Fault-tolerant system reliability evaluation method

Abstract

The invention relates to a fault-tolerant system reliability evaluation method, belongs to the technical field of fault-tolerant analysis, and solves the problem of inaccurate fault-tolerant reliability evaluation in the prior art. The method for evaluating the reliability of the fault-tolerant system comprises the following specific steps of: 1, determining the uncertainty of a structure fault-tolerant degree and a professional performance fault-tolerant degree; 2, obtaining the uncertainty of the overall fault-tolerant capability of the system based on the uncertainty of the structure fault-tolerant degree and the professional performance fault-tolerant degree; step 3, obtaining an uncertainty quantification result of the fault-tolerant capability threshold value; and step 4, based on the uncertainty of the fault-tolerant capability of the whole system and the uncertainty quantification result of the fault-tolerant capability threshold, obtaining a reliability quantification result of the fault-tolerant capability. According to the reliability evaluation method for the fault-tolerant system, uncertainty analysis is integrated into the fault-tolerant evaluation process, multiple factors with uncertainty are comprehensively considered, and compared with a traditional determinacy evaluation method, the fault-tolerant level of the system can be more comprehensively quantified.

Description

Technical Field

[0001] This invention belongs to the field of fault tolerance analysis technology, specifically relating to a method for assessing the reliability of a fault-tolerant system, and more particularly to a method for assessing the reliability of a fault-tolerant system considering uncertainty. Background Technology

[0002] With technological advancements and increasing system complexity, high reliability and safety have become critical requirements in aerospace, battery, energy, and transportation industries. In these fields, the failure of any single component can lead to the loss of entire system functionality, causing catastrophic consequences. Ensuring continued system operation even when components fail is a key challenge in reliability engineering. The ability of a system to continue functioning despite component failures is known as fault tolerance.

[0003] In practical engineering, to improve the safety and reliability of a system in complex operating environments, it is necessary to analyze and quantify the system's fault tolerance capability, which is itself considered a performance characteristic. Furthermore, system operation is often accompanied by various uncertainties, including the uncertainty of failure occurrence time and the impact of environmental fluctuations on system performance. This demonstrates that fault tolerance capability also has uncertainties. Therefore, fault tolerance capability possesses reliability.

[0004] In existing technologies, the assessment of system fault tolerance capabilities primarily employs deterministic analysis methods, neglecting the comprehensive consideration of uncertainties. Due to the lack of accurate modeling and quantification of these uncertainties, existing assessment methods struggle to comprehensively and objectively reflect the system's true performance and safety margins under fault conditions, thus impacting the effectiveness of system design improvements and subsequent operation and maintenance. Therefore, effectively integrating uncertainty analysis into fault tolerance capability assessment and obtaining the reliability of system fault tolerance capabilities has become a crucial technical problem that urgently needs to be solved. Summary of the Invention

[0005] In view of the above problems, the present invention provides a method for evaluating the reliability of fault-tolerant systems, which solves the problem of inaccurate fault-tolerant reliability evaluation in the prior art.

[0006] This invention provides a method for evaluating the reliability of a fault-tolerant system, the specific steps of which are as follows: Step 1. Determine the uncertainties in structural tolerance and professional performance tolerance; Step 2. Based on the uncertainties of structural fault tolerance and professional performance fault tolerance, obtain the uncertainty of the overall fault tolerance capability of the system; Step 3. Obtain the uncertainty quantification result of the fault tolerance threshold; Step 4. Based on the quantification results of the uncertainty of the overall system's fault tolerance capability and the uncertainty of the fault tolerance threshold, obtain a reliable quantification result of the fault tolerance capability.

[0007] Optionally, the uncertainty of the structural tolerance is obtained based on the uncertainty of the system state.

[0008] Alternatively, the expression for the uncertainty of the professional performance tolerance is:

[0009] in, Indicates degradation time Professional performance tolerance at that time Uncertainty; Represents a random process In the interval Integrals on; The derivative of time; This indicates the first pass when the professional performance tolerance is exceeded, which is the first time the professional performance requirement is met.

[0010] Optionally, the uncertainty of the overall fault tolerance capability of the system. The expression is:

[0011] in, Indicates degradation time The uncertainty of structural tolerance; Indicates degradation time Professional performance tolerance Uncertainty.

