Abstract:
A system, method, and apparatus for detecting and reporting track defects while a train is in motion on railway tracks includes at least one defect sensor configured to sense an acceleration of at least a portion of the train; and at least one computer-readable medium. The at least one computer-readable medium comprises program instructions that, when executed by at least one processor, cause the at least one processor to: detect, while the train is in motion on the railway tracks, at least one track defect in the railway tracks based at least partially on the acceleration of the at least a portion of the train; and generate track defect data based at least partially on a location of the train when the at least one track defect is detected.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to track defect detection and, in particular, a system, method, and apparatus for detecting and reporting track defects in a track network. 
     2. Description of Related Art 
     Through regular use and environmental influences, railroad track structures experience wear, damage, and movement of ballasts, ties, and other components that result in track defects, reduced ride quality, and potentially unsafe conditions. Such track defects may cause passenger discomfort and, in some instances, derailments and other undesired effects. 
     Thus, there is a need for a system, method, and apparatus to detect and report track defects to alert maintenance and repair crews, to initiate speed restriction bulletins, and/or to otherwise log and track the track defects in a track network. 
     Existing approaches to identifying and locating track defects and/or anomalies are described in U.S. Pat. No. 5,791,063 to Kesler et al., which is directed to a method and apparatus for locating a track defect, and U.S. Pat. No. 5,987,979 to Bryan, which is directed to a method and apparatus for monitoring anomalies in a railway system to predict future track behavior. The Kesler patent compares profiles of track geometry parameters to identify a position of a defect or vehicle along the track, and the Bryan patent predicts defects by analyzing data collected over time. However, the systems in both of the Kesler patent and the Bryan patent specifically rely upon GPS coordinates to provide location information, and the resulting defect or anomaly determinations are limited in accuracy and real-time identification. 
     SUMMARY OF THE INVENTION 
     Generally, the present invention provides a system, method, and apparatus for detecting and reporting track defects based at least partially on a vertical, lateral, or angular acceleration, movement, and/or tilt of a train or a portion of a train while the train is traveling over railway tracks. 
     According to one preferred and non-limiting embodiment of the present invention, provided is a track defect detection system for detecting track defects while a train is in motion on railway tracks, comprising: at least one defect sensor configured to sense an acceleration of at least a portion of the train; and at least one computer-readable medium comprising program instructions that, when executed by at least one processor, cause the at least one processor to: detect, while the train is in motion on the railway tracks, at least one track defect in the railway tracks based at least partially on the acceleration of the at least a portion of the train; and generate track defect data based at least partially on a location of the train when the at least one track defect is detected. 
     According to another preferred and non-limiting embodiment of the present invention, provided is a system for detecting and reporting track defects while a train travels over railway tracks, comprising a track defect detection device comprising at least one defect sensor; and a locomotive computer in communication with the track defect detection device, the locomotive computer configured to: detect a track defect based at least partially on an acceleration sensed by the at least one defect sensor while the train is in motion; generate track defect data comprising a magnitude and location of the track defect; and communicate at least a portion of the track defect data to a remote server. 
     According to a further preferred and non-limiting embodiment of the present invention, provided is a method of detecting track defects in railway tracks while a rail vehicle is in motion, comprising: monitoring an acceleration of at least a portion of a rail vehicle while the rail vehicle is in motion; determining, with at least one processer, if a track defect exists on the railway tracks based at least partially on the acceleration; and generating track defect data comprising a location of the track defect and at least one of the following: a magnitude of the track defect, a severity of the track defect, the acceleration, a vertical acceleration, a lateral acceleration, an angular acceleration, a velocity of the rail vehicle, a characteristic of the track defect, a type of the track defect, or any combination thereof. 
     According to another preferred and non-limiting embodiment of the present invention, provided is a computer program product comprising at least one non-transitory computer-readable medium including program instructions that, when executed by at least one computer including at least one processor, causes the at least one computer to: monitor an acceleration of at least a portion of a rail vehicle while the rail vehicle is in motion; determine if a track defect exists on the railway tracks based at least partially on the acceleration; and generate track defect data comprising a location of the track defect and at least one of the following: a magnitude of the track defect, a severity of the track defect, the acceleration, a vertical acceleration, a lateral acceleration, an angular acceleration, a velocity of the train, a characteristic of the track defect, a type of the track defect, or any combination thereof. 
