of aerospace technology, people have higher and higher requirements for the life and reliability of spacecraft mechanical products. However, due to the complex composition and process of spacecraft mechanical products, their cost is relatively high. It is difficult to quantitatively verify their actual life and reliability in orbit through ground tests. Therefore, only a very small number of test pieces (usually only 1 to 2) can be used in engineering projects to conduct limited tests on one or several of the worst working conditions that are basically impossible to occur during the on-orbit operation, so as to verify their working ability under extreme working conditions, and it is impossible to obtain the true reliability level under actual working conditions. In addition, due to the special working environment of spacecraft, its accurate working environment conditions are often difficult to predict in advance before entering orbit for formal work. Taking the landing process of extraterrestrial bodies as an example, the landing speed and landing attitude of the spacecraft, the surface morphology of the landing area of ​​the celestial body (slope size, whether there are meteorites or craters, etc.), the mechanical properties of the celestial soil, the illumination and reflection conditions, etc. that affect the landing reliability cannot be accurately obtained before landing, and only the possible distribution range can be determined in advance. Therefore, it is impossible to obtain the reliability level of the actual working state through physical experiments during the development of spacecraft. Usually, only extremely conservative reliability assessment results of the worst working conditions can be obtained in engineering, resulting in over-design of spacecraft mechanical products. Digital simulation technology has become an indispensable and important design method for spacecraft mechanical products, but the existing simulation technology can usually only carry out deterministic simulation for nominal working conditions, and then verify the design plan or pre-analyze the test plan. Although there are studies on randomized simulation of uncertainty factors from the perspective of reliability, the accuracy of the simulation results can only be qualitatively analyzed, and quantitative evaluation cannot be carried out. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art to at least a certain extent. To this end, the purpose of the present invention is to propose a reliability test method for spacecraft mechanical products based on digital simulation, so as to achieve a quantitative evaluation of the digital simulation model through a limited number of nominal working condition physical experiments with an easy-to-simulate working environment, combined with a large sample data obtained through digital simulation, so as to obtain the full working condition reliability evaluation result of the spacecraft mechanical product.

[0004] To achieve the above-mentioned purpose, an embodiment of the present invention proposes a reliability testing method for a spacecraft mechanical product based on digital simulation, the method comprising the following steps: obtaining the mission and function requirements of the spacecraft mechanical product, and constructing a digital simulation model of the spacecraft mechanical product according to the mission and function requirements; determining the nominal operating conditions according to the mission and function requirements, and performing nominal operating condition physical experiments and nominal operating condition simulation analysis based on the digital simulation model to obtain performance data and simulation analysis results of the spacecraft mechanical product under the nominal operating conditions; quantitatively verifying the accuracy of the digital simulation model based on the performance data and simulation analysis results under the nominal operating conditions; after the accuracy of the digital simulation model is verified, obtaining full operating conditions based on possible operating conditions when the spacecraft mechanical product is actually working, and performing full operating condition simulation analysis based on the digital simulation model to obtain simulation analysis results of the spacecraft mechanical product under the full operating conditions; comprehensively evaluating the reliability of the spacecraft mechanical product based on the simulation results under the full operating conditions to obtain a comprehensive reliability evaluation result.

[0005] The reliability test method of a spacecraft mechanical product based on digital simulation in the embodiment of the present invention obtains the mission and function requirements of the spacecraft mechanical product, and constructs a digital simulation model of the spacecraft mechanical product according to the mission and function requirements; then determines the nominal working condition according to the mission and function requirements, and performs the nominal working condition physical experiment and the nominal working condition simulation analysis based on the digital simulation model, and obtains the performance data and simulation analysis results of the spacecraft mechanical product under the nominal working condition; quantitatively verifies the accuracy of the digital simulation model according to the performance data and simulation analysis results under the nominal working condition; then, after the accuracy of the digital simulation model is verified, the full working condition is obtained based on the possible working condition of the spacecraft mechanical product when it is actually working, and the full working condition simulation analysis is performed based on the digital simulation model to obtain the simulation analysis results of the spacecraft mechanical product under the full working condition; thus, the reliability of the spacecraft mechanical product is comprehensively evaluated according to the simulation results under the full working condition, and the comprehensive reliability evaluation result is obtained. Thus, it is possible to quantitatively judge the digital simulation model through the nominal working condition physical experiment with a limited number of times and an easy-to-simulate working environment, combined with the large sample data obtained through digital simulation, so as to obtain the full working condition reliability evaluation result of the spacecraft mechanical product.

