Aircraft health evaluation method based on functional ladder

Abstract

The invention belongs to the technical field of aircraft health evaluation, and particularly relates to an aircraft health evaluation method based on a functional ladder. The method comprises the following steps: acquiring task information of an aircraft task, respectively determining function lists contained in an aircraft level, a system level, a subsystem level, a subsystem level and an LRU / LRM level according to the task information, and determining fault information contained in the LRU / LRM level; establishing a functional ladder; evaluating the health state of the aircraft according to the function ladder; and dividing the aircraft health state evaluation result into a plurality of health states, and calculating the confidence coefficient of each health state from the lower layer to the upper layer according to the functional ladder. According to the method, the function mapping relation between the layers of the aircraft is combed layer by layer, the function ladder from the outfield replaceable unit / module to the specific task executed by the aircraft is established in combination with different task requirements of the aircraft, and the health state of the aircraft is evaluated according to the function ladder. And the health state level and the confidence coefficient of the aircraft when different tasks are executed are given in a qualitative analysis and quantitative calculation combined mode.

Description

Technical Field

[0001] The present application belongs to the technical field of aircraft health assessment, and in particular relates to an aircraft health assessment method based on a functional ladder. Background Art

[0002] Health evaluation is an important function of the fault prediction and health management (PHM) system. It is defined in GJB451A-2005 "Reliability, Maintainability and Supportability Terms" as: analysis and evaluation of the health status of the product based on current and historical information. Although the meaning of the term has been explained in the national military standard, health evaluation has not received enough attention. Different equipment has not formed a unified understanding of its connotation and implementation methods, and there is also a lack of qualitative and quantitative health evaluation indicators.

[0003] Therefore, it is desired to have a technical solution to overcome or at least alleviate at least one of the above-mentioned defects of the prior art. Summary of the invention

[0004] The purpose of this application is to provide an aircraft health assessment method based on a functional ladder to solve at least one problem existing in the prior art.

[0005] The technical solution of this application is:

[0006] An aircraft health assessment method based on a functional ladder includes:

[0007] Step 1: Obtain mission information of the aircraft mission, and determine the function lists included in the aircraft level, system level, subsystem level, subsystem level, and LRU / LRM level respectively according to the mission information, and determine the fault information included in the LRU / LRM level;

[0008] Step 2: Establish a functional ladder, including:

[0009] Determine the functional mapping relationship between the mission information and the aircraft level, and generate an association relationship matrix;

[0010] Determine the function mapping relationship between adjacent levels at the aircraft level, system level, subsystem level, subsystem level, and LRU / LRM level, and generate a function relationship matrix;

[0011] According to the association relationship matrix and the function relationship matrix, a function ladder having a function transfer relationship carrying fault information is generated from a lower layer to an upper layer in sequence;

[0012] Step 3: According to the functional ladder, evaluate the aircraft health status from the perspectives of reliability, life, maintainability, testability, safety and usage data;

[0013] Step 4: Divide the aircraft health status evaluation results into multiple health statuses, and calculate the confidence of each health status from the lower level to the upper level according to the functional ladder.

[0014] In at least one embodiment of the present application, in step 1, obtaining mission information of an aircraft mission, determining function lists included in the aircraft level, system level, subsystem level, subsystem level, and LRU / LRM level, and determining fault information included in the LRU / LRM level, respectively, according to the mission information, includes:

[0015] Get mission information for aircraft missions;

[0016] Determine the task type to which the task information belongs;

[0017] Determine the task phases included in the task type;

[0018] Identify the activities included in each of the described mission phases;

[0019] According to the activities included in the task information, the function lists included in the aircraft level, system level, subsystem level, subsystem level, and LRU / LRM level are determined respectively, and the fault information included in the LRU / LRM level is determined.

[0020] In at least one embodiment of the present application, the mission types include air control, ground control, sea control, reconnaissance, and electronic warfare.

[0021] In at least one embodiment of the present application, the sea mission includes a mission preparation phase, an air mission execution phase, and a mission assessment phase.

