Patent Publication Number: US-11030503-B2

Title: Mobile card reader for lightning protection systems

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Patent Application No. 62/630,083, titled “Mobile Card Reader for Lightning Protection Systems” and filed on Feb. 13, 2018, and to U.S. Non-Provisional patent application Ser. No. 16/272,862, titled “Mobile Card Reader for Lightning Protection Systems” and filed on Feb. 11, 2019, the entirety of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     Wind turbines and other structures can be subject to lightning strikes, which have the potential to damage electronic and other components of the structures. For reasons relating to maintenance, insurance, and other considerations, it may be useful to understand the severity of a lightning strike or strikes that have occurred for a particular structure. Assessing strike severity can be complicated, however, due the unpredictability of lightning strikes, the remoteness or general inaccessibility of relevant systems, and other factors. 
     SUMMARY 
     Some embodiments of the disclosure provide a mobile reader system for lightning protection systems that include a magnetic stripe card, with the magnetic stripe card being configured to retain data on a data-storage stripe and to have a portion of the data erased in response to one or more lightning strikes on a structure. A reader body can support a magnetic reader assembly with an output module, the magnetic reader assembly being configured to read the data-storage stripe to output a lightning-indicator signal to the output module. One or more computer-implemented modules can be configured to receive the lightning-indicator signal via an input module in communication with the output module, and to identify, based on analysis of the lightning-indicator signal, an indicator of a maximum current passing through a portion of the structure from the one or more lightning strikes. 
     Some embodiments of the disclosure provide a lightning protection system for a structure that is exposed to one or more lightning strikes. A magnetic stripe card can be configured to retain data on a data-storage stripe and to have a portion of the data erased in response to the one or more lightning strikes. A mobile reader body can support a magnetic reader assembly that includes an output module, the magnetic reader assembly being configured to read the data-storage stripe to output a lightning-indicator signal via the output module. One or more computer-implemented modules can be configured to receive the lightning-indicator signal via an input module of a handheld computing device that is in communication with the output module, and to identify, based on analysis of the lightning-indicator signal, an indicator of a maximum current passing through the structure from the one or more lightning strikes. 
     Some embodiments of the disclosure provide a method of monitoring a structure that is exposed to one or more lightning strikes. A magnetic stripe card can be retrieved from the structure, with the magnetic stripe card being configured to retain data on a data-storage stripe and having had a portion of the data erased in response to the one or more lightning strikes on the structure. The data-storage stripe can be scanned with a mobile reader system to provide a lightning-indicator signal at an output module of the mobile reader system. The lightning-indicator signal can be received, via the output module, at an input module of a mobile computing device. Based on computer-implemented analysis of the received lightning-indicator signal, an indicator can be identified of a maximum current passing through a portion of the structure from the one or more lightning strikes. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of embodiments of the invention: 
         FIG. 1  is a schematic view of a conventional magnetic stripe card and certain data-storage principles thereof; 
         FIGS. 2 through 4  are schematic views of aspects of an installation of a magnetic stripe card with a lightning protection system for a wind turbine, according to an embodiment of the invention; 
         FIG. 5  is an isometric view of the magnetic stripe card of  FIGS. 2 through 4  with a card reader according to an embodiment of the invention; 
         FIG. 6  is a schematic view of certain components of the card reader of  FIG. 5 ; 
         FIG. 7  is a schematic view of a method of using of the card reader of  FIG. 5  with example mobile devices, according to embodiments of the invention; 
         FIG. 8A  is a schematic view of an output from the reader of  FIG. 5  upon reading the magnetic stripe card of  FIGS. 2 through 4  before a lightning strike; 
         FIG. 8B  is a schematic view of an output from the reader of  FIG. 5  upon reading the magnetic stripe card of  FIGS. 2 through 4  after one or more lightning strikes; 
         FIG. 9  is a schematic view of example results from analysis of a magnetic stripe card, relative to physical effects of a lightning strike on the magnetic stripe card, according to an embodiment of the invention; 
         FIGS. 10 and 11  are schematic views of aspects of a method for identifying lightning strikes according to an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. 
     In some embodiments, aspects of the invention, including computerized implementations of methods according to the invention, can be implemented as a system, method, apparatus, or article of manufacture using standard programming or engineering techniques to produce software, firmware, hardware, or any combination thereof to control a computer or other processor device to implement aspects detailed herein. Accordingly, for example, embodiments of the invention can be implemented as a set of instructions, tangibly embodied on a non-transitory computer-readable media, such that a processor device can implement the instructions based upon reading the instructions from the computer-readable media. 