[0006] In addition, the above-mentioned spacecraft mechanical product reliability testing method based on digital simulation of the present invention may also have the following additional technical features:

[0007] According to one embodiment of the present invention, constructing a digital simulation model of a spacecraft mechanical product according to the mission and functional requirements includes: determining a full mission profile and a design scheme of the spacecraft mechanical product according to the mission and functional requirements; determining a full operating range, a three-dimensional design model and influencing factors of the spacecraft mechanical product according to the full mission profile and the design scheme; and constructing a digital simulation model of the spacecraft mechanical product according to the full operating range, the three-dimensional design model and the influencing factors.

[0008] According to one embodiment of the present invention, after constructing the digital simulation model of the spacecraft mechanical product, the spacecraft mechanical product reliability testing method based on digital simulation further includes: checking the correctness of the digital simulation model; wherein, after the correctness check of the digital simulation model is passed, executing the step of determining the nominal operating conditions according to the mission and functional requirements.

[0009] According to one embodiment of the present invention, performing physical experiments under nominal working conditions based on the digital simulation model to obtain performance data of the spacecraft mechanical product under the nominal working conditions includes: performing multiple physical experiments under the nominal working conditions based on the digital simulation model to obtain performance data of the spacecraft mechanical product under the nominal working conditions.

[0010] According to one embodiment of the present invention, performing a simulation analysis of nominal working conditions based on the digital simulation model to obtain a simulation analysis result of the spacecraft mechanical product under the nominal working conditions includes: determining an uncertain sensitive factor under the nominal working conditions; determining a simulation model under the nominal working conditions according to the uncertain sensitive factor under the nominal working conditions; performing a simulation analysis on the simulation model under the nominal working conditions to obtain a simulation analysis result of the spacecraft mechanical product under the nominal working conditions.

[0011] According to one embodiment of the present invention, the quantitative verification of the accuracy of the digital simulation model based on the performance data and simulation analysis results under the nominal operating conditions includes: determining the probability distribution type of the simulation analysis results under the nominal operating conditions; calculating the typical statistical characteristics of the nominal operating conditions according to the probability distribution type; constructing a nominal operating condition test statistic based on the typical statistical characteristics of the nominal operating conditions; and performing a hypothesis test analysis at a given confidence level based on the nominal operating condition test statistic and the performance data under the nominal operating conditions to achieve quantitative verification of the accuracy of the digital simulation model.

[0012] According to one embodiment of the present invention, performing full-operating-condition simulation analysis based on the digital simulation model to obtain simulation analysis results of the spacecraft mechanical product under the full operating conditions includes: determining uncertain sensitive factors under the full operating conditions; determining the simulation model under the full operating conditions according to the uncertain sensitive factors under the full operating conditions; performing simulation analysis on the simulation model under the full operating conditions to obtain simulation analysis results of the spacecraft mechanical product under the full operating conditions.

[0013] According to one embodiment of the present invention, the reliability of the spacecraft mechanical product is comprehensively evaluated based on the simulation results under the full working conditions to obtain the comprehensive reliability evaluation results, including: determining the probability distribution type of the simulation analysis results under the full working conditions; calculating the typical statistical characteristics of the full working conditions according to the probability distribution type; and calculating the reliability confidence lower limit value at a given confidence level based on the typical statistical characteristics of the full working conditions to obtain the comprehensive reliability evaluation results.

