METHOD FOR ANALYZING AN AIRCRAFT ELECTRICAL STRUCTURE BY SEARCHING FOR EQUIPOTENTIALS IN NESTED GRAPHS

Abstract

An aircraft electrical structure comprises equipment interconnected by cables. A processing system (400) constructs a digital representation of the electrical structure in the form of nested graphs. A first graph represents the electrical structure with first arcs representing the cables and first nodes representing the equipment. A second graph represents an internal interconnection structure between at least one input and at least one output of each piece of equipment that has such an internal interconnection structure, with second arcs representing interconnections between inputs and outputs, and second nodes representing the inputs and outputs in question. The first graph is obtained from contextual data (411) describing the electrical structure, and each second graph is obtained from a generic model (412) for each type of equipment concerned.An analysis is performed by conducting a (404) equipotential search through nested graphs. This simplifies the analysis. Figure to be published with the abbreviation: Fig. 4.

Description

Title of the invention: METHOD FOR ANALYZING AN ELECTRICAL STRUCTURE OF AN AIRCRAFT BY SEARCHING FOR EQUIPOTENTIALS IN NESTED GRAPHS Technical field

[0001] The present invention relates to the field of constructing digital representations of aircraft electrical circuits. The present invention also relates to the field of locating and repairing faults in electrical structures installed in an aircraft. STATE OF PRIOR ART

[0002] Many pieces of equipment on an aircraft are powered by electrical structures, including cables, harnesses and interconnecting equipment. This can represent many kilometers of cables within the aircraft.

[0003] To locate faults or defects in such communication structures, reflectometry tools are typically used. Reflectometry is a diagnostic method based on the principle of radar. A probe signal is injected into the electrical structure, and when this probe signal encounters an impedance discontinuity, part of its energy is reflected back to the injection point. A detailed analysis of this reflected energy makes it possible to deduce information on the actual characteristics of the electrical structure. This technique is more particularly used to investigate, during the assembly of an aircraft, a fault or defect in an electrical structure of the aircraft.

[0004] Thus, thanks to reflectometry, it is possible to determine at what distance in the electrical structure a break exists in relation to a termination point of the electrical structure, such as a connector. However, currently, with this distance information, an operator seeking the exact location of the fault or defect begins an arbitrary search by examining previously selected plans of the wiring of the electrical structure of the aircraft, in order to identify potential locations of the fault or defect. The operator's experience and intuition are then very important in choosing which elements of the aircraft to dismantle, for example cabin trim panels, to access portions of the electrical structure where the fault or defect is likely to be located.In addition to the time-consuming nature of this approach, the unnecessary disassembly of aircraft components, such as the cabin trim panels mentioned above, carries a risk of damage to them.

[0005] It is then desirable to overcome these drawbacks of the state of the art. It is particularly desirable to provide a solution which makes it possible to simplify the location and repair of faults or defects in electrical structures installed in an aircraft. Statement of the invention

[0006] For this purpose, a method is proposed for analyzing an electrical structure of an aircraft, the electrical structure comprising equipment interconnected by cables, the method comprising the following steps performed by a processing system in the form of electronic circuitry: constructing a digital representation in the form of nested graphs of the electrical structure, a first graph representing the electrical structure by first nodes and first arcs, the first arcs representing the cables of the electrical structure, the first nodes representing the equipment of the electrical structure interconnected by the cables, and a second graph representing an internal interconnection structure between at least one input and at least one output of the equipment which has an internal interconnection structure among the equipment of the electrical structure,second arcs representing interconnections of the internal interconnection structure between inputs and outputs, second nodes representing the inputs and outputs, the first graph being obtained from contextual data relating to the electrical structure and each second graph being obtained from a generic model associated with a type of equipment to which the equipment in question corresponds; and carrying out the analysis by carrying out a search for equipotentials in the digital representation by traversing the nested graphs. Thus, the construction of the digital representation is particularly facilitated due to the use of a generic model per type of equipment, which makes it possible to obtain a digital representation with nested graphs, and thus facilitates the analysis by a graph traversal algorithm.

