A method for assessing the storage lifetime of missile-borne fiber optic inertial navigation systems

Abstract

This invention discloses a method for evaluating the storage lifetime of a missile-borne fiber optic inertial navigation system, comprising: determining the acceleration temperature value T of the test. k The acceleration temperature value T was obtained. k Under these conditions, the acceleration coefficient A of the fiber optic inertial navigation system F According to the acceleration coefficient A of the fiber optic inertial navigation system F Storage time t required for fiber optic inertial navigation systems 贮存时间 The acceleration temperature value T was obtained. k Under these conditions, the time t required to conduct accelerated testing 加速时间 According to t 加速时间 Determine several sampling times; at the accelerating temperature value T k Under certain conditions, accelerated testing was conducted on the fiber optic inertial navigation system (INS), and degradation-sensitive parameters of the INS were acquired at each sampling time. A relationship between these degradation-sensitive parameters and time was constructed. Based on the relationship between these parameters and time under storage temperature conditions, and the out-of-tolerance criterion for the degradation-sensitive parameters, the storage lifetime of the INS under storage temperature conditions was obtained. This invention achieves the assessment of the storage lifetime of fiber optic INS, with advantages such as short testing time, scientific evaluation method, and reasonable evaluation results.

Description

Technical Field

[0001] This invention relates to a method for evaluating the storage life of missile-borne fiber optic inertial navigation systems, which is particularly suitable for long-life, high-reliability autonomous navigation on missile platforms and belongs to the field of inertial measurement technology. Background Technology

[0002] As the most critical component in a missile control system, the accuracy and reliability of the inertial reference directly affect the missile's accuracy and performance. The fiber optic gyroscope is a novel all-solid-state inertial instrument characterized by its all-solid-state nature, high precision, and high reliability. It possesses advantages not found in traditional electromechanical instruments. The fiber optic gyroscope inertial measurement unit, comprised of the core fiber optic gyroscope instrument, is a primary inertial reference for future navigation weapon systems.

[0003] Most navigation weapon systems are characterized by "long-term storage, single-use," with storage periods often lasting decades. This requires all internal components to meet the operating conditions necessary for this storage period. While 1:1 storage tests can effectively verify changes in product characteristics during storage, this approach is clearly insufficient for current national defense needs. Accelerated scientific testing of individual components on the missile is required to assess its storage life. The commonly used method for assessing storage life both domestically and internationally involves accelerated storage testing. This involves applying environmental stresses exceeding natural storage conditions to the samples, collecting and recording failure or degradation data for relevant parameters, analyzing and modeling the test data under specific conditions, and extrapolating the storage period under normal stress.

[0004] In the existing technology, the methods for assessing storage life are all for electronic products. The core component of the fiber optic inertial measurement device, the fiber optic gyroscope, is mainly composed of optical devices such as light sources and detectors, as well as electronic processing circuits. Currently, there are no systematic means and methods for assessing the storage life of fiber optic inertial measurement devices composed of fiber optic gyroscopes and accelerometers. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned defects and provide a method for evaluating the storage life of a missile-grade fiber optic inertial navigation system (INS). This method solves the technical problem that the storage life of existing INS composed of fiber optic gyroscopes and accelerometers cannot be effectively evaluated. This invention realizes the evaluation of the storage life of INS and has the advantages of short test time, scientific evaluation method, and reasonable evaluation results.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] This invention provides a method for evaluating the storage life of a missile-borne fiber optic inertial navigation system (IFS), specifically applicable to the high-dynamic, all-weather autonomous navigation environment of missile platforms, belonging to the field of inertial measurement technology. The IFS of this invention comprises a structural component, three fiber optic gyroscopes, three quartz flexural accelerometers, a DSP circuit, an I / F circuit, a power supply component, four sets of vibration dampers, and a connector. The structural component consists of four cover plates and a main body. The IFS provides an RS-422 communication interface, capable of receiving GPS data, PPS hard synchronization signals, and transmitting position, velocity, attitude, angular velocity, and acceleration information.

