A flight control system fault diagnosis method based on PL code list

Abstract

The present application provides a flight control system fault diagnosis method based on a PL code list, the method comprising: establishing a flight control system PL code fault tree database; establishing a flight control system LRU database; wherein the LRU database includes a troubleshooting method corresponding to the LRU; based on the flight control system PL code fault tree database, diagnosing the flight control system fault; or, based on the flight control system PL code fault tree database and the flight control system LRU database, diagnosing the flight control system fault; The present application also provides a flight control system fault diagnosis method based on a PL code list, the method comprising: establishing a fault case library; wherein the fault case library includes a PL code list of fault cases, fault causes and troubleshooting methods corresponding to the PL code list; based on the fault case library, diagnosing the flight control system fault.

Description

Technical Field

[0001] The present application belongs to the technical field of flight control system fault diagnosis, and in particular, relates to a flight control system fault diagnosis method based on a PL code list. Background Art

[0002] The Pilot List (PL) is a list of monitoring results of the flight control system. The PL list consists of PL codes. The PL code is the monitoring result of various software and hardware fault monitors of the flight control system. When the fault monitor detects a corresponding fault, a message containing the PL code, fault time, fault name and fault site value will be recorded in the PL list. If a flight control system fault occurs during the flight, the maintenance staff can extract and analyze the PL list through external equipment after the flight to locate and isolate the fault. The PL list is an effective means for maintenance staff to troubleshoot flight control system faults in the field, but there are currently the following problems:

[0003] 1.PL code is the result of various fault monitors of the flight control system, but the maintenance staff is not clear about the design logic of the fault monitor. Even maintenance staff with many troubleshooting experiences can only master the principles of some PL codes, and once some fault monitors are re-optimized, the principles of the PL codes mastered by the maintenance staff are no longer applicable.

[0004] 2. The flight control system is highly complex. When a certain fault occurs in the flight control system, several fault monitors may be triggered at the same time to meet the conditions, and the PL list contains several PL codes. Similarly, due to the lack of understanding of the design logic of the fault monitor, the maintenance staff cannot analyze the relationship between these PL codes, let alone analyze the specific fault pointed to by the PL list.

[0005] 3. Even if the PL list is analyzed to be caused by a certain fault, due to the lack of knowledge about the normal range of the flight control system's external interface, software and hardware interface, and related parameter indicators, the maintenance staff does not know what measures to take to isolate and locate these faults.

[0006] Based on the above three points, the troubleshooting process of the field flight control system always requires the involvement of the flight control system designer. On the one hand, the designer analyzes the possible causes of the fault based on the PL list, and on the other hand, based on the analyzed causes of the fault, guides the maintenance staff on what troubleshooting measures should be taken in order to finally locate the fault. This undoubtedly reduces the efficiency of field troubleshooting and consumes the human resources of the flight control system designer. Summary of the invention

[0007] In view of the above technical problems, in a first aspect, the present application provides a flight control system fault diagnosis method based on a PL code list, the method comprising:

[0008] Establish the flight control system PL code fault tree database;

[0009] Establishing a flight control system LRU database; wherein the LRU database includes a troubleshooting method corresponding to the LRU;

[0010] Diagnose the fault of the flight control system based on the flight control system PL code fault tree database;

[0011] or,

[0012] Based on the flight control system PL code fault tree database and the flight control system LRU database, the fault of the flight control system is diagnosed.

[0013] Preferably, the establishing of the flight control system PL code fault tree database includes:

[0014] Establish a fault tree for each PL code in the flight control system;

[0015] Based on the fault tree of each PL code, a flight control system PL code fault tree database is established.

[0016] Preferably, the fault tree includes a fault tree top event and a fault tree bottom event.

[0017] Preferably, the top event of the fault tree includes the occurrence of a PL code, and the bottom event of the fault tree includes a fault cause; wherein the fault cause is bound to an LRU and a troubleshooting method corresponding to the fault cause.

[0018] Preferably, the diagnosing a fault of the flight control system based on the flight control system PL code fault tree database includes:

[0019] If the PL code list is a single PL code, the fault cause specified by the fault tree of the single PL code, the LRU bound to the fault cause, and the troubleshooting method corresponding to the fault cause are displayed.

[0020] Preferably, the diagnosing a fault of the flight control system based on the flight control system PL code fault tree database and the flight control system LRU database includes:

[0021] If the PL code list contains multiple PL codes, searching for the intersection of LRUs bound to the fault cause in the fault trees of the multiple PL codes to obtain the target LRU;

[0022] The target LRU is searched from the flight control system LRU database, and a troubleshooting method corresponding to the target LRU is displayed.

