Abstract:
a plurality of RFIDs is installed on aircraft or other structure. The RFIDs can query one another upon original installation and in response to predetermined event detection, and determine their relative locations within a mesh. The determined location data and other information are stored within the respect memories of the RFIDs. The stored data can be later accessed and used in analyzing damage or structural failure of the aircraft. Corrective measures are thus expedited because before-and-after structural comparisons can be readily made, with or without reference to original engineering data for the aircraft.

Description:
FIELD OF THE DISCLOSURE 
       [0001]    The field of the present disclosure relates to aircraft instrumentation, and more specifically, to automatically detecting and reporting damage and related structural data for an aircraft by way of a mesh of radio frequency identification devices. 
       BACKGROUND OF THE DISCLOSURE 
       [0002]    Aircraft occasionally sustain damage that is overlooked. In rare cases, stress and the resulting material fatigue can worsen. Once damage is reported, repair team personnel often expend a considerable amount of time locating, retrieving and analyzing structural and design data for an aircraft. Such retrieval and analysis can require many days or weeks, resulting in protracted “down time” for the aircraft. Additionally, analysis and determination of corrective measures requires that the necessary structural and design information be accessible in the first place. Therefore, improved damage detection and reporting, as a well as ready access to necessary data, would have great utility. 
       SUMMARY 
       [0003]    Damage and other structural failures are detected and represented by data stored within the memories of RFIDs installed within an aircraft or on another structure. Data stored therein can be retrieved at a later time and analyzed towards determining corrective actions. Structural trouble detection and correction is thus expedited by the present teachings. 
         [0004]    In one implementation, a system includes a structure and a plurality of radio frequency identification devices (RFIDs) supported by the structure. At least one of the RFIDs is configured to determine a designation and a location of at least one other RFID proximate thereto by way of wireless signals. 
         [0005]    In another implementation, an aircraft includes one or more structural elements. The aircraft further includes a plurality of radio frequency identification devices (RFIDs) supported at respective locations by the one or more structural elements. The plurality of RFIDs define respective nodes of a mesh. At least one of the RFIDs includes a memory and is configured to determine a designation and a location of at least one other RFID proximate thereto within the mesh by way of wireless signals. The at least one RFID is also configured to store the designation and the location of the at least one other RFID in the memory. The at least one RFID is further configured to transmit at least some information stored in the memory by way of wireless signals. 
         [0006]    In yet another implementation, a method includes providing first and second radio frequency identification devices (RFIDs). The first RFID includes a memory. The method also includes determining a designation and a location of the second RFID by way of wireless signals, wherein the determination is made by the first RFID. The method also includes storing the designation and the location of the second RFID in the memory of the first RFID. 
         [0007]    The features, functions, and advantages that are discussed herein can be achieved independently in various embodiments of the present disclosure or may be combined various other embodiments, the further details of which can be seen with reference to the following description and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    Embodiments of systems and methods in accordance with the teachings of the present disclosure are described in detail below with reference to the following drawings. 
           [0009]      FIG. 1  is a partial cutaway view of an aircraft according to one operational environment; 
           [0010]      FIG. 2  is a perspective view depicting an illustrative RFID mesh according to one implementation; 
           [0011]      FIG. 3  is table depicting illustrative data according to one implementation; 
           [0012]      FIG. 4  is an diagrammatic view depicting an RFID mesh in accordance with one implementation; 
           [0013]      FIG. 5  is a flow diagram depicting a method in accordance with one implementation; 
           [0014]      FIG. 6  is a block diagrammatic view depicting an RFID in accordance with one implementation. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    The present disclosure introduces systems and methods for implementing a damage and/or structural failure detection system within an aircraft or other entity. Many specific details of certain embodiments of the disclosure are set forth in the following description and in  FIGS. 1-6  to provide a thorough understanding of such embodiments. One skilled in the art, however, will understand that the disclosure may have additional embodiments, or that the disclosure may be implemented without several of the details described in the following description. 
         [0016]    Illustrative Operating Environment 
         [0017]      FIG. 1  is a partial cutaway view of an aircraft  100 . The aircraft  100  is illustrative and non-limiting with respect to the present teachings. The aircraft  100  includes a structure  102  comprising a plurality of structural elements  104 . The structural elements  104  collectively define a framework or “skeleton” for the aircraft  100 . In particular, structural elements  104  that are oriented fore-to-aft (i.e., longitudinally) with respect to the overall aircraft are referred to as stringers  106 . Structural elements  104  that extend circumferentially (i.e., about the longitudinal axis) are referred to as frame elements  108 . The structure  102  further includes a plurality of skin panels  110  that are respectively joined or bonded to the structural elements  104 . 