     These and other features and characteristics of the present invention, as well as the methods of operation and functions of the related elements of structures and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention. As used in the specification and the claims, the singular form of “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a schematic diagram of one embodiment of a system for detecting and reporting track defects according to the principles of the present invention; 
         FIG. 2  illustrates a schematic diagram of another embodiment of a system for detecting and reporting track defects according to the principles of the present invention; 
         FIGS. 3   a  and  3   b  illustrate step-diagrams for embodiments of a system and method for detecting and reporting track defects according to the principles of the present invention; 
         FIG. 4  illustrates an interface including visualized track defect data according to the principles of the present invention; 
         FIG. 5   a  illustrates a defect determination chart of track defect magnitude over time according to the principles of the present invention; 
         FIG. 5   b  illustrates a defect magnitude chart of vertical acceleration over train velocity according to the principles of the present invention; and 
         FIG. 6  illustrates a track defect data report according to the principles of the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     For purposes of the description hereinafter, the terms “upper”, “lower”, “right”, “left”, “vertical”, “horizontal”, “top”, “bottom”, “lateral”, “longitudinal” and derivatives thereof shall relate to the invention as it is oriented in the drawing figures. However, it is to be understood that the invention may assume various alternative variations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the invention. Hence, specific dimensions and other physical characteristics related to the embodiments disclosed herein are not to be considered as limiting. 
     As used herein, the terms “communication” and “communicate” refer to the receipt, transmission, or transfer of one or more signals, messages, commands, or other type of data. For one unit or device to be in communication with another unit or device means that the one unit or device is able to receive data from and/or transmit data to the other unit or device. A communication may use a direct or indirect connection, and may be wired and/or wireless in nature. Additionally, two units or devices may be in communication with each other even though the data transmitted may be modified, processed, routed, etc., between the first and second unit or device. For example, a first unit may be in communication with a second unit even though the first unit passively receives data, and does not actively transmit data to the second unit. As another example, a first unit may be in communication with a second unit if an intermediary unit processes data from one unit and transmits processed data to the second unit. It will be appreciated that numerous other arrangements are possible. Any known electronic communication protocols and/or algorithms may be used such as, for example, TCP/IP (including HTTP and other protocols), WLAN (including 802.11 and other radio frequency-based protocols and methods), analog transmissions, Global System for Mobile Communications (GSM), and/or the like. 
     In one preferred and non-limiting embodiment of the present invention, provided is a system, method, and apparatus for detecting and reporting track defects while a train is in motion. Track defects, including but not limited to wear, damage, track obstacles and obstructions, and the movement or shifting of ballasts, ties, and other railroad track structures, are detected based at least partially on a vertical, lateral, or angular acceleration, movement or force, and/or tilt of a train or a portion of a train. It will be appreciated that a track defect may include defects in the track itself, influences from the surrounding area or environment, obstructions, natural occurrences, weather effects, and/or other like conditions that would affect a smooth wheel-to-rail interface. When a track defect is detected, the locomotive computer or other onboard controller generates track defect data by associating a magnitude and/or characteristic of the track defect with the location of the detected track defect in a track network. The track defect data is communicated to a back office system that stores the track defect data. The back office system may then use the track defect data to, for example, alert and dispatch repair crews, monitor track condition trends, issue speed restriction bulletins, and/or the like. 
     Referring to  FIG. 1 , a track defect detection system  1000  is shown according to one preferred and non-limiting embodiment. A train  116  is traveling on a track  112  that has a track defect  110 . The locomotive  114  of the train  116  includes a locomotive computer  109 , such as a train management computer or other onboard controller, track data  106 , and a defect sensor  101 . The defect sensor  101  is configured to detect and measure acceleration, tilt, movement, and/or force, and may be further configured to detect and measure acceleration or force at any angle or axis. The defect sensor  101  may include, but is not limited to, an accelerometer, gyroscope, pressure/force sensor, and/or other like device. It will be appreciated that the acceleration, movement, tilt, or force detected and measured by the defect sensor  101  may include vertical, lateral, and/or angular acceleration, thrust, or the like, and may be measured and detected at a variety of different angles. 