[0012] Optionally, the fault tolerance threshold includes a structural fault tolerance threshold and a professional performance fault tolerance threshold.

[0013] Optionally, the uncertainty of the structural tolerance threshold is related to the redundancy requirements of the system.

[0014] Optionally, the expression for the uncertainty of the professional performance tolerance threshold is:

[0015] in, This indicates the first wear test when the professional performance requirement is met for the first time. This indicates a system performance degradation trajectory with uncertainty; This indicates that for a random process When the professional performance tolerance is first exceeded, the professional performance requirement is met for the first pass. When the professional performance is first worn, it meets the professional performance requirements. Integrals on; The derivative of time.

[0016] Optionally, the specific steps to obtain a reliable quantification of fault tolerance are as follows: The uncertainty of the overall fault tolerance capability of the system Uncertainty related to the professional performance tolerance threshold Margin model for achieving fault tolerance The expression is: ; The reliability of the fault-tolerant system is obtained based on the margin model of fault tolerance, and the expression is:

[0017] in, This indicates the reliability of the fault-tolerant system's fault-tolerance capability. Indicates degradation time The margin of fault tolerance at that time.

[0018] Compared with the prior art, the present invention has at least the following beneficial effects: (1) More comprehensive quantification of fault tolerance capability: The fault tolerance system reliability assessment method of the present invention integrates uncertainty analysis into the fault tolerance assessment process, and comprehensively considers a variety of uncertain factors. Compared with the traditional deterministic assessment method, it can more comprehensively quantify the fault tolerance level of the system.

[0019] (2) By quantitatively analyzing the uncertain factors, the reliability of the fault tolerance capability can be obtained. As a means of evaluating the fault tolerance capability, it is highly accurate and more credible. Attached Figure Description

[0020] The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention.

[0021] Figure 1 A flowchart of the reliability assessment method for fault-tolerant systems under uncertainty in this invention; Figure 2 This is a schematic diagram of the five-parameter equivalent circuit model of the photovoltaic unit in an embodiment of the present invention; Figure 3 This is a structural diagram of the solar cell array in an embodiment of the present invention; Figure 4 The degradation trajectory of the maximum power and remaining photovoltaic units of the solar cell array in the embodiments of the present invention; Figure 5 This refers to the reliability of the professional performance and fault tolerance of the solar cell array in the embodiments of the present invention. Detailed Implementation

[0022] To better understand the above-described objectives, features, and advantages of the present invention, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other. Furthermore, the present invention can be implemented in other ways different from those described herein; therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0023] A specific embodiment of the present invention, such as Figure 1-5 A reliability assessment method for fault-tolerant systems is disclosed, with the following specific steps: Step 1. Determine the structural tolerance. With professional performance tolerance Uncertainty.

[0024] Furthermore, structural tolerance Uncertainty It is obtained based on the uncertainty of the system state, and its value is uniquely determined by the real-time state of the system.

[0025] Furthermore, professional performance tolerance The expression for uncertainty is:

[0026] in, Indicates degradation time Professional performance tolerance Uncertainty; Represents a random process In the interval Integrals on; The derivative of time; This indicates the first pass when the professional performance tolerance is exceeded, which is the first time the professional performance requirement is met.

[0027] Furthermore, based on the system's professional performance margin The expression for obtaining the professional performance tolerance during the first pass of the professional performance requirement is:

[0028] in, Indicates the infimum; Represent the set of positive real numbers; Indicates degradation time The system's professional performance margin.

[0029] Furthermore, considering uncertainty, for stochastic processes... Record its interval The integral on is The expression is: .

[0030] Furthermore, system structural fault tolerance The specific steps of the estimation method are as follows: Step 111. Construct a directed graph of the system based on a component-oriented architecture.

[0031] Specifically, the system includes a single-input single-output (SISO) system and a multiple-input multiple-output (MIMO) system.

[0032] For a single-input single-output system, there is only one start point and one end point in its directed graph.

[0033] The expression for the directed graph of a single-input single-output system is:

[0034] in, V Represents the set of nodes in a directed graph. , s The starting point of the directed graph represents the system's input. e The endpoint of the directed graph represents the system's output; For components Functional components; E This represents the set of edges in a directed graph.