     The term “article of manufacture” as used herein is intended to encompass a computer program accessible from any computer-readable device, carrier (e.g., non-transitory signals), or media (e.g., non-transitory media). For example, computer-readable media can include but are not limited to magnetic storage devices (e.g., hard disk, floppy disk, magnetic strips, and so on), optical disks (e.g., compact disk (CD), digital versatile disk (DVD), and so on), smart cards, and flash memory devices (e.g., card, stick, and so on). Additionally it should be appreciated that a carrier wave can be employed to carry computer-readable electronic data such as those used in transmitting and receiving electronic mail or in accessing a network such as the Internet or a local area network (LAN). Those skilled in the art will recognize many modifications may be made to these configurations without departing from the scope or spirit of the claimed subject matter. 
     Some embodiments of the invention can be implemented as systems and/or methods, including computer-implemented methods. Some embodiments of the invention can include (or utilize) a device such as an automation device, a special purpose or general purpose computer including various computer hardware, software, firmware, and so on, consistent with the discussion below. 
     Certain operations of methods according to the invention, or of systems executing those methods, may be represented schematically in the FIGS. Unless otherwise specified or limited, representation in the FIGS. of particular operations in particular spatial order is not intended to require those operations to be executed in a particular order. Certain operations represented in the FIGS., or otherwise disclosed herein, can be executed in different orders, as appropriate for particular embodiments of the invention. Further, in some embodiments, certain operations can be executed in parallel, including by dedicated parallel processing devices, or separate computing devices configured to interoperate as part of a large system. 
     As used herein in the context of computer implementation, unless otherwise specified or limited, the terms “component,” “system,” “module,” and the like are intended to refer to a computer-related system that includes hardware, software, a combination of hardware and software, or software in execution. For example, a component may be, but is not limited to being, a processor device, a process running on a processor device, an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a computer and the computer can be a component. One or more components (or system, module, and so on) may reside within a process and/or thread of execution, may be localized on one computer, distributed between two or more computers or other processor devices, and/or included within another component (or system, module, and so on). 
     The discussion herein is presented to enable a person skilled in the art to make and use embodiments of the invention. Various modifications to the illustrated embodiments will be readily apparent to those skilled in the art, and the generic principles herein can be applied to other embodiments and applications without departing from embodiments of the invention. Thus, embodiments of the invention are not intended to be limited to embodiments shown, but are to be accorded the widest scope consistent with the principles and features disclosed herein. The following detailed description is to be read with reference to the figures, in which like elements in different figures have like reference numerals. The figures, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of embodiments of the invention. Skilled artisans will recognize the examples provided herein have many useful alternatives and fall within the scope of embodiments of the invention. 
     As noted above, it may be useful to record or otherwise monitor lightning strikes on certain installations, such as wind turbines. In some conventional arrangements, a magnetic stripe card (“MSC”) and an associated stationary reader can be used for this purpose. 
     As illustrated in  FIG. 1 , a conventional MSC  20  can exhibit a characteristic rectangular shape, with a plastic body  22  and a data-storage stripe  24 . In conventional arrangements, as illustrated in  FIG. 1 , the data-storage stripe  24  is divided into three tracks  24   a ,  24   b ,  24   c  that are formed to include iron oxide. By magnetizing the iron oxide into an array  26  of magnetic poles, data of various types can be stored on the MSC  20 . For example, as illustrated in the enlarged view of the track  24   c  and corresponding schematic in  FIG. 1 , binary data  30  can be converted to a binary waveform  32 , which can be expressed by a card-writing device (not shown in  FIG. 1 ) as a temporally varying pattern of magnetic flux  34 . By moving the MSC  20  across the card-writing device in a swipe direction (e.g., as illustrated by arrow  28 ), the magnetic flux  34  can be encoded in the pole arrangement of the array  26  (e.g. in the illustrated arrangement of “N” and “S” poles on the track  24   c ). Generally, the data encoded in the array  26  can then be read using a reversed process. 
     In conventional arrangements for financial data storage (e.g., for credit cards), each of the three tracks on the data-storage stripe  24  are encoded using different respective bit densities and encoding schemes. However, for other applications, other types of encoding and bit densities can be used, as can other numbers or arrangements of tracks. 
     It has been recognized that MSCs can be used to record the magnitude of lightning strikes on structures, such as wind turbines. But conventional approaches to reading the recorded magnitudes from such MSCs can tend to be cumbersome. For example, conventional readers for recorded lightning strikes may be configured to desktop use rather than being usefully portable (e.g., easily transported by hand, in a small pocket or other enclosure, and so on). Further, in some cases, conventional readers can require dedicated power sources or can provide displays and other user interfaces that have relatively minimal utility. For example, some conventional readers may use liquid-crystal display technology and be equipped to display merely the recorded maximum voltage of a lightning strike, without being able to make available other information or to receive customizing user input. Embodiments of the invention can address these and other issues. 