[0007] Also provided is a computer program product, which can be stored on a medium and / or downloaded from a communication network, in order to be read by a processor. This computer program comprises instructions for implementing the above-mentioned method, when said program is executed by the processor. Also provided is a non-transitory information storage medium on which such a computer program is stored.

[0008] In a particular embodiment, the analysis relates to a diagnosis of a fault or breakdown in the electrical structure of the aircraft, the method comprising the following steps: carrying out a reflectometry operation on the electrical structure from a termination point or an input of said equipment or an output of a said equipment, and determine by means of the reflectometry operation at what distance in the electrical structure a break exists in relation to said termination point or to said input of the equipment in question or to said output of the equipment in question. Furthermore, the method is such that the search for equipotentials is carried out from the node corresponding to said termination point or to said input of the equipment in question or to said output of the equipment in question.

[0009] In a particular embodiment, the traversal of the nested graphs is carried out using a depth-first traversal algorithm.

[0010] There is also provided a processing system configured to perform an analysis of an electrical structure of an aircraft, the electrical structure comprising equipment interconnected by cables, the processing system being in the form of electronic circuitry configured to: construct a digital representation in the form of nested graphs of the electrical structure, a first graph representing the electrical structure by first nodes and first arcs, the first arcs representing the cables of the electrical structure, the first nodes representing the equipment of the electrical structure interconnected by the cables, and a second graph representing an internal interconnection structure between at least one input and at least one output of the equipment which has an internal interconnection structure among the equipment of the electrical structure,second arcs representing interconnections of the internal interconnection structure between inputs and outputs, second nodes representing the inputs and outputs, the first graph being obtained from contextual data relating to the electrical structure and each second graph being obtained from a generic model associated with a type of equipment to which the equipment in question corresponds; and carrying out the analysis by carrying out a search for equipotentials in the digital representation by traversing the nested graphs. Brief description of the drawings

[0011] The characteristics of the invention mentioned above, as well as others, will appear more clearly on reading the following description of at least one exemplary embodiment, said description being made in relation to the attached drawings, among which:

[0012] [Fig-1] schematically illustrates, in top view, an aircraft equipped with at least an electrical structure;

[0013] [Fig.2A] schematically illustrates an example of a first graph representing a part of the electrical structure;

[0014] [Fig.2B] schematically illustrates an example of a second graph representing an interconnection structure internal to an interconnection device in the electrical structure represented by the first graph of [Fig.2A];

[0015] [Fig.3] schematically illustrates an example of a hardware platform configured to construct a digital representation of the electrical structure and to use this digital representation in particular to search for a fault or a breakdown in the electrical structure; and

[0016] [Fig.4] schematically illustrates a flowchart of a method of constructing a digital representation of the electrical structure and using this digital representation to search for a fault or breakdown in the electrical structure.

[0017] DETAILED DESCRIPTION OF EMBODIMENTS

[0018] [Fig.l] thus schematically illustrates, in top view, an aircraft 10. The aircraft 10 comprises one or more electrical structures 100 for interconnecting equipment 101 to 104, such as power sources, connectors and loads. Each electrical structure comprises cables and interconnection devices 105, such as harnesses, connectors and switches. As detailed below, the electrical structure is described by a first graph.

[0019] Each interconnection device 105 comprises an internal interconnection structure making it possible to interconnect one or more inputs of said interconnection device 105 and one or more outputs of said interconnection device 105. As detailed below, the internal interconnection structure is described by a second graph. Note that each equipment 101 to 104 may also include such an internal interconnection structure.

[0020] [Fig.l] represents, in a purely illustrative manner, four pieces of equipment 101 to 104 interconnected by means of wiring and an interconnection device 105, but modern aircraft typically comprise such electrical structures 100 with a much larger quantity of elements.