[0035] It is understandable that the starting point of a directed graph is the first functional step that the system needs to go through to complete its function; the focus of a directed graph is the system's output.

[0036] For a multiple-input multiple-output system, its directed graph has multiple start and end points, and the expression of the directed graph is:

[0037] in, , Represents the set of starting points of a directed graph. Represents the set of endpoints in a directed graph. , , Indicates the first m A starting point of a directed graph, Indicates the first n A directed graph endpoint; E This represents the set of edges in a directed graph.

[0038] Furthermore, E The elements in the text represent the interaction relationships between components, for example, the flow of matter, energy, and information between various functional links.

[0039] It is understandable that a function requires multiple functional components, and the function can only be realized when all functional components are complete.

[0040] Step 112. Obtain the fault tolerance of the system structure based on the directed graph of the component-oriented system structure.

[0041] Specifically, for a single-input single-output system, based on the directed graph of the system, the redundancy between the starting point and the ending point is obtained, the redundancy is normalized, and the fault tolerance of the system structure is obtained.

[0042] Furthermore, the redundancy between the start and end points refers to the redundant functional paths between the start and end points.

[0043] Furthermore, the structural tolerance of the system is obtained, expressed as:

[0044] in, Indicates the system in state Structural tolerance; Indicates the system in state Lower system directed graph From the starting point s To the finish line e The total number of all unique function paths; Indicates the system in state The system is a directed graph; This indicates the system in its initial state. The system is a directed graph; Indicates the system's degradation time state of time The following is a directed graph of component structure.

[0045] Understandably, when When this occurs, it means that the system initially lacks redundancy and therefore does not possess structural fault tolerance. ;and This indicates that the system currently does not have a functional path and cannot perform the function. In this case, the system's structural fault tolerance is 0.

[0046] Specifically, for a multiple-input multiple-output (MIMO) system, based on the directed graph of the MIMO system, the redundancy between the start and end points is obtained and used as an element of the MIMO system's fault tolerance matrix. Then, the effective start-end node pairs of the system's functional path are selected, and finally, the average structural fault tolerance of the effective start-end node pairs is used as the system fault tolerance of the MIMO system.

[0047] Furthermore, the structural tolerance of the system is obtained, expressed as:

[0048]

[0049] in, P This represents the structural tolerance matrix of the system; Indicates the first i The starting point and the first directed graph k The structural tolerance of the start and end nodes of a directed graph. , , m This represents the total number of starting points in a directed graph. n This represents the total number of endpoints in a directed graph; Indicates the first i A starting point of a directed graph, Indicates the first k The endpoint of a directed graph.

[0050] Furthermore, in MIMO systems, There are two scenarios: one is that the start and end node pairs of the directed graph are valid but there is no functional path, resulting in system failure; the other is that the start and end node pairs of the directed graph are invalid, and the lack of a functional path does not affect the system's functionality. For start and end node pairs that do not meet the requirements (i.e., the aforementioned system failure and invalid states), a Boolean matrix is ​​used. The redundancy matrix is ​​used as a filtering matrix to filter and correct it, and its first... i The starting point and the first directed graph k The start and end nodes of a directed graph. Satisfy: When the start and end nodes are paired When it is the start and end point of the system's functional path, A value of 1 indicates a valid start-end node pair; when the start-end node pair... When it is not the start or end point of the system's functional implementation path, A value of 0 indicates an invalid start-end node pair.

[0051] Based on the Boolean matrix, obtain the effective redundancy matrix. U , , No. i The starting point and the first directed graph k Redundancy of valid start and end node pairs at the endpoint of a directed graph. satisfy:

[0052] in, This represents an invalid value, which is not included in the calculation. All addition and multiplication calculations return the original value, that is, for ,have , ; This indicates the value used in the calculation. This process distinguishes between invalid and valid start / endpoints, thus accurately quantifying the overall structural fault tolerance of the system.

[0053] This invention, through this process, can distinguish between invalid and valid start and end points, thereby accurately quantifying the overall structural fault tolerance capability of the system.