       FIGS. 2 and 3  illustrate the use of a customized MSC  40 , according to an embodiment of the invention, in order to record data regarding lightning strikes on a wind turbine  42 . In the illustrated example installation, the MSC  40  is mounted proximate and perpendicular to a conductor  44  of the wind turbine  42 . The conductor  44  is electrically connected to points on the wind turbine  42  that act as receptors for lightning strikes, such as tip receptors or other strike points (not shown) of a lightning protection system. Accordingly, when lightning  46  strikes the wind turbine  42 , current generated by the strike flows through the conductor  44 , generating a magnetic field  48  (see  FIG. 3 ) in the vicinity of the MSC  40 . 
     Due to electro-magnetic interactions, when the magnetic field  48  is sufficiently strong, it will tend to erase any magnetically encoded data on the MSC  40 . Moreover, the strength of the magnetic field  48  at a given distance from the conductor  44  can be reliably correlated to the magnitude of the current flow through the conductor  44  and, thereby, to the severity (i.e., strength) of the relevant lightning strike. Accordingly, with the MSC  40  oriented generally perpendicularly to the conductor  44 , an approximate magnitude of a lightning strike on the wind turbine  42  can be determined based on identifying a length  50  of a data-storage stripe  52  of the MSC  40  (or of a track thereof) along which data has been erased. Further, because the erasure of data from the data-storage stripe  52  is cumulative for any given installation, the total erased length on a card (e.g., the length  50 ) can be used to approximate the magnitude of the most severe lightning strike of a series of strikes after the initial installation of the MSC  40  (i.e., the lightning strike that causes the largest current to flow through the conductor  44 ). 
     In some embodiments, rather than using the conventional bit density and encoding schemes illustrated in  FIG. 1 , the data-storage stripe  52  of the MSC  40  can be written with a customized data scheme. Customized data schemes can be useful, for example, in order to optimize performance for recording lightning strike severity or to improve card security by increasing the difficulty of copying a particular card. As one example, as illustrated in particular in  FIG. 4 , the MSC  40  is configured with at least one data track on the data-storage stripe  52  having been encoded with a regularly repeating magnetic array that includes the maximum number of alternating magnetic poles that can be maintained on the MSC  40 . This may be useful, for example, in order to maximize the accuracy with which the magnitude of a lightning strike can be determined. In other embodiments, other approaches are possible. 
     In some embodiments, MSCs can be designed to exhibit relatively high resilience to erasure from exposure to magnetic fields. For example, whereas conventional arrangements may employ 2750 oersted cards, the MSC  40  can be configured as a 4000 oersted card. This arrangement can allow the MSC  40  to record a greater range of lightning strike intensities than a conventional MSC. 
     As also discussed above, conventional systems for reading MSCs to assess lightning strikes can be unwieldy, expensive, and relatively non-portable. Further, some conventional systems can rely on proprietary output devices in order to provide relevant data to system users. This can significantly reduce the ability of users to readily evaluate lightning activity for wind turbines, particularly in widely dispersed, numerous, remote locations at which wind turbines are often installed. 
     In contrast, embodiments of the invention can include relatively small, highly portable readers with output modules that are configured to interface input modules of a variety of mobile devices, including consumer smartphones and tablets. Accordingly, by using a reader and a mobile-device module (e.g., mobile app or other software) according to embodiments of the invention, a user can easily check an MSC for evidence of a lightning strike from any number of locations. Further, due to relatively low cost, high portability, and significant interoperability with different mobile devices, some embodiments can allow for users to easily implement widespread monitoring of a very large number of highly dispersed installations. 
     In different embodiments, different output modules can be used, including cellular, Wi-Fi, or other radio-enabled modules, wired modules such as standard audio plugs, and so on. In some embodiments, output modules can include configurable hardware or software modules, such as devices configured as universal asynchronous receiver-transmitters (“UARTs”). Similarly, different input modules can be used, including cellular, Wi-Fi, or other radio-enabled modules, wired modules such as standard audio input ports, configurable hardware or software modules, and so on. 
     In some examples presented below, wired audio plugs and input ports are discussed in particular. Unless otherwise specified, discussion of audio plugs and input ports below can be applied to other types of input and output modules capable of analog or digital communication, including UART modules and others. 