[0022] In at least one embodiment of the present application, in step 2, the functional relationship matrix includes: aircraft level, system level, subsystem level, subsystem level, LRU / LRM level,

[0023] The relationship between the bottom-level functions and the upper-level functions;

[0024] The relationship between functions at the same level.

[0025] In at least one embodiment of the present application, the association relationship between the bottom layer function and the upper layer function includes:

[0026] Strong correlation: the underlying functions have a strong dependency on the upper-level functions / tasks, that is, failure of the underlying functions will directly affect the upper-level functions / tasks;

[0027] Weak correlation: the underlying function does not affect the completion of the upper-level function / task, but will lead to reduced safety or task reliability;

[0028] There is no correlation. The underlying functions have no correlation with the upper-level functions / tasks.

[0029] In at least one embodiment of the present application, the association relationship between the functions at the same level for the underlying functions that are strongly or weakly related to the upper-level functions / tasks includes:

[0030] Independent functional relationship, each underlying function independently affects the upper-level function / task;

[0031] Serial dependency: multiple underlying functions form a function set, and all functions in the function set have a serial relationship;

[0032] Parallel dependency, multiple underlying functions form a function set, and all functions in the function set have a parallel relationship;

[0033] Voting dependency, multiple underlying functions form a function set, and the functions in the function set have a voting relationship.

[0034] In at least one embodiment of the present application, in step 4, the aircraft health status evaluation result is divided into multiple health states, including:

[0035] Green status: indicates that the aircraft has all the functions to perform the mission and is in good condition, i.e., according to the function ladder from LRU / LRM level functions to specific aircraft missions, all functions that are strongly or weakly related to the mission are normal;

[0036] Blue status: indicates that the aircraft has all the functions to perform the mission, but there is a fault and the fault leads to reduced safety or mission reliability, that is, according to the function ladder from LRU / LRM level functions to specific aircraft missions, from the bottom to the top, all functions strongly related to the mission are normal; and when the aircraft is in the blue status, the degree of reduction in safety and mission reliability will be given additionally;

[0037] Yellow status: indicates that the aircraft has partial capability to perform the mission, but is unable to complete the entire mission, or requires a significant increase in the pilot's burden to complete the entire mission. That is, according to the function ladder from the LRU / LRM level to the specific aircraft mission, the functions that are strongly related to the mission are partially normal;

[0038] Red status: It means that the aircraft does not have the ability to perform the mission and the key functions of the aircraft related to the mission are lost. That is, according to the function ladder from LRU / LRM level functions to specific aircraft missions, the functions that are strongly related to the mission are summarized layer by layer from the bottom to the top, and all functions that are strongly related to the mission are invalid.

[0039] In at least one embodiment of the present application, in step 4, the confidence level of each health state is calculated from the lower level to the upper level according to the functional ladder, including:

[0040] (a) For LRU / LRM with BIT capability, when false alarm is not considered, the confidence level is 1. When false alarm is considered, the confidence level is determined according to the false alarm rate.

[0041] (b) For LRU / LRM with partial BIT capability, the confidence level of the partial LRU / LRM that can achieve BIT capability is determined according to the method in (a), and the confidence level of the partial LRU / LRM that cannot achieve BIT capability is determined according to the following method:

[0042] Confidence = e -G1*t1 ×(G1 / G2)

[0043] Among them, t1 is the operation time of the part of LRU / LRM that cannot achieve BIT capability, G1 is the failure rate of the part of LRU / LRM that cannot achieve BIT capability, and G2 is the total failure rate;

[0044] (c) For LRU / LRM without BIT capability, the confidence level is determined as follows:

[0045] R=α t / s

[0046] Among them, R is the confidence of LRU / LRM without BIT capability, a is the life design margin parameter, t is the usage time, and s is the life index.

