Qualitative analysis method and device for task reliability of ship electronic information system, medium and product

Abstract

The invention discloses a ship electronic information system task reliability qualitative analysis method and device, a medium and a product, and relates to the field of task reliability analysis. The method comprises the steps that after an SFT model is constructed based on external influence factors, features and a probability function equation are solved; constructing a reliability block diagram of each stage based on a solving result and the internal influence factors, converting the reliability block diagram into an SFT model, and performing equivalence on the SFT model based on an infinitesimal substitution principle and performing integration to obtain an ISFT model of the whole stage; representing a structure function as a Boolean function based on an overall stage ISFT model, and obtaining system reliability through non-intersection; a basic event is determined based on system reliability, an AHP model is established, after an AHP judgment matrix is obtained, the weight of each layer in the AHP model is determined, hierarchical sorting and consistency verification are carried out, and qualitative analysis of task reliability is achieved. The problems that an existing reliability analysis method is poor in qualitative effect, incomplete in analysis and the like can be solved.

Description

Technical Field

[0001] The present application relates to the field of mission reliability analysis, and in particular to a qualitative analysis method, equipment, medium and product for mission reliability of a ship electronic information system. Background Art

[0002] The ship's electronic information system consists of control systems, communication systems, command systems, management systems, etc. Its information types are diverse and come from a wide range of sources, so it can be regarded as a complex system. The task description of this complex system is as follows: Figure 2 As shown. Specifically, it can be described as the following five aspects: (1) Collect, process, store, transmit, retrieve and other information according to certain application purposes and rules; (2) Organize and command the execution process of tasks at each stage; (3) Control the execution process; (4) Feedback all online detection data and control information to the system for process monitoring; (5) Correct the control information to ensure that the system correctly executes and processes tasks. The mission reliability of the ship's electronic information system is mainly affected by various factors, such as random uncertainty interference from the system's external environment, fault interference from the system's internal system, and human interference. In order to ensure the normal operation of the ship's electronic information system when executing and processing tasks, it is very important to conduct an accurate qualitative analysis of its mission reliability.

[0003] At present, in the research field of qualitative analysis of the mission reliability of ship electronic information systems, it is usually based on a single reliability analysis model, such as Naive Bayes (NB), Fault Tree Analysis (FTA), Neural Network (NN) and other methods. However, when the ship faces sudden external interference, this simple reliability analysis method is difficult to accurately and quantitatively reflect the reliability of the system mission. In addition, with the influx of large amounts of information from multiple sources, the processing burden of the ship's electronic information system is also increasing. A single mathematical analytical method is difficult to effectively describe the reliability of a complex system. Summary of the invention

[0004] The purpose of this application is to provide a qualitative analysis method, equipment, medium and product for the mission reliability of a ship's electronic information system, which can solve the problems of poor qualitative effect and incomplete analysis in existing reliability analysis methods, and thus can accurately and quantitatively reflect the reliability of a ship's electronic information system mission.

[0005] To achieve the above objectives, this application provides the following solutions:

[0006] In a first aspect, the present application provides a method for qualitatively analyzing mission reliability of a ship electronic information system, comprising:

[0007] Determine the external influencing factors of the ship's electronic information system mission, and construct an SFT (Space Fault Tree) model based on the external influencing factors; the external influencing factors include: temperature influencing factors, humidity influencing factors, smoke influencing factors, storm influencing factors, sea wave influencing factors and haze influencing factors;

[0008] Based on the SFT model, characteristic function equations and probability function equations of external influencing factors are solved to obtain reliability parameters of each stage of the ship's electronic information system;

[0009] Constructing a reliability block diagram of each stage of the ship's electronic information system based on the reliability parameters and internal influencing factors of the ship's electronic information system mission;

[0010] The reliability block diagram is converted into an SFT model, and based on the infinitesimal substitution principle, the SFT models corresponding to each stage are equivalently obtained to obtain a single-stage ISFT model, and the single-stage ISFT model is integrated to obtain an overall stage ISFT (Infinitesimal Space Fault Tree) model;

[0011] Acquire the structure function of the ship electronic information system, express the structure function as a Boolean function based on the overall stage ISFT model, and perform disjoint processing on the Boolean function using a disjoint algorithm;

[0012] The Boolean function after the non-intersection process is simplified and solved by using a simplified rule to obtain the system reliability;

[0013] Based on the system reliability, basic events related to the top events are determined, and the top events are used as the target layer, the basic events are used as the indicator layer, and the criterion layer is formed through classification and induction to establish an AHP (Ayalytic Hierarchy Process) model; the top events are used to represent the total failure state of the ship's electronic information system; the basic events are used to represent the fault events that cause the top events, which are the failure states of a single component or subsystem;

[0014] Construct AHP judgment matrix based on AHP model;

[0015] Based on the AHP judgment matrix, the weight of each layer in the AHP model is determined, and the hierarchical sorting and consistency verification are performed to achieve a qualitative analysis of the mission reliability of the ship's electronic information system.