     An example mobile reader  60  according to one embodiment of the invention is illustrated, during operation with the MSC  40 , in  FIG. 5 . In particular, the mobile reader  60  includes a portable body  62  that encloses a magnetic head assembly  64  (see  FIG. 6 ). As detailed below, the portable body  62  can be used in combination with a mobile device in order to extract lightning strike data from the MSC  40  or other relevant MSC. 
     Various types of magnetic head assemblies can be used to read magnetic data from an MSC. In the illustrated embodiment, as shown in particular in  FIG. 6 , the magnetic head assembly  64  includes a magnetically permeable toroidal core  66  that is wound with a coil of conductive wire  68 . A gap  70  is provided in the core  66 , and can be configured an air gap or can be filled with a diamagnetic material, such as gold. With the assembly  64  thus arranged, as a magnetized material, such as the data-storage stripe  52 , is moved past the gap  70  a resultant temporally changing magnetic field  72  induces a magnetic flux in the core  66 . This flux, in turn, induces a current to flow in the wire  68 , which can be conducted by the wire  68  to an audio plug  74  that is also attached to the portable body  62  (see also  FIG. 5 ) in order to generate an electrical waveform signal at the audio plug  74 . In the embodiment illustrated, the magnetic head assembly  64  further includes a resistor  76 , as may be required by some mobile-device architectures. 
     As also discussed above, embodiments of the invention can be configured for use with a variety of mobile devices, such as tablets, smartphones, laptop computers, and so on. This may, for example, usefully allow users to utilize a variety of devices, including personal mobility devices, to assist in lightning monitoring, including at locations that may not readily provide a plug-in or other power supply. Further, for some devices, inherent connectivity (e.g., cellular capability) can allow for lightning strike data to be readily and immediately transmitted to other locations, such as for remote storage, remote monitoring, cloud-based or other analysis, and so on. 
     In this regard, for example, as illustrated in  FIG. 7 , a user can insert the audio plug  74  into a headphone jack or other audio port of a mobile device, such as a tablet  78  or a smartphone  80 . Accordingly, as the MSC  40  is slid past the by the magnetic head assembly  64 , voltage changes in the audio plug  74  corresponding to the noted waveform can be received as an “audio” signal at the tablet  78  or the smartphone  80 . Usefully, although such a signal may have a relatively small magnitude, such as on the order of micro-Volts (μV), appropriate audio ports for mobile devices can generally include or be connected to appropriate modules, such as operational amplifiers or other amplifying circuitry, that may allow the signal to be received and usefully processed. 
     Once received in the relevant mobile device, a signal from reader  60  that represents data from the MSC  40 , can be processed, including in order to identify whether a lightning strike has been recorded, and the magnitude thereof. Generally, for example, software or hardware modules within the mobile device, or within a computing system that is in wireless (or other) communication with the mobile device, can be configured to decode, sample, and otherwise process the received waveform in order to identify a relevant indicator of the magnitude of any lightning strike. For an instance of the MSC  40 , for example, that was encoded with a regularly repeating magnetic array of the maximum possible number of alternating magnetic poles (see also  FIG. 4 ), relevant software or hardware modules can be configured to execute computer-implemented methods to identify and count a total number of peaks or troughs (or both) in the waveform received from the mobile reader  60 . In other embodiments, other processing can be employed. 
     For the MSC  40  or another similar MSC, once a total number of peaks or troughs have been identified, this total can be compared with an expected total number of peaks or troughs in order to determine what portion of the data-storage stripe  52  has been erased. For example, software modules within a mobile app on the smartphone  80  or the tablet  78  can be configured to determine, based on an identified total of peaks or troughs in a signal and an expected (e.g., maximum possible) number of peaks or troughs, a length of a particular track of the data-storage stripe  52  (see, e.g.,  FIG. 3 ) that has been erased. 
     As noted above, the identified erased portion of the MSC  40  can then be directly correlated to the magnitude of current that was generated in the conductor  44  (see, e.g.,  FIG. 3 ) by the most severe lightning strike at the wind turbine  42 . For example, based on the example waveform  82  illustrated in  FIG. 8A , relevant software may identify that an entire signal from the MSC  40  includes regular peaks and troughs, which may indicate no portion of the data-storage stripe  52  has been erased. The software may accordingly determine that the MSC  40  was not exposed to significant magnetic flux when installed in the relevant lightning protection system and, correspondingly, that the wind turbine  42  was not subject to a lightning strike at all. In contrast, based on the example waveform  84  illustrated in  FIG. 8B , relevant software may identify that the total number of peaks and troughs in the waveform correspond to approximately half of the expected number of peaks and troughs (e.g., as represented in the waveform  82  of  FIG. 8A ). This may in turn be determined to indicate that approximately half of the data-storage stripe  52  has been erased, and a magnitude of a lightning strike can be determined accordingly. 