[0047] The invention has at least the following beneficial technical effects:

[0048] The aircraft health evaluation method based on the functional ladder of the present application, by combing through the functional mapping relationship between each level of the aircraft layer by layer, combined with the different mission requirements of the aircraft, establishes a functional ladder from field replaceable units / modules to specific tasks performed by the aircraft, and combines reliability, life, maintainability, testability, safety and usage data with the functional ladder to achieve a bottom-up aircraft health status evaluation oriented to mission requirements, and uses a combination of qualitative analysis and quantitative calculation to give the aircraft's health status level and confidence when performing different tasks. The result can serve as one of the important bases for supporting aircraft release decisions. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 is a schematic diagram of a functional ladder in one embodiment of the present application;

[0050] Figure 2 is a schematic diagram of an aircraft health status evaluation result according to an embodiment of the present application;

[0051] Figure 3 It is a schematic diagram of a partial functional ladder of an embodiment of the present application. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical scheme and advantages of the implementation of this application clearer, the technical scheme in the embodiment of this application will be described in more detail below in conjunction with the drawings in the embodiment of this application. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described embodiments are part of the embodiments of this application, not all of them. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain this application, and should not be construed as limitations on this application. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The embodiments of this application are described in detail below in conjunction with the drawings.

[0053] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the scope of protection of the present application.

[0054] The following is combined with Figures 1 to 3 This application is described in further detail.

[0055] The present application provides an aircraft health assessment method based on a functional ladder, comprising the following steps:

[0056] Step 1: Obtain mission information of the aircraft mission, and determine the function lists included in the aircraft level, system level, subsystem level, subsystem level, and LRU / LRM (line replaceable unit / line replaceable module) level according to the mission information, and determine the fault information included in the LRU / LRM level;

[0057] Step 2: Establish a functional ladder, including:

[0058] Determine the functional mapping relationship between mission information and aircraft level, and generate an association relationship matrix;

[0059] Determine the function mapping relationship between adjacent levels at the aircraft level, system level, subsystem level, subsystem level, and LRU / LRM level, and generate a function relationship matrix;

[0060] According to the association relationship matrix and the function relationship matrix, a function ladder having a function transfer relationship carrying fault information from the lower layer to the upper layer is generated;

[0061] Step 3: According to the functional ladder, evaluate the aircraft health status from the perspectives of reliability, life, maintainability, testability, safety and usage data;

[0062] Step 4: Divide the aircraft health status evaluation results into multiple health states, and calculate the confidence of each health state from the lower level to the upper level according to the functional ladder.

[0063] The aircraft health assessment method based on the functional ladder of the present application first needs to analyze the typical mission types of the aircraft, conduct function list analysis at the aircraft level, system level, subsystem level, subsystem level, and LRU / LRM level, and conduct failure mode and effect analysis at the LRU / LRM level.

[0064] In a preferred embodiment of the present application, step 1 specifically includes:

[0065] Get mission information for aircraft missions;

[0066] Determine the task type to which the task information belongs;

[0067] Determine the task phases included in the task type;

[0068] Identify the activities included in each task phase;

[0069] According to the activities included in the mission information, determine the function lists included in the aircraft level, system level, subsystem level, subsystem level, and LRU / LRM level, and determine the fault information included in the LRU / LRM level.

[0070] In this embodiment, it is necessary to analyze the typical mission types performed by the aircraft and sort out the activities of each mission stage based on the mission types. Common mission types include air control, ground control, sea control, reconnaissance and electronic warfare. Taking the sea mission as an example, it mainly includes the mission preparation stage, the air mission execution stage and the mission evaluation stage. Each mission stage contains multiple independent and inseparable activities. The analysis here should be as comprehensive as possible. Since the mission execution capability of the aircraft is a comprehensive reflection of the aircraft functions, and the aircraft functions are supported by the functional combination of the system, it is transmitted layer by layer from the top layer to the bottom layer until the field replaceable unit / module level. Therefore, it is necessary to further carry out the function list analysis from the aircraft level to the subsystem level and the failure mode and impact analysis of the field replaceable unit / module level, obtain the function list in each level and the fault information of each LRU / LRM in the bottom layer, and provide input for the establishment of subsequent function ladders.