[0008] This invention provides a method for evaluating the storage lifetime of a missile-borne fiber optic inertial navigation system, comprising:

[0009] Determine the acceleration temperature value for the experiment. ;

[0010] Based on acceleration temperature value The acceleration temperature value was obtained. Acceleration coefficients of various types of components in fiber optic inertial navigation systems under specific conditions;

[0011] The acceleration coefficient of the fiber optic inertial navigation system (FISH) is obtained based on the acceleration coefficients of various components. ;

[0012] Based on the acceleration coefficient of fiber optic inertial navigation systems Storage time required for fiber optic inertial navigation systems The acceleration temperature value was obtained. Under these conditions, the time required to conduct accelerated testing ;

[0013] according to Determine several sampling times;

[0014] Accelerating temperature value Under these conditions, accelerated tests were conducted on the fiber optic inertial navigation system to obtain degradation-sensitive parameters of the fiber optic inertial navigation system at each sampling time.

[0015] Accelerating temperature value Under the given conditions, based on each sampling time and the degradation-sensitive parameters of the fiber optic inertial navigation system obtained at each sampling time, a relationship between the degradation-sensitive parameters and time is constructed.

[0016] According to different acceleration temperature values The relationship between the degradation sensitivity parameter and time under the given conditions is obtained by obtaining the relationship between the degradation sensitivity parameter and time under the storage temperature condition.

[0017] Based on the relationship between the degradation-sensitive parameters and time under storage temperature conditions, and the out-of-tolerance criteria for the degradation-sensitive parameters, the storage lifetime of the fiber optic inertial navigation system under storage temperature conditions is obtained.

[0018] Furthermore, the acceleration temperature value for the accelerated test is determined according to the following formula. :

[0019]

[0020] in, Given a starting temperature point, Defined as a given cutoff temperature point, Indicates the number of acceleration temperature values ​​required; Indicates the first One acceleration temperature value, This represents the stress gradient coefficient.

[0021] Furthermore, according to the following formula, based on the acceleration temperature value... The acceleration coefficients of various types of components in the fiber optic inertial navigation system were obtained:

[0022]

[0023] in, For the first The acceleration coefficient of the various components, , This represents the total number of different types of components in a fiber optic inertial navigation system. Boltzmann's constant, For the first Activation energy of such components This is the standard room temperature.

[0024] Furthermore, the acceleration coefficient of the fiber optic inertial navigation system The following formula is used to obtain:

[0025]

[0026] in, For the first The total number of various components; For the first time under normal temperature conditions Failure rate of various components.

[0027] Furthermore, .

[0028] Furthermore, the degradation-sensitive parameters of fiber optic inertial navigation systems include the zero bias of the fiber optic gyroscope. Fiber optic gyroscope calibration factor Zero bias stability of fiber optic gyroscope Absolute error of fiber optic gyroscope Quartz accelerometer zero bias Quartz accelerometer scale factor Quartz accelerometer zero bias stability Or quartz accelerometer monthly repeatability One or more of the following; preferably, a fiber optic gyroscope with zero bias is selected. Fiber optic gyroscope calibration factor Quartz accelerometer zero bias Quartz accelerometer scale factor As a degradation-sensitive parameter.

[0029] Furthermore, several sampling times are between 0 and... Set at equal intervals within the range.

[0030] Furthermore, in accelerating the temperature value Under these conditions, based on the sampling times and the degradation sensitivity parameters of the fiber optic inertial navigation system obtained at each sampling time, the method for constructing the relationship between the degradation sensitivity parameters and time is as follows:

[0031] Linear fitting was performed on each sampling time and the degradation-sensitive parameters of the fiber optic inertial navigation system acquired at each sampling time to obtain... Formal relation, in which Represents a degradation-sensitive parameter. Represents time, , These are the linear fitting coefficients;

[0032] For different acceleration temperature values The linear fitting coefficients obtained under the given conditions are used for linear fitting to obtain the fitting coefficients under the storage temperature conditions, which in turn yields the relationship between the degradation sensitive parameter and time under the storage temperature conditions.