         [0018]    The stringers  106 , frame elements  108  and skin panels  110  are typically—but not necessarily—formed of aluminum alloys. However, other materials can also be used for the respective elements  106 ,  108  and  110  of the structure  102 . In any case, the aircraft  100  includes skin panels  110  mechanically bonded to a frame-like structure  102  so as to define an enclosed interior volume or cabin space. 
         [0019]    During normal flight operations, the various structural aspects of the aircraft  100  will shift a minimal amount. In the event of damage due to collision, mechanical fatigue, weld or joint failure, etc., one or more structural aspects (frame members, skin panels, etc.) will be deformed and/or displaced relative to their original conditions or locations. Thus, for example, if a weld at one end of a stringer  106  fails, then that particular stringer  106  is likely to shift in position relative to other stringers  106 , frame elements  108  and/or skin panels  110  proximate thereto. Similar changes can also be expected when two or more structural elements are involved. 
         [0020]    If the relative positions of most or all structural elements are determined at some original time (i.e., newly assembled state), and then their relative positions compared at some future time, any change in those relative positions can be used to detect and analyze damage, fatigue, etc. sustained by the aircraft  100 . Furthermore, if the geometry (i.e., dimensions, planar or curved surface form, etc.) of individual structural elements—such as respective skin panels—can be determined at an original time, and then compared to the geometry of that element at some future time, than deformation (e.g., bending or denting) of that structural element can be detected and analyzed. In any case, the capacity to detect changes in the structural form  102  of aircraft  100  relative to a previously determined data set is germane to the present teachings. 
         [0021]    Illustrative Mesh 
         [0022]      FIG. 2  is a perspective view depicting a structural element  200  according to an illustrative implementation of the present teachings. The structural element  200  is a skin panel  202  of an aircraft (e.g.,  100 ) defined by a curved surface geometry. For purposes of illustration, it is assumed that the skin panel  202  is formed of 2024 aluminum alloy. However, it is to be understood that the skin panel  202  is illustrative in nature, and that the particular geometry and/or constituency thereof are neither critical to nor limiting of the present teachings. The skin panel  202  is understood to be in new condition and form. 
         [0023]    The skin panel  202  supports a plurality of radio frequency identification devices (RFIDs)  204 . The RFIDs  204  are supported by and bonded to the skin panel  204  in an arrangement defining a mesh  206 . The mesh  206  is defined such that each RFID  204  is located at a respective vertex (i.e., node) thereof. Thus, the mesh  206  is a conceptual construct, representative of the arrangement of the respective RFIDs  204  relative to one another. The mesh  206  can be considered to comprise numerous triangular finite elements  208 , each defined by a triad of particular RFIDs  204 . Any particular RFID  204  can define a node of one or more finite elements  208 . Thus, as depicted, the mesh  206  is inclusive of thirteen RFIDs  204  defining sixteen finite elements  208 . It is further noted that the particular placement of the RFIDs  204  and the finite elements  208  defined thereby is/are arbitrary in nature, and that other placement schemes and/or mesh constructs (i.e., conceptual connections between vertices) can also be defined and used. In any case, the mesh  206  is representative of the dimensions and surface curvature—the original physical state—of the skin panel  202 . 
         [0024]    The RFIDs  204  are respectively configured to communicate with each other and with external entities by way of wireless signals. Each RFID  204  is configured to determine the relative location of other RFIDs  204  proximate thereto (i.e., neighboring nodes) within the mesh  206 . Each RFID  204  is further configured to store the determined relative locations in an internal memory for future reference. The location determinations can be related in 2-space (e.g., x,y) or 3-space (e.g., x,y,z) relative to the particular RFID  204  making the determination. Such determinations can be made, for example, using time-of-flight analysis, Doppler shift analysis, phase shifting analysis, or other methods involving wireless signals for determining relative location in terms of direction and distance (i.e., spatial vectors). The internal memory of each RFID  204  can be non-volatile such that information can be stored therein without a continual drain on power resources (internal or external). Further elaboration on the resources and information storage of the RFIDs  204  is provided hereinafter. 