[0016] Optionally, the characteristic function equation of the external influencing factor is expressed as:

[0017]

[0018] P i t (t) = 1-λt;

[0019] The probability function equation is expressed as:

[0020]

[0021] Where P i t (t) is the reliability change characteristic of the system under the influence of feature t in the i-th information transmission link, P i h (h) is the reliability change characteristic of the system under the influence of feature h in the i-th information transmission link, λ is the failure rate of the system link, A is the change of the external environment, P i (x1,x2,…,x n ) is the probability function, n is the number of influencing factors, x1,x2,…,x n For different influencing factors, is the influencing factor x in the i-th information transmission link k The reliability change characteristics of the system under the influence of

[0022] Optionally, based on the microelement substitution principle, the SFT models corresponding to each stage are equivalently obtained to obtain a single-stage ISFT model, including:

[0023] The links are replaced by microelements with the same sequence number as the stage, and the SFT model representing each stage in the ship electronic information system is replaced by microelements to obtain the single-stage ISFT model.

[0024] Optionally, integrating the single-stage ISFT model to obtain an overall stage ISFT model includes:

[0025] Each of the single-stage ISFT models is used as a fault subtree of top-level task failure in the form of an OR gate to obtain the overall stage ISFT model.

[0026] Optionally, before performing disjoint processing on the Boolean function, the method further includes:

[0027] Dependency processing is performed on the Boolean function.

[0028] Optionally, two sets of stage-dependent algebraic rules are used to perform the dependency processing.

[0029] Optionally, the independent variable of the Boolean function is the state variable of the bottom event in the overall stage ISFT model.

[0030] In a second aspect, the present application provides a computer device comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of any one of the above-mentioned methods for qualitative analysis of mission reliability of a ship's electronic information system.

[0031] In a third aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the above-mentioned methods for qualitative analysis of mission reliability of a ship's electronic information system.

[0032] In a fourth aspect, the present application provides a computer program product, including a computer program, which, when executed by a processor, implements the steps of any of the above-mentioned methods for qualitative analysis of the mission reliability of a ship's electronic information system.

[0033] According to the specific embodiments provided in this application, this application has the following technical effects:

[0034] The present application provides a method, equipment, medium and product for qualitative analysis of the reliability of ship electronic information system tasks, which determines the main external influencing factors of ship electronic information system tasks and constructs an SFT model, which can avoid the influence of external influencing factors on task reliability analysis. The ISFT model of the overall stage is constructed by drawing on the principle of microelement substitution, which can further avoid the influence of internal interference factors of the system. Taking into account the human interference factors, an AHP model is constructed based on the top events and related basic events in the ISFT model of the overall stage. Through the fusion of the ISFT model and the AHP model, the characteristics of various influencing factors such as external, internal and human factors can be fully considered to achieve accurate qualitative analysis of the reliability of complex system tasks, and accurately and quantitatively reflect the reliability of ship electronic information system tasks. Based on the reliability analysis results with high credibility, the probability of danger can be effectively reduced, and the smooth execution of ship electronic information system tasks can be guaranteed, thereby solving the problems of poor qualitative effect and incomplete analysis in the existing reliability analysis methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 A flowchart of a method for qualitatively analyzing mission reliability of a ship electronic information system provided in one embodiment of the present application;

[0037] Figure 2 It is a mission description diagram for the ship's electronic information system;

[0038] Figure 3 A schematic diagram of an SFT model based on external influencing factors provided in one embodiment of the present application;

[0039] Figure 4 A failure standard diagram for each stage in the SFT model under the influence of internal factors provided by another embodiment of the present application;

[0040] Figure 5 A schematic diagram of a single-stage ISFT model based on microelement substitution provided in one embodiment of the present application;

[0041] Figure 6 A flowchart of qualitative analysis modeling of task reliability of the overall stage ISFT model provided in one embodiment of the present application;

[0042] Figure 7 A form and structure diagram of an AHP model provided in another embodiment of the present application;

[0043] Figure 8 A technical roadmap for the application of a qualitative analysis method for mission reliability of a ship electronic information system provided in an embodiment of the present application;

[0044] Fig. 9 A schematic diagram of the structure of a computer device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0046] The qualitative analysis method for the mission reliability of a ship's electronic information system provided in this application can solve the problems of poor qualitative effect and incomplete analysis of the mission reliability analysis method due to the randomness and uncertainty of external environmental interference, as well as internal system or human failures when conducting qualitative analysis of the mission reliability of a ship's electronic information system.

[0047] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0048] In an exemplary embodiment, Figure 1As shown, a method for qualitative analysis of mission reliability of a ship electronic information system is provided. The method is executed by a computer device, specifically, it can be executed by a computer device such as a terminal or a server alone, or it can be executed by a terminal and a server together. In the embodiment of the present application, the method is applied to a server as an example for explanation, including the following steps 100 to 108. Among them:

[0049] Step 100: Determine the external influencing factors of the ship electronic information system (hereinafter referred to as the system) task, and build an SFT model based on the external influencing factors. The external influencing factors include: temperature influencing factors, humidity influencing factors, smoke influencing factors, storm influencing factors, sea wave influencing factors and haze influencing factors.

[0050] Step 101: Solve the characteristic function equation and probability function equation of the external influencing factors based on the SFT model to obtain the reliability parameters of the ship's electronic information system at each stage.