[0014] According to one embodiment of the present invention, the reliability testing method of spacecraft mechanical products based on digital simulation also includes: judging whether the comprehensive reliability evaluation result meets the given reliability index; if the comprehensive reliability evaluation result does not meet the given reliability index, determining the design parameters that need to be optimized and / or the working environment constraints that need to be improved according to the simulation analysis results under the full working conditions, and optimizing the design scheme according to the design parameters that need to be optimized and / or the working environment constraints that need to be improved; if the comprehensive reliability evaluation result meets the given reliability index, further judging whether to optimize the design scheme, and improving the design scheme according to the judgment result or ending the reliability testing process.

[0015] According to one embodiment of the present invention, the judgment of whether to optimize the design scheme includes: judging whether the digital simulation model is over-designed according to the comprehensive reliability evaluation result; if the digital simulation model is over-designed, determining that the design scheme needs to be optimized, and determining the design parameters that need to be optimized based on the simulation analysis results under all working conditions, and optimizing the design scheme based on the design parameters that need to be optimized.

[0016] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a flow chart of a method for reliability testing of a spacecraft mechanical product based on digital simulation according to a first embodiment of the present invention;

[0018] Figure 2 is a flow chart of a method for reliability testing of a spacecraft mechanical product based on digital simulation according to a second embodiment of the present invention;

[0019] Figure 3 is a flow chart of a method for reliability testing of a spacecraft mechanical product based on digital simulation according to a third embodiment of the present invention;

[0020] Figure 4 is a flow chart of a method for reliability testing of a spacecraft mechanical product based on digital simulation according to a fourth embodiment of the present invention;

[0021] Figure 5 is a flow chart of a method for reliability testing of a spacecraft mechanical product based on digital simulation according to a fifth embodiment of the present invention;

[0022] Figure 6 is a flow chart of a method for reliability testing of a spacecraft mechanical product based on digital simulation according to a sixth embodiment of the present invention;

[0023] Figure 7 It is a specific implementation flow chart of a method for testing the reliability of a spacecraft mechanical product based on digital simulation according to an embodiment of the present invention;

[0024] Figure 8 It is a structural schematic diagram of a system for implementing a reliability testing method for spacecraft mechanical products based on digital simulation according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0026] Please refer to the following Figure 1-8 A method for testing the reliability of a spacecraft mechanical product based on digital simulation according to an embodiment of the present invention is described.

[0027] In an embodiment of the present invention, Figure 8 As shown, the reliability testing method of spacecraft mechanical products based on digital simulation in the embodiment of the present invention can be implemented through a digital model construction and inspection module, a nominal operating condition physical experiment module, a nominal operating condition simulation analysis module, a digital model quantitative verification module, a full operating condition reliability system simulation module, a reliability comprehensive evaluation module and a reliability growth and optimization module.

[0028] Figure 1 It is a flow chart of a method for reliability testing of spacecraft mechanical products based on digital simulation according to an embodiment of the present invention.

[0029] S11, obtain the mission and functional requirements of spacecraft mechanical products, and build a digital simulation model of spacecraft mechanical products based on the mission and functional requirements.

[0030] Specifically, the full operating range of the spacecraft mechanical product and the three-dimensional design model of the product can be determined according to the mission and functional requirements of the spacecraft mechanical product, thereby constructing a digital simulation model based on the full operating range of the spacecraft mechanical product and the three-dimensional design model of the product.

[0031] It should be noted that the above digital simulation model is a randomized digital simulation model, that is, the model is not accurate and its correctness needs to be checked.

[0032] Furthermore, the correctness of the digital simulation model can be checked. If the digital simulation model fails the check, the digital simulation model is corrected and checked again until the corrected digital simulation model passes the check; if the digital simulation model passes the check, after the correctness check of the digital simulation model passes, the step of determining the nominal working condition according to the task and functional requirements is performed.

