A method for evaluating similarity of aircraft systems

Abstract

The present application discloses a method for evaluating the similarity of aircraft systems, the method comprising the following steps: comparing the manufacturer data, ATA chapter data, main minimum equipment list item function data and installation quantity data of the target model aircraft and the mature model aircraft. Screening out aircraft of the same level as the target model aircraft and having special flight missions from the mature model aircraft. Based on the Euclidean distance algorithm and the nearest neighbor matching algorithm, the system-level functional similarity, subsystem-level functional similarity and component-level functional similarity of the target model aircraft and the screened aircraft are evaluated and calculated respectively. When the system-level functional similarity, subsystem-level functional similarity and component-level functional similarity are all evaluated as similar, it is evaluated and determined that the system of the screened aircraft is similar to that of the target model aircraft.

Description

Technical Field

[0001] The present application relates to aircraft system evaluation, and more particularly to a method for evaluating aircraft system similarity. Background Art

[0002] The Master Minimum Equipment List (MMEL) is an important tool for balancing the economy and safety of aircraft, and is the main review item of the Flight Operations Review Board (FOEB). Civil aircraft manufacturers submit a Master Minimum Equipment List Proposal (PMMEL), which is released after passing the review by the authority. During the operation of civil aircraft, when an aircraft system fails and cannot be repaired in a short period of time, it is necessary to confirm whether it can be released through the Minimum Equipment List (MEL). If the Minimum Equipment List contains the equipment that caused the aircraft failure, the aircraft is allowed to be released, which will greatly improve the economy of the aircraft and enhance the market competitiveness of the aircraft.

[0003] The main purpose of the minimum equipment list is to make full use of the safety margin of the aircraft design, and to allow the aircraft to continue flying with faults within the prescribed period under the premise of ensuring operational safety. The rational use of the minimum equipment list can effectively improve the aircraft utilization rate and flight punctuality, and reduce operating costs. According to regulations, the minimum equipment list should comply with the master minimum equipment list of the corresponding aircraft model, or be more stringent than it.

[0004] Therefore, when formulating the MMEL proposal project, aircraft manufacturers not only need to meet the minimum requirements of the regulations, but also need to consider and meet the user's needs for the MMEL in order to improve user satisfaction. Since the requirements of the MMEL need to be met, the MMEL manual of mature aircraft models can be referred to to carry out the preliminary work of the MMEL proposal. Therefore, there is a reasonable aircraft system similarity assessment method to determine the mature aircraft models that are similar to the target aircraft models in terms of system functions and structures. Then, the MMEL proposal for the target aircraft model is prepared based on the MMEL of similar mature aircraft models, which will greatly reduce the preliminary work of preparing the list proposal.

[0005] However, at present, the preliminary work of formulating the MMEL proposal is mainly done by people subjectively completing the assessment of aircraft system similarity. Factors such as different professional backgrounds and work experience lead to large differences in assessment results and high risks. If an effective method for automatically assessing the similarity of aircraft systems can be adopted, by selecting the MMEL manuals of mature aircraft models with similar systems, the development cycle of the MMEL proposal for new civil aircraft models will be effectively shortened, thereby further reducing aircraft operation risks. Summary of the invention

[0006] Therefore, the technical problem to be solved by this application is to overcome the problem that the evaluation of the similarity of aircraft systems in the prior art mainly relies on subjective judgment by humans, and the evaluation results are quite different due to factors such as different professional backgrounds and work experience of the evaluators, thereby increasing the operational risk of the flying aircraft, and to provide an effective method for evaluating the similarity of aircraft systems. This method can quantitatively and accurately evaluate the similarity of aircraft systems, so that the master minimum equipment list proposal can be formulated by referring to the master minimum equipment list of similar mature aircraft models, effectively shortening the development cycle of the master minimum equipment list proposal for civil aircraft, thereby reducing the operational risk of aircraft.

[0007] Specifically, the present application solves the above technical problems through the following technical solutions:

[0008] The present application provides a method for evaluating the similarity of aircraft systems, wherein the method comprises the following steps:

[0009] Obtain the database corresponding to the target aircraft model and mature aircraft model, where the database includes manufacturer data, ATA chapter data, MMEL item function data and installation quantity data;

[0010] Compare the database of the target aircraft model with that of mature aircraft models. If any of the manufacturer data, ATA chapter data, MMEL item function data, and installation quantity data are different, select the aircraft of the same level as the target aircraft model and with special flight missions from the mature aircraft models;

[0011] Based on the Euclidean distance algorithm and the nearest neighbor matching algorithm, the system-level functional similarity, subsystem-level functional similarity and component-level functional similarity of the target aircraft and the screened aircraft are evaluated and calculated respectively, wherein the system-level functional similarity is evaluated by analyzing the energy source similarity of the same system and the functional similarity of the subsystems constituting the same system, the subsystem-level functional similarity is evaluated by analyzing the energy source similarity of the same subsystem and the functional similarity of the functional component set constituting the same subsystem, and the component-level functional similarity is evaluated by analyzing the energy source similarity of the same functional component set; and

[0012] When the system-level functional similarity, subsystem-level functional similarity and component-level functional similarity are all evaluated as similar, the evaluation determines that the system of the screened aircraft is similar to that of the target aircraft model.