[0021] [Fig.2A] schematically illustrates an example of a first graph 201 representing a part of an electrical structure. The first graph 201 comprises arcs 110 to 115, also called edges, representing cables of the electrical structure. The first graph 201 also comprises nodes 210 to 216, also called vertices, representing equipment of the electrical structure interconnected by the cables in question. The equipment in question is interconnection devices 105 or termination points, such as sockets or connectors. In the example of [Fig.2A], the node 210 is connected to the node 212 by the arc 110, which represents a termination point (node ​​210) connected by a cable (arc 110) to an interconnection device (node ​​212). Also, in the example of [Fig.2A], node 212 is connected to node 213 by arc 113, which represents an interconnection device (node ​​212) connected by a cable (arc 113) to another interconnection device (node ​​213). Arcs 110 to 115 thus represent the equipotential connections between equipment 101 to 104 and interconnection devices 105.

[0022] The entire electrical structure 100 can thus be described by graph.

[0023] [Fig.2B] schematically illustrates an example of a second graph 202 representing the internal interconnection structure of the interconnection device 105 which is represented by the node 212 in the first graph 201. The second graph 202 comprises arcs 241 to 243 (or edges) representing internal electrical connections of the interconnection device 105 represented by the node 212 in the first graph 201. These internal electrical connections connect inputs to outputs of the interconnection device 105. In the second graph 202, the inputs of the interconnection device 105 are represented by nodes 222 and 223 (or vertices), and the outputs of the interconnection device 105 are represented by nodes 232 to 234.

[0024] The entire interconnection structure internal to the interconnection device 105 can thus be described by graph. This graph may differ from one configuration to another of the interconnection device 105. For example, if the interconnection device 105 comprises a switch, the internal interconnection structure is different depending on whether the switch in question is open or closed. The equipotentials of the interconnection structure internal to the interconnection device 105, and therefore of the electrical structure 100, then typically differ from one configuration to another of the interconnection device 105.

[0025] Thus, with regard to Figs. 2A and 2B, in a given context or a given configuration, the electrical structure 100 of the aircraft 10 can be represented with two levels of nested graphs. As explained below, this approach facilitates the construction of the digital representation of the electrical structure 100 of the aircraft 10, as well as the search for equipotentials in the electrical structure 100 of the aircraft 10, by traversing these nested graphs, in order in particular to assist in the location of a breakdown or fault in the electrical structure 100 of the aircraft 10.

[0026] [Fig.3] schematically illustrates an example of a hardware platform of processing system 300, in the form of electronic circuitry, which is adapted and configured to construct a digital representation of the electrical structure 100, based on nested graphs, and to use this digital representation in particular to search for equipotentials in the electrical structure 100.

[0027] The hardware platform then comprises, connected by a communication bus 310: a processor or CPU (“Central Processing Unit” in English) 301; a RAM (“Read-Only Memory” in English) 302; a read-only memory 303, for example of the ROM (“Read Only Memory” in English) or EEPROM (“Electrically-Erasable Programmable ROM” in English) type; a storage unit 304, such as a hard disk HDD (“Hard Disk Drive” in English), or a storage media reader, such as an SD (“Secure Digital” in English) card reader; and an I / f interface manager 305.

[0028] The I / f interface manager 305 makes it possible to interact with one or more peripheral devices and / or a communication network. For example, the I / f interface manager 305 is adapted and configured to make it possible to interact with a human operator in order to receive contextual data for the construction of the digital representation of the electrical structure 100, in order also to receive parameters for searching for equipotentials in the electrical structure 100, and in order to provide (eg, display) a result of the search for equipotentials in the electrical structure 100.

[0029] The processor 301 is capable of executing instructions loaded into the RAM 302 from the ROM 303, an external memory, a storage medium (such as an SD card), or a communications network. When the hardware platform is powered on, the processor 301 is capable of reading instructions from the RAM 302 and executing them. These instructions form a computer program causing the processor 301 to implement all or part of the steps and operations described herein.