[0033] It should be noted that the above-mentioned check on the correctness of the digital simulation model is a qualitative check, which can be specifically: under the nominal state of all influencing factors, a deterministic simulation of simple input is carried out, and the model simplification, input-output relationship, dimension setting, etc. of the simulation model are analyzed and calculated under deterministic conditions, and the correctness of the simulation model is qualitatively checked based on the calculation results. After the qualitative check is passed, the step of determining the nominal working condition according to the task and functional requirements is executed, so as to quantitatively verify the correctness of the digital simulation model.

[0034] As an example, Figure 7 As shown, the above step S11 can be performed in the digital model building and inspection module.

[0035] S12, determine the nominal working conditions according to the mission and functional requirements, and conduct nominal working condition physical experiments and nominal working condition simulation analysis based on the digital simulation model to obtain the performance data and simulation analysis results of the spacecraft mechanical products under the nominal working conditions.

[0036] Specifically, the full working condition analysis of the spacecraft mechanical product can be carried out according to the mission and functional requirements of the spacecraft mechanical product, and the nominal working condition can be determined, and then the nominal working condition test conditions can be determined. Therefore, the nominal working condition physical experiment and nominal working condition simulation experiment can be carried out on the spacecraft mechanical product based on the digital simulation model according to the determined nominal working condition test conditions. As an example, Figure 7 As shown, the nominal operating condition identification step can be performed in the nominal operating condition physical experiment module.

[0037] It should be noted that the above nominal working conditions need to comprehensively consider feasibility and economy, such as the initial state setting of the spacecraft mechanical product, the test environment condition structure, the test duration, the performance parameter test, and whether it is easy to simulate. At the same time, it should be as harsh as possible to fully assess the ultimate capability of the spacecraft mechanical product.

[0038] Furthermore, a nominal working condition physical experiment can be conducted to conduct multiple physical experiments under nominal working conditions based on the digital simulation model to obtain the performance data and simulation analysis results of the spacecraft mechanical product under nominal working conditions. It should be noted that only a limited number of physical experiments are conducted on some sensitive factors under nominal working conditions. As an example, Figure 7 As shown, the nominal operating condition physical experiment can be carried out in the nominal operating condition physical experiment module.

[0039] At the same time, nominal working condition simulation tests can also be carried out to obtain the performance data and simulation analysis results of spacecraft mechanical products under nominal working conditions. Figure 7 As shown, the nominal operating condition simulation experiment can be carried out in the nominal operating condition simulation analysis module.

[0040] S13, quantitatively verify the accuracy of the digital simulation model based on the performance data and simulation analysis results under nominal working conditions.

[0041] Specifically, the above-mentioned simulation analysis results of nominal working conditions can be combined with the physical experimental results under nominal working conditions to perform hypothesis testing analysis at a given confidence level, thereby quantitatively verifying the accuracy of the digital simulation model.

[0042] It should be noted that if the quantitative verification of the accuracy of the digital simulation model fails, the digital simulation model needs to be corrected, and the process returns to step S11 to perform a qualitative test on the corrected digital simulation model.

[0043] As an example, Figure 7 As shown, step S13 can be performed in the digital model quantitative verification module.

[0044] S14, after the accuracy of the digital simulation model is verified, the full working condition is obtained based on the possible working conditions of the spacecraft mechanical product when it is actually working, and the full working condition simulation analysis is performed based on the digital simulation model to obtain the simulation analysis results of the spacecraft mechanical product under the full working condition.

[0045] As an example, Figure 7 As shown, step S14 can be performed in the full-operating-condition reliability system simulation module.

[0046] S15, comprehensively evaluate the reliability of spacecraft mechanical products according to the simulation results under all working conditions to obtain comprehensive reliability evaluation results.

[0047] Specifically, the probability distribution of simulation results under all working conditions can be determined, and then the statistical characteristics of all working conditions can be calculated, so as to obtain a comprehensive reliability evaluation based on the simulation of all working conditions.

[0048] As an example, Figure 7 As shown, step S15 can be performed in the comprehensive reliability evaluation module.