[0033] Furthermore, the out-of-tolerance criterion for the degradation-sensitive parameter is:

[0034] ;

[0035] in, For a certain time The change in the time-degradation sensitive parameter A preset threshold is set. When this threshold is exceeded, the degradation-sensitive parameter is considered to have degraded, leading to the failure of the fiber optic inertial navigation system. The change can be a relative change or an absolute change.

[0036] Based on the relationship between degradation-sensitive parameters and time under storage temperature conditions, and the out-of-tolerance criterion for degradation-sensitive parameters, the method for obtaining the storage lifetime of fiber optic inertial navigation systems under storage temperature conditions is as follows:

[0037] Will Substituting the obtained degradation sensitivity parameter values ​​into the relationship between the degradation sensitivity parameter and time under storage temperature conditions, the storage lifetime of the fiber optic inertial navigation system under storage temperature conditions is obtained.

[0038] Furthermore, when the degradation sensitivity parameter is N At that time, N >1, the out-of-tolerance criteria for each degradation-sensitive parameter are denoted as follows:

[0039] ≥ , ≥ … ≥ ;

[0040] Will = , = … = Substituting the degradation sensitivity parameters obtained at that time into the relationship between the degradation sensitivity parameters and time under storage temperature conditions, we obtain the following results: N indivual value;

[0041] Will N indivual The minimum value among the values ​​is taken as the storage lifetime of the fiber optic inertial navigation system under the storage temperature condition.

[0042] Compared with the prior art, the present invention has at least one of the following advantages:

[0043] (1) This invention provides a method for evaluating the storage life of a missile-mounted fiber optic inertial navigation system. It provides constant stress tests at multiple temperature points and evaluates the storage life of the device by the trend relationship between temperature stress and degradation parameters. It has the advantages of short test time, scientific evaluation method and reasonable evaluation results.

[0044] (2) This invention clarifies that the zero bias and scaling factor parameters of fiber optic gyroscopes and accelerometers are used as degradation parameters, thereby enabling effective storage lifetime assessment tests;

[0045] (3) The present invention provides a constant stress test at multiple temperature points, which has the advantages of small sample size and short test time;

[0046] (4) The method used in this invention is applicable not only to fiber optic inertial measurement devices, but also to the storage life assessment of other electronic products, and has universality. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the fiber optic inertial navigation system of the present invention;

[0048] Figure 2 This is a flowchart of the accelerated testing process of the present invention;

[0049] Figure 3This is a flowchart of a method for evaluating the storage lifetime of a missile-borne fiber optic inertial navigation system according to the present invention. Detailed Implementation

[0050] The features and advantages of the present invention will become clearer and more apparent from the following detailed description.

[0051] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments. Although various aspects of embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated otherwise.

[0052] Based on the characteristics of fiber optic inertial measurement units (FIMs) and the environmental requirements for navigation applications, this method establishes various temperature stress models, sets degradation-sensitive parameters, and proposes a method for evaluating the storage life of missile-grade FIMs. This invention has advantages such as simple operation, scientific evaluation, and a reasonable and feasible method.