[0013] The method for evaluating the similarity of aircraft systems disclosed in the present application performs similarity analysis of the aircraft system at the system level, subsystem level and component level through a similarity calculation method, thereby being able to quantitatively and accurately evaluate the similarity of aircraft systems of different models. It is also possible to formulate a master minimum equipment list proposal for a target aircraft model based on the master minimum equipment list of mature aircraft models with similar systems, thereby shortening the development cycle of the proposal and ultimately achieving a significant improvement in the operating economy of the aircraft.

[0014] According to one embodiment of the present invention, the method further includes: dividing the functional component set into an execution functional component set and a general functional component set according to whether the functional component set has an impact on the function execution, wherein by analyzing the functional similarity, structural similarity and supplier similarity of each component constituting the same execution functional component set, when the functions, structures and suppliers of the components are similar, it is evaluated and determined that the components of the screened-out aircraft are similar to those of the target aircraft model.

[0015] According to another embodiment of the present invention, the method further includes: by analyzing the functional similarity and supplier similarity of each component constituting the same general functional component set, when the functions and suppliers of the components are similar, evaluating and determining that the components of the screened-out aircraft are similar to those of the target model aircraft.

[0016] According to another embodiment of the present invention, the method further comprises: based on the screened MMEL of aircraft with systems similar to the target aircraft, outputting a MMEL recommendation for the target aircraft according to similar components determined through evaluation.

[0017] According to another embodiment of the present invention, the method further includes: comparing the target model aircraft with the mature model aircraft, and directly outputting the master minimum equipment list of the mature model aircraft as the master minimum equipment list recommendation for the target model aircraft when the manufacturer data, ATA chapter data, master minimum equipment list item function data and installation quantity data are all the same.

[0018] According to another embodiment of the present invention, the step of determining as the same system or the same subsystem or the same functional component set includes: obtaining the position of the system or subsystem or the functional component set of the target aircraft model according to the ATA chapter data in the database of the target aircraft model, obtaining the position of the system or subsystem or the functional component set of the screened aircraft according to the ATA chapter data in the database of the screened aircraft, comparing the distance between the position corresponding to the target aircraft model and the position of the screened aircraft, and if the distance is 0, determining as the same system or the same subsystem or the same functional component set, wherein the distance d x，y Calculated by the following formula:

[0019] dx，y =|X i -Y i |

[0020] Where, d x，y Indicates the distance between the position y corresponding to the target aircraft and the position x corresponding to the selected aircraft, Y i represents the position data corresponding to the i-th system, subsystem or functional component set in the target aircraft, X i Represents the position data corresponding to the i-th system, subsystem or functional component set in the filtered aircraft.

[0021] According to another embodiment of the present invention, the step of determining the functional similarity between the components of the target aircraft and the selected aircraft includes: calculating the functional similarity value Sim(Y) between the components of the target aircraft and the components of the selected aircraft by the following formula: p , X p ), if the difference between the functional similarity value and 1 is within a predetermined range, that is, close to or equal to 1, then it is determined that the functions of the components are similar:

[0022] Sim(Y p , X p )=1-dis(y p , x p )

[0023]

[0024] In the formula, Sim(Y p , X p ) is the component Y of the target aircraft model p With the selected aircraft parts X p The functional similarity value between p , x p ) is the component y of the target aircraft p Parts of the aircraft with the selected p The distance between features, y pi Component y of the target aircraft p Input stream data, operation data or output stream data, x pi The selected aircraft parts x p Input stream data, operation data or output stream data.

[0025] According to another embodiment of the present invention, according to the component data of the aircraft system in the database of the target aircraft model and the mature aircraft model, the corresponding functional ontology library of the aircraft system of the target aircraft model and the mature aircraft model is established based on the functions of the components constituting the aircraft system of the target aircraft model and the mature aircraft model and the flow ontology flowing through the components. The numerical data of the components can be obtained through the functional ontology library, the numerical data includes the flow data and operation data of the components, and the flow data includes input flow data and output flow data.

[0026] Based on the ontology method, a shared vocabulary describing the functions of aircraft system components is established to achieve the normative description of professional terms for expressing functions and the relationship between terms. According to the aircraft system and its components, a corresponding functional ontology library is established, in which the functional ontology describes the knowledge in the functional field in a unified way, which is conducive to the sharing and reuse of knowledge. According to the operations performed by the aircraft system components and the flow ontology flowing through the components, the functional ontology library is established, which is conducive to the subsequent application in the similarity algorithm.

[0027] According to another embodiment of the present invention, the step of determining the functional similarity of the components of the target aircraft and the selected aircraft further includes: using an expert scoring method, inviting experts to weight the input flow, operation, and output flow to obtain corresponding weight values ​​ω i , and then use the following formula to calculate the distance dis(y between the target aircraft model component and the selected aircraft component function p , x p ):

[0028]

[0029] In the formula, dis(y p , x p ) is the component y of the target aircraft p Parts of the aircraft with the selected p The distance between features, y pi Component y of the target aircraft p Input stream data, operation data or output stream data, x pi The selected aircraft parts x p Input stream data, operation data or output stream data, ω i It is weight score data corresponding to input stream data, operation data or output stream data.

[0030] According to another embodiment of the present invention, manufacturer data, main minimum equipment list item function data, installation quantity data, aircraft level data, special flight mission data, energy source data, function data of subsystems constituting the same system, and function data of functional component sets constituting the same subsystem are all data matrices composed of Boolean type data, wherein the value of the Boolean type data is 0 or 1.

