A System Maintenance Strategy Design Method Based on Data Flow Fault Tree

Abstract

This invention belongs to the technical field of avionics product maintenance, reliability, testability, and maintainability, and relates to a system maintenance strategy design method based on a data flow fault tree. It includes the following steps: Step 1: Design the data flow according to the system; Step 2: Identify the system's common and dedicated resources; Step 3: Generate a fault tree based on the data flow and common and dedicated resources; Step 4: Generate a fault correlation matrix based on the fault tree; Step 5: Generate a fault diagnosis sequence list based on the fault correlation matrix.

Description

Technical Field

[0001] This invention belongs to the field of avionics technology, and specifically relates to a system maintenance strategy design method based on data flow fault trees. Background Technology

[0002] With the increasing integration of aviation products, the hardware and software components and failure mechanisms of avionics systems are becoming increasingly complex. The large volume, multi-level, and strongly coupled fault information poses a significant challenge to improving maintenance efficiency and ensuring maintenance quality. Currently, airborne electronic product fault detection data is vast, but the inherent correlations between different object levels and different faults are not explicitly expressed, making fault isolation and localization difficult. This often relies heavily on the experience of maintenance personnel, resulting in non-standardized fault diagnosis processes. Fault tree analysis, a tool for reliability analysis, clearly represents the relationships between fault events, causes, and combinations of causes. Fault isolation based on fault trees optimizes the maintenance process, ensuring maintenance quality. Utilizing the correlation of fault information can improve the rationality of fault isolation, localization, and troubleshooting processes, thereby increasing maintenance efficiency. Summary of the Invention

[0003] The purpose of this invention is to optimize the difficulties in fault isolation and location in avionics systems and the lack of standardization in the fault investigation process, and to improve the efficiency of fault record data in the fault analysis and isolation and location process. This invention proposes a fault tree-based avionics product maintenance strategy design method.

[0004] The technical solution of the present invention:

[0005] A system maintenance strategy design method based on data flow fault tree includes the following steps:

[0006] Step 1: Design the data flow according to the system design;

[0007] Step 2: Identify the system's public and private resources;

[0008] Step 3: Generate a fault tree based on data flow and public and private resources;

[0009] Step 4: Generate a fault correlation matrix based on the fault tree;

[0010] Step 5: Generate a fault diagnosis sequence list based on the fault correlation matrix.

[0011] Furthermore, in step one, each function of the system corresponds to a data stream;

[0012] Specifically, this includes: data processing data stream, data storage data stream, video compression processing data stream, and control sampling processing data stream;

[0013] Each data stream includes an input section, a processing section, and an output section.

[0014] The data flow drawn using this method can lay the foundation for the subsequent standardized and rapid drawing of fault trees.

[0015] Furthermore, the data flow design process is as follows: Identify the input interfaces, processing nodes, and output interfaces corresponding to the functions on the system hardware topology diagram;

[0016] Identify the supporting nodes and their supporting relationships with input interfaces, processing nodes, and output interfaces. The supporting nodes include power nodes, clock nodes, storage nodes, status control nodes, and timing configuration nodes.

[0017] Different functions are connected by lines of different forms according to the topological path to form different data flows;

[0018] Identify public resources and supporting nodes at the intersection of different data streams;

[0019] Identify dedicated resources and supporting nodes for dedicated resources in different data streams;

[0020] Public resources and their corresponding supporting nodes outside of public resources are dedicated resources.

[0021] Identifying public resources and their corresponding supporting nodes can lay the foundation for repeatedly applying the same content when drawing fault trees later.

[0022] Furthermore, each data stream corresponds to a fault tree for a function, and the first-level nodes of each fault tree include: the failure modes of common resources and the failure modes of private resources in the data stream;

[0023] The second-level nodes of each fault tree include: failure modes of supporting nodes for public resources and failure modes of supporting nodes for private resources. Failure modes of resources with supporting relationships are connected to their supporting node failure modes according to their causal relationships.

[0024] There is no upper limit to the number of levels in each fault tree. If the supporting node of level i still has a supporting node, then the supporting node of the supporting node is the (i+1)th level, i≥2.

[0025] When a resource has multiple supporting nodes, the failure modes of the resource and the failure modes of the supporting nodes are connected by logic gates according to the causal relationship.

[0026] The fault tree drawn using this method is directly mapped to the data stream, making the drawing process simple and intuitive.

[0027] Furthermore, the top event of each fault tree represents the failure mode of the function;

[0028] The top event is connected to all first-level events through logic gates according to their causal relationships.

[0029] Furthermore, causal relationships are described using logic gate notation to depict the causal relationships between various events in a system.

[0030] Furthermore, each row of the fault correlation matrix corresponds to the top event of a fault tree;

[0031] Each column of the fault correlation matrix corresponds to a node that has no connection to the next level. Duplicate nodes must be merged and cannot appear repeatedly.