         [0025]    Illustrative Data Store 
         [0026]      FIG. 3  depicts a table  300  including data stored within a memory of particular RFID according to an illustrative implementation. The table  300  includes particular information and order of storage. However, it is to be understood that certain information can be omitted, and/or other information included and stored as depicted or in another order, within respective data slots according to other implementations. Thus, the table  300  is illustrative and non-limiting with respect to the present teachings. Certain aspects of the table  300  will be described with reference to the RFID mesh  400  of  FIG. 4  in the interest of clarity. 
         [0027]    The table  300  includes a unique tag designation, or serial number,  302 . For purposes of non-limiting illustrations, it is assumed that the designation  302  corresponds to the RFID  402  of  FIG. 4 . The designation can include any sequence of alphanumeric characters, symbology, and/or other suitable information. Table  300  also includes a craft designation  304 . The craft designation  304  corresponds to the unique identity of an aircraft in which the RFID of table  300  is installed. The craft designation  304  can include any suitable identifying information (serial numbers, model numbers, etc.). For purposes of the ongoing example, it is assumed that the RFID  402  is installed within a particular aircraft owned by a commercial air carrier. 
         [0028]    The table  300  also includes general location information  306 . The general location  306  can be the designation for a particular structural element of the corresponding aircraft and can be keyed to an overall designation plan for such elements. As depicted, the RFID  402  is installed on a particular skin panel. The table  300  includes a material type or reference number  308  for the element supporting the RFID. The material reference can refer to a metallic alloy, synthetic composite material, etc. In any case, the material type  308  provides engineers and other personnel with structural data that can be used during future analysis. 
         [0029]    The table  300  includes drawing reference number(s)  310 . The drawing reference(s)  310  can include any information keyed to original plans or drawings corresponding to the installed location of the corresponding RFID (e.g.,  402 ). In this way, engineers can refer to these numbers or identifying marks when seeking original and/or amended technical information regarding the aircraft (or other vehicle or structure) in which the RFID  402  is mounted. The table  300  also includes installation date  312 . The installation date  312  can include calendar date information, time of day, or any other similar data corresponding to the mounting and/or original activation of the RFID  402  within an aircraft or other structure. Any suitable formatting, time zone-related information, universal time and/or date, etc., can be stored under installation date  312 . The table  300  also includes a last event date  314 . The last event date  314  can include calendar date information, time of day, or any other similar data corresponding to the most recent occurrence of a predefined (i.e., predetermined) event detected by the RFID  402 . Such predetermined events can include, for example, query of the RFID by wireless signals, detection of a mechanical shock in excess of a selected threshold, detection of vibration in excess of a selected threshold, etc. Other predetermined events can also be defined and used. Any suitable formatting, time zone-related information, universal time and/or date, etc., can be stored under last event date  314 . 
         [0030]    The table  300  further includes first origin data  316 . The first origin data  316  corresponds to information determined in regard to another RFID adjacent to, or proximate, the corresponding RFID storing the table  300 . For purpose of ongoing example, it is assumed that the first origin data  316  corresponds to a wireless query of the RFID  404  within mesh  400  at the time recorded under installation date  312 . The first origin data  316  includes a (unique) designation for RFID  404 , as well as the relative location of RFID  404  with respect to RFID  402 . The location data can be provided as any units appropriate to the coordinate system employed such as, for example, inches, feet, millimeters, centimeters, etc. Other units can also be used. The location data within first origin data  316  refers to the 3-space location of the RFID  404  relative to RFID  402 . As depicted, RFID  404 , as determined at the time of installation, was located 20 millimeters by 20 millimeters by 0 millimeters from RFID  402  in the context of a 3-dimensional Cartesian coordinate system (i.e., x,y,z). Other locating systems using appropriate units can also be employed (e.g., spherical coordinates, polar coordinates, etc.). 
         [0031]    The table  300  further includes first last-event data  318 . The last-event data  318  includes the designation for RFID  404  (i.e., the RFID determined at time of installation date  312 ) for verification purposes, and the relative location of RFID  404 , as determined by wireless signals at the time of the last event date  314 . Thus, the location data recorded (stored to memory) under  318  can be compared to the location data recorded under first origin data  316  to determine if the RFID  404  has been displaced (e.g., due to collision, fatigue, joint failure, etc.). Coordinates (e.g., x,y,z, etc.) consistent with those of the first origin data  316  can be stored under  318 . As depicted, for purposes of non-limiting example, the information “UNCHANGED” is recorded at  318  to indicate that no shift in relative position for RFID  404  has been determined. 