[0030] All or part of the steps and operations described herein may thus be implemented in software form by executing a set of instructions by a programmable machine, for example a DSP (Digital Signal Processor) type processor or a microcontroller, or be implemented in hardware form by a machine or a dedicated electronic component (chip) or a set of dedicated electronic components (chipset), for example an FPGA (Field Programmable Gate Array) or ASIC (Application Specified Integrated Circuit) component. Generally speaking, the hardware platform comprises electronic circuitry adapted and configured to implement the operations and steps described herein.

[0031] [Fig.4] schematically illustrates a flowchart of a method of constructing a digital representation of the electrical structure 100 and using this digital representation to search for equipotentials in the electrical structure 100, in order to help locate and correct a fault or defect in the electrical structure 100 of the aircraft 10.

[0032] In a step 400, the processing system 300 constructs the digital representation of the electrical structure 100. To do this, the processing system 300 uses contextual data 411 of the electrical structure 100 and models generics 412 of the interconnection devices 105 and of the equipment 101 to 104 of the electrical structure 100.

[0033] The contextual data 411 is a description of the electrical structure 100, with its cables and the different equipment that these cables interconnect. In this description, the cables are at least characterized by their length. In this description, the different equipment is characterized by its type. Each type of equipment has its associated generic model 412. Each generic model 412 defines each input and each output that the equipment, of the type associated with the generic model 412 in question, possibly comprises, as well as at least one internal interconnection structure as soon as the equipment comprises at least one input and at least one output. When a piece of equipment has several possible internal structures depending on a configuration of said equipment (eg, open / closed switch, as already mentioned), the contextual data 411 specifies which configuration is applicable to said equipment, which defines the effective internal interconnection structure of said equipment.

[0034] In step 400, the processing system 300 constructs the digital representation of the electrical structure 100 in the form of graphs. A first graph represents the electrical structure 100 by nodes and arcs according to the principles set out above in relation to [Fig.2A]. A second graph represents each internal equipment interconnection structure of the electrical structure 100.

[0035] Thus, thanks to the use of the generic models 412, the digital representation by graphs of the entire electrical structure 100, including the internals of the equipment of said electrical structure 100, is easily achievable. In addition, this digital representation is easily modifiable to test hypotheses for modifying the electrical structure 100.

[0036] The digital representation thus constructed makes it possible to harmonize different contextual data that may come from different databases, such as for example a database containing architectural information of an aircraft model and a database containing configuration customization information for airlines for which aircraft according to said aircraft model have been produced. The digital representation then links these data together to structure them, contextualize them, and create axes of exploration for different design or diagnostic hypotheses. A method of analyzing the electrical structure 100 can thus be easily carried out. Indeed, thanks to the graphs thus nested, a graph path makes it possible to easily find the equipotentials in the electrical structure 100.So, starting from an endpoint or an input of a device or an output of a device, a traversal algorithm of . graph allows to find all the equipotentials of this endpoint or this input or this output (respectively).

[0037] More particularly, by having knowledge of a discontinuity distance obtained by reflectometry from this termination point or this input or this output in the actual electrical structure 100 of the aircraft 10, an analysis of the equipotentials makes it possible to determine where this discontinuity is likely to be located and to evaluate whether this discontinuity is in accordance with the electrical structure 100 as planned or whether this discontinuity corresponds to a failure or a defect in the production of the electrical structure 100 in the aircraft 10. The flowchart of [Fig. 4] thus presents, in a particular embodiment, a use of this digital representation to help locate and correct a failure or a defect in the electrical structure 100 of the aircraft 10.

[0038] In a step 401, a failure or defect is detected in the electrical structure 100 of the aircraft 10. For example, this failure or defect is detected following validation operations during the assembly of the aircraft 10 in production.

[0039] In a step 402, a reflectometry operation is performed on the electrical structure 100 from a termination point or an input of a piece of equipment or an output of a piece of equipment. The reflectometry operation makes it possible to determine at what distance in the electrical structure a cut exists relative to the termination point or the input of the equipment or the output of the equipment in question.