[0054] Furthermore, after filtering and correcting the tolerance matrix, the average structural tolerance of effective start-end node pairs is obtained based on the redundancy of the multi-input multi-output system. The expression is:

[0055] It is understandable that when the fault tolerance between any valid start-end pair is greater than 0, it means that there are redundant functional paths between all inputs and outputs of the system at this moment. The average value of the structural fault tolerance of each valid node pair is used as the redundancy measure of the system. When there is no redundancy in the number of functional paths between a certain pair of valid start-end pairs, it is considered that the system no longer has structural fault tolerance, that is, the structural fault tolerance of the system is 0.

[0056] Furthermore, the system's professional performance tolerance. The specific steps of the estimation method are as follows: Step 121. Based on the interdisciplinary equation, degradation equation, and margin equation, construct the professional performance margin model of the system, with the following expression:

[0057] in, For return / exchange time The professional performance margin of the timing system; Indicates the system in state The system's internal dependent variables; It is an external variable of the system.

[0058] For example, the internal variables are the system's design parameters, material properties, or geometric dimensions; the external variables are temperature, vibration, or voltage and current.

[0059] Furthermore, the interdisciplinary equation is:

[0060] in, P These are the system's performance parameters.

[0061] For example, for a mobile phone, the system's performance parameters include screen refresh rate, battery capacity, etc.

[0062] Furthermore, the degradation equation is:

[0063] in, Indicates the time of degradation System performance.

[0064] Furthermore, the margin equation is:

[0065] in, P th A threshold representing system performance.

[0066] Step 122. Based on the system's professional performance margin When retrieving the first pass, the expression is:

[0067] in, This indicates the moment when the system's performance margin first becomes less than 0; Indicates the infimum; Represent the set of positive real numbers; Indicates degradation time The system's professional performance margin.

[0068] Furthermore, based on a given discrete degradation time vector The transformation formula for obtaining the first penetration is:

[0069] in, Indicates the first j When a degeneration occurs The system's professional performance margin; Indicates the first j +1 degeneration time The system's professional performance margin; Understandably, First Passage Time refers to the time when a system or process first reaches a specific state or goal.

[0070] Step 123. Based on the reliable degradation time range of the system determined at the first crossing. To obtain the system's professional performance tolerance The expression is:

[0071] in, Indicates degradation time The professional performance tolerance of the time system; Indicates degradation time The differential; Indicates the initial degradation time.

[0072] Understandably, the professional performance tolerance of a system represents its fault tolerance capability, which is the integral of its professional performance margin over the remaining degradation time.

[0073] Step 124. Use the trapezoidal integral method to assess the system's performance tolerance. An approximate solution is performed to obtain the performance tolerance for degradation time in the discrete case, expressed as:

[0074] in, This indicates a focus on degradation time. Professional performance tolerance under discrete time conditions; q This represents the total number of elements in the degraded time series.

[0075] Furthermore, the aforementioned professional performance tolerance of this invention refers to a single professional performance characteristic. For a system with multiple professional performance characteristics, the professional performance margins are respectively... The corresponding professional performance tolerance is Then the overall professional performance tolerance of the system is:

[0076] It is understandable that the tolerance for all professional performance characteristics is set to a smaller value.

[0077] Step 2. Based on structural tolerance With professional performance tolerance The uncertainty of the system is quantified to obtain the uncertainty of the overall fault tolerance capability of the system. The expression is:

[0078] in, Indicates degradation time The uncertainty of structural tolerance; Indicates degradation time Uncertainty regarding the tolerance of professional performance.

[0079] Step 3. Obtain the uncertainty quantification result of the fault tolerance threshold.

[0080] Furthermore, the fault tolerance threshold includes the structural fault tolerance threshold and the professional performance fault tolerance threshold.

[0081] Specifically, structural tolerance threshold Only with the system's redundancy requirements It is relevant, and certain; Professional performance tolerance threshold It is related to the system's state and professional performance, and therefore has uncertainties. The expression is:

[0082] in, This indicates the first wear test when the professional performance requirement is met for the first time. This indicates a system performance degradation trajectory with uncertainty; This indicates that for a random process ,exist arrive The points on the scale.