[0049] Furthermore, it is also possible to determine whether the comprehensive reliability evaluation result meets the given reliability index; if the comprehensive reliability evaluation result meets the given reliability index, it is further determined whether to optimize the design solution. If the design solution does not need to be improved, the reliability test process can be terminated. As an example, if Figure 7 As shown, the steps of judging whether the reliability index requirements are met and judging whether optimization is needed can be performed in the comprehensive reliability evaluation module.

[0050] Optionally, if the comprehensive reliability evaluation result does not meet the given reliability index, the design parameters that need to be optimized and / or the working environment constraints that need to be improved are determined based on the simulation analysis results under all working conditions, and the design scheme is optimized based on the design parameters that need to be optimized and / or the working environment constraints that need to be improved, thereby optimizing the design scheme. In this way, the reliability of the spacecraft can be improved.

[0051] If the comprehensive reliability evaluation results meet the given reliability index but the design scheme still needs to be improved, the design scheme is improved, that is, if it is determined that the scheme in question needs to be improved, the design parameters that need to be optimized are determined, and then the design scheme is optimized based on the design parameters that need to be optimized. For example, after the comprehensive reliability evaluation results meet the given reliability index, it can also be determined based on the comprehensive reliability evaluation results whether the digital simulation model has an over-design situation; if the digital simulation model has an over-design situation, it is determined that the design scheme needs to be optimized, and the design parameters that need to be optimized are determined based on the simulation analysis results under all working conditions, and the design scheme is optimized based on the design parameters that need to be optimized.

[0052] As an example, Figure 7 As shown, the above steps of optimizing the design solution and / or improving the working environment can be performed in the reliability growth and optimization module.

[0053] In this way, it is possible to conduct physical experiments on nominal working conditions with a limited number of times and in an easily simulated working environment, and combine them with large sample data obtained through digital simulation to quantitatively evaluate the digital simulation model, thereby obtaining the full-condition reliability assessment results of spacecraft mechanical products and improving the reliability of the spacecraft.

[0054] It should be noted that the testing method of the embodiment of the present invention is not only applicable to spacecraft mechanical products, but can also be extended to apply to and test other products that cannot be fully simulated under actual working conditions.

[0055] In one embodiment of the present invention, Figure 2 As shown, the process of constructing a digital simulation model of a spacecraft mechanical product according to mission and functional requirements may include:

[0056] S21, determine the full mission profile and design plan of spacecraft mechanical products based on mission and functional requirements.

[0057] S22, determine the full operating range, three-dimensional design model and influencing factors of spacecraft mechanical products based on the full mission profile and design plan.

[0058] S23, constructs a digital simulation model of spacecraft mechanical products based on the full range of operating conditions, three-dimensional design models and influencing factors.

[0059] Specifically, the full mission profile and design scheme of the spacecraft mechanical product can be determined according to the mission and functional requirements of the spacecraft mechanical product, and then the full operating range and three-dimensional design model of the spacecraft mechanical product can be determined. At the same time, all influencing factors can be identified and the probability distribution type of the influencing factors can be determined, so as to screen out the main sensitive factors.

[0060] Thus, a digital simulation model of a spacecraft mechanical product can be constructed. Among them, the above-mentioned sensitive factors can be factors with a greater probability of occurrence among the above-mentioned influencing factors.

[0061] In one embodiment of the present invention, Figure 3 As shown, the above process of performing simulation analysis of nominal working conditions based on the digital simulation model to obtain simulation analysis results of the spacecraft mechanical product under nominal working conditions may include:

[0062] S31, determine the uncertain sensitivity factors under nominal operating conditions.

[0063] S32, determining a simulation model under the nominal operating condition according to the uncertain sensitive factors under the nominal operating condition.

[0064] S33, performing simulation analysis on the simulation model under the nominal working condition to obtain simulation analysis results of the spacecraft mechanical product under the nominal working condition.