[0031] According to another embodiment of the present invention, by calculating the similarity value between the data matrix of the target aircraft model and the corresponding data matrix of the screened aircraft, it is determined whether the manufacturer, main minimum equipment list item function, installation quantity, aircraft level, energy source, function of subsystems constituting the same system and functional component set constituting the same subsystem of the screened aircraft and the target aircraft model are the same or similar. When the similarity value is 1, it is determined to be the same or similar, wherein the similarity value S(x, y) is calculated by the following formula:

[0032]

[0033] In the formula, S(x, y) represents the similarity between the data matrix x of the selected aircraft and the data matrix y of the target aircraft, x i Represents the i-th data in the data matrix x of the screened aircraft, y i Represents the i-th data in the data matrix y of the target aircraft model.

[0034] According to another embodiment of the present invention, an expert scoring method is used to invite experts to weight each data in the data matrix to obtain a corresponding weight value ω i , and then use the following formula to calculate the similarity value S(x, y):

[0035]

[0036] In the formula, S(x, y) represents the similarity between the data matrix x of the selected aircraft and the data matrix y of the target aircraft, x i Represents the i-th data in the data matrix x of the screened aircraft, y i Represents the i-th data in the data matrix y of the target aircraft model, ω i is the corresponding weight score data.

[0037] According to another embodiment of the present invention, the ATA chapter data includes aircraft system data, data of each subsystem constituting the aircraft system, data of each component set constituting each aircraft subsystem, and data of each component constituting each component set.

[0038] Based on the common sense in this field, the above-mentioned various implementation modes can be combined arbitrarily to obtain the preferred implementation modes of the present application.

[0039] The beneficial technical effects and advantages that can be achieved by the method for evaluating the similarity of aircraft systems according to the above-mentioned embodiment of the present application are:

[0040] According to the method for evaluating the similarity of aircraft systems of the present application, a functional ontology library is established based on the operations performed by the components of the aircraft system and the flow ontology flowing through the components, and the data related to the aircraft system attributes and the data related to the operation and flow ontology are respectively divided into Boolean data and numerical type data. By using the Euclidean distance method to calculate the similarity of the system level, subsystem level and component level of the aircraft systems of different models, the similarity of the systems of aircraft of different models can be quantitatively and accurately evaluated, thereby obtaining a mature model of aircraft similar to the aircraft system of the target model. Moreover, by referring to the master minimum equipment list of mature aircraft models, the master minimum equipment list proposal of the target aircraft model can be quickly formulated, thereby effectively shortening the development cycle, reducing the risk of aircraft operation, and greatly improving the economy of aircraft operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a schematic diagram of the steps of a method for evaluating similarity of aircraft systems according to a preferred embodiment of the present application.

[0042] Figure 2 It is a schematic diagram of a function ontology library of aircraft system components established according to a preferred embodiment of the present application. DETAILED DESCRIPTION

[0043] The preferred embodiments of the present application are further described in detail below in conjunction with the drawings in the specification. The following description is exemplary and not limiting of the present application. Any other similar situations also fall within the protection scope of the present application.

[0044] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as those commonly understood by technicians in the technical field to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "include", "comprising", "having", "having", "containing", "including" and the like in the specification and claims of this application and the above-mentioned figure descriptions are open-ended terms. Therefore, "include", "comprising", "having" and a method or device, such as one or more steps or components, have one or more steps or components, but are not limited to having only these one or more steps.

[0045] The term "functional ontology" in this application is a shared vocabulary for describing system functions based on the ontological method. It is a normative description of the professional terms for expressing functions and the relationship between terms. The functional ontology describes the knowledge in the functional field in a unified manner, which is conducive to the sharing and reuse of knowledge. In the similarity algorithm, the construction of the functional ontology library is based on the operations performed by the aircraft system components and the flow ontology flowing through the components. The flow ontology is an object used to express the functions performed by the system components, and the operation ontology is a general vocabulary for describing the functional operations performed by the system equipment.

[0046] During the operation of civil aircraft, when an aircraft system fails and cannot be repaired in a short period of time, it is necessary to confirm whether it can be released through the minimum equipment list. If the minimum equipment list contains the equipment that caused the aircraft failure, confirming that the aircraft can be released will greatly improve the economy of the aircraft and enhance the market competitiveness of the aircraft. The main purpose of the minimum equipment list is to make full use of the safety margin of the aircraft design, and allow the failure to continue flying within the prescribed period under the premise of ensuring operational safety. The reasonable use of the minimum equipment list can effectively improve the utilization rate of the aircraft and the flight punctuality rate, and reduce operating costs.

[0047] The Minimum Equipment List is an important technical document prepared by the aircraft operator and approved by the country's airworthiness agency. The basis for the preparation of the Minimum Equipment List is the Master Minimum Equipment List. The Minimum Equipment List is a document that allows inoperative equipment and systems for a certain period of time for aircraft of a specific model with a serial number and registration number, based on the Master Minimum Equipment List, according to the differences in aircraft configurations selected by the airline, and combined with the differences in the company's operating level and experience.

[0048] The minimum equipment list should comply with the master minimum equipment list of the corresponding aircraft model, or be more stringent than it. The master minimum equipment list stipulates which inoperative instruments and equipment are allowed to be dispatched with the aircraft of this model, and makes principled requirements for the minimum dispatch quantity of working instruments and equipment and the restrictions on retaining fault dispatch.

[0049] The Master Minimum Equipment List is a programmatic document developed by aircraft manufacturers and approved by civil aviation authorities and airworthiness agencies to guide aircraft users and airlines in the specific preparation of the minimum equipment list. Civil aircraft manufacturers submit proposals for the Master Minimum Equipment List, which will be published after being reviewed and approved by the authority. The Master Minimum Equipment List is an important tool for balancing the economy and safety of aircraft and is the main review item of the Flight Operations Review Committee.