[0051] Step 102: Based on the reliability parameters and the internal influencing factors of the ship's electronic information system mission, a reliability block diagram of each stage of the ship's electronic information system is constructed. The reliability parameters of the mission stage and each sub-link within the system are determined, and after obtaining the data of all mission processes, a reliability block diagram of each stage of the ship's electronic information system is constructed.

[0052] Step 103: Convert the reliability block diagram into an SFT model, and based on the microelement substitution principle, perform the equivalent of the SFT model corresponding to each stage to obtain a single-stage ISFT model, and integrate the single-stage ISFT model to obtain the overall stage ISFT model.

[0053] Step 104: Obtain the structure function of the ship electronic information system, express the structure function as a Boolean function based on the overall stage ISFT model, and use a disjointness algorithm to disjointly process the Boolean function.

[0054] Step 105: Simplify and solve the disjoint Boolean function using simplification rules to obtain system reliability.

[0055] Step 106: Determine the basic events related to the top events based on the system reliability, and take the top events as the target layer and the basic events as the indicator layer, form the criterion layer through classification and induction, and establish the AHP model. The top events are used to represent the total failure state of the ship's electronic information system, that is, the failure of the entire ship's electronic information system mission. The basic events are used to represent the failure events that lead to the top events, which are the failure states of a single component or subsystem.

[0056] Step 107: Construct an AHP judgment matrix based on the AHP model.

[0057] Step 108: Determine the weight of each layer in the AHP model based on the AHP judgment matrix, and perform hierarchical sorting and consistency verification to achieve qualitative analysis of the mission reliability of the ship's electronic information system.

[0058] In an exemplary embodiment of the present application, Figure 8 As shown, the actual application process of the qualitative analysis method for mission reliability of ship electronic information system provided by this application can be described as follows:

[0059] Step 1: Determine the main external factors that affect the mission reliability of the ship's electronic information system, and then build the SFT model based on the main external factors and the FT model. This is mainly affected by environmental factors, including temperature, humidity, smoke, storms, waves, and haze. Among them, the influencing factors of waves include wave height, wave speed, wavelength, wind speed, and tide.

[0060] Step 2: Use the reliability probability distribution to derive the probability function equation of the sub-links of the ship's electronic information system based on the main external factors. The process of determining the reliability probability distribution is:

[0061] 1) Collect and analyze reliability data of similar systems under different external factors.

[0062] 2) Conduct experiments on the system and its components to collect failure data.

[0063] 3) Use reliability modeling tools to simulate the system's performance under different conditions.

[0064] 4) Determine the reliability distribution under different circumstances with the help of experts’ experience and knowledge.

[0065] Step 3: Determine the reliability parameters of the task stage and each sub-link within the system. After obtaining the data of all task processes, convert the reliability block diagram of each stage of the system into the corresponding SFT model, and then make the SFT converted in each stage equivalent based on the micro-element substitution principle to realize the construction of the micro-element space fault tree (ISFT) model, that is, to obtain a single-stage ISFT model. The construction process of the reliability block diagram of each stage includes:

[0066] 1) Collect data from the system at different mission stages.

[0067] 2) Use the collected data to build a reliability diagram to reflect the relationship between each sub-link and its reliability parameters. The reliability parameters determined in the reliability diagram directly affect the failure rate and availability of each sub-link and are the basis for subsequent analysis.

[0068] Step 4: Construct the overall stage ISFT model and solve the structure function. Then, disjoint and simplify the structure function, and solve the system reliability based on the disjoint expression.

[0069] Step 5: According to the overall stage ISFT model, find out the basic events related to the top events, take the top events as the target layer, the basic events as the indicator layer (scheme layer), form the criterion layer through classification and induction, and establish the AHP model of system reliability. Among them, the object of classification and induction is the relationship between the top events and the basic events, the purpose is to identify the nature and interaction of each event, and form an orderly hierarchical structure for subsequent analysis.

[0070] Step 6: By constructing a judgment matrix, hierarchical sorting and consistency verification, the subjectivity of the infinite space fault tree-analysis process (ISFT-AHP) model is reduced, and finally a qualitative analysis of the mission reliability of the ship's electronic information system is achieved. Among them:

[0071] 1. Construction of judgment matrix: Through expert evaluation, a judgment matrix of the relative importance of different events is constructed.

[0072] 2. Hierarchical sorting: Use the hierarchical analysis method to decompose the eigenvalues ​​of the judgment matrix and obtain the importance weight of each event.

[0073] 3. Consistency check: Calculate the consistency ratio (CR) to ensure the consistency of the judgment matrix. If the CR value exceeds 0.1, the judgment matrix needs to be adjusted.

[0074] In an exemplary embodiment of the present application, for a ship electronic information system task, the mathematical expression of the FTA (Fault Tree Analysis) model can be described as:

[0075]

[0076] Where: x i ′ is the probability of the bottom event occurring. Φ is the probability of the top event occurring.

[0077] Its structural function is:

[0078]

[0079] Where: φ is the structure function of the FTA model. is the set of events. X1,X2,...,X n Represents each event.