[0071] In the aircraft health assessment method based on the functional ladder of the present application, in step 2, the functional mapping relationship between the specific tasks performed by the aircraft and the aircraft level is first sorted out, and an association relationship matrix is ​​formed. The main association relationships in the association relationship matrix include both the relationship between aircraft-level functions and the association relationship between specific tasks and aircraft-level functions. Then, the functional mapping relationship between adjacent levels from the aircraft level to the LRU / LRM level is further sorted out layer by layer, and a functional relationship matrix is ​​established layer by layer. Similarly, the functional relationship in the functional relationship matrix includes both the influence relationship of the bottom-level function on the upper-level function and the association relationship between functions at the same level.

[0072] In the preferred implementation of the present application, the association relationship between the bottom layer functions and the upper layer functions is divided into the following three categories according to the degree of influence:

[0073] Strong correlation: the underlying functions have a strong dependency on the upper-level functions / tasks, that is, failure of the underlying functions will directly affect the upper-level functions / tasks;

[0074] Weak correlation: the underlying function does not affect the completion of the upper-level function / task, but will lead to reduced safety or task reliability;

[0075] There is no correlation. The underlying functions have no correlation with the upper-level functions / tasks.

[0076] Further drawing on the ideas in reliability modeling and analysis, the association between the underlying functions at the same level that are strongly or weakly related to the upper-level functions / tasks includes the following four categories:

[0077] Independent functional relationship, each underlying function independently affects the upper-level function / task;

[0078] Serial dependency: multiple underlying functions form a function set, and all functions in the function set have a serial relationship;

[0079] Parallel dependency, multiple underlying functions form a function set, and all functions in the function set have a parallel relationship;

[0080] Voting dependency, multiple underlying functions form a function set, and the functions in the function set have a voting relationship.

[0081] Finally, a function ladder is established based on the above analysis results, so as to obtain the function transfer relationship from the LRU / LRM level function to the specific aircraft mission from the low layer to the upper layer. This function transfer relationship carries the fault information transmitted from the LRU / LRM level layer by layer, providing a basis for the subsequent mission-oriented aircraft health evaluation.

[0082] In the aircraft health evaluation method based on the functional ladder of this application, in step 3, the aircraft health status is evaluated from the perspectives of reliability, life, maintainability, testability, safety, and usage data according to the functional ladder. Aircraft health status evaluation is a bottom-up process that needs to be combined with specific mission requirements and reliability, life, maintainability, testability, safety, and usage data combined with the functional ladder. The evaluation process is as follows: Figure 1 shown.

[0083] The detailed information requirements for each level are as follows:

[0084] (a) LRU / LRM level information: LRU / LRM level function list, function failure mode and its corresponding failure rate, whether BIT or status monitoring is possible, fault and health codes, life-limited parts information, internal redundancy configuration, LRU usage time, maintenance information, etc.;

[0085] (b) Subsystem-level information: functional ladder information (including subsystem-level function list, subsystem-level function and LRU / LRM-level function relationship matrix), functional failure mode, subsystem-level enhanced fault diagnosis fault code, redundancy configuration, maintenance information, etc.;

[0086] (c) Subsystem-level information: functional ladder information (including subsystem-level function list, subsystem-level function and subsystem-level function relationship matrix), functional failure mode, subsystem-level enhanced fault diagnosis fault code, redundancy configuration, maintenance information, etc.;

[0087] (d) System-level information: functional ladder information (including system-level function list, system-level function and subsystem-level function relationship matrix), functional failure mode, system-level enhanced fault diagnosis fault code, redundancy configuration, maintenance information, etc.;

[0088] (e) Aircraft-level information: function ladder information (including aircraft-level function list, aircraft-level function and system-level function relationship matrix), function failure mode, maintenance information, etc.;

[0089] (f) Mission information: aircraft typical mission code, function ladder information (matrix of aircraft mission and aircraft-level function correlation), function failure mode, maintenance information, etc.

[0090] When analyzing the aircraft health status based on mission requirements, it should be divided into two situations, namely before performing the aircraft mission and during the aircraft mission, which are defined as follows:

[0091] Before performing an aircraft mission, an aircraft health status evaluation is given for an aircraft in a ready state to complete a specific aircraft mission from the perspective of performance degradation and risk assessment.