[0040] In a step 403, the processing system 300 obtains a digital representation of the electrical structure 100 of the aircraft 10. The digital representation is constructed as described above in relation to step 400, and is therefore made up of two levels of nested graphs.

[0041] In a step 404, the processing system 300 performs a search for equipotentials by traversing the nested graphs. A graph traversal algorithm, for example of the depth-first search (DFS) type or of the breadth-first search (BFS) type, can be used to do this, in particular by using artificial intelligence. The depth-first search (DFS) algorithm is particularly suitable for fault or defect diagnosis.

[0042] The graph traversal algorithm manages the nesting of the two graph levels: when the algorithm encounters in the traversal of the first graph a device having an internal interconnection structure, the algorithm switches to the second graph defined for the device in question to continue the search for equipotentials, and switches back to the traversal of the first graph when said second graph has been traversed.

[0043] The search for equipotentials can relate to all the equipotentials of the electrical structure 100 as described in the digital representation. Since the equipotentials are independent of each other in their creation, parallel processing can be implemented for their search, starting from the different possible points of the electrical structure 100. For example, a MapReduce (from the company Google) or multi-threaded approach can be used to reduce the calculation time.

[0044] In the context of the diagnosis of the fault or defect detected in step 401, the search for equipotentials relates more particularly to the determination of the equipotentials corresponding to the termination point or the equipment input or the equipment output from which the reflectometry operation was carried out in step 402. This makes it possible to browse only the part of the graphs useful for the diagnosis, and thus to limit the calculation time, the processing resources required, and the energy consumption for carrying out the diagnosis. This indicates what distance without connection discontinuity is assumed to exist in the electrical structure 100 from the termination point or the equipment input or the equipment output from which the reflectometry operation was carried out in step 402.In addition, this makes it possible to identify, taking into account the length of cabling in the first graph and the interconnections present in the second graph(s), at which location in the electrical structure 100 the detected fault or defect appears to be present.

[0045] Such a digital representation also makes it possible, within the framework of the diagnosis of the breakdown or fault detected in step 401, to modify configuration hypotheses of equipment of the electrical structure 100, to search for the new equipotentials with this new configuration, and thus to evaluate whether the breakdown or fault detected would simply be due to a bad configuration of equipment.

[0046] In a step 405, the processing system 300 provides an equipotential search result by traversing the nested graphs. The result can be provided in textual or graphical form. The result can be displayed in an immersed manner in a three-dimensional model of an aircraft by highlighting the equipotentials found (for example, when each piece of equipment is precisely located in the aircraft model considered). Other types of human-machine interfaces can also be used. The result can also be communicated to another system or machine to carry out other processing.

[0047] In a step 406, an intervention is carried out to correct the detected fault or repair the detected breakdown. Thanks to the assistance provided by the digital representation and the search for equipotentials, the location of the fault or defect has been facilitated. Thus, the possible dismantling of elements of the aircraft, such as for example cabin trim panels, in order to access portions of the electrical structure 100 where the fault or defect in question is likely to be located, is targeted.

Claims

1. Claims Method for analyzing an electrical structure (100) of an aircraft (10), the electrical structure (100) comprising equipment (101, 102, 103, 104, 105) interconnected by cables, the method comprising the following steps carried out by a processing system (300) in the form of electronic circuitry: - constructing (400) a digital representation in the form of nested graphs (201, 202) of the electrical structure (100), a first graph (201) representing the electrical structure (100) by first nodes (210, 211, 212, 213, 214, 215, 216) and first arcs (110, 111, 112, 113, 114, 115), the first arcs (110, 111, 112, 113, 114, 115) representing the cables of the electrical structure (100), the first nodes (210, 211, 212, 213, 214, 215, 216) representing the equipment (101, 102, 103, 104, 105) of the electrical structure (100) interconnected by the cables, and a second graph (202) representing an internal interconnection structure between at least one input and at least one output of the equipment (102) which have an internal interconnection structure among the equipment (101, 102, 103, 104, 105) of the electrical structure (100), second arcs (241, 242,243) representing interconnections of the internal interconnection structure between inputs and outputs, second nodes (222, 223, 232, 233, 234) representing the inputs and the outputs, the first graph (201) being obtained from contextual data (411) relating to the electrical structure (100) and each second graph (202) being obtained from a generic model (412) associated with a type of equipment to which the equipment (102) in question corresponds; and, - carry out the analysis by performing a search (404) for equipotentials in the digital representation by browsing the nested graphs (201, 202); method in which the analysis relates to a diagnosis of a fault or breakdown in the electrical structure (100) of the aircraft (10), identifying at which location in the electrical structure the fault or breakdown appears to be present, taking into account the length of wiring in the first graph and the interconnections in each second graph, the method further comprising the following steps:

2.

3. - performing (402) a reflectometry operation on the electrical structure (100) from a termination point or an input of said equipment (101, 102, 103, 104, 105) or from an output of said equipment (101, 102, 103, 104, 105), and determining by means of the reflectometry operation at what distance in the electrical structure (100) a break exists with respect to said termination point or to said input of the equipment (101, 102, 103, 104, 105) in question or to said output of the equipment (101, 102, 103, 104, 105) in question; and wherein the search for equipotentials is carried out from the node corresponding to said termination point or said input of the equipment (101, 102, 103, 104, 105) in question or said output of the equipment (101, 102, 103, 104, 105) in question. Method according to claim 1, wherein the traversal of the nested graphs (201, 202) is carried out using a depth-first traversal algorithm.Processing system (300) configured to perform an analysis of an electrical structure (100) of an aircraft (10), the electrical structure (100) comprising equipment (101, 102, 103, 104, 105) interconnected by cables, the processing system (300) being in the form of electronic circuitry configured to: - construct (400) a digital representation in the form of nested graphs (201, 202) of the electrical structure (100), a first graph (201) representing the electrical structure (100) by first nodes (210, 211, 212, 213, 214, 215, 216) and first arcs (110, 111, 112, 113, 114, 115), the first arcs (110, 111, 112, 113, 114, 115) representing the cables of the electrical structure (100), the first nodes (210, 211, 212, 213, 214, 215, 216) representing the equipment (101, 102, 103, 104, 105) of the electrical structure (100) interconnected by the cables,and a second graph (202) representing an internal interconnection structure between at least one input and at least one output of the equipment (102) which has an internal interconnection structure among the equipment (101, 102, 103, 104, 105) of the electrical structure (100), second arcs (241, 242, 243) representing interconnections of the internal interconnection structure between inputs and outputs, second nodes (222, 223, 232, 233, 234) representing the inputs and the outputs, the, first graph (201) being obtained from contextual data (411) relating to the electrical structure (100) and each second graph (202) being obtained from a generic model (412) associated with a type of equipment to which the equipment (102) in question corresponds; and - carry out the analysis by performing a search (404) for equipotentials in the digital representation by browsing the nested graphs (201, 202); wherein the analysis relates to a diagnosis of a fault or breakdown in the electrical structure (100) of the aircraft (10), identifying at which location in the electrical structure the fault or breakdown appears to be present, taking into account the length of wiring in the first graph and the interconnections in each second graph, the processing system being such that on the basis of prior steps consisting in carrying out (402) a reflectometry operation on the electrical structure (100) from a termination point or an input of said equipment (101, 102, 103, 104, 105) or from an output of said equipment (101, 102, 103, 104, 105), and in determining by means of the reflectometry operation at what distance in the electrical structure (100) a break exists in relation to said termination point or to said input of the equipment (101, 102, 103, 104, 105) in question or at said output of the equipment (101, 102, 103, 104, 105) in question, the electronic circuitry is further configured to perform the search for equipotentials from the node corresponding to said termination point or said input of the equipment (101, 102, 103, 104, 105) in question or said output of the equipment (101, 102, 103, 104, 105) in question.

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