[0050] Therefore, when formulating the MMEL proposal items, aircraft manufacturers need not only to meet the minimum requirements of the regulations, but also to consider and meet the needs of users for the MMEL in order to improve user satisfaction. In addition, in order to obtain the MMEL proposal of the aircraft system of a new model more quickly and accurately, a reasonable aircraft system similarity evaluation method is needed to determine the mature models that are similar to the target model in terms of system functions and structures, and thus carry out the preliminary work of the MMEL proposal by referring to the MMEL manual of similar mature models.

[0051] Specifically, the similarity analysis algorithm of aircraft systems is used in the process of aircraft manufacturers compiling the Master Minimum Equipment List Recommendation Manual. With reference to the Master Minimum Equipment List Manual of mature similar aircraft models, it is evaluated whether the Master Minimum Equipment List items of components with similar system functions and structures can be added to the Master Minimum Equipment List Recommendation Manual of the target aircraft model.

[0052] However, at present, in the early stage of the MMEL proposal, the aircraft similarity assessment is mainly completed subjectively by people. Due to factors such as different professional backgrounds and work experience of the assessors, the assessment results will be quite different and the risk is high. Therefore, if a quantitative and accurate aircraft system similarity assessment method can be adopted to determine the mature aircraft models similar to the target aircraft model, and then select the MMEL items of the aircraft systems of similar mature aircraft models, it will be able to further reduce the aircraft operation risk and effectively shorten the development cycle of the MMEL proposal for new civil aircraft models.

[0053] In various applications, regarding the similarity evaluation of systems, many experts and scholars at home and abroad have explored and studied similarity algorithms. For example, the invention patent (CN114154586A) applied by Yan Feng et al. introduced a quantitative similarity analysis method, device and medium for aircraft systems to calculate the structural importance, probability importance and key importance of aircraft systems respectively, and to calculate the cosine similarity of the probability and key importance data matrices, and finally obtain the similarity values ​​of the two aircraft models. Zhang Deqing used Euclidean distance to calculate the difference in the distance between the two corresponding attributes as the similarity between the two attributes in "Research on Database Design and Case Similarity Algorithm of Pediatric Disease Diagnosis and Treatment System Based on CBR", which is used to retrieve cases similar to the target case from the case library; Zhang Xiaonan proposed a similarity matching algorithm based on rough set Euclidean distance in "Research on Case-based Mobile Phone Fault Similarity Matching Algorithm" to improve the diagnosis ability of mobile phone faults.

[0054] In addition, Zhang Kai and Wang Yingming proposed an emergency case adjustment method in "Emergency Case Adjustment Method Considering Multi-angle Utility" to improve the accuracy of emergency case library retrieval. First, the comprehensive similarity was calculated using Euclidean distance, Gaussian distance, and FAN, and then the relationship between cases was obtained using gray correlation analysis. Finally, the feasibility of the algorithm was verified using the fire emergency case library as an example; further, in terms of system engineering, Wang Ailun, Zhang Yingying, etc. divided the system into various subsystems until the most basic unit components of the system in "Research on Similarity Criteria of Complex Systems Based on Functional / Structural Similarity" to obtain the similarity between two complex systems, and then used matrices to calculate the functional and structural similarity of the system level, subsystem level, and component level. Although algorithms for evaluating the similarity of aircraft systems are not common, these explorations and existing achievements in system similarity algorithms fully prove the feasibility of similarity evaluation methods for aircraft systems.

[0055] Therefore, the present application is based on such a concept, comparing the database of the target model aircraft with that of the mature model aircraft, and in the case that any of the manufacturer data, ATA chapter data, main minimum equipment list item function data and installation quantity data are different, selecting the aircraft of the same level as the target model aircraft and having special flight missions from the mature model aircraft, and then evaluating and calculating the system-level functional similarity, subsystem-level functional similarity and component-level functional similarity of the target model aircraft and the selected aircraft based on the Euclidean distance algorithm and the nearest neighbor matching algorithm, respectively; subsequently, when the system-level functional similarity, subsystem-level functional similarity and component-level functional similarity are all evaluated to be similar, finally evaluating and determining that the system of the selected aircraft is similar to that of the target model aircraft.

[0056] Through this method for evaluating the similarity of aircraft systems, not only can a comprehensive analysis of the functional similarity of different aircraft models at the system level, subsystem and subsystem component level be performed, but also the functional and structural similarity of the components of different aircraft systems can be quantitatively compared, so as to accurately obtain mature aircraft models that are similar to the target aircraft model systems. In addition, it is also possible to refer to the master minimum equipment list items of the systems of similar mature aircraft models, and quickly formulate a reliable master minimum equipment list proposal for the target aircraft model, thereby effectively shortening the development cycle of the master minimum equipment list proposal for new civil aircraft models, thereby improving the economy of aircraft operations and further reducing aircraft operation risks. The specific process of the method for evaluating the similarity of aircraft systems according to the present invention will be further described in detail below in conjunction with the drawings of the specification.

[0057] like Figure 1As shown, firstly, the database corresponding to the target aircraft model and the mature aircraft model is obtained, wherein the database includes manufacturer data, ATA chapter data, main minimum equipment list item function data and installation quantity data. Exemplarily, the database of the mature aircraft model has been loaded into the computer device or the airborne device, and the user only needs to input the relevant data of the database of the target aircraft model. Subsequently, the database of the target aircraft model is compared with the database of the mature aircraft model.