[0080] In an exemplary embodiment of the present application, the specific steps of constructing the SFT model based on the FTA model are:

[0081] Step (1), determine the main external factors that affect the ship's electronic information system mission.

[0082] Step (2), taking weather factor t and wave intensity h as the main external factors, construct Figure 3 The SFT model shown.

[0083] Furthermore, based on the reliability probability distribution, the probability function equations of each link in the ship's electronic information system are derived.

[0084] Depend on Figure 3 It can be seen that the construction of the SFT model requires the use of characteristic functions to clarify the probability of occurrence of the two external factors of SFT. Assume that the model Q is affected by two external factors: weather factors (i.e., characteristic t) and wave intensity (i.e., characteristic h), and t and h contain some more specific factors. Then, let the specific influencing factor be D, and the expression of Q is:

[0085] Q=D1D2D3+D1D4+D3D5.

[0086] In the formula, D1, D2, D3, D4 and D5 are different influencing factors. Weather factor t and wave intensity h work together through a series of intermediate events (such as t1, h1, h2), and finally lead to system failure Q. The connection between the two is that they represent different external environmental influences, which lead to the occurrence of the top event through different paths (intermediate events and basic events). The logic gates in the model (such as AND gates or OR gates) connect these events to show how external factors combine to cause system failure.

[0087] In an exemplary embodiment of the present application, the specific steps of solving the probability function equation based on the SFT model are:

[0088] Step 1: Let function P i x (x) represents the reliability change characteristics of the system under the influence of t and h. Among them, the ordinal number of the failure link is i, so the function expressions of the t characteristic and h characteristic of the i-th information transmission link in the system are:

[0089]

[0090] P i t (t) = 1 - λt.

[0091] Step 2: Assume that the number of influencing factors is n. When the system link is disturbed by the external environmental factors, the independent variables are set as influencing factors. The function value is the probability of occurrence of the system link. The probability function equation of the occurrence of the system link is defined by the following equation:

[0092]

[0093] Where P i t (t) is the reliability change characteristic of the system under the influence of feature t in the i-th information transmission link, P i h (h) is the reliability change characteristic of the system under the influence of feature h in the i-th information transmission link, λ is the failure rate of the system link, A is the change of the external environment, P i (x1,x2,…,x n ) is the probability function, n is the number of influencing factors, x1,x2,…,x n For different influencing factors, is the influencing factor x in the i-th information transmission link k The reliability change characteristics of the system under the influence of

[0094] Step 3: Based on the characteristics of t and h, the probability function equation of the ship's electronic information system is derived as follows:

[0095] P i (t,h)=1-(1-P i t (t))(1-P i h (h)).

[0096] Where: P i (t,h) is the probability of failure occurring.

[0097] In an exemplary embodiment of the present application, it is assumed that the failures of different links within the system do not affect each other, that is, each link is managed by a different operator and has no correlation with each other. However, it is obvious that the aggregation and joint processing of information between different links is necessary when executing and processing tasks. Therefore, the microelement substitution principle can be used to solve this problem. Use the microelement H with the same stage number as the stage number. i (i=1,2,…) is used to replace link H, and then the related information between different micro-elements of the same unit is processed. The SFT model representing each stage in the system is replaced by micro-elements to obtain a single-stage ISFT model after micro-element replacement, and the overall stage ISFT model is established based on this.

[0098] Assume that the ship's electronic information system mission consists of three non-overlapping continuous stages, each of which contains three failure modes: L, M, and N. Figure 4 The failure criteria for each stage in the SFT designed from the internal influencing factors of the system are shown. The three-stage system failure is described as follows:

[0099] In stage 1, if L, M and N occur simultaneously, the system is considered to have failed.

[0100] In stage 2, if only L occurs, or M and N occur together, the system is considered to have failed.

[0101] In stage three, if one of L, M and N occurs, the system is considered to have failed.

[0102] Figure 4 The single-stage ISFT model after the SFT model shown in the figure is replaced by the infinitesimal element is as follows Figure 5 As shown, based on this, the present application not only solves the problem of correlation between the stages of each bottom event, but also makes reliability analysis easier.

[0103] In an exemplary embodiment of the present application, the steps for constructing the overall stage ISFT model are:

[0104] Step 1: Construct a single mission phase spatial fault subtree, and establish the ISFT model of each phase (i.e., single-phase ISFT model) based on the mission reliability block diagram of each phase. Considering that there are multiple failure modes in the sub-links of the system, and the failure modes are interdependent, the following assumptions are made:

[0105] 1) In the overall system, different links and functions are independent of each other.

[0106] 2) If a function of a link changes from a normal state to a faulty state, it will always be in a faulty state thereafter.

[0107] 3) The function of a certain link can only be in normal state or a certain failure mode at any point in time.

[0108] Assuming that link H has f failure modes, the bottom event represented by each failure mode in the link is H p (p=1,2,…f) indicates.

[0109] Step 2: Based on the principle of microelement substitution, in order to distinguish the failure modes of different stages in each task stage of the system, the failure modes are defined as follows: Assuming that in n task stages, link H has f failure modes, then the Boolean variable H is used pq (p=1,2,…f;q=1,2,…n) is used to express the bottom event represented by each failure mode in the unit. Among them, H pq=1 indicates that link H is in failure mode p at task stage q. pq =0 means that link H is not in failure mode p at task stage q, that is, the link is in normal state or other task failure mode p' (p'=1, 2, ...f, p'≠p).