[0032] Furthermore, the data in the i-th row and j-th column of the fault correlation matrix is ​​0 or an integer not less than 1, representing whether there is a causal relationship between the failure mode of the i-th function and the failure mode of the j-th node.

[0033] 0 represents no correlation, and all other values ​​represent correlation, with larger values ​​indicating greater correlation.

[0034] i takes values ​​from 1 to m, where m is the number of failure modes of the system function;

[0035] j takes values ​​from 1 to n, where n is the number of unique nodes in the fault tree that have no connection to the next level.

[0036] Furthermore, the process of generating the fault diagnosis sequence list is as follows:

[0037] Match the top event of each function with the fault phenomenon that occurred;

[0038] The rows corresponding to the matched top events and the rows corresponding to the unmatched top events are divided into a matching matrix and an unmatched matrix;

[0039] Summing the matching matrix column by column;

[0040] Summing each column of the unmatched matrix;

[0041] Multiply the sum of the j-th column of the matching matrix with the sum of the j-th column of the unmatched matrix;

[0042] Remove the non-zero data after multiplication in the summation result of the matching matrix and the zero data in the summation result of the matching matrix, and sort the remaining data from largest to smallest;

[0043] And perform fault detection on the corresponding nodes according to the sorting results.

[0044] The beneficial effects of this invention are:

[0045] This invention provides a system maintenance strategy design method based on a dataflow fault tree for avionics system maintenance. By drawing functional data flows and identifying corresponding physical nodes, and based on the data flow paths, common resources, dedicated resources, and supporting nodes are identified, and a fault tree is constructed. This is a standardized engineering method that is easy to implement, and the relationships between the hierarchical levels of the fault tree are intuitive and clear. Common resources and their supporting nodes are used by multiple fault trees, and can be reused after being drawn once, shortening the time required for fault tree construction. A fault correlation matrix is ​​generated based on the fault tree. When a fault occurs, the fault correlation matrix is ​​divided into a matching matrix and an unmatched matrix by matching fault phenomena. After eliminating fault sources through unmatched faults, the scope of fault source investigation is further narrowed. Then, fault sources are investigated sequentially from high to low correlation values. This method can effectively improve the maintenance quality and efficiency of current highly integrated avionics systems, addressing the problems of insufficient standardization in fault isolation methods and insufficient correlation between fault information and fault sources. It can be widely applied in the field of avionics and has strong practical and promotional value. Attached Figure Description

[0046] Figure 1 Hardware topology diagram of the video data processing module.

[0047] Figure 2 Data flow diagram of the video data processing module.

[0048] Figure 3 Fault tree for loss of FC bus data processing function.

[0049] Figure 4 Ethernet data storage function loss fault tree.

[0050] Figure 5 Video data processing and compression function loss fault tree.

[0051] Figure 6 A diagram illustrating the fault correlation matrix of the video data processing module.

[0052] Figure 7 A schematic diagram of the fault correlation matching matrix and the unmatched matrix.

[0053] Figure 8 A schematic diagram of summing the fault correlation matching matrix.

[0054] Figure 9 A schematic diagram of the operation of the fault correlation matching matrix and the unmatched matrix.

[0055] Figure 10 Diagram showing the troubleshooting and diagnostic sequence. Detailed Implementation

[0056] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0057] Taking a video data processing module as an example, its functions are as follows:

[0058] FC bus data processing function;

[0059] Ethernet data storage function;

[0060] Video data processing and compression functions;

[0061] The hardware topology diagram of this module is as follows: Figure 1 As shown, the corresponding nodes include:

[0062]

[0063] Data flow diagrams generated based on functions, such as Figure 2 As shown.

[0064] FC bus data processing data flow:

[0065] FC interface input interface → CPU processing node → Ethernet interface output interface. Ethernet data storage data flow:

[0066] Ethernet interface input interface → CPU processing node → SSD disk output interface.

[0067] Video data processing and compression of data streams:

[0068] ARINC818 Interface - Input Interface → FPGA Processing Node → CPU Processing Node → FPGA Processing Node → PCIe Interface Output Interface.

[0069] Public resources: CPU, Ethernet interface

[0070] Dedicated resources: FC interface, ARINC818 interface, SSD disk, FPGA, PCIe interface

[0071] Supporting nodes: DC / DC1, DC / DC2, Clock 1, Clock 2, CPLD, FLASH storage node, DDR3, Storage node 1, DDR3 storage node 2, SSD disk storage node.

[0072] Based on the data flow, draw fault trees for FC bus data processing function loss, Ethernet data storage function loss, and video data processing compression function loss, respectively, such as... Figures 3-5 As shown.