[0058] Specifically, first compare the manufacturer data of the target aircraft model with that of the mature aircraft model. If the manufacturer data of the target aircraft model is the same as that of the mature aircraft model, then compare the ATA chapter data of the target aircraft model with that of the mature aircraft model. If the ATA chapter data of the target aircraft model is the same as that of the mature aircraft model, compare the function data of the MMEL items of the target aircraft model with that of the mature aircraft model. Finally, if the function data of the MMEL items of the target aircraft model is the same as that of the mature aircraft model, compare the installation quantity data of the target aircraft model with that of the mature aircraft model.

[0059] Among them, the manufacturer data, ATA chapter data, MMEL item function data and installation quantity data are all data matrices composed of Boolean type data, and the value of Boolean type data can only be 0 or 1. For example, as shown in Table 1, the manufacturer data of the target aircraft model is [0, 1, 0], and the manufacturer data of the mature aircraft model is [1, 0, 1].

[0060] Table 1:

[0061]

[0062] Based on the Euclidean distance algorithm and the nearest neighbor matching algorithm, the similarity value between the above data matrix of the target aircraft model and the mature aircraft model can be calculated. When the similarity value is 1, it is determined that the aircraft attributes corresponding to the data matrix are the same or similar. The similarity value is calculated by the following formula (1):

[0063]

[0064] In the formula, S(x, y) represents the similarity between the data matrix x of the selected aircraft and the data matrix y of the target aircraft, x i Represents the i-th data in the data matrix x of the screened aircraft, y i Represents the i-th data in the data matrix y of the target aircraft model.

[0065] In addition, we can also use the expert scoring method to invite experts to weight each data in the data matrix to obtain the corresponding weight value ω i , and then use the following formula (2) to calculate the similarity value:

[0066]

[0067] In the formula, S(x, y) represents the similarity between the data matrix x of the selected aircraft and the data matrix y of the target aircraft, x i Represents the i-th data in the data matrix x of the screened aircraft, y i Represents the i-th data in the data matrix y of the target aircraft model, ω i is the corresponding weight score data.

[0068] When the manufacturer data, ATA chapter data, MMEL item function data and installation quantity data of the target model aircraft and the mature model aircraft are the same, the MMEL of the mature model aircraft is directly output as the MMEL recommendation of the target model aircraft.

[0069] When any of the manufacturer data, ATA chapter data, main minimum equipment list item function data and installation quantity data of the target aircraft and the mature aircraft are different, that is, when the corresponding similarity value is not 1, the aircraft of the same level as the target aircraft and having special flight missions are selected from the mature aircraft. The aircraft level data and special flight data are also data matrices composed of Boolean type data. According to whether the value corresponding to the special flight mission data is 1, it can be judged whether there is a characteristic flight mission. In addition, whether the aircraft level is the same and whether there is a special flight mission can also be calculated and judged according to formula (1) or formula (2).

[0070] Subsequently, based on the Euclidean distance algorithm and the nearest neighbor matching algorithm, the system-level functional similarity, subsystem-level functional similarity, and component-level functional similarity of the target aircraft and the selected aircraft are evaluated and calculated respectively. According to the ATA chapter data in the aircraft database, the aircraft system data, the data of each subsystem constituting the aircraft system, the data of each component set constituting each aircraft subsystem, and the data of each component constituting each component set can be obtained.

[0071] Specifically, the system-level functional similarity between the target aircraft and the selected aircraft is first evaluated, and the system-level functional similarity is evaluated by analyzing the energy source similarity of the same system and the functional similarity of the subsystems that constitute the same system. Among them, the energy source data and the functional data of the subsystems that constitute the same system are also data matrices composed of Boolean type data. Just like the method of determining whether the manufacturers are the same, the energy source similarity and the functional similarity of the subsystems that constitute the same system can be calculated and determined by formula (1) or (2). Perform a system-level functional similarity comparison, first determine whether the system of the target aircraft to be compared and the selected aircraft are the same system.

[0072] Specifically, the step of determining that they are the same system includes: obtaining the position of the system of the target aircraft model according to the ATA chapter data in the database of the target aircraft model, obtaining the position of the system of the selected aircraft according to the ATA chapter data in the database of the selected aircraft, and comparing the distance between the position corresponding to the target aircraft model and the position of the selected aircraft. If the distance is 0, it is determined that they are the same system. The distance between the positions can be calculated by the following formula (3).

[0073] d x，y =|X i -Y i | (3)

[0074] Where, d x，y Indicates the distance between the position y corresponding to the target aircraft and the position x corresponding to the selected aircraft, Y i represents the position data corresponding to the i-th system in the target aircraft, X i Represents the position data of the i-th system in the filtered aircraft.

[0075] If it is determined that the system of the target aircraft model for comparison is not the same system as the system of the selected aircraft, then it is determined that the system of the target aircraft model is not similar to the system of the selected aircraft. In the case where it is determined that the system of the target aircraft model for comparison is the same system as the system of the selected aircraft, it is possible to determine whether the energy sources are similar and whether the functions of the subsystems constituting the same system are similar by using formula (1) or (2).

[0076] If the system of the target aircraft model and the system of the screened aircraft are the same system, it is determined that any one of the energy source or the function of the subsystems constituting the same system is not similar, then the system of the target aircraft model and the system of the screened aircraft are not similar. If the system of the target aircraft model and the system of the screened aircraft are the same system, it is determined that the energy source is similar, and the functions of the subsystems constituting the same system are also similar, then the system-level functions of the target aircraft model and the screened aircraft are determined to be similar, and further subsystem function similarity judgment is performed.