[0110] Step 3: Construct the overall stage ISFT model. According to the task failure criterion, any single-stage task failure will lead to the failure of the top-level task. Therefore, each single-stage ISFT model can be used as a fault subtree of the top-level task failure in the form of an OR gate to obtain the ISFT model of the overall stage task failure (i.e., the overall stage ISFT model).

[0111] In an exemplary embodiment of the present application, the steps of solving the structure function and the system reliability can be described as follows:

[0112] Step 1: Based on the overall stage ISFT model, the system structure function is further expressed as a Boolean function, whose independent variable is the state variable of the bottom event in the overall stage ISFT model. The determination process of the system structure function is:

[0113] 1. Determine the bottom event and top event. The bottom event is represented by Boolean variables D1, D2, D3, D4, D5 ∈ {0, 1}. The top event is also represented by Boolean variables Q ∈ {0, 1}.

[0114] 2. Determine the logic gate. AND gate: Q = D1∧D2 = D1·D2. OR gate: Q = D1∨D2 = D1+D2-D1·D2.

[0115] 3. According to the structure of the ISFT model in the overall stage, the bottom events related to the weather factor t and the wave intensity h are connected through logic gates.

[0116] Step 2: Considering the correlation and dependency between faults, before disjointing the structure functions, the structure functions of multiple combinations need to be processed for dependency. This can be handled using two sets of stage-dependent algebraic rules. Rule 1 is for variables in different stages of the same fault mode, as shown in Table 1. Rule 2 is for variables in different fault modes, as shown in Table 2.

[0117] Table 1 Algebraic rules for the same failure mode dependence (q1<q2)

[0118]

[0119] Table 2 Different failure modes depend on algebraic rules (p1≠p2,q1≤q2)

[0120]

[0121]

[0122] After preliminary simplification, the structure function is processed by the disjointness algorithm. The specific algorithm is as follows:

[0123] Let g1, g2, … g s is the minimum cut set of all, but:

[0124]

[0125] In the formula, g represents the state of the top event, g i represents a specific fault event related to a sub-event in the system, where i is the index of the event and g r Indicates a specific fault event, g s Represents the sth fault event in the system, and together with other fault events constitutes the overall fault logic. Indicates non-fault events related to the system status. Indicates the specific fault in the overall system g q The combination of all relevant non-fault events. i The state variable representing event i. p Represents the state of the pth event.

[0126] In view of the mutual exclusivity of the fault modes, the disjoint structure function is further simplified using simplification rules. The purposes of simplification include:

[0127] 1. Eliminate unnecessary high-order terms.

[0128] 2. Use symmetry to reduce independent variables and parameters in the structure function.

[0129] 3. Combine constant factors in the expression to make the entire structural function form more concise.

[0130] 4. Replace complex function forms with simpler approximate expressions.

[0131] Step 3: Solve the system reliability. Due to the repetitiveness of the underlying events, the minimum cut sets often intersect. When the number of minimum cut sets is too large, the "combinatorial explosion" problem will occur when using formula 10 and formula 11 for calculation, which will lead to a surge in the amount of calculation. In this case, the recursive method of converting the intersection and disjointness into disjointness can be used for calculation.

[0132] According to the characteristics of disjointness, the product terms are disjoint sets, which satisfies:

[0133]

[0134] Where: P(*) is the probability value of the event.

[0135] In the actual application of ship electronic information systems, it is difficult to perform accurate calculations because there is a lot of information flowing in from multiple sources and the error in the probability of occurrence of the bottom event is large. This can be solved using the following two approximate algorithms, which can also meet the actual needs of mission reliability analysis:

[0136] (1) Calculation based on the approximate formula of the inclusion-exclusion principle. The principle of this method is: assuming that the probability of occurrence of each minimum cut set event is small enough, then the cut sets can be regarded as mutually exclusive. Based on the first approximate calculation formula in the inclusion-exclusion principle, we have:

[0137]

[0138] Where: P(F) is the approximate event probability value.

[0139] (2) Independent approximate calculation. Assuming that each minimum cut set is independent of each other, according to the multiplication theorem of probability theory, we can get:

[0140]

[0141] The effects of the above two approximate calculation methods are similar. When analyzing the mission reliability of the ship's electronic information system, it is sufficient to select the appropriate approximate method based on the actual mission requirements.

[0142] In summary, the modeling process of qualitative analysis of task reliability based on the overall stage ISFT model is as follows: Figure 6 shown.

[0143] In an exemplary embodiment of the present application, the design steps for establishing a system reliability AHP model based on ISFT are:

[0144] Step 1: Determine the form and structure of the basic AHP model, such as Figure 7 shown.

[0145] Step 2: List the basic events that may cause the ship's electronic information system mission to be unreliable, including the system's internal failure factors and human factors, see Table 3.

