Rule-based avionics system fault code design method

Abstract

The invention belongs to the field of avionics product reliability and testability design, and discloses a rule-based avionics system fault code design method, and fault codes comprise a single fault code and a combined fault code; the fault judgment result of the single fault code associated with the combined fault code is stored in the combined fault code. The single fault code comprises a code type, a single object domain identifier, a result identifier, a time identifier and a state identifier. The combined fault code comprises a code type, a combined object domain identifier, a result identifier, a time identifier and cause information.

Description

Technical Field

[0001] The invention belongs to the technical field of reliability and testability design of avionics products, and in particular relates to a rule-based avionics system fault coding design method. Background Art

[0002] With the increasing integration of aviation products, the hardware and software components of avionics systems and their failure mechanisms are becoming more complex. The system will generate large quantities of multi-level and strongly coupled fault information during the work process. Due to the huge amount of product fault detection data, there is no unified design specification for the coding rules of fault records. Most fault coding principles are customized by designers based on engineering experience. There are hidden dangers such as incomplete coverage of the state and result information when the fault occurs, and the implicit expression of the inherent correlation between different object levels and different faults. This poses a huge challenge to ground analysis and data utilization, resulting in the difficulty and long cycle of related fault analysis. Fault coding, as a design method, can alleviate the problem of difficulty in indexing fault information elements from the front end. Defining and recording faults based on coding rules is the premise for instant and effective acquisition and analysis of fault information. It can not only improve the rationality of online fault handling measures, but also enhance the utilization rate of fault information in offline state, providing more valuable related information for fault analysis. Summary of the invention

[0003] The purpose of the present invention is to optimize the problem that the amount of avionics system fault detection data is large but the record standardization and data correlation are insufficient, and to enhance the information value of fault record data in fault analysis and isolation positioning. The present invention proposes a rule-based avionics system fault coding design method.

[0004] The technical solution of the present invention:

[0005] A rule-based avionics system fault coding design method, wherein the fault coding includes single fault coding and combined fault coding;

[0006] The combined fault code stores the fault determination results of the single fault codes associated therewith.

[0007] Furthermore, the single fault code includes: a code type, a single object domain identifier, a result identifier, a time identifier, and a status identifier.

[0008] Furthermore, the combined fault code includes: code type, combined object domain identifier, result identifier, time identifier and cause information.

[0009] Furthermore, the number of causal information bits of the combined fault code is equal to the number of single fault codes associated with the combined fault code.

[0010] Further, each bit of data in the causal information of the combined fault code is associated with a single fault code.

[0011] Furthermore, each bit of data in the cause information of the combined fault code stores the result identifier of the single fault code associated therewith.

[0012] Furthermore, a single object domain identifier includes: platform bit, system bit, device bit, module bit, functional circuit bit and fault detection item.

[0013] Furthermore, the combined object domain identifier includes: platform bit, system bit, device bit, module bit, fault level and fault name.

[0014] Furthermore, the fault time includes: the first fault time and the end fault time.

[0015] Furthermore, the cause information is a state value directly collected by the current fault detection item and used for determining the detection result.

[0016] Beneficial effects of the present invention:

[0017] The present invention provides a rule-based fault coding design method for avionics systems. Through hierarchical coding field attribute definition, it can maximize the coverage of fault information in dimensions such as time, object level, detection result and immediate status. The coding field index based on the fault dictionary can realize the explicitness of the causal association of related fault record data. This method can effectively alleviate the problems of insufficient standardization of fault data coding, comprehensiveness and correlation of records in current highly integrated avionics systems, improve the application value of fault records in analysis and maintenance activities, can be widely used in the field of avionics, and has strong practical and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Flowchart of rule-based fault record coding design;

[0019] Figure 2 Single fault code field attribute definition and example;

[0020] Figure 3 Combined fault code field attribute definition and examples;

[0021] Figure 4 Single fault detection item information field coding and detection item T mi relevance;

[0022] Figure 5 The correlation between the detection item information field coding of the combined fault and the comprehensive fault;

[0023] Figure 6 The fault code index based on the fault dictionary is associated with the fault judgment result data. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] In response to the requirements of standardized recording of avionics product fault information and traceability of fault analysis, the present invention proposes a rule-based avionics system fault coding design method. According to the test architecture design logic of avionics products based on detection item judgment, layer-by-layer reporting, and fault integration, the coding field attributes of single faults and combined faults are defined, and the correlation between the coding of single fault detection items and the integrated combined faults is designed based on the correlation of the fault dictionary, and then the data record type and occupied space of each field of the fault code are allocated and defined, and finally hierarchical standardized fault coding records and cause tracing are realized, which improves the efficiency of fault analysis and location in ground maintenance and field troubleshooting.