[0023] In a second aspect, the present application provides a flight control system fault diagnosis method based on a PL code list, the method comprising:

[0024] Establishing a fault case library; wherein the fault case library includes a PL code list of the fault case, the fault causes and troubleshooting methods corresponding to the PL code list;

[0025] Based on the fault case library, the fault of the flight control system is diagnosed.

[0026] Preferably, diagnosing a fault of the flight control system based on the fault case library includes:

[0027] If a PL code list appears, searching the fault case library to see if there is a fault case matching the PL code list;

[0028] If there is a matching case, the fault cause and troubleshooting method of the matching case are displayed.

[0029] Beneficial technical effects of this application:

[0030] This application essentially algorithmizes the designer's analysis process based on the PL list through a fault tree, and case-based the designer's experience-based troubleshooting. Using this application, in most cases, when a flight control system failure occurs in the field, the maintenance staff can directly troubleshoot based on the fault tree analysis results and case matching results without the intervention of the designer, which can greatly improve the efficiency of field troubleshooting and relieve the troubleshooting pressure of the designer. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A flowchart of a flight control system fault diagnosis method based on a PL code list provided in an embodiment of the present application;

[0032] Figure 2 An example diagram of a PL code fault tree provided in an embodiment of the present application;

[0033] Figure 3 An example diagram of a fault case library provided in an embodiment of the present application;

[0034] Figure 4 An example diagram of an LRU database provided in an embodiment of the present application. DETAILED DESCRIPTION

[0035] 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.

[0036] It should be noted that this application is aimed at the problems currently faced by maintenance personnel in troubleshooting in the field through the PL list. The present invention proposes a flight control system fault diagnosis method based on the PL list. This method can enable maintenance personnel to independently complete field troubleshooting work, improve troubleshooting efficiency, and reduce the troubleshooting pressure of designers so that they can focus on design work.

[0037] The technical solution of the present application includes two independent and parallel solutions: fault tree analysis and case library matching.

[0038] The scheme of fault tree analysis is as follows:

[0039] 1. Establish a PL code fault tree database for the flight control system. Statistically list all PL codes of the flight control system, and establish a fault tree for each PL code of the flight control system. The top event of the fault tree is "the PL code appears", and the bottom event of the fault tree is the possible cause of the fault. Based on the design logic of the fault monitor corresponding to the PL code, combined with the hardware interface and cable connection relationship of the flight control system, analyze the possible causes of the fault, and bind each cause of the fault to the corresponding line replaceable unit (LRU) of the flight control system and the troubleshooting method corresponding to the cause of the fault. Finally, the fault tree of all PL codes of the flight control system is obtained, forming a PL code fault tree database for the flight control system.

[0040] 2. Establish a flight control system LRU database. Statistically list all LRUs in the flight control system, and bind each LRU with the corresponding troubleshooting method. Finally, all LRUs in the flight control system and their corresponding troubleshooting methods are obtained to form a flight control system LRU database.

[0041] 3. When a fault occurs in the field, extract the PL list;

[0042] 4. When the PL list is a single PL code, based on the flight control system PL code fault tree database, the fault causes specified in the fault tree of the PL code, the LRU bound to each fault cause, and the troubleshooting method corresponding to the fault cause are displayed to the maintenance staff;

[0043] 5. When the PL list contains multiple PL codes, search for the intersection of the LRUs bound to the fault causes of these PL code fault trees based on the flight control system PL code fault tree database. If there is an intersection of the LRUs, search the flight control system LRU database and display the LRU and the troubleshooting method corresponding to the LRU to the maintenance staff; if there is no intersection, it means that the fault cannot be diagnosed through the fault tree analysis solution.

[0044] The scheme for case library matching is as follows:

[0045] 1. Establish a flight control system fault case library. Fault cases include PL list, fault causes, and troubleshooting methods.

[0046] 2. Collect cases where faults have occurred in the field and where the faults have been successfully located, and enter the PL list of these cases, the causes of the faults at the time, and the methods used to troubleshoot them into the fault case library. This will eventually form a flight control system fault case library.

[0047] 3. When a fault occurs in the field, extract the PL list;

[0048] 4. Check whether there is a matching case in the flight control system fault case library for the PL list. If there is a matching case, the fault cause and troubleshooting method of the matching case will be displayed to the maintenance staff; if there is no matching case, it means that the fault cannot be diagnosed through the case library matching solution.