[0053] like Figure 1 The fiber optic inertial measurement unit (IMU) used in this invention has the following composition and structure: three fiber optic gyroscopes 1 and three quartz flexible accelerometers 2 are respectively installed in three cavities of the main body 3 and covered by three cover plates; an I / F circuit 4 is installed in the upper surface cavity of the main body and covered by a cover plate 5; a DSP circuit 6 and a power supply component 7 are located on the same side and installed on one side of the main body; the main body adopts a four-point vibration damping at the waist, and four vibration dampers 8 are respectively installed at the waist of the main body; a connector 9 is located above the main body 3 for connecting to the control system for information transmission; the components are connected by flexible wires without wire bundles. In a specific embodiment, the DSP circuit uses a processor with "DSP+FPGA" as the core, and is peripherally configured with a watchdog circuit, flash memory, and RS422 interface circuit, etc. The inertial measurement unit is used to measure the angular velocity and linear acceleration of the carrier; and performs attitude, position, and linear velocity calculations based on the angular velocity and linear acceleration, which can obtain the zero bias of the fiber optic gyroscope. and calibration factor and the zero bias of the quartz accelerometer and scaling factor Degradation-sensitive parameters. The fiber optic inertial measurement unit is designed to have an outer envelope size of no more than 152mm×152mm×72mm, a weight of no more than 1.8kg, and a power consumption of no more than 18W at room temperature.

[0054] As a precision instrument integrating optoelectronics, the fiber optic inertial measurement unit (FIRST) consists of electronic components in its DSP circuit, I / F circuit, and power supply components. These components can be analyzed according to their degradation characteristics. However, the degradation characteristics of fiber optic gyroscopes and quartz flexural accelerometers are quite unique and cannot be analyzed according to the degradation characteristics of electronic equipment. Therefore, the storage life of FIRST needs to be evaluated through accelerated degradation testing.

[0055] This invention discloses a method for assessing the storage life of a missile-grade fiber optic inertial measurement unit (IMU). This method involves conducting accelerated degradation tests on the IMU under temperature stress. Specifically, by testing key data from accelerated degradation tests under multiple temperature stress conditions, a degradation model is established to predict the time when performance parameters exceed acceptable limits under actual storage conditions, thereby determining the device's storage performance retention period. The fiber optic inertial measurement unit is designed according to... Figure 2 The process shown is used to conduct accelerated degradation tests.

[0056] Temperature stress The acceleration temperature value is determined using the following formula:

[0057] (1)

[0058] Defined as the starting temperature point, it can typically be the high-temperature operating temperature point. Defined as the cutoff temperature point. Indicates the middle number A temperature point.

[0059] The stress-life model of fiber optic inertial navigation systems is described using the Arrhenius equation, as shown in the following formula:

[0060] (2)

[0061] in, , - Thermodynamic temperature, absolute temperature;

[0062] -temperature Fiber optic gyroscope lifetime, in hours;

[0063] -temperature Fiber optic gyroscope lifetime, in hours;

[0064] - Activation energy, unit: electron volt;

[0065] - Boltzmann constant;

[0066] Definition of the first Acceleration coefficient of various components for:

[0067] (3)

[0068] in For the first The activation energy of the component. Then the acceleration coefficient of the device. Defined as:

[0069] (4)

[0070] in For the first The total number of various components; For the first time under normal conditions Failure rate of various components;

[0071] Based on the selected stress temperature, the corresponding accelerated storage test time for:

[0072] (5)

[0073] in Indicates the required storage time for the product; This indicates the required accelerated testing time for the product under stress temperature.

[0074] Select fiber optic gyroscope zero bias , calibration factor Zero bias of quartz accelerometer and scaling factor As a degradation-sensitive parameter, its zero-bias change and the relative change of scale factor ,as follows:

[0075] (6)

[0076] By setting a threshold for degradation-sensitive parameters, the performance of the device during accelerated testing can be determined.

[0077] Under the same temperature conditions, different test times were used. Linear fitting is performed on the degradation parameters:

[0078]

[0079] Fitting parameters can be obtained under the same temperature stress condition. Under stress at multiple different temperatures Under these conditions, multiple fitting parameters can be obtained. , , Again, parameters under different temperature stresses were compared. Perform linear fitting.

[0080] (7)

[0081] It can be deduced that at room temperature (general storage temperature is room temperature) and By combining the parameters with the requirements for out-of-tolerance criteria, the storage life can be calculated. That is, the storage life can be calculated for each degradation parameter. Storage time Minimum value:

[0082] (8)

[0083] This is the assessed storage life.