[0077] The subsystem-level functional similarity between the target aircraft and the selected aircraft is calculated and evaluated by analyzing the energy source similarity of the same subsystem and the functional similarity of the functional component set that constitutes the same subsystem. Among them, the energy source data and the functional data of the functional component set that constitutes the same subsystem are also data matrices composed of Boolean type data. Just like the method of determining whether the manufacturers are the same, the energy source similarity and the functional similarity of the functional component set that constitutes the same subsystem can be calculated and determined by formula (1) or formula (2). Perform a subsystem-level functional similarity comparison, first determine whether the subsystems of the target aircraft and the selected aircraft are the same subsystems.

[0078] Specifically, the step of determining that they are the same subsystem includes: obtaining the position of the subsystem of the target aircraft model according to the ATA chapter data in the database of the target aircraft model, obtaining the position of the subsystem of the selected aircraft according to the ATA chapter data in the database of the selected aircraft, and comparing the distance between the position corresponding to the target aircraft model and the position of the selected aircraft. If the distance is 0, it is determined that they are the same subsystem. The distance between the positions can also be calculated by formula (3).

[0079] If it is determined that the subsystem of the target aircraft model for comparison is not the same subsystem as the subsystem of the screened aircraft, then it is determined that the target aircraft model system is not similar to the screened aircraft system. In the case where it is determined that the subsystem of the target aircraft model for comparison is the same subsystem as the subsystem of the screened aircraft, it is possible to determine whether the energy sources are similar and whether the functions of the functional component sets constituting the same subsystem are similar by using formula (1) or (2). If it is determined that any one of the energy sources or the functions of the functional component sets constituting the same subsystem is not similar, then it is determined that the target aircraft model system is not similar to the screened aircraft system.

[0080] If the subsystem of the target aircraft model is the same subsystem as the subsystem of the screened aircraft, it is determined that the energy sources are similar, and the functions of the functional component sets that make up the same subsystem are also similar, then it is determined that the target aircraft model is similar to the screened aircraft at the system level, and further component-level functional similarity judgment is performed.

[0081] Specifically, the component-level functional similarity is evaluated by analyzing the energy source similarity calculation of the same functional component set. Formula (1) or (2) can be used to determine whether the energy sources are similar. If the energy sources are different, it is determined that the system of the target aircraft model is not similar to the system of the screened aircraft. If the energy sources are the same, it is determined that the subsystem of the target aircraft model is similar to the screened aircraft in component-level function.

[0082] When the system-level functional similarity, subsystem-level functional similarity and component-level functional similarity between the target aircraft and the screened aircraft are all assessed to be similar, and the aircraft are of the same level and have special flight missions, it is assessed that the systems of the screened aircraft are similar to those of the target aircraft.

[0083] Furthermore, according to whether the functional component set has an impact on the function execution, the functional component set is divided into an execution functional component set and a general functional component set, wherein by analyzing the functional similarity, structural similarity and supplier similarity of each component constituting the same execution functional component set, when the functions, structures and suppliers of the components are similar, it is evaluated and determined that the components of the selected aircraft are similar to those of the target aircraft model. Alternatively, by analyzing the functional similarity and supplier similarity of each component constituting the same general functional component set, when the functions and suppliers of the components are similar, it is evaluated and determined that the components of the selected aircraft are similar to those of the target aircraft model.

[0084] Then, based on the screened MMELs of aircraft with systems similar to the target aircraft, the MMEL proposal for the target aircraft is output according to similar components determined by the evaluation.

[0085] Specifically, the component data of the functional component set, the structural data of the functional component set and the supplier data of the functional component set are also data matrices composed of Boolean type data. Just like the method of determining whether the manufacturers are the same, formula (1) or formula (2) can be used to determine whether the functional component sets have similar structures and similar suppliers.

[0086] Then, the step of determining the functional similarity of the components includes establishing a functional ontology library of the aircraft system components including operations and flows. Figure 2 As shown, the functional ontology of the aircraft system components established includes two major categories of ontology: operation and flow. Among them, the operation ontology includes functional operations such as generation and separation, and the flow includes objects such as gas, liquid, electrical signal, thermal energy, and mechanical energy. However, it is difficult to use these general professional vocabulary in actual application, so these general vocabulary can be refined into general vocabulary. For example, the flow and operation are refined into secondary flow and secondary operation. For example, the gas in the flow is refined to include air, etc., and the generation in the operation is refined to include mixing, introduction, etc.

[0087] The function of the component is expressed by establishing a functional database corresponding to the functional ontology. Specifically, the function of each component is described as "input flow, operation, output flow", so that the operation completed by each component and the changes in the flow before and after the component (also known as the medium) can be clearly expressed. According to the functional code data of the component, the numerical type data including input flow data, operation data and output flow data of each component can be obtained, thereby establishing a functional database corresponding to the functional ontology of the entire aircraft system.

[0088] Exemplarily, as shown in Table 2, according to the function code data of the riser component and the air conditioning outlet component of the aircraft air conditioning distribution system, the input flow data, operation data and output flow data of the riser and the air conditioning outlet are obtained respectively.