[0146] Table 3 List of basic events of unreliable mission of ship electronic information system

[0147] symbol Event Type Symbols (continued) Event Type (continued) M Mission Unreliable Overall Event <![CDATA[E8]]> Installation Errors <![CDATA[E1]]> Unreasonable design <![CDATA[E9]]> Unreasonable scheduling <![CDATA[E2]]> Safety link failure <![CDATA[E 10 ]]> Missing inspection <![CDATA[E3]]> Failure of monitoring link <![CDATA[E 11 ]]> Not maintained in time <![CDATA[E4]]> Control link failure <![CDATA[E 12 ]]> Problem Ignore <![CDATA[E5]]> Outdated equipment <![CDATA[E 13 ]]> Operation Violation <![CDATA[E6]]> Electromagnetic Interference <![CDATA[E 14 ]]> Unreasonable operation <![CDATA[E7]]> Circuit connection failure <![CDATA[E 15 ]]> Electronic device failure

[0148] Among them, basic events provide the basis for the analysis of the overall stage ISFT model, and the overall stage ISFT model identifies, analyzes and quantifies the impact of these events on system failure in a structured way, thereby supporting system reliability assessment and risk management.

[0149] In the overall stage ISFT model, basic events are considered as components of the fault tree, and the top event represents system failure or task unreliability. The basic events are combined through logic gates (such as AND gates, OR gates, etc.) to form an overall fault tree structure to help identify the root cause of system failure.

[0150] The overall stage ISFT model allows quantifying the probability of occurrence of basic events and then calculating the probability of occurrence of top events. This process enables analysts to evaluate the impact of different basic events on system reliability and identify key risk factors.

[0151] Through the overall stage ISFT model, it is possible to clarify how different basic events affect top events through fault propagation paths. This helps to understand and predict the response of the system when facing specific basic events and take corresponding risk management measures.

[0152] The overall stage ISFT model provides a systematic framework for risk assessment of ship electronic information systems. By identifying and analyzing the basic events that lead to mission unreliability, decision makers can develop more effective maintenance and protection strategies, thereby improving the overall reliability of the system.

[0153] Step 3: Structural importance analysis. On the basis of the same probability of occurrence of basic events, analyze the impact of basic events on top events from a structural perspective. Structural importance can be approximately expressed as:

[0154]

[0155] Where: G δ(p) is the structural importance of the pth basic event. s is the number of minimum cut sets in the ISFT model. r is the number of minimum cut sets that include the pth basic event. q is the total number of basic events in the qth minimum cut set where the pth basic event is located.

[0156] Step 4: According to the established overall stage ISFT model, find out the basic events related to the top events, then take the top events as the target layer, the basic events as the indicator layer (i.e., the solution layer), form the criterion layer through classification and induction, and finally establish the AHP model for qualitative analysis of the reliability of the ship electronic information system. The specific AHP model is shown in Table 4.

[0157] Table 4 AHP model table for qualitative analysis of ship electronic information system reliability

[0158]

[0159]

[0160] Among them, structural importance analysis: assuming that the probability of occurrence of basic events is the same, evaluate the impact of each basic event on the top event (system failure) from a structural perspective. This analysis can help identify which basic events are key risk factors.

[0161] In an exemplary embodiment of the present application, the construction and optimization process of the ISFT-AHP model are as follows:

[0162] Step 1: Obtain the minimum cut set of task unreliable events through Boolean operations, which are:

[0163]

[0164] Determine the structural importance coefficients of the basic events and sort them according to the structural importance. Assume that the structural importance coefficients of the above basic events are G x , where x = 1, 2, …, 15, the structural importance coefficient is shown in Table 5.

[0165] Table 5 Structural importance coefficient table of basic events

[0166] Basic Events <![CDATA[E1]]> <![CDATA[E2]]> <![CDATA[E3]]> <![CDATA[E4]]> <![CDATA[E5]]> <![CDATA[E6]]> <![CDATA[E7]]> <![CDATA[E8 <!-- 12 -->]]> coefficient <![CDATA[G1]]> <![CDATA[G2]]> <![CDATA[G3]]> <![CDATA[G4]]> <![CDATA[G5]]> <![CDATA[G6]]> <![CDATA[G7]]> <![CDATA[G8]]> Basic Events (Continued) <![CDATA[E9]]> <![CDATA[E 10 ]]> <![CDATA[E 11 ]]> <![CDATA[E 12 ]]> <![CDATA[E 13 ]]> <![CDATA[E 14 ]]> <![CDATA[E 15 ]]> Coefficient (continued) <![CDATA[G9]]> <![CDATA[G 10 ]]> <![CDATA[G 11 ]]> <![CDATA[G 12 ]]> <![CDATA[G 13 ]]> <![CDATA[G 14 ]]> <![CDATA[G 15 ]]>

[0167] in,

[0168] Assume that E2, E9, E 13 、E 15 The structural importance of E3, E7, E 10 、E 11 、E 12 、E 14 The structural importance of E1, E4, E5, E6, and E8 is the smallest, so there will be the following relationship: G δ(2) =G δ(9) =G δ(13) =G δ(15) >G δ(3) =G δ(7) =G δ(10) =G δ(11) =G δ(12) =G δ(14) >G δ(1) =G δ(4) =G δ(5) =G δ(6) =G δ(8) .