[0073] Based on the three fault trees, the fault correlation matrix is ​​as follows: Figure 6 As shown.

[0074] If a fault occurs resulting in the loss of FC bus data processing and Ethernet data storage functions, but not the loss of video data processing and compression functions, then the fault correlation matrix is ​​divided into a matched matrix and an unmatched matrix. The matched matrix consists of data rows indicating the loss of FC bus data processing and Ethernet data storage functions, while the unmatched matrix consists of data rows indicating the loss of video data processing and compression functions. Figure 7 As shown.

[0075] Summing the matching matrix column by column, and summing the unmatched matrix column by column, the results are as follows: Figure 8 As shown.

[0076] Multiply the sum of the matching matrices by the sum of the unmatched matrices;

[0077] Remove non-zero data from the multiplication result and zero data from the summation result of the matching matrix. Figure 9 As shown.

[0078] The remaining nodes are sorted according to the sum of the matching matrix values ​​for fault detection, such as... Figure 10 As shown.

[0079] The order is:

[0080] Ethernet interface functionality lost;

[0081] FC interface functionality lost;

[0082] The SSD disk storage node function has been lost.

[0083] The above description is merely a specific embodiment of the present invention, providing a detailed description of the invention. Parts not covered herein are conventional techniques. However, the scope of protection of the present invention is not limited thereto. Any variations 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. The scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A system maintenance strategy design method based on data flow fault tree, characterized in that: Includes the following steps: Step 1: Design the data flow according to the system design; Step 2: Identify the system's public and private resources; Step 3: Generate a fault tree based on data flow and public and private resources; Step 4: Generate a fault correlation matrix based on the fault tree; each row of the fault correlation matrix corresponds to the top event of the fault tree; each column of the fault correlation matrix corresponds to a node that has no connection with the next level; the data in the i-th row and j-th column of the fault correlation matrix is ​​0 or an integer not less than 1, representing whether there is a causal relationship between the failure mode of the i-th function and the failure mode of the j-th node; 0 represents no relationship, and others represent a relationship, and the larger the value, the stronger the correlation; duplicate nodes need to be merged and cannot appear repeatedly; i takes the value from 1 to m, where m is the number of failure modes of the system function; j takes the value from 1 to n, where n is the number of non-duplicate nodes in the fault tree that have no connection with the next level. Step 5: Generate a fault diagnosis sequence list based on the fault correlation matrix. The process is as follows: Match the top event of each function with the fault phenomenon that occurred; divide the corresponding rows of the matched top events and the corresponding rows of the unmatched top events into a matching matrix and an unmatched matrix; sum the matching matrix column by column; sum the unmatched matrix column by column; multiply the sum of the j-th column of the matching matrix with the sum of the j-th column of the unmatched matrix; remove the non-zero data in the multiplication result and the zero data in the sum of the matching matrix, sort the remaining data from largest to smallest; and perform fault detection on the corresponding nodes according to the sorting result.

2. The method according to claim 1, characterized in that: In step one, each function of the system corresponds to a data stream; Specifically, this includes: data processing data stream, data storage data stream, video compression processing data stream, and control sampling processing data stream; Each data stream includes an input section, a processing section, and an output section.

3. The method according to claim 2, characterized in that: The data flow design process is as follows: Locate the input interface, processing node, and output interface corresponding to the function on the system hardware topology diagram; Identify the supporting nodes and their supporting relationships with input interfaces, processing nodes, and output interfaces. The supporting nodes include power nodes, clock nodes, storage nodes, status control nodes, and timing configuration nodes. Different functions are connected by lines of different forms according to the topological path to form different data flows; Identify public resources and supporting nodes at the intersection of different data streams; Identify dedicated resources and supporting nodes for dedicated resources in different data streams; Public resources and their corresponding supporting nodes outside of public resources are dedicated resources.

4. The method according to claim 3, characterized in that: Each data stream corresponds to a fault tree for a function. The first-level nodes of each fault tree include: common resource failure modes and dedicated resource failure modes in the data stream. The second-level nodes of each fault tree include: failure modes of supporting nodes for public resources and failure modes of supporting nodes for private resources. Failure modes of resources with supporting relationships are connected to their supporting node failure modes according to their causal relationships. There is no upper limit to the number of levels in each fault tree. If the supporting node of level i still has a supporting node, then the supporting node of the supporting node is the (i+1)th level, i≥2. When a resource has multiple supporting nodes, the failure modes of the resource and the failure modes of the supporting nodes are connected by logic gates according to the causal relationship.

5. The method according to claim 4, characterized in that: The top event of each fault tree represents the failure mode of the function; The top event is connected to all first-level events through logic gates according to their causal relationships.

6. The method according to claim 5, characterized in that: Causality is a logical gate notation used to describe the causal relationships between various events in a system.

Images