[0089] Table 2:

[0090]

[0091] Then, the Euclidean distance method is used to calculate the distance between the functions of the target aircraft and the mature aircraft according to the following formula (4), and then the functional similarity value Sim (Y) between the components of the target aircraft and the components of the selected aircraft is calculated according to the following formula (5) based on the nearest neighbor matching method. p , X p ), if the difference between the functional similarity value and 1 is within a predetermined range, or the functional similarity value is close to or equal to 1, then it is determined that the functions of the components are similar.

[0092]

[0093] Sim(Y p , x p )=1-dis(y p , x p ) (5)

[0094] In the formula, Sim(Y p , X p ) is the component Y of the target aircraft model p With the selected aircraft parts X p The functional similarity value between p , x p ) is the component y of the target aircraft p Parts of the aircraft with the selected p The distance between features, y pi Component y of the target aircraft p Input stream data, operation data or output stream data, x pi The selected aircraft parts xp Input stream data, operation data or output stream data.

[0095] The smaller the distance between the two functional components is, the more similar the functions performed by the functional components are, that is, the larger the similarity value is, the higher the similarity between the functional components of the two models is. By calculating in this way, it is possible to calculate the recommended solutions with similar component functions to the target model case in the similar model case library.

[0096] In addition, we can also use the expert scoring method to invite experts to weight the input flow, operation, and output flow to obtain the corresponding weight value ω i As shown in Table 3, the weight values ​​of the characteristic attributes of "input flow, operation, output flow" are determined, where the weight values ​​of "input flow" and "output flow" are 0.3, and the weight value of "operation" is 0.4.

[0097] Table 3:

[0098]

[0099] Then use the following formula (6) to calculate the functional distance dis(y between the target aircraft model component and the selected aircraft component p , x p ):

[0100]

[0101] In the formula, dis(y p , x p ) is the component y of the target aircraft p Parts of the aircraft with the selected p The distance between features, y pi Component y of the target aircraft p Input stream data, operation data or output stream data, x pi The selected aircraft parts x p Input stream data, operation data or output stream data, ω i is the corresponding weight score data.

[0102] Next, the functional similarity value Sim(Y) between the components of the target aircraft and the components of the selected aircraft can be calculated using the following formula (5) p , X p ), if the function similarity value is closer to 1, the functions of the components are more similar. Based on the MMEL of the aircraft that are similar to the target aircraft, the MMEL recommendation of the target aircraft is output according to the similar components determined by the evaluation.

[0103] Through the method for evaluating the similarity of target aircraft systems in this application, when analyzing the requirements of the target aircraft's MMEL proposal, the similarity of the system function and structure of the equipment or item is taken into consideration, and an aircraft system similarity algorithm is formulated based on the functional ontology library technology to form a similarity criterion judgment method. The similar MMEL proposal items of the target aircraft are extracted to form a list of similar MMEL proposal items of the target aircraft, which can make the user demand analysis of civil aircraft manufacturers comparable.

[0104] The beneficial technical effects of the above specific implementation methods of the present application are as follows:

[0105] 1. Through a quantitative similarity assessment method for systems of different aircraft models, it is possible to accurately and comprehensively assess mature aircraft models that have systems similar to the target aircraft model and screen them out.

[0106] 2. By establishing a functional ontology library of the aircraft system, not only can the operations performed by aircraft components and the corresponding functions achieved be clearly displayed, but also the knowledge of the functional field of the aircraft system can be described in a unified manner, which is conducive to the subsequent sharing and reuse of knowledge.

[0107] 3. Based on the MMEL of similar mature aircraft models, the preliminary development work of the MMEL proposal can be effectively reduced, thereby effectively shortening the development cycle of the MMEL proposal for new civil aircraft models, further reducing aircraft operation risks, and significantly improving the economy and competitiveness of aircraft operations.

[0108] Although the specific implementation methods of the present application are described above, those skilled in the art should understand that these are only examples, and the protection scope of the present application is defined by the appended claims. Those skilled in the art may make various changes or modifications to these implementation methods without departing from the principles and essence of the present application, but these changes and modifications all fall within the protection scope of the present application.

Claims

1. A method for evaluating aircraft system similarity, characterized in that The method comprises the following steps: Obtaining a database corresponding to the target aircraft model and the mature aircraft model, wherein the database includes manufacturer data, ATA chapter data, MMEL item function data and installation quantity data; Compare the database of the target aircraft model with that of mature aircraft model, and select from the mature aircraft model aircraft the aircraft of the same level as the target aircraft model and having special flight missions if any of the manufacturer data, ATA chapter data, MMEL item function data and installation quantity data are different; Based on the Euclidean distance algorithm and the nearest neighbor matching algorithm, the system-level functional similarity, subsystem-level functional similarity and component-level functional similarity of the target aircraft and the screened aircraft are evaluated and calculated respectively, wherein the system-level functional similarity is evaluated by analyzing the energy source similarity of the same system and the functional similarity of the subsystems constituting the same system, the subsystem-level functional similarity is evaluated by analyzing the energy source similarity of the same subsystem and the functional similarity of the functional component set constituting the same subsystem, and the component-level functional similarity is evaluated by analyzing the energy source similarity of the same functional component set; and When the system-level functional similarity, the subsystem-level functional similarity and the component-level functional similarity are all evaluated to be similar, evaluating and determining that the screened aircraft system is similar to the target aircraft model aircraft system; Furthermore, the method further comprises: After comparing the target model aircraft with the mature model aircraft, if the manufacturer data, ATA chapter data, MMEL item function data and installation quantity data are the same, the MMEL of the mature model aircraft is directly output as the MMEL recommendation for the target model aircraft.