[0065] Specifically, the uncertain sensitive factors of the spacecraft mechanical products under the nominal working conditions can be determined, and then the simulation model under the nominal working conditions can be determined according to the determined nominal working conditions and the uncertain sensitive factors under the nominal working conditions. Thus, randomized simulation analysis can be performed on the simulation model under the nominal working conditions to obtain the simulation analysis results of the spacecraft mechanical products under the nominal working conditions. Based on the simulation analysis results, the product performance data of the spacecraft mechanical products can be obtained, thereby providing a big data sample for the quantitative verification of the digital simulation model.

[0066] Thus, it is possible to implement a nominal working condition simulation analysis on the digital simulation model. The uncertainty sensitive factor may be a sensitive factor not involved in the nominal working condition physical experiment.

[0067] In one embodiment of the present invention, Figure 4 As shown, the process of quantitatively verifying the accuracy of the digital simulation model based on the performance data and simulation analysis results under nominal conditions may include:

[0068] S41, determining the probability distribution type of the simulation analysis results under the nominal working condition.

[0069] S42, calculating typical statistical characteristics of the nominal operating condition according to the probability distribution type.

[0070] S43, constructing a nominal operating condition test statistic based on typical statistical characteristics of the nominal operating condition.

[0071] S44, based on the nominal operating condition test statistics and the performance data under the nominal operating condition, a hypothesis test analysis is performed at a given confidence level to quantitatively verify the accuracy of the digital simulation model.

[0072] Among them, the performance data under the above-mentioned nominal working conditions are the results of physical experiments under nominal working conditions.

[0073] It should be noted that, since the performance data of spacecraft mechanical products under nominal working conditions usually obey normal distribution, the above nominal working condition test statistics can be tested for normal distribution. If they cannot pass the normal distribution test, they can be transformed into normal distribution. As an example, the method in the national standard "Normality Test for Statistical Processing and Interpretation of Data" (standard number GB / T 4771-2001) can be used to test the normal distribution of the above nominal working condition test statistics, and the significance level of the test is usually 5%. If they cannot pass the normal distribution test, they can be transformed into normal distribution by the Box-Cox transformation method proposed in the paper An analysis of transformation published by Box GEP and Cox DR in the Journal of the Royal Statistical Society in 1964.

[0074] In this way, the accuracy of the digital simulation model can be quantitatively verified.

[0075] In one embodiment of the present invention, Figure 5 As shown, the above-mentioned process of performing full-operating-condition simulation analysis based on the digital simulation model to obtain simulation analysis results of the spacecraft mechanical product under full operating conditions may include:

[0076] S51, determine the uncertain sensitivity factors under all operating conditions.

[0077] S52, determining a simulation model under all operating conditions according to the uncertain sensitive factors under all operating conditions.

[0078] S53, performing simulation analysis on the simulation model under all working conditions to obtain simulation analysis results of the spacecraft mechanical product under all working conditions.

[0079] Specifically, for all possible situations that may occur when spacecraft mechanical products are actually working, all uncertain sensitive factors under all working conditions can be identified, and the probability distribution of the uncertain sensitive factors can be determined. Then, the simulation distribution model under all working conditions can be set according to the uncertain sensitive factors under all working conditions, and random digital simulation under all working conditions can be carried out.

[0080] In this way, the simulation results of the working performance parameters of spacecraft mechanical products under all working conditions can be obtained.

[0081] In one embodiment of the present invention, Figure 6 As shown, the above process of comprehensively evaluating the reliability of spacecraft mechanical products based on the simulation results under all working conditions and obtaining the comprehensive reliability evaluation results may include:

[0082] S61, determining the probability distribution type of the simulation analysis results under all working conditions.

[0083] S62, calculating typical statistical characteristics of all operating conditions according to the probability distribution type.

[0084] S63, based on the typical statistical characteristics of all working conditions, calculate the lower confidence limit of reliability at a given confidence level to obtain a comprehensive reliability evaluation result.

[0085] Specifically, the probability distribution type can be identified and determined based on the extracted simulation analysis results of the full working condition of the spacecraft mechanical products, and the typical statistical characteristics can be calculated. In this way, a comprehensive evaluation of the reliability of the full working condition can be carried out, and the confidence lower limit of the reliability under a given confidence level can be obtained, and on this basis, it can be compared with the given reliability index.