[0083] Furthermore, based on the uncertainty of the fault tolerance threshold, a fault tolerance threshold that takes uncertainty into account is obtained. The expression is: .

[0084] Step 4. Based on the quantification results of the uncertainty of the overall system's fault tolerance capability and the uncertainty of the fault tolerance threshold, obtain a reliable quantification result of the fault tolerance capability.

[0085] Furthermore, combined and Margin model for achieving fault tolerance The expression is: .

[0086] Furthermore, based on the margin model of fault tolerance, the reliability of the fault tolerance system is obtained, expressed as:

[0087] in, This indicates the reliability of the fault-tolerant system's fault-tolerance capability. Indicates degradation time The margin of fault tolerance at that time.

[0088] To illustrate the effectiveness of the method proposed in this invention, the following detailed description of the above technical solution of this invention is provided through specific embodiments of solar cells. The specific implementation steps are as follows: (1) Professional performance tolerance of computing system A solar cell array consists of photovoltaic cells and diodes. Modeling the photovoltaic cells and diodes yields their current-voltage characteristic curves. The current-voltage characteristic curve of the entire array is then obtained, and its maximum power is calculated. .

[0089] For photovoltaic units, see Figure 2A five-parameter equivalent circuit model is adopted.

[0090] Specifically, the current and voltage of the photovoltaic unit satisfy the expression:

[0091] in, The current of the photovoltaic unit is expressed in amperes (A). This represents photocurrent, measured in amperes (A). This indicates the reverse saturation current of the diode, measured in amperes (A). This indicates the voltage of the photovoltaic unit, measured in volts (V). This represents the equivalent series resistance, and the unit is ohms (Ω). Indicates the charge of an electron; Ideal factor; Represents the Boltzmann constant; This indicates the temperature of the solar cell, measured in Kelvin (K). This represents the equivalent parallel resistance, and the unit is ohms (Ω).

[0092] Furthermore, the bypass diodes in the battery array are treated as ideal diodes. The isolation diodes are treated as non-ideal diodes, and the expression is:

[0093] in, This indicates the diode current, measured in amperes (A). This indicates the diode voltage, measured in volts (V). This indicates the on-resistance, measured in ohms (Ω). ); Indicates the cut-off inductance, measured in Henry (H); This indicates the on-state voltage, measured in volts (V). Indicates virtual voltage. .

[0094] Furthermore, the solar cell array is composed of It is composed of batteries connected in series and parallel. Each battery string is divided into two parts: The substring consists of one photovoltaic unit and one bypass diode, totaling... One; and one isolation diode. The first j The voltage and current of the isolation diodes in each battery string are denoted as follows: and , of which i The voltage and current of each photovoltaic unit are denoted as... and The entire solar cell array satisfies the following system of equations:

[0095] in, This indicates the voltage of the entire solar array; This represents the current of the entire solar cell array; Indicates the first i One and j The voltage of each photovoltaic unit.

[0096] Furthermore, by solving the system of equations, the current-voltage characteristic curve of the solar cell array is obtained, and the maximum power is calculated. Thus, professional performance is achieved. The model.

[0097] Furthermore, with long-term use, the performance of solar cell arrays will undergo irreversible degradation over time, leading to maximum power attenuation.

[0098] Specifically, with the time of degradation The increase in the equivalent series resistance of the photovoltaic unit It will gradually increase, equivalent parallel resistance It will gradually decrease, and the degradation equations for both can be constructed as follows:

[0099] in, and Represent Rs and Rsh under the influence of degradation time, respectively; and Let Rs and Rsh represent time 0, respectively; and They represent the parameters to be estimated; Indicates the degradation rate of the series resistor; This indicates the degradation rate of the parallel resistor.

[0100] Then, the corresponding photovoltaic units and Substituting this into the interdisciplinary equations of solar cell arrays, we obtain the degradation equation for maximum power. .

[0101] This performance parameter is a high-potential parameter; for the load, a higher power rating ensures a more reliable power supply for subsequent electrical equipment. Let its threshold be... The performance margin degradation equation for a solar cell array is:

[0102] Then, calculate First penetration against 0 To achieve professional performance tolerance for: .