         [0032]    The table  300  further includes second, third and fourth origin data  320 ,  324 , and  328 , respectively, corresponding to other RFIDs adjacent to RFID  402  in the mesh  400 . As depicted data  320 ,  324  and  328  correspond to RFIDs  406 ,  408  and  410 , respectively. Each of the stored data  320 ,  324  and  328  includes a unique designation for the corresponding RFID, as well as the originally determined relative location of that RFID in 3-space Cartesian coordinates, as determined at installation date  312 . The table  300  further includes second, third and fourth last-event data  322 ,  326 , and  330 , respectively, corresponding to RFIDs  406 ,  408  and  410 . The last-event data  322 ,  326  and  330  include the designation and relative location of the RFIDs  406 ,  408  and  410 , respectively, as determined at the last event date  314 . As depicted, the second last-event data  322  for RFID  406  is “UNCHANGED”, indicating that no shift in relative location was determined (i.e., detected, or calculated). In contrast, the third and fourth last-event data  326  and  330  indicate that RFIDs  408  and  410  have shifted by respective amounts to new relative locations, as depicted by  408 ′ and  410 ′. Thus, as depicted, RFID  408  has been displaced by (−4 mm, 2 mm, 1 mm) relative to its original location as determined at date  316 . In turn, RFID  410  has been displaced by (−2 mm, 4 mm, 2 mm) relative to its original location as determined at date  316 . The origin and last-event data can be compared and analyzed so as to calculate (i.e., estimate) the location and extent of damage or fatigue suffered by the structural element (i.e., skin panel  157 ) supporting the mesh  400 . 
         [0033]    The table  300  includes origin and last-event data corresponding to four distinct RFID devices adjacent to the RFID device of the table  300  (i.e., RFID  402 ). However, the table  300  is an illustrative and non-limiting implementation, and other tables consistent with the present teachings can include data corresponding to any practical number of adjacent RFID devices. It is further understood that every RFID within a mesh (e.g.,  402 ,  404 ,  406 ,  408  and  410 , etc.) includes a corresponding table according to the present teachings. In this way, the respective tables of data for all of the RFID devices installed on a particular craft or structure collectively represent the original and last-event geometric condition of the craft (or structure) as a finite element mesh. The overall scale of such a mesh, in terms of typical or average finite element size, is determined by the number and spacing of the RFIDs installed. Thus, both the quantity of stored data and the physical resolution thereof are selectively determinable. 
         [0034]    Illustrative Method 
         [0035]      FIG. 5  is a flow diagram  500  depicting a method in accordance with one implementation of the present teachings. The diagram  500  depicts particular method steps and order of execution. However, it is to be understood that other implementations can be used including other steps, omitting one or more depicted steps, and/or progressing in other orders of execution without departing from the scope of the present teachings. 
         [0036]    At  502 , an RFID is installed on a structural element of an aircraft. For purposes of non-limiting illustration, it is assumed that the RFID is bonded to a stringer (e.g.,  104 ) of a commercial airliner. It is further assumed that numerous other RFIDs have been similarly installed on the same or other structural elements within the same aircraft such that the whole aircraft structure, or select portions thereof, is/are represented by way of one or more meshes defined by the RFIDs. In another implementation, the RFIDs are installed on another structure or entity (marine vessel, building structure, automobile, bridge, etc.). It is further assumed that the RFID is provided with certain initial information from an external entity. Such provision can be made by wireless signals, direct cabling, optical signal communication, a temporarily wired connection, etc. The initial information can include any suitable data such as, for non-limiting example, a unique designation (identity) of the RFID, an identity of the supporting structure or craft, information keyed to engineering data regarding the structure or craft, etc. Furthermore, one (or more) of the RFIDs may be installed at a location (arbitrarily) designated as an origin or master reference point (i.e., 0,0,0) location on the aircraft such as, for example, the inside geometric center of the nose, etc. 
         [0037]    At  504 , the newly installed RFID queries neighboring RFIDs within the associated mesh by way of wireless signals and stores correspondingly determined original data within a memory. For example, such stored data may define a table  300  or the like according to the present teachings. The stored data can include, as non-limiting examples, respective designations and relative locations of the neighboring RFIDs, etc. At this point, the RFIDs and their respective data collectively represent the initial geometric condition of the aircraft or other structure on which they are installed. 