2. The method according to claim 1, characterized in that The method further includes: dividing the functional component set into an execution functional component set and a general functional component set according to whether the functional component set has an impact on function execution, wherein by analyzing the functional similarity, structural similarity and supplier similarity of each component constituting the same execution functional component set, when the functions, structures and suppliers of the components are similar, evaluating and determining that the components of the screened aircraft are similar to those of the target aircraft model.

3. The method according to claim 2, characterized in that The method further includes: by analyzing the functional similarity and supplier similarity of the components constituting the same general functional component set, when the functions and suppliers of the components are similar, evaluating and determining that the components of the screened aircraft are similar to those of the target aircraft model.

4. The method according to claim 3, characterized in that: The method further includes: based on the screened MMELs of aircraft with systems similar to the target aircraft model, outputting a MMEL proposal for the target aircraft model according to similar components determined through evaluation.

5. The method according to claim 1, characterized in that The step of determining as the same system or the same subsystem or the same functional component set comprises: obtaining the position of the system or subsystem or the functional component set of the target aircraft model according to the ATA chapter data in the database of the target aircraft model, obtaining the position of the system or subsystem or the functional component set of the screened aircraft according to the ATA chapter data in the database of the screened aircraft, comparing the distance between the position corresponding to the target aircraft model and the position of the screened aircraft, and if the distance is 0, determining as the same system or the same subsystem or the same functional component set, wherein the distance d x，y Calculated by the following formula: d x,y =|X i -Y i | Where, d x，y Indicates the distance between the position y corresponding to the target aircraft and the position x corresponding to the selected aircraft, Y i represents the position data corresponding to the i-th system, subsystem or functional component set in the target aircraft, X i Represents the position data corresponding to the i-th system, subsystem or functional component set in the filtered aircraft.

6. The method according to claim 2, characterized in that The step of determining the functional similarity of the components of the target aircraft model and the selected aircraft includes: calculating the functional similarity value Sim(Y) between the components of the target aircraft model and the components of the selected aircraft by the following formula: p , X p ), if the difference between the functional similarity value and 1 is within a predetermined range, then it is determined that the functions of the components are similar: Sim(Y p ,X p )=1-dis(y p ,x p ) In the formula, Sim(Y p , X p ) is the component Y of the target aircraft model p With the selected aircraft parts X p The functional similarity value between p , x p ) is the component y of the target aircraft p Parts of the aircraft with the selected p The distance between features, y pi Component y of the target aircraft p Input stream data, operation data or output stream data, x pi The selected aircraft parts x p Input stream data, operation data or output stream data.

7. The method according to claim 6, characterized in that According to the component data of the aircraft system in the database of the target aircraft model and the mature aircraft model, the corresponding functional ontology library of the aircraft system of the target aircraft model and the mature aircraft model is established based on the functions of the components constituting the aircraft system of the target aircraft model and the mature aircraft model and the flow ontology flowing through the components. The numerical data of the components can be obtained through the functional ontology library, and the numerical data includes the flow data and operation data of the components, and the flow data includes input flow data and output flow data.

8. The method according to claim 6, characterized in that The step of determining the functional similarity of the target aircraft and the components of the selected aircraft also includes: using an expert scoring method, inviting experts to weight the input flow, operation, and output flow to obtain corresponding weight values ​​ω i , and then use the following formula to calculate the distance dis(y between the target aircraft model component and the selected aircraft component function p , x p ): In the formula, dis(y p , x p ) is the component y of the target aircraft p Parts of the aircraft with the selected p The distance between features, y pi Component y of the target aircraft p Input stream data, operation data or output stream data, x pi The selected aircraft parts x p Input stream data, operation data or output stream data, ω i It is weight score data corresponding to input stream data, operation data or output stream data.

9. The method according to claim 1, characterized in that: The manufacturer data, main minimum equipment list item function data, installation quantity data, aircraft level data, special flight mission data, energy source data, function data of subsystems constituting the same system, and function data of functional component sets constituting the same subsystem are all data matrices composed of Boolean type data, wherein the value of the Boolean type data is 0 or 1.

10. The method according to claim 9, characterized in that By calculating the similarity value between the data matrix of the target aircraft and the corresponding data matrix of the screened aircraft, it is determined whether the manufacturer, main minimum equipment list item function, installation quantity, aircraft level, energy source, function of subsystems constituting the same system and functional component set constituting the same subsystem of the screened aircraft and the target aircraft are the same or similar. When the similarity value is 1, it is determined to be the same or similar, wherein the similarity value is calculated by the following formula: In the formula, S(x, y) represents the similarity between the data matrix x of the selected aircraft and the data matrix y of the target aircraft, x i Represents the i-th data in the data matrix x of the screened aircraft, y i Represents the i-th data in the data matrix y of the target aircraft model.

11. The method according to claim 10, characterized in that Using the expert scoring method, invite experts to weight each data in the data matrix to obtain the corresponding weight value ω i , and then use the following formula to calculate the similarity value: In the formula, S(x, y) represents the similarity between the data matrix x of the selected aircraft and the data matrix y of the target aircraft, x i Represents the i-th data in the data matrix x of the screened aircraft, y i Represents the i-th data in the data matrix y of the target aircraft model, ω i is the corresponding weight score data.

12. The method according to claim 1, characterized in that The ATA chapter data includes aircraft system data, data of each subsystem constituting the aircraft system, data of each component set constituting each aircraft subsystem, and data of each component constituting each component set.

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