[0103] Furthermore, the bypass diodes in the battery array are treated as ideal diodes. The isolation diodes are treated as non-ideal diodes, and the expression is: (2) Calculate the system's structural fault tolerance By integrating the fault-tolerant functional logic into the structure diagram, the total number of paths that a battery string can use to complete its function is the number of its remaining photovoltaic units. See the structure diagram of a solar cell array. Figure 3 .

[0104] Thus, the system structural tolerance of the solar cell array is obtained. for: .

[0105] in, express Moment

[0106] (3) Construct the margin equation for the system's fault tolerance capability The product of professional performance tolerance and system structure tolerance is used as the quantitative result of the overall system tolerance capability:

[0107] In the event of partial unit failure, the fault tolerance of the solar array satisfies: the system has at least... One photovoltaic unit; the maximum power should not be less than the initial power. r %, from which the system's fault tolerance threshold is obtained. The margin degradation equation for the solar cell array system is constructed as follows:

[0108]

[0109]

[0110]

[0111] in, express The margin of error tolerance at any time; Indicates the structural tolerance threshold; This indicates the professional performance tolerance threshold; express Real-time performance; Indicates performance at time 0; express Upon first penetration reaching its threshold; This represents the characteristic function, which takes the value 1 when the performance increases with degradation time and -1 when it decreases.

[0112] (4) Construct a reliability metric equation for the system's fault tolerance capability. First, the uncertainties need to be analyzed and quantified. Solar cell arrays have multiple sources of uncertainty, including uncertainties in component state transitions, physical properties, and degradation processes.

[0113] Quantify the uncertainty of system state transitions. For the state of a photovoltaic unit... In this case, there are only two possible state transitions: from 0 to 1 and from 0 to 2, corresponding to the photovoltaic unit transitioning from normal to short circuit and from normal to open circuit, respectively. The state transitions between each photovoltaic unit are independent, and the two fault modes of open circuit and short circuit are in a competing logical relationship, with the fault mode that occurs first being taken as the state of the photovoltaic unit.

[0114] From the perspective of failure physics, it is believed that the short circuit of the photovoltaic unit is caused by the accumulation of static electricity, and when the static voltage exceeds the breakdown voltage... This will lead to electrostatic discharge breakdown, causing a short circuit in the photovoltaic unit. Let the electrostatic voltage accumulation process be... :

[0115] in, Degeneracy parameters that represent deterministic behavior; Degeneracy parameters that represent deterministic behavior; Represents standard Brownian motion; This represents the diffusion coefficient.

[0116] Similarly, from the perspective of failure physics, the open circuit of the photovoltaic unit is considered to be due to fatigue or chemical corrosion at the electrical connection points, which leads to a decrease in the strength of the material. A decrease occurs when Exceeding mechanical stress S At that time, the connection structure could not support it, resulting in an open circuit in the photovoltaic unit. Let... The degradation follows a stochastic process. :

[0117] in, Degeneracy parameters that represent deterministic behavior; Degeneracy parameters that represent deterministic behavior; This represents the diffusion coefficient.

[0118] Describe the stochastic processes separately and The first time I wore it was and Treating both as random variables, denoted as and Obtain the state transition probabilities The expression is:

[0119] The uncertainty of the dependent variable within the quantification system is addressed. Different solar cell arrays exhibit inter-sample variability, which manifests in the model as static uncertainty in the dependent variable. Specifically, this refers to the probability distribution of physical property parameters related to the equivalent circuit of the photovoltaic unit.

[0120] also, and The degradation process exhibits dynamic uncertainty, denoted as ... and :

[0121] Based on the above uncertainty quantification structure, the margin equation considering the system's fault tolerance capability is obtained, and its expression is:

[0122] Next, we construct a metric equation for the system's fault tolerance. After comprehensively considering the system's uncertainties, we find that the fault tolerance margin of the photovoltaic array is a stochastic process in terms of degradation time. When the value is greater than 0, the system's fault tolerance is reliable, and the equation for measuring the system's fault tolerance is:

[0123] Furthermore, the reliability of the fault tolerance capability of solar cells is analyzed.