[0026] It contains the following four parts:

[0027] (1) Single fault coding field attribute definition

[0028] A single fault is an original fault directly detected by the current level through self-detection in a specific stage and cycle according to the designed fault detection items. A unique fault product code is established for the object of the fault coding. The single fault code should reflect the time, object, result, scenario and other fault information of the basic detection item. Therefore, the definition of a single fault code includes the following attributes:

[0029] 1) Coding type identification:

[0030] It can be distinguished whether the recorded code belongs to basic detection data or comprehensive fault data.

[0031] 2) Object domain identification, i.e. detection item information:

[0032] In a specific engineering context, different project platforms can be distinguished, and avionics systems must be distinguished between aircraft platforms;

[0033] ·In the current airborne platform, the avionics system / subsystem to which the fault belongs can be identified.

[0034] Such as: flight control system, cockpit display and control system or mission system, etc.;

[0035] ●In the current system / subsystem, the device to which the fault belongs can be distinguished. For example, in the display and control system, the head-up display or display and control processor can be represented by the unique identifier;

[0036] In the current device, the module to which the fault belongs can be distinguished. For example, in the display and control processor, the unique identifier can be used to represent the video processing module or the power module, etc.

[0037] In the current module, the functional circuit to which the fault belongs can be distinguished. For example, in the video processing module, the unique identifier can be used to represent the graphics generation circuit or the secondary power conversion circuit.

[0038] ●In the fault list of the current product level, the fault name can be distinguished. For example, in the graphics generation circuit, the unique identifier can be used to represent the circuit's failure modes such as no video output or unexpected error video output;

[0039] In the current fault mode, the fault detection items can be distinguished. For example, for unexpected error video output, the unique identifier can be used to represent the refresh rate detection or color gradient detection of the picture.

[0040] 3) Result domain identifier, i.e., determination result:

[0041] It can represent the judgment result of the current fault detection item. For example, for the picture refresh rate detection, the unique identifier can be used to represent whether the refresh rate is normal or abnormal after detection.

[0042] 4) Time domain identifier, i.e. failure time:

[0043] It can represent the time when the current detection item is first judged to be in a fault state, with an accuracy of at least seconds. For example: the year, month, day, hour, minute, and second when the refresh rate abnormality occurs; or the cumulative number of seconds from a certain reference time to the refresh rate abnormality;

[0044] ·It can represent the moment when the current detection item is judged from the fault state to the working state, with an accuracy of at least seconds. For example: the year, month, day, hour, minute and second when the refresh rate of the current fault is restored to normal after detection and judgment; or

[0045] The cumulative number of seconds from a certain base time until the refresh rate returns to normal.

[0046] 5) Status domain identification, i.e., detailed fault data:

[0047] It can represent the state value of the current fault detection item that is directly collected and used for the determination of the detection result. For example, for the fault of abnormal refresh rate, the packet number / packet number of the video data packet within the specified period must be recorded in the fault data; for the fault of secondary voltage undervoltage, the output voltage value must be recorded in the fault data; for the fault of processor overheating and frequency reduction, the device temperature must be recorded, etc.

[0048] (2) Definition of the coding field attributes of combined faults

[0049] Combined faults are faults that must be recorded and reported after the judgment results of single fault detection items at each level are combined. The fault code should reflect the time, object, result and traceability of the fault to the cause. The recorded combined fault code should cover the following attributes:

[0050] 1) Code type identification: used to distinguish whether the recorded code belongs to basic detection data or comprehensive fault data;

[0051] 2) Object domain identification, i.e. detection item information:

[0052] In a specific engineering context, it is used to distinguish between different aviation aircraft platforms;

[0053] In the current airborne platform, it is used to distinguish the avionics system / subsystem to which the fault belongs;

[0054] In the current system / subsystem, it is used to distinguish the equipment to which the fault belongs;

[0055] In the current device, it is used to distinguish the module to which the fault belongs;

[0056] Used to characterize the product level to which the current integrated fault belongs;

[0057] In the list of fault modes for which fault judgment logic has been set at the current product level, it is used to distinguish the names of fault modes;

[0058] 3) Result domain information, i.e., judgment result: represents the judgment result of the current combined fault, which can be in two states: normal or faulty;

[0059] 4) Time domain information, i.e. failure time:

[0060] ·Represents the moment when the combined fault is first determined to have occurred at the current level;

[0061] ●The moment when the combined fault occurring at the current level is judged to have returned to normal;

[0062] 5) Causal fault information: characterizes the judgment result of the single fault basic detection item that has a causal relationship with the combined fault.

[0063] The three fields of coding type identification, detection item information, and judgment result contain the faulty product and fault name information that need to be reported after the fault at this level is integrated. Therefore, by reading the above three attribute fields of the combined fault code and converting them according to the whole machine level fault code format, a fault reporting code can be generated to realize the reporting or display of comprehensive faults.