[0086] As an example, probability distribution theory can be used to carry out comprehensive reliability evaluation of all working conditions. Specifically: for a normal distribution performance parameter X, if its allowable distribution interval is (x L ,x 1U ), that is, x L <X<x 1U When the spacecraft mechanical product is considered to be working normally, otherwise it is considered to be failed. The reliability of the spacecraft mechanical product can be expressed as R = P{x L <X<x 1U Assume that the performance data x obtained through n times of full-condition reliability system simulation is i (i=1,2,…,n), then its reliability coefficient is

[0087]

[0088] Among them, the average performance parameters obtained by simulation and standard deviation s are

[0089]

[0090] Therefore, for a given confidence level γ, the one-sided lower confidence limit R of the full-condition reliability of spacecraft mechanical products is L , according to the random simulation times n, confidence γ, reliability coefficient K L and K U , obtained from the national standard "Confidence Lower Limit of Reliability of Complete Sample of Normal Distribution" (standard number GB / T 4885-2009). Among them, the confidence level γ of the reliability evaluation of the above-mentioned spacecraft mechanical products can be taken as 0.7.

[0091] It should be noted that, since the performance parameters of spacecraft mechanical products under all working conditions usually obey the normal distribution, the simulation analysis results under all working conditions mentioned above can be tested for normal distribution. If they cannot pass the normal distribution test, they can be transformed into normal distribution. As an example, the method in the national standard "Normality Test for Statistical Processing and Interpretation of Data" (standard number GB / T 4881-2001) can be used to test the normal distribution of the simulation analysis results under all working conditions mentioned above, and the significance level of the test is usually 5%. If the normal distribution test cannot be passed, it can be transformed into a normal distribution by the Box-Cox transformation method proposed in the paper An analysis of transformation published by Box GEP and Cox DR in the Journal of the Royal Statistical Society in 1964.

[0092] In this way, a comprehensive evaluation of the reliability of spacecraft mechanical products under all operating conditions can be achieved.

[0093] In summary, the reliability testing method for spacecraft mechanical products based on digital simulation in the embodiment of the present invention can realize the nominal working condition physical experiment with a limited number of times and an easy-to-simulate working environment, combined with the large sample data obtained through digital simulation, to conduct quantitative evaluation of the digital simulation model, thereby obtaining the full-working condition reliability evaluation result of the spacecraft mechanical product and improving the reliability of the spacecraft.