[0092] When performing an aircraft mission, an aircraft health status evaluation that affects the aircraft's ability to perform subsequent specific aircraft missions is given from the perspectives of mission loss and environmental impact.

[0093] Before executing an aircraft mission, it mainly focuses on the health status of the aircraft in a ready state to complete a specific mission from the perspective of performance degradation and risk assessment, after all systems have undergone necessary maintenance and regular inspections before the aircraft is released. This will allow for a horizontal comparison of the health conditions of different aircraft in the fleet, and give priority to deploying aircraft with higher health to perform specific tasks. During the execution of an aircraft mission, it mainly focuses on the real-time health evaluation of the aircraft's health status changes caused by external factors such as mission loss and environmental impacts that affect the aircraft's ability to perform subsequent tasks after the aircraft is released during the execution of a specific mission, so as to determine whether the aircraft has the ability to continue to perform the mission, and issue a return order to abnormal aircraft.

[0094] In the aircraft health assessment method based on the functional ladder of the present application, in step 4, the aircraft health assessment result includes two parts: one is the qualitative health status, which is defined as four states of green, blue, yellow and red in the present application, among which the blue state includes a quantitative representation of the degree of impact on safety and mission reliability, Figure 2 The second is the confidence level, which appears in conjunction with the four states. Based on the data and confidence level algorithm, the confidence level of the aircraft health evaluation results is given from the bottom to the top, generally expressed as a percentage. Its significance lies mainly in the vertical comparison of a single aircraft and the horizontal comparison of multiple aircraft at the same time.

[0095] In the preferred embodiment of the present application, the criteria for determining the four health states of green, blue, yellow and red are as follows:

[0096] Green status: indicates that the aircraft has all the functions to perform the mission and is in good condition, i.e., according to the function ladder from LRU / LRM level functions to specific aircraft missions, all functions that are strongly or weakly related to the mission are normal;

[0097] Blue status: indicates that the aircraft has all the functions to perform the mission, but there is a fault and the fault leads to reduced safety or mission reliability, that is, according to the function ladder from LRU / LRM level functions to specific aircraft missions, from the bottom to the top, all functions strongly related to the mission are normal; and when the aircraft is in the blue status, the degree of reduction in safety and mission reliability will be given additionally;

[0098] Yellow status: indicates that the aircraft has partial capability to perform the mission, but is unable to complete the entire mission, or requires a significant increase in the pilot's burden to complete the entire mission. That is, according to the function ladder from the LRU / LRM level to the specific aircraft mission, the functions that are strongly related to the mission are partially normal;

[0099] Red status: It means that the aircraft does not have the ability to perform the mission and the key functions of the aircraft related to the mission are lost. That is, according to the function ladder from LRU / LRM level functions to specific aircraft missions, the functions that are strongly related to the mission are summarized layer by layer from the bottom to the top, and all functions that are strongly related to the mission are invalid.

[0100] The confidence levels corresponding to the four health states and the reliability and safety impact evaluation results unique to the blue state need to be analyzed from the bottom to the top by the field replaceable unit / module using the function ladder. The specific algorithm is described as follows:

[0101] (a) For LRU / LRM (line replaceable unit / line replaceable module) with BIT (built-in test) capability, the confidence level is 1 when false alarms are not considered. When false alarms are considered, the confidence level is determined based on the false alarm rate.

[0102] The LRU / LRM that can achieve BIT capability has only two states: 0 / 1. When false alarms are not considered, the confidence level is 1. When a large number of field false alarm rate evaluation results are obtained, the confidence level is given according to the false alarm rate.