[0169] Through the structural importance analysis, it can be concluded that: safety link failure E2, unreasonable scheduling E9, operation violation E 13 , and electronic failure E 15It is the most important factor affecting the unreliability of the ship's electronic information system mission. This analysis does not take into account the probability of occurrence of basic events, so it is necessary to calculate the judgment factors of each basic event. The judgment factors are shown in Table 6.

[0170] Table 6 Basic event judgment factor table

[0171] Basic Events <![CDATA[E1]]> <![CDATA[E2]]> <![CDATA[E3]]> <![CDATA[E4]]> <![CDATA[E5]]> <![CDATA[E6]]> <![CDATA[E7]]> <![CDATA[E8]]> Judgment Factor <![CDATA[y3]]> <![CDATA[y1]]> <![CDATA[y2]]> <![CDATA[y3]]> <![CDATA[y3]]> <![CDATA[y3]]> <![CDATA[y2]]> <![CDATA[y3]]> Basic Events (Continued) <![CDATA[E9]]> <![CDATA[E 10 ]]> <![CDATA[E 11 ]]> <![CDATA[E 12 ]]> <![CDATA[E 13 ]]> <![CDATA[E 14 ]]> <![CDATA[E 15 ]]> Judgment Factors (Continued) <![CDATA[y1]]> <![CDATA[y2]]> <![CDATA[y2]]> <![CDATA[y2]]> <![CDATA[y1]]> <![CDATA[y2]]> <![CDATA[y1]]>

[0172] Among them, y1, y2, and y3 represent the impact factor values ​​of the most important event, the medium-important event, and the relatively unimportant event, respectively, and have the following relationship:

[0173] y1>y2>y3.

[0174] According to the AHP relationship and the discriminant factor values ​​in Table 6, the discriminant factors Y1, Y2 and Y3 of the criterion layers L1, L2 and L3 are calculated respectively, and the following can be obtained:

[0175]

[0176] Then, the judgment matrix of the AHP model can be constructed by comparing the judgment factors pairwise.

[0177] Step 2: Perform hierarchical sorting and consistency verification. Using the constructed judgment matrix, calculate the weights W1, W2, and W3 of each matrix respectively, and perform consistency verification. From the criterion layer weights, it can be seen that the first type of unsafe behavior (L1) is the main factor affecting system reliability, and the second type of unsafe behavior (L2) and the third type of unsafe behavior (L3) have a relatively weak impact on accidents, but they are still not negligible.

[0178] Specifically, the unreliable factors of the task include safety link failure E2, unreasonable scheduling E9, and illegal operation E1. 13 , and electronic failure E 15 The weight of is the largest, so it is the main influencing factor. Failure of monitoring link E3, failure of circuit connection E7, and failure to maintain in time E 10 The weights of the other six factors are second. The weights of the other five factors, such as unreasonable design E1, control link failure E4, and backward equipment E5, are relatively small, so they are secondary influencing factors.

[0179] In order to better analyze the impact of various factors on the mission reliability of ship electronic information systems, different factors can be divided into three categories according to weight differences, namely Z1, Z2 and Z3, which are:

[0180]

[0181] Among them, the Z1 factor has the largest weight (for example, in the range of 0.12 to 0.15). The Z2 factor has the second largest weight (for example, in the range of 0.06 to 0.12). The Z3 factor has the smallest weight (for example, in the range of 0.02 to 0.06).

[0182] Finally, combining all the above design processes and optimization schemes, the ISFT-AHP model was constructed to achieve qualitative analysis of the mission reliability of ship electronic information systems.

[0183] In summary, this application establishes an ISFT-AHP model for the complexity and uncertainty of different types of interference factors that exist when the ship's electronic information system executes and processes tasks. First, the main external factors that affect the ship's electronic information system tasks are determined, and the SFT model is constructed. Then, the characteristic function expression and probability function equation of the external factors are solved based on the SFT model. Next, the principle of differential substitution is used to distinguish the internal failure modes of the system in different mission stages, and an overall stage ISFT model is constructed. After that, based on the structure of the overall stage ISFT model, the system structure function is expressed as a Boolean function and non-intersected. The reliability of the overall system is solved by further simplifying the non-intersected structure function using simplification rules. Through the analysis of the importance of the structure and the determination of the basic events related to the top events in the overall stage ISFT model, the top events are used as the target layer, the basic events are used as the indicator layer, and the criterion layer is formed through classification and induction to establish an AHP model for qualitative analysis of task reliability. Finally, the influence of human interference factors was taken into account, the minimum cut set of mission unreliable events was obtained through Boolean operations and the AHP judgment matrix was constructed. Then hierarchical sorting and consistency verification were performed, and finally the ISFT-AHP model was designed to realize the qualitative analysis of the reliability of ship electronic information system missions.