[0084] In summary, firstly, existing technologies mostly employ constant stress tests at a single temperature point, but this method requires large equipment and sample sizes, and is time-consuming. This invention provides constant stress tests at multiple temperature points, which has the advantages of small sample sizes and short test times. Secondly, existing technologies often use time-truncated methods to assess storage life, which is time-consuming and labor-intensive. This invention provides constant stress tests at multiple temperature points, assessing the storage life of the device through the trend relationship between temperature stress and degradation parameters, which has the advantages of short test time, scientific evaluation method, and reasonable evaluation results. Thirdly, existing technologies often fail to analyze and interpret the data during the test. This invention clarifies the changes in the zero bias and scaling factor parameters of the fiber optic gyroscope and accelerometer as degradation parameters, thus enabling effective storage life assessment tests. Finally, the method used in this invention is not only applicable to fiber optic inertial measurement devices but also to the storage life assessment of other electronic products, possessing universality. In contrast, existing technologies can only assess electronic products, i.e., products using the Weibull distribution, and use the maximum likelihood method for parameter estimation, resulting in poor universality.

[0085] Example:

[0086] like Figure 3 This invention provides a method for assessing the storage life of a missile-grade fiber optic inertial navigation system (INS). This method involves conducting accelerated degradation tests on the device under temperature stress. Specifically, by testing key data from the device under multiple temperature stress conditions, a degradation model is established to predict the time it takes for performance parameters to exceed acceptable limits under actual storage conditions, thereby determining the device's storage performance retention period. Temperature stress The acceleration temperature value is determined by the following formula:

[0087] (1)

[0088] Defined as the starting temperature point, it can typically be the high-temperature operating temperature point. Defined as the cutoff temperature point. Indicates the number of stresses required; Indicates the middle number A temperature point, This represents the stress gradient coefficient. For practical engineering applications, a gradient that is too small will affect the accuracy of the evaluation; the temperature gradient between adjacent groups should not be less than 10℃. For example, if three temperature stresses are selected, with the high operating temperature of the inertial navigation system being 50℃ and the highest temperature being 70℃, then the intermediate temperature calculated using the above formula is 58.47℃. For the convenience of the experiment, 60℃ is selected, as shown in Table 1 below.

[0089] Table 1 Selection of Temperature Stress Values

[0090]

[0091] (3) The stress-life model of the fiber optic inertial measurement unit is described by the Arrhenius equation, as follows:

[0092] (2)

[0093] in, , - Thermodynamic temperature, absolute temperature, usually At standard room temperature, 293.15K. To accelerate the temperature value;

[0094] -temperature Fiber optic gyroscope lifetime, in hours;

[0095] -temperature Fiber optic gyroscope lifetime, in hours;

[0096] - Activation energy, unit: electron volt;

[0097] - Boltzmann constant, which is 8.167 × 10 -5 eV / K;

[0098] Definition of the first Acceleration coefficient of various components for:

[0099] (3)

[0100] in For the first The activation energies and failure rates of various components in fiber optic inertial navigation systems are shown in Table 2 below.

[0101] Table 2 Activation Energy of Typical Fiber Optic Inertial Navigation Devices

[0102]

[0103] The acceleration coefficient of the fiber optic inertial navigation system Defined as:

[0104] (4)

[0105] in For the first The total number of various components; For the first time under normal conditions Failure rate of various components;

[0106] Using a timed truncation method, the accelerated storage test time is determined based on the selected stress temperature. for:

[0107] (5)

[0108] in Indicates the required storage time for the product; This indicates the time required for accelerated testing of the product under stress temperature. For example, if the storage life of the device is required to be 10 years, the acceleration coefficient at different temperatures can be calculated by combining Table 1 with formulas (3), (4) and (5), as shown in Table 3 below.