[0103] (b) For LRU / LRM with partial BIT capability, the confidence level of the partial LRU / LRM that can achieve BIT capability is determined according to the method in (a), and the confidence level of the partial LRU / LRM that cannot achieve BIT capability is determined according to the following method:

[0104] Confidence = e -G1*t1 ×(G1 / G2)

[0105] Among them, t1 is the operation time of the part of LRU / LRM that cannot achieve BIT capability, G1 is the failure rate of the part of LRU / LRM that cannot achieve BIT capability, and G2 is the total failure rate;

[0106] The confidence of the partial LRU / LRM that can achieve BIT capability is determined according to the first method. The partial LRU / LRM that cannot achieve BIT capability is given a reliability, i.e. the probability of this part being fault-free, taking into account its failure rate and operation time. Therefore, for the LRU / LRM with partial BIT capability, if BIT fails, it is directly set to 1, and the confidence is 1. If no failure is reported, the product is set to 0 without fault, and the confidence is calculated according to the formula in (b) above.

[0107] (c) LRU / LRM without BIT capability, generally refers to life-long parts, the confidence level is determined according to the following method:

[0108] R=α t / s

[0109] Among them, R is the confidence of LRU / LRM without BIT capability, a is the life design margin parameter, t is the usage time, and s is the life index.

[0110] From the above, we can see that step four mainly includes two parts: one part is the 0 / 1 state, which analyzes the impact of the failure of the underlying function on the top-level function and gives the judgment result of the light color. When the result is blue, the degree of reduced reliability and safety should be given in addition. The other part is the confidence level. The calculation of the confidence level is determined according to the functional relationship, which basically includes three methods: series connection, parallel connection, and voting. Explanation of the change in confidence level: When a special test is carried out to prove that the part of the equipment without BIT capability is fault-free, the confidence level is increased to 1, and the time is restarted from 0. For life parts after replacement, the confidence level is increased to 1, and the time is restarted from 0. Therefore, when calculating the aircraft health status evaluation, it is necessary to ensure that the system gives daily maintenance results.

[0111] The whole-machine health evaluation involves too much content. From the perspective of explaining the effectiveness of this application, in one embodiment of this application, only the working mode and state determination function in the integrated avionics system management in the integrated core processor (ICP) subsystem is taken as an example, and the health evaluation result of this function is obtained according to the function ladder. To obtain the aircraft-level health evaluation result, it is necessary to analyze upward layer by layer according to the function ladder. Here, only this example is used to illustrate the implementation steps and calculation method of this method. The specific implementation process is as follows:

[0112] First, the LRU / LRM level function list analysis is performed. Since the working mode and state determination functions involve LRU / LRM as DPM1, DPM2, ..., DPMn, the function list of DPM is mainly analyzed here. The results are shown in Table 1.

[0113] Table 1

[0114] Serial number Function Remark 1 DPM Enable Function Strong correlation 2 AFDX communication function Strong correlation 3 Watchdog monitoring function Unrelated 4 Power-on loading function Strong correlation 5 Serial port debugging function Unrelated 6 Ethernet debugging function Unrelated 7 Fault log recording function Unrelated 8 Power monitoring function Unrelated 9 Temperature monitoring function Unrelated

[0115] Secondly, the relationship between the influence of the bottom-level relationship on the upper-level relationship and the bottom-level function is analyzed, and the local function ladder is obtained. Figure 3 . Figure 3 The horizontal axis in represents the LRU / LRM level function list. For ease of representation, the letters a to i represent the 9 functions in Table 1 respectively. Figure 3 The vertical axis represents the subsystem (integrated core processor (ICP) subsystem) function. Here we mainly analyze the working mode and state determination function. The relationship between this function and the functions in DPM1 to DPMn is shown in the notes of Table 1.

[0116] Further, determine the design analysis process of the analysis object. This embodiment starts with the integrated core processor (ICP) subsystem, combines the working mode and state determination function of the subsystem in the functional ladder, and conducts analysis from the bottom to the top by integrating reliability, life, maintainability, testability, safety and usage data.

[0117] Finally, because DPM has BIT capability, if there is no BIT fault in DPM1 to DPMn, then according to the functional association relationship in the function ladder, it can be obtained that the subsystem (ICP) function (working mode and state determination function) is intact at this time, and the confidence is 1 without considering false alarms. Since there is no weak correlation between the subsystem function and the LRU / LRM function, it is not necessary to give the relevant parameters of reliability and safety reduction at this time. If there is a BIT fault in DPM1 to DPMn, then according to the function ladder and the fault result, it can be obtained that the subsystem function is partially / completely lost at this time.