[0094] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection portion with one or more wirings (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0095] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0096] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0097] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0098] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0099] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0100] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0101] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A reliability testing method for spacecraft mechanical products based on digital simulation, characterized in that: The following steps are involved: Obtaining the mission and functional requirements of spacecraft mechanical products, and building a digital simulation model of the spacecraft mechanical products according to the mission and functional requirements; Determine the nominal working condition according to the mission and functional requirements, and perform nominal working condition physical experiments and nominal working condition simulation analysis based on the digital simulation model to obtain performance data and simulation analysis results of the spacecraft mechanical product under the nominal working condition; Quantitatively verify the accuracy of the digital simulation model based on the performance data and simulation analysis results under the nominal working conditions; After the accuracy of the digital simulation model is verified, the full working condition is obtained based on the possible working conditions of the spacecraft mechanical product when it is actually working, and the full working condition simulation analysis is performed based on the digital simulation model to obtain the simulation analysis results of the spacecraft mechanical product under the full working condition; Comprehensively evaluate the reliability of the spacecraft mechanical product according to the simulation results under the full working conditions to obtain a comprehensive reliability evaluation result; The digital simulation model of the spacecraft mechanical product is constructed according to the mission and functional requirements, including: Determine the full mission profile and design plan of the spacecraft mechanical product according to the mission and functional requirements; Determine the full operating range, three-dimensional design model and influencing factors of the spacecraft mechanical product according to the full mission profile and the design scheme; Constructing a digital simulation model of the spacecraft mechanical product according to the full operating range, the three-dimensional design model and the influencing factors; The performing of full-operating-condition simulation analysis based on the digital simulation model to obtain simulation analysis results of the spacecraft mechanical product under the full-operating conditions includes: Determine the uncertainty sensitivity factor under the full operating conditions; Determine the simulation model under all working conditions according to the uncertain sensitive factors under all working conditions; Performing simulation analysis on the simulation model under the full working conditions to obtain simulation analysis results of the spacecraft mechanical product under the full working conditions; The reliability of the spacecraft mechanical product is comprehensively evaluated according to the simulation results under the full working conditions to obtain a comprehensive reliability evaluation result, including: Determining the probability distribution type of the simulation analysis results under the full working conditions; Calculate typical statistical characteristics of all working conditions according to the probability distribution type; Based on the typical statistical characteristics of the full working conditions, a reliability confidence lower limit value under a given confidence level is calculated to obtain the comprehensive reliability evaluation result; The method further comprises: Determining whether the comprehensive reliability evaluation result meets a given reliability index; If the comprehensive reliability evaluation result does not meet the given reliability index, then according to the simulation analysis results under the full working conditions, determine the design parameters that need to be optimized and / or the working environment constraints that need to be improved, and optimize the design scheme according to the design parameters that need to be optimized and / or the working environment constraints that need to be improved; If the comprehensive reliability evaluation result meets the given reliability index, it is determined whether to optimize the design solution, and the design solution is improved or the reliability test process is terminated according to the determination result.

2. The method for reliability testing of spacecraft mechanical products based on digital simulation according to claim 1, characterized in that: After constructing the digital simulation model of the spacecraft mechanical product, the method further includes: Checking the correctness of the digital simulation model; Wherein, after the correctness check of the digital simulation model is passed, the step of determining the nominal working condition according to the task and functional requirements is performed.

3. The method for reliability testing of spacecraft mechanical products based on digital simulation according to claim 1, characterized in that: Based on the digital simulation model, a nominal working condition physical experiment is performed to obtain performance data of the spacecraft mechanical product under the nominal working condition, including: Based on the digital simulation model, multiple physical experiments are carried out under the nominal working conditions to obtain performance data of the spacecraft mechanical product under the nominal working conditions.

4. The method for reliability testing of spacecraft mechanical products based on digital simulation according to claim 1, characterized in that: Performing a nominal working condition simulation analysis based on the digital simulation model to obtain a simulation analysis result of the spacecraft mechanical product under the nominal working condition includes: Determine the uncertainty sensitivity factor under the nominal operating conditions; Determining a simulation model under the nominal working condition according to the uncertain sensitive factors under the nominal working condition; A simulation analysis is performed on the simulation model under the nominal working condition to obtain a simulation analysis result of the spacecraft mechanical product under the nominal working condition.

5. The method for reliability testing of spacecraft mechanical products based on digital simulation according to claim 1, characterized in that: The quantitative verification of the accuracy of the digital simulation model according to the performance data and simulation analysis results under the nominal working conditions includes: Determining a probability distribution type of the simulation analysis results under the nominal working condition; Calculate typical statistical characteristics of nominal operating conditions according to the probability distribution type; Constructing a nominal operating condition test statistic based on the typical statistical characteristics of the nominal operating condition; Based on the nominal operating condition test statistics and the performance data under the nominal operating condition, a hypothesis test analysis is performed at a given confidence level to achieve quantitative verification of the accuracy of the digital simulation model.

6. The method for reliability testing of spacecraft mechanical products based on digital simulation according to claim 1, characterized in that: The determining whether to optimize the design solution includes: Determining whether the digital simulation model is over-designed according to the comprehensive reliability evaluation result; If the digital simulation model is over-designed, it is determined that the design scheme needs to be optimized, and based on the simulation analysis results under the full working conditions, the design parameters that need to be optimized are determined, and the design scheme is optimized based on the design parameters that need to be optimized.

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