     In different implementations, modules for a relevant mobile device (or remote system) can be configured to provide different degrees of accuracy in identifying and counting a total number of peaks or troughs in a received waveform. An example implementation is illustrated in the graph in  FIG. 9 , which presents data points relative to a vertical axis that indicates a total number of identified magnetic poles (e.g., as represented by a total number of waveform peaks or valleys) and relative to a horizontal axis that indicates a total distance on a data-storage stripe that has been erased. As illustrated by a trend-line  90 , a generally linear correlation can be established between identified magnetic poles and the distance of data that was erased from a relevant MSC. Further, as also noted above, the distance of erased data can be readily correlated to the magnitude of the strongest lightning strike to which the MSC was exposed (see also  FIGS. 2 through 4 ). 
     In some implementations, as indicated by the somewhat scattered data points in  FIG. 9 , software modules of a mobile device for identifying and counting waveform contours can be configured to exhibit less than absolute accuracy (i.e., relatively substantial uncertainty) with regard to the actual number of waveform peaks or valleys in a given signal. Usefully, this can allow for faster operation of the software and of the relevant system in general once a waveform from a scanned MSC has been received. Further, through the use of the expected trend-line  90 , the disclosed system can obtain a relatively reliable measure of the actual distance of erased data (and thereby the magnitude of a lightning strike), even with imperfect accuracy in identifying and counting the relevant number of poles. 
     In some implementations, aspects of the invention can be implemented through a method, certain operations of which can be executed by one or more computing devices, including via software or hardware modules or combinations thereof implemented, in whole or in part, on mobile devices such as the tablet  78  or the smartphone  80  illustrated in  FIG. 7 . As illustrated in  FIG. 10 , for example, a method  100  can include encoding  102  an MSC with reference data, such as by configuring a data-storage stripe of the MSC with a maximum number of alternating magnetic poles  104  (see also, e.g.,  FIG. 4 ). The MSC can then be subjected  106  to one or more lightning strikes, such as through the use of the system illustrated in  FIGS. 2 and 3 . If the MSC has been subjected  106  to a lightning strike, or even if a lightning strike is merely suspected, a mobile reader, such as the mobile reader  60  illustrated in  FIGS. 5 through 7 , can be engaged  108  with an input module (e.g., an audio port) of a mobile device. For example, an wired output module of the mobile reader, such as an audio plug, can be engaged with mechanical (or other) connection to a relevant mechanical port of the mobile device, or a wireless output module can be engaged by establishing a communications link between the output module and the relevant input module. 
     The MSC can then be scanned  110  using a mobile reader and an output from the scanning  110  can be converted  112  to an indicator of a magnitude of the lightning strikes. In some embodiments, as also discussed above, the resulting indicator can be an indicator  114  (e.g., a value in kilo-Amperes) of a maximum current to which the MSC was exposed due to a strongest of one or more lightning strikes on a relevant structure. 
     As also discussed above, in some implementations, converting  112  the output from the scanning  110  of a MSC with a mobile reader can be implemented in various ways, via processing of signals received via an audio input port of a mobile device. As illustrated in  FIG. 12 , for example, a mobile device can be configured to receive  120  an electrical signal (e.g., a voltage waveform) at an input module (e.g., an audio input port) of the mobile device. Software or hardware modules associated with (e.g., installed on) the mobile device can then process the received  120  signal in order to identify and count  122  a number of peaks or troughs (or both) of the signal. The same or different modules can then correlate  124  the counted  122  number of peaks or troughs to a portion (e.g., a length) of a data-storage stripe that has been erased, and can correlate  126  that portion to a maximum current to which the MSC has been exposed. Finally, the same or different modules can report  128  the maximum current or another indicator for the measured lightning strike(s), including by using a display of the mobile device (e.g., a display of the smartphone  80  or the tablet  78  of  FIG. 7 ) or by using communication devices of the mobile device to transmit relevant data to another location. 
     Thus, embodiments of the invention can provide an improved system or method for identifying and measuring lightning strikes on structures, particularly wind turbines. For example, through the provision and use of a portable reader that can operate with a variety of conventional mobile devices, embodiments of the invention can allow users to quickly and economically obtain data regarding lightning strikes, even at relatively remote locations that may not have ready access to power. Further, because embodiments of the invention can be used with cellular-enabled devices, users may be able to rapidly (e.g., immediately) transmit and analyze the data obtained, including in combination with data from multiple installations that may be located at substantial distances from each other. 
     The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.