[0109] Table 3 Acceleration coefficients of the device at different temperatures

[0110]

[0111] (5) Select fiber optic gyroscope with zero bias for missile-grade fiber optic inertial measurement unit , calibration factor Zero bias of quartz accelerometer and scaling factor As a degradation-sensitive parameter, this degradation-sensitive parameter can be selected as needed. In addition to the parameters mentioned above, zero-bias stability, absolute error, and zero-bias repeatability can also be selected, along with their zero-bias variation. and the relative change of scale factor It can be a relative change or an absolute change. When it is a relative change, it can be expressed as follows:

[0112] (6)

[0113] in, , They represent the first Time (the first) The zero bias value at each sampling time and the initial time. , They represent the first Time (the first) The scaling factor values ​​at each sampling time and the initial time. Indicates the first Time (the first) The test results obtained at each sampling time point =1, 2... , representing 0~ The first sampling time Test results at the next sampling time.

[0114] By setting a threshold for degradation-sensitive parameters, the performance of the device during accelerated testing can be determined.

[0115] Accelerated tests were conducted at 50℃, 60℃ and 70℃, and the degradation-sensitive parameters of the device were tested at equal intervals of a certain number of hours, as shown in Table 4 below.

[0116] Table 4 Device Test Data

[0117]

[0118] The specific method for setting the sampling time is based on different acceleration temperature values. The minimum envelope is determined based on actual engineering conditions, and the optimal sampling time interval is obtained from different acceleration temperature values. The common divisor of .

[0119] Different time values ​​at 50℃, 60℃ and 70℃ The accelerated life test results were obtained by linear fitting to obtain the fitting parameters a and b at each temperature, as shown in Table 5 below.

[0120] Table 5. Fitting of Degradation Parameters

[0121]

[0122] Linear fitting was performed on the parameter a and b values ​​obtained at 50℃, 60℃, and 70℃ respectively, and the parameter a and b values ​​at room temperature (generally the storage temperature is room temperature) can be derived, denoted as . and Therefore, the equivalent relationship between the degradation parameters of the product under storage conditions and time can be obtained:

[0123] (7)

[0124] If the out-of-range criterion is defined as:

[0125]

[0126] in , , , It can be the relative change expressed by formula (6), or it can be other forms of relative change or absolute change. According to Obtain the absolute value of the degradation sensitivity parameter ( y The storage life can be derived from the value.

[0127]

[0128] Take storage time The minimum time obtained for each degradation parameter, i.e., the first component to fail, determines the storage life of the entire inertial navigation system:

[0129] (8)

[0130] This is the assessed storage lifespan. This assessment method is simple, feasible, and has high accuracy and engineering applicability.