[0184] This application first determines the main external factors that affect the tasks of the ship's electronic information system and constructs an SFT model to avoid the impact of external interference factors on the task reliability analysis. Then, the ISFT model of the overall stage is constructed based on the principle of microelement substitution, which enables the improved model to further avoid the impact of internal interference factors in the system. Subsequently, considering the human interference factors, the ISFT-AHP model is constructed based on the top events and related basic events in the ISFT model. The ISFT-AHP model fully considers the characteristics of various interference factors such as external, internal, and human factors, and realizes accurate qualitative analysis of the reliability of complex system tasks. Based on the reliability analysis results with higher credibility, the probability of danger can be effectively reduced and the smooth execution of the ship's electronic information system tasks can be ensured.

[0185] In an exemplary embodiment, a computer device is provided. The computer device may be a server or a terminal. The internal structure diagram thereof may be as follows: Fig. 9 As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. Among them, the processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store qualitative analysis data of the mission reliability of the ship's electronic information system. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a qualitative analysis method for the mission reliability of a ship's electronic information system is implemented.

[0186] Those skilled in the art will understand that Fig. 9 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components. In an exemplary embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0187] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0188] In an exemplary embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0189] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0190] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM may be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0191] The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. The non-relational database may include a distributed database based on blockchain, etc., but is not limited thereto. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but is not limited thereto.

[0192] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0193] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A qualitative analysis method for mission reliability of ship electronic information system, characterized in that: The qualitative analysis method of mission reliability of ship electronic information system includes: Determine the external influencing factors of the ship's electronic information system mission, and construct an SFT model based on the external influencing factors; the external influencing factors include: temperature influencing factors, humidity influencing factors, smoke influencing factors, storm influencing factors, sea wave influencing factors and haze influencing factors; Based on the SFT model, characteristic function equations and probability function equations of external influencing factors are solved to obtain reliability parameters of each stage of the ship's electronic information system; Constructing a reliability block diagram of each stage of the ship's electronic information system based on the reliability parameters and internal influencing factors of the ship's electronic information system mission; The reliability block diagram is converted into an SFT model, and based on the microelement substitution principle, the SFT models corresponding to each stage are equivalently obtained to obtain a single-stage ISFT model, and the single-stage ISFT model is integrated to obtain an overall stage ISFT model; Acquire the structure function of the ship electronic information system, express the structure function as a Boolean function based on the overall stage ISFT model, and perform disjoint processing on the Boolean function using a disjoint algorithm; The Boolean function after the non-intersection process is simplified and solved by using a simplified rule to obtain the system reliability; Based on the system reliability, basic events related to the top events are determined, and the top events are used as the target layer, the basic events are used as the indicator layer, and the criterion layer is formed by classification and induction to establish an AHP model; the top events are used to represent the total failure state of the ship's electronic information system; the basic events are used to represent the fault events that cause the top events, which are the failure states of a single component or subsystem; Construct AHP judgment matrix based on AHP model; Based on the AHP judgment matrix, the weight of each layer in the AHP model is determined, and the hierarchical sorting and consistency verification are performed to achieve a qualitative analysis of the mission reliability of the ship's electronic information system.

2. The method for qualitative analysis of mission reliability of ship electronic information system according to claim 1 is characterized in that: The characteristic function equation of external influencing factors is expressed as: P i t (t)=1-λt; The probability function equation is expressed as: Where P i t (t) is the reliability change characteristic of the system under the influence of feature t in the i-th information transmission link, P i h (h) is the reliability change characteristic of the system under the influence of feature h in the i-th information transmission link, λ is the failure rate of the system link, A is the change of the external environment, P i (x1,x2,…,x n ) is the probability function, n is the number of influencing factors, x1,x2,…,x n For different influencing factors, is the influencing factor x in the i-th information transmission link k The reliability change characteristics of the system under the influence of 3. The method for qualitative analysis of mission reliability of ship electronic information system according to claim 1 is characterized in that: Based on the principle of infinitesimal substitution, the SFT models corresponding to each stage are equivalent to the single-stage ISFT model, including: The links are replaced by microelements with the same sequence number as the stage, and the SFT model representing each stage in the ship electronic information system is replaced by microelements to obtain the single-stage ISFT model.

4. The method for qualitative analysis of mission reliability of ship electronic information system according to claim 1 is characterized in that: The single-stage ISFT model is integrated to obtain the overall stage ISFT model, including: Each of the single-stage ISFT models is used as a fault subtree of top-level task failure in the form of an OR gate to obtain the overall stage ISFT model.

5. The method for qualitative analysis of mission reliability of ship electronic information system according to claim 1 is characterized in that: Before performing disjoint processing on the Boolean function, the method further comprises: Dependency processing is performed on the Boolean function.

6. The method for qualitative analysis of mission reliability of ship electronic information system according to claim 5 is characterized in that: The dependency handling is performed using two sets of stage-dependent algebraic rules.

7. The method for qualitative analysis of mission reliability of ship electronic information system according to claim 1 is characterized in that: The independent variable of the Boolean function is the state variable of the bottom event in the overall stage ISFT model.

8. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the qualitative analysis method for mission reliability of a ship electronic information system according to any one of claims 1 to 7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for qualitatively analyzing the mission reliability of a ship electronic information system according to any one of claims 1 to 7 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the method for qualitatively analyzing the mission reliability of a ship electronic information system according to any one of claims 1 to 7 is implemented.

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