[0064] (3) Coding relevance design based on fault dictionary

[0065] According to the definition of the "fault judgment logic data" attribute at the end of the combined fault code in (2), this field mainly includes the judgment results of the single fault detection items related to the current combined fault. Therefore, the coding of the combined fault can establish a traceable association with the single fault code through the fault judgment logic data to support the effective analysis of relevant fault information.

[0066] The fault dictionary is a fault status table. As an important carrier of fault diagnosis and integrated logic design, it reflects the corresponding relationship between fault phenomena and their fault causes. It can be used to establish the causal mapping relationship between single faults and combined faults. The former is identified by the test results of the basic test item T, and the latter establishes a causal relationship with the former based on the test results and the fault dictionary. m There are n valid test items T, which are recorded in order as T m ={T mi}, where i = 1, 2, ..., n, then according to the single fault code definition in (1), T mi At any time, it corresponds to a unique "detection item information" field, such as Figure 4 As shown, similarly F m At any time, it corresponds to a unique "detection item information" field, such as Figure 5 After completing a fault detection and synthesis, F m Obtain T by indexing the unique code in the fault dictionary m The corresponding n single fault record codes are based on the “detection item judgment result” field defined in (1) containing T mi Normal / fault state, read the fault judgment results in n single fault record codes in sequence according to the test items in the fault dictionary, as F m The fault judgment logic data of the current cycle is recorded in the cause fault code field, thereby realizing the coding information association between the combined fault and the single fault.

[0067] (4) Allocation and use of coding space

[0068] In combination with the testability design architecture of the avionics system and the data record storage resource requirements, based on the data volume of the coding type identification bit, object field, result field, and status field, the data type, byte offset, and space allocation of each field are defined and explained according to the following principles:

[0069] 1. Each field data is defined as an unsigned integer type;

[0070] 2. The space occupied by each field is an integer multiple of 1B;

[0071] 3. The 0x00 bit of each field of "Detection Item Information" should be reserved or set to the default:

[0072] 4. "Fault determination result" field definition 0x00-normal / 0x01-fault,

[0073] 5. The judgment result of each associated detection item in the "fault judgment logic data" occupies 2 bits of space. m Related single faults are filled in sequence, and a maximum of 50 related faults can be represented. m1 ~T m50 The judgment result; due to the different number of valid associated detection items for different faults, this field is indefinite length data with a maximum length of no more than 13B; the validity of the written judgment result is judged by the invalid flag and reserved flag. In addition, when data is written in a space greater than the number of associated detection items, it should be able to recognize that the data is invalid.

[0074] Example

[0075] Based on the steps listed in the specific implementation method, the fault coding design of the B-111 aircraft display and control system is carried out. The single fault coding at the functional circuit level includes Figure 2 The attribute fields shown in the figure, the module-level combined fault coding is defined as follows Figure 3 The attribute fields shown.

[0076] According to the fault dictionary, module-level combined fault F m - There is no output fault on the map screen. There are n valid test items in total, T m1 Through the "Detection Item Information" field and F m To associate, such as Figure 4-5 As shown, F m Obtain T by indexing the unique code in the fault dictionary mi The "Test Item Judgment Result" field is recorded in the Cause Fault Code field, such as Figure 6 shown.

[0077] The design requirements for the data type and occupied space of each field of avionics product fault record coding are defined according to the following specifications.

[0078] Single fault coding data interface definition

[0079]

[0080]

[0081] Combined fault coding data interface definition

[0082]

[0083]

[0084] The above is only a specific embodiment of the present invention, and the present invention is described in detail. The unexplained part is a conventional technology. However, the protection scope of the present invention is not limited to this. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A rule-based avionics system fault coding design method, characterized by: The fault codes include single fault codes and combined fault codes; The combined fault code stores the fault determination results of the single fault codes associated therewith.

2. The method according to claim 1, characterized in that: Single fault coding includes: coding type, single object domain identifier, result identifier, time identifier and status identifier.

3. The method according to claim 2, characterized in that: The combined fault code includes: code type, combined object domain identifier, result identifier, time identifier and cause information.

4. The method according to claim 3, characterized in that: The number of causal information bits of a combined fault code is equal to the number of single fault codes associated with the combined fault code.

5. The method according to claim 4, characterized in that: Each bit of data in the causal information of the combined fault code is associated with a single fault code.

6. The method according to claim 5, characterized in that: Each bit of data in the cause information of the combined fault code stores the result identifier of the single fault code associated therewith.

7. The method according to claim 6, characterized in that: The single object domain identifier includes: platform bit, system bit, device bit, module bit, functional circuit bit and fault detection item.

8. The method according to claim 7, characterized in that: The combined object field identifier includes: platform bit, system bit, device bit, module bit, fault level and fault name.

9. The method according to claim 8, characterized in that: The fault time includes: the first fault time and the end fault time.

10. The method according to claim 9, characterized in that: The cause information is the status value directly collected by the current fault detection item and used to determine the detection result.

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