[0131] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

[0132] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A method for evaluating the storage lifetime of a missile-borne fiber optic inertial navigation system, characterized in that, include: Determine the acceleration temperature value for the experiment. ; Based on acceleration temperature value The acceleration temperature value was obtained. Acceleration coefficients of various types of components in fiber optic inertial navigation systems under specific conditions; The acceleration coefficient of the fiber optic inertial navigation system (FISH) is obtained based on the acceleration coefficients of various components. ; Based on the acceleration coefficient of fiber optic inertial navigation systems Storage time required for fiber optic inertial navigation systems The acceleration temperature value was obtained. Under these conditions, the time required to conduct accelerated testing ; according to Determine several sampling times; Accelerating temperature value Under these conditions, accelerated tests were conducted on the fiber optic inertial navigation system to obtain degradation-sensitive parameters of the fiber optic inertial navigation system at each sampling time. Accelerating temperature value Under the given conditions, based on each sampling time and the degradation-sensitive parameters of the fiber optic inertial navigation system obtained at each sampling time, a relationship between the degradation-sensitive parameters and time is constructed. According to different acceleration temperature values The relationship between the degradation sensitivity parameter and time under the given conditions is obtained by obtaining the relationship between the degradation sensitivity parameter and time under the storage temperature condition. Based on the relationship between the degradation sensitive parameter and time under storage temperature conditions and the out-of-tolerance criterion of the degradation sensitive parameter, the storage lifetime of the fiber optic inertial navigation system under storage temperature conditions is obtained. Degradation-sensitive parameters of fiber optic inertial navigation systems include fiber optic gyroscope zero bias. Fiber optic gyroscope calibration factor Zero bias stability of fiber optic gyroscope Absolute error of fiber optic gyroscope Quartz accelerometer zero bias Quartz accelerometer scale factor Quartz accelerometer zero bias stability Or quartz accelerometer monthly repeatability One or more of them; The criterion for out-of-tolerance behavior of degradation-sensitive parameters is: ； in, For a certain time The change in the time-degradation sensitive parameter A preset threshold is set; when this threshold is exceeded, it is considered that the degradation-sensitive parameter has degraded, leading to the failure of the fiber optic inertial navigation system. Based on the relationship between degradation-sensitive parameters and time under storage temperature conditions, and the out-of-tolerance criterion for degradation-sensitive parameters, the method for obtaining the storage lifetime of fiber optic inertial navigation systems under storage temperature conditions is as follows: Will Substituting the relationship between the degradation-sensitive parameter and time under storage temperature conditions, the storage lifetime of the fiber optic inertial navigation system under storage temperature conditions is obtained; When the degradation sensitivity parameter is N At that time, N >1, the out-of-tolerance criteria for each degradation-sensitive parameter are denoted as follows: ≥ 、 ≥ … ≥ ； Will = , = … = Substituting the degradation sensitivity parameters obtained at that time into the relationship between the degradation sensitivity parameters and time under storage temperature conditions, we obtain the following results: N indivual value; Will N indivual The minimum value among the values ​​is taken as the storage lifetime of the fiber optic inertial navigation system under the storage temperature condition.

2. The method for evaluating the storage lifetime of a missile-borne fiber optic inertial navigation system according to claim 1, characterized in that, The acceleration temperature value for the accelerated test is determined according to the following formula. : in, Given a starting temperature point, Defined as a given cutoff temperature point, Indicates the number of acceleration temperature values ​​required; Indicates the first One acceleration temperature value, This represents the stress gradient coefficient.

3. The method for evaluating the storage lifetime of a missile-borne fiber optic inertial navigation system according to claim 1, characterized in that, According to the following formula, based on the acceleration temperature value The acceleration coefficients of various types of components in the fiber optic inertial navigation system were obtained: in, For the first The acceleration coefficient of the various components, , This represents the total number of different types of components in a fiber optic inertial navigation system. Boltzmann's constant, For the first Activation energy of such components This is the standard room temperature.

4. The method for evaluating the storage lifetime of a missile-borne fiber optic inertial navigation system according to claim 3, characterized in that, Acceleration coefficient of fiber optic inertial navigation system The following formula is used to obtain: in, For the first The total number of various components; For the first time under normal temperature conditions Failure rate of various components.

5. The method for evaluating the storage lifetime of a missile-borne fiber optic inertial navigation system according to claim 1, characterized in that, 。 6. The method for evaluating the storage lifetime of a missile-borne fiber optic inertial navigation system according to claim 1, characterized in that, Several sampling times at 0~ Set at equal intervals within the range.

7. The method for evaluating the storage lifetime of a missile-borne fiber optic inertial navigation system according to claim 1, characterized in that, Accelerating temperature value Under these conditions, based on the sampling times and the degradation sensitivity parameters of the fiber optic inertial navigation system obtained at each sampling time, the method for constructing the relationship between the degradation sensitivity parameters and time is as follows: Linear fitting was performed on each sampling time and the degradation-sensitive parameters of the fiber optic inertial navigation system acquired at each sampling time to obtain... Formal relation, in which Represents a degradation-sensitive parameter. Represents time, , These are the linear fitting coefficients; Acceleration temperature value The linear fitting coefficients obtained under the given conditions are used for linear fitting to obtain the fitting coefficients under the storage temperature conditions, which in turn yields the relationship between the degradation sensitive parameter and time under the storage temperature conditions.

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