[0049] At the same time, the fault tree analysis results and case matching results are displayed to the field maintenance staff, who then decide which troubleshooting method to adopt.

[0050] This application essentially algorithmizes the designer's analysis process based on the PL list through a fault tree, and case-based the designer's troubleshooting through experience. Using the present invention, in most cases, when a flight control system failure occurs in the field, the maintenance personnel can directly troubleshoot the failure based on the fault tree analysis results and case matching results without the intervention of the designer, which can greatly improve the troubleshooting efficiency in the field and relieve the troubleshooting pressure of the designer.

[0051] In a feasible implementation, according to the technical solution of the present application, a specific implementation example for a certain type of aircraft is as follows:

[0052] The flight control system of the aircraft contains a total of 893 PL codes. Fault tree modeling is performed on all PL codes to obtain the flight control system PL code fault tree database.

[0053] The flight control system of the aircraft contains a total of 43 LRUs. The troubleshooting methods of all LRUs are clarified to obtain the flight control system LRU database.

[0054] The PL code fault tree database and the flight control system LRU database together constitute the fault tree analysis database of this type of aircraft.

[0055] According to the characteristics of this type of aircraft, a total of 323 fault cases were collected and a fault case library was formed.

[0056] The fault tree analysis database and the fault case database together constitute the fault diagnosis database of this type of aircraft based on the PL list. Based on the fault diagnosis database, a fault diagnosis software for field maintenance was developed. When encountering field failures, maintenance personnel can use this software to independently locate and isolate the faults of the flight control system.

[0057] See also Figure 1-4 For an example of a fault tree for PL code, see Figure 2The top event of the fault tree is "the occurrence of the PL code", and the bottom event of the fault tree is the possible fault cause of the occurrence of the PL code. Based on the design logic of the fault monitor corresponding to the PL code, combined with the hardware interface and cable connection relationship of the flight control system, the possible fault causes are analyzed, and each fault cause is bound to the corresponding flight control system LRU and the troubleshooting method corresponding to the fault cause.

[0058] For examples of fault case libraries, see Figure 3 Fault cases include PL list, fault cause, and troubleshooting method. Collect cases where faults have occurred in the field and the faults have been successfully located, and enter the PL list, fault cause and troubleshooting method of these cases into the fault case library. Finally, a flight control system fault case library is formed.

[0059] For an example of LRU database, see Figure 4 . Statistically list all LRUs of the flight control system, and bind each LRU with the corresponding troubleshooting method. Finally, all LRUs of the flight control system and their corresponding troubleshooting methods are obtained to form a flight control system LRU database.

[0060] 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 flight control system fault diagnosis method based on PL code list, characterized in that: The method comprises: Establish the flight control system PL code fault tree database; Establishing a flight control system LRU database; wherein the LRU database includes a troubleshooting method corresponding to the LRU; Diagnose the fault of the flight control system based on the flight control system PL code fault tree database and the flight control system LRU database; Wherein, the establishment of the flight control system PL code fault tree database includes: Statistically list all PL codes of the flight control system and establish a fault tree for each PL code of the flight control system; the top event of the fault tree is "the occurrence of the PL code", and the bottom event of the fault tree is the possible cause of the fault; Based on the design logic of the fault monitor corresponding to the PL code, combined with the hardware interface and cable connection relationship of the flight control system, the possible fault causes are analyzed, and each fault cause is bound to the corresponding flight control system field replaceable unit LRU and the corresponding troubleshooting method; Finally, the fault tree of all PL codes of the flight control system is obtained to form a PL code fault tree database of the flight control system; The step of establishing the flight control system LRU database includes: Count and list all LRUs of the flight control system, and bind the corresponding troubleshooting method to each LRU; Finally, all LRUs of the flight control system and their corresponding troubleshooting methods are obtained to form a flight control system LRU database; Wherein, diagnosing the fault of the flight control system based on the flight control system PL code fault tree database and the flight control system LRU database includes: When the PL list contains multiple PL codes, the intersection of the LRUs bound to the fault causes of these PL code fault trees is searched based on the flight control system PL code fault tree database; if the LRUs have an intersection, the flight control system LRU database is searched, and the LRU and the troubleshooting method corresponding to the LRU are displayed to the maintenance staff; if there is no intersection, it indicates that the fault cannot be diagnosed through the fault tree analysis solution.

Images