[0118] The aircraft health evaluation method based on the functional ladder of the present application first defines the functional connotation of aircraft health evaluation from the perspective of the aircraft object (oriented to mission requirements, with the aircraft as the final evaluation object, comprehensive reliability, life, maintainability, testability, safety and usage data, and completing the health evaluation from the field replaceable unit / module level from the bottom to the top), and establishes an aircraft functional ladder oriented to mission requirements. Finally, by collecting various parameters related to aircraft health and combining the functional ladder from the bottom to the top, the aircraft health status is rated and the confidence is given, thereby achieving an effective evaluation of the aircraft health status.

[0119] This application is based on the aircraft health assessment method of the functional ladder,

[0120] By using the functional mapping relationship between the various levels of the aircraft and comprehensively considering the mission requirements of the aircraft, a functional ladder from the field replaceable unit / module to the aircraft mission is established. The reliability, life, maintainability, testability, safety and usage data are integrated to achieve the aircraft health status evaluation from the bottom to the top facing the mission requirements. This method can standardize the design process and give the aircraft health status level and confidence when performing different tasks by combining qualitative analysis with quantitative calculation. Among them, the qualitative analysis part evaluates the aircraft health status from the perspective of the aircraft performing a specific mission. Through the functional ladder design, the mapping relationship between the aircraft mission information and the functions of each level of the aircraft is analyzed layer by layer to determine the LRU / LRM related to the specific mission, and the fault information of the LRU / LRM is transmitted layer by layer from the bottom to the top to obtain the aircraft health status. The quantitative calculation part gives the credibility of the aircraft health status from the perspective of confidence. On the one hand, this can be used as a basis for longitudinal comparison of a single aircraft or horizontal comparison of multiple aircraft at the same time, which can serve as an important basis for aircraft deployment and release. On the other hand, by calculating whether an aircraft has all the functions to perform a specific task, but the impact of a fault on the safety and reliability of the aircraft is present, it is also of great significance for the horizontal comparison of aircraft in the fleet, and provides an effective reference for the reasonable selection of aircraft to perform tasks under different mission requirements.

[0121] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. An aircraft health assessment method based on a functional ladder, characterized in that: include: Step 1: Obtain mission information of the aircraft mission, and determine the function lists included in the aircraft level, system level, subsystem level, subsystem level, and LRU / LRM level respectively according to the mission information, and determine the fault information included in the LRU / LRM level; Step 2: Establish a functional ladder, including: Determine the functional mapping relationship between the mission information and the aircraft level, and generate an association relationship matrix; Determine the function mapping relationship between adjacent levels at the aircraft level, system level, subsystem level, subsystem level, and LRU / LRM level, and generate a function relationship matrix; According to the association relationship matrix and the function relationship matrix, a function ladder having a function transfer relationship carrying fault information is generated from a lower layer to an upper layer in sequence; Step 3: According to the functional ladder, evaluate the aircraft health status from the perspectives of reliability, life, maintainability, testability, safety and usage data; Step 4: Divide the aircraft health status evaluation results into multiple health statuses, and calculate the confidence of each health status from the lower level to the upper level according to the functional ladder.

2. The aircraft health assessment method based on functional ladder according to claim 1 is characterized in that: In step 1, task information of the aircraft task is obtained, and the function lists included in the aircraft level, system level, subsystem level, subsystem level, and LRU / LRM level are determined according to the task information, and the fault information included in the LRU / LRM level is determined, including: Get mission information of aircraft missions; Determine the task type to which the task information belongs; Determine the task phases included in the task type; Identify the activities included in each of the described mission phases; According to the activities included in the task information, the function lists included in the aircraft level, system level, subsystem level, subsystem level, and LRU / LRM level are determined respectively, and the fault information included in the LRU / LRM level is determined.