         [0038]    At  506 , the RFID detects a predetermined event. The predetermined event is assumed to occur at some future time (minutes, days, years, etc.) with respect to the installation and determinations of  502  and  504  above. The predetermined event can be defined by any suitable criteria such as, for non-limiting example, a wireless instruction to query the mesh of RFIDs, the detection of mechanical shock, etc. Other predetermined events can also be defined and used. In any case, the RFID queries at least the previously determined neighboring RFIDs and determines/verifies their respective designations and relative locations. The event-related data determinations are now stored to memory within the RFID. One or more other RFIDs within the associated mesh can also perform similar query, determination and data storage operations responsive to detecting the predetermined event. 
         [0039]    At  508 , the RFID communicates (i.e., transmits) some or all of the data stored within its memory to another entity by way of wireless signals. The data communication can be performed, for example, in response to a wireless query by the other entity, in response to the same or a different predetermined event as that of  506  above, etc. The communicated data can include, for example, origin and last-event data corresponding to various RFIDs of the mesh, the installed date of the RFID, the date of the last-event detection, or any or all other data stored in memory. One or more other RFIDs within the associated mesh can also perform similar data communication (i.e., upload) operations. The data can be communicated, for example, to a flight computer of the aircraft, to repair personnel by way of satellite communications equipment, etc. 
         [0040]    At  510 , the data communicated from the one or more RFIDs is analyzed to determine if damage or other failure has been sustained by the aircraft (or structure), and corrective actions are determined, if necessary. Such analysis can include, for example, finite element modeling, cross-referencing of remotely stored engineering data, consideration of materials properties, etc. Any suitable analytic techniques can be employed with respect to the data gleaned from the RFIDs and/or other resources. 
         [0041]    Illustrative RFID 
         [0042]      FIG. 6  is an illustrative RFID  600  in accordance with the present teachings. The features and resources of the RFID  600  are exemplary and non-limiting in nature, and are intended to provide clear understanding of the present teachings. However, other RFIDs having respectively varying characteristics and resources can also be used in accordance with the present teachings. 
         [0043]    The RFID  600  includes a transceiver  602  coupled to one or more antennas  604 . The transceiver  602  is configured to bi-directionally communicate with other entities external to (distinct from) the RFID  600  by way of wireless signals. While a total of two antennas  604  are depicted, it is to be understood that any suitable number of antennas can be used in accordance with the transceiver  602  so as to query other RFIDs, determine their respective locations via Doppler or phase-shifting principles, etc. 
         [0044]    The RFID  600  also includes a processor  606 . The processor  606  is configured to control various functions and operations of the RFID  600  in accordance with an executable program code. Such a program code can be included within memory (non-volatile or otherwise) of the processor  606 , or stored within a memory  608 , etc. In any case, the overall range of functions and capabilities of the RFID  600  are determined in whole or in part by program code executed by the processor  606 . The RFID  600  includes memory  608 . The memory  608  can be volatile or non-volatile in operation, or a combination of the two, and can be configured to store and retrieve data communicated to and/or determined by the RFID  600  during typical operations (e.g., flow diagram  500 , etc.). The memory  608  can also store a program code for execution by the processor  606 . 
         [0045]    The RFID  600  also includes one or more sensors  610 . The sensor(s)  610  can respectively include any instrumentation configured to detect one or more predetermined events. As non-limiting examples, the sensor(s)  610  can include accelerometers, thermistor or other temperature sensing components, electromagnetic radiation detectors, particle radiation detectors, etc. Other suitable sensor(s)  610  can also be used. 
         [0046]    The RFID  600  further includes energy storage  612  and associated energy conditioning  614 . The energy storage  612  can include any suitable battery, super-capacitor, or other electrical storage element or elements. In turn, the energy conditioning  614  is configured to properly regulate electrical power from and/or to the energy storage  612 . For example, the energy conditioning  614  can be configured to recharge the battery or batteries of energy storage  612  when the RFID  600  is illuminated by (i.e., proximate to) an electromagnetic field of suitable characteristics. As another example, the energy conditioning  614  can control one or more aspects (voltage regulation, over current protection, etc.) of electrical energy being drawn from the energy storage  612  by one or more of the other resources  602 ,  606 ,  608  and/or  610  of the RFID  600 . 
         [0047]    The RFID  600  is illustrative of at least some of the features and resources of an RFID (e.g.,  204 ,  402 - 410 , etc.) according to the present teachings. Other RFIDs having other operative characteristics and/or resources can also be used. 
         [0048]    While specific embodiments of the disclosure have been illustrated and described herein, as noted above, many changes can be made without departing from the spirit and scope of the disclosure. Accordingly, the scope of the disclosure should not be limited by the disclosure of the specific embodiments set forth above. Instead, the scope of the disclosure should be determined entirely by reference to the claims that follow.