[0124] First, determine the parameter values ​​in the certainty reliability equation for the fault tolerance of the solar cell array. For parameters with uncertainty, set their normal distribution mean as a deterministic parameter value, and use a uniform coefficient of variation for the standard deviation. CV Configure the settings. The parameter values ​​are shown in Table 1.

[0125] Table 1. Parameter values ​​for the reliable model of solar cell array fault tolerance.

[0126] After substituting the above parameters and sampling using Monte Carlo simulation, the mean of the system fault tolerance capability of the solar cell array and its 90% confidence interval can be obtained as follows: Figure 4As shown, it can be observed that the degradation of the system's fault tolerance capability, due to the comprehensive consideration of the degradation of both professional performance fault tolerance and system structure fault tolerance, has a relatively fast degradation rate. Within a degradation time range of 500 to 600 days, the system is on the verge of failure, and its fault tolerance capability is about to return to zero.

[0127] Substituting the above parameter results into the system's fault tolerance measurement equation, the fault tolerance of the solar cell array can be calculated. The certainty reliability curve. Besides the reliability of the system's fault tolerance. In addition, the certainty reliability of the maximum power of the solar array can be analyzed and expressed as... This characterizes the reliability of the solar cell array in fulfilling its functions. It also assesses the system's fault-tolerant reliability. and the reliability of system professional performance Calculations and analyses were performed, and the results are as follows: Figure 5 As shown.

[0128] It can be seen that the reliability of fault tolerance capability Reliability consistently below professional performance levels This aligns with the expected conclusion that "functions come first, then fault tolerance." The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for evaluating the reliability of a fault-tolerant system, characterized in that, The specific steps are as follows: Step 1. Determine the uncertainties in structural tolerance and professional performance tolerance; Step 2. Based on the uncertainties of structural fault tolerance and professional performance fault tolerance, obtain the uncertainty of the overall fault tolerance capability of the system; Step 3. Obtain the uncertainty quantification result of the fault tolerance threshold; Step 4. Based on the quantification results of the uncertainty of the overall system's fault tolerance capability and the uncertainty of the fault tolerance threshold, obtain a reliable quantification result of the fault tolerance capability.

2. The reliability assessment method for fault-tolerant systems according to claim 1, characterized in that, The uncertainty of structural tolerance is obtained from the uncertainty of the system state.

3. The reliability assessment method for fault-tolerant systems according to claim 1, characterized in that, The expression for the uncertainty of professional performance tolerance is: in, Indicates degradation time Professional performance tolerance at that time Uncertainty; Represents a random process In the interval Integrals on; The derivative of time; This indicates the first pass when the professional performance tolerance is exceeded, which is the first time the professional performance requirement is met.

4. The reliability assessment method for fault-tolerant systems according to claim 1, characterized in that, Uncertainty in the overall fault tolerance of the system The expression is: in, Indicates degradation time The uncertainty of structural tolerance; Indicates degradation time Professional performance tolerance Uncertainty.

5. The reliability assessment method for fault-tolerant systems according to claim 1, characterized in that, The fault tolerance threshold includes the structural fault tolerance threshold and the professional performance fault tolerance threshold.

6. The reliability assessment method for a fault-tolerant system according to claim 5, characterized in that, The uncertainty of the structural tolerance threshold is related to the redundancy requirements of the system.

7. The reliability assessment method for fault-tolerant systems according to claim 5, characterized in that, The expression for the uncertainty of the professional performance tolerance threshold is: in, This indicates the first wear test when the professional performance requirement is met for the first time. This indicates a system performance degradation trajectory with uncertainty; This indicates that for a random process When the professional performance tolerance is first exceeded, the professional performance requirement is met for the first pass. When the professional performance is first worn, it meets the professional performance requirements. Integrals on; The derivative of time.

8. The reliability assessment method for fault-tolerant systems according to claim 1, characterized in that, The specific steps to obtain a reliable quantification of fault tolerance are as follows: The uncertainty of the overall fault tolerance capability of the system Uncertainty related to the professional performance tolerance threshold Margin model for achieving fault tolerance The expression is: ； The reliability of the fault-tolerant system is obtained based on the margin model of fault tolerance, and the expression is: in, This indicates the reliability of the fault-tolerant system's fault-tolerance capability. Indicates degradation time The margin of fault tolerance at that time.

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