3. The aircraft health assessment method based on functional ladder according to claim 2 is characterized in that: The mission types include air superiority, ground attack, sea attack, reconnaissance and electronic warfare.

4. The aircraft health assessment method based on functional ladder according to claim 3 is characterized in that: The sea mission includes the mission preparation phase, the air mission execution phase and the mission evaluation phase.

5. The aircraft health assessment method based on functional ladder according to claim 4 is characterized in that: In step 2, the functional relationship matrix includes: aircraft level, system level, subsystem level, subsystem level, LRU / LRM level, The relationship between the bottom-level functions and the upper-level functions; The relationship between functions at the same level.

6. The aircraft health assessment method based on functional ladder according to claim 5 is characterized in that: The relationship between the bottom-level functions and the upper-level functions includes: Strong correlation: the underlying functions have a strong dependency on the upper-level functions / tasks, that is, failure of the underlying functions will directly affect the upper-level functions / tasks; Weak correlation: the underlying function does not affect the completion of the upper-level function / task, but will lead to reduced safety or task reliability; There is no correlation. The underlying functions have no correlation with the upper-level functions / tasks.

7. The aircraft health assessment method based on functional ladder according to claim 6 is characterized in that: The relationship between the underlying functions at the same level that are strongly or weakly related to the upper-level functions / tasks includes: Independent functional relationship, each underlying function independently affects the upper-level function / task; Serial dependency: multiple underlying functions form a function set, and all functions in the function set have a serial relationship; Parallel dependency, multiple underlying functions form a function set, and all functions in the function set have a parallel relationship; Voting dependency, multiple underlying functions form a function set, and the functions in the function set have a voting relationship.

8. The aircraft health assessment method based on functional ladder according to claim 7 is characterized in that: In step 4, the aircraft health status evaluation results are divided into multiple health states, including: Green status: indicates that the aircraft has all the functions to perform the mission and is in good condition, i.e., according to the function ladder from LRU / LRM level functions to specific aircraft missions, all functions that are strongly or weakly related to the mission are normal; Blue status: indicates that the aircraft has all the functions to perform the mission, but there is a fault and the fault leads to reduced safety or mission reliability, that is, according to the function ladder from LRU / LRM level functions to specific aircraft missions, from the bottom to the top, all functions strongly related to the mission are normal; and when the aircraft is in the blue status, the degree of reduction in safety and mission reliability will be given additionally; Yellow status: indicates that the aircraft has partial capability to perform the mission, but is unable to complete the entire mission, or requires a significant increase in the pilot's burden to complete the entire mission. That is, according to the function ladder from the LRU / LRM level to the specific aircraft mission, the functions that are strongly related to the mission are partially normal; Red status: It means that the aircraft does not have the ability to perform the mission and the key functions of the aircraft related to the mission are lost. That is, according to the function ladder from LRU / LRM level functions to specific aircraft missions, the functions that are strongly related to the mission are summarized layer by layer from the bottom to the top, and all functions that are strongly related to the mission are invalid.

9. The aircraft health assessment method based on functional ladder according to claim 8 is characterized in that: In step 4, the confidence level of each health status is calculated from the lower level to the upper level according to the functional ladder, including: (a) For LRU / LRM with BIT capability, when false alarm is not considered, the confidence level is 1. When false alarm is considered, the confidence level is determined according to the false alarm rate. (b) For LRU / LRM with partial BIT capability, the confidence level of the partial LRU / LRM that can achieve BIT capability is determined according to the method in (a), and the confidence level of the partial LRU / LRM that cannot achieve BIT capability is determined according to the following method: Confidence = e -G1*t1 ×(G1 / G2) Among them, t1 is the operation time of the part of LRU / LRM that cannot achieve BIT capability, G1 is the failure rate of the part of LRU / LRM that cannot achieve BIT capability, and G2 is the total failure rate; (c) For LRU / LRM without BIT capability, the confidence level is determined as follows: R＝α t / s Among them, R is the confidence of LRU / LRM without BIT capability, a is the life design margin parameter, t is the usage time, and s is the life index.

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