     In a preferred and non-limiting embodiment, the track data  106  may specify various features of the track network and, in particular, the track  112  that the train  116  is traveling on and/or is scheduled to travel on. The track data  106  may be stored on any number of data storage devices such as, but not limited to, one or more hard drives, memory devices, and/or the like. The track data  106  may be in the form of any number of data structures and may include, for example, an identifier or name for the track  112  or region for a given location, an associated repair crew, an associated entity, and/or other like features. The track data  106  may identify the track  112  by milepost or other landmarks, authority blocks, longitude and latitude coordinates, and/or other identifying features or attributes of the track  112 . 
     With continued reference to  FIG. 1 , the locomotive computer  109  is in communication with a back office system  104 , including a server computer  105  and track defect database  107 . The locomotive computer  109  determines when the train  116  travels over a track defect  110  by comparing a measured defect sensor output with a predetermined threshold. In some non-limiting embodiments, a defect magnitude is calculated based at least in part on the defect sensor output and the velocity of the train  116 . In such embodiments, the defect magnitude may be proportional to the defect sensor output, which may include a vertical acceleration, and inversely proportional to the train velocity. For example, a defect sensor  101  output indicating a minor vertical, lateral, or angular acceleration may indicate a track defect  110  at a slow train velocity, but not necessarily at a faster train velocity. It will be appreciated that various other ways to calculate a track defect magnitude based on the defect sensor  101  output may be used. 
     Still referring to  FIG. 1 , and according to one preferred and non-limiting embodiment, when a track defect  110  is detected with a magnitude greater than a predetermined threshold, track defect data  108  is generated and communicated to the back office system  104 . Alternatively, a sliding scale, range, percentage, and/or the like, may be used to determine if the magnitude of the track defect  110  is significant enough to report. The track defect data  108  indicates a track defect  110  and includes, as an example, a magnitude of the track defect  110  associated with a track location and/or other identifying feature or attribute of the track  112 . The track defect data  108  may include data received directly from the defect sensor  101  and/or data processed by the locomotive computer  109 . The track defect data  108  may also include at least a portion of the track data  106 , or may be generated based at least partially on the track data  106 . For example, when a track defect  110  is detected, the track data  106  may be used to map the track defect  110  to a location or an identifiable feature or attribute. The track defect data  108  may then include a magnitude and/or character of the track defect  110  and associated location information including, for example, milepost or other landmark location, authority block location, longitude and latitude coordinates, and/or other like identifying features or attributes. 
     With continued reference to  FIG. 1 , in one preferred and non-limiting embodiment, the locomotive computer  109  is in communication with a Global Positioning System (GPS) satellite  103 . The locomotive computer  109  may receive real-time location information directly from the GPS satellite  103 , or indirectly through an onboard navigation system or other like device or system in communication with the GPS satellite  103 . Thus, the geographic coordinates (i.e., longitude and latitude coordinates) may be used to determine the location of the detected track defect  110  in addition to, or in place of, a location based on milepost marker, authority block, or the like. Further, if the defect sensor  101  is mid-train, and not part of the locomotive  114 , GPS and/or velocity data received from the head-of-train (HOT) unit, end-of-train (EOT) unit, and/or other computing devices on different railcars may be used to determine the location. For example, if a defect sensor  101  indicates a track defect  110  mid-train, and a GPS device is not located proximate to the defect sensor  101 , GPS, velocity, and/or length-of-train data from elsewhere (e.g., the EOT or HOT units, the locomotive computer  109 , etc.) may be used to calculate the exact location of the track defect  110  on the track  112 . 
     In some non-limiting embodiments, the track defect data  108  may be in the form of a track defect report, and may include other information such as, but not limited to, a date and time the defect is detected, repair information, railroad information, operator information, trend information and/or the like. The repair information may indicate, for example, an associated repair crew, repair schedule, or scheduled maintenance time. The railroad information may include, for example, an entity in charge of track repairs and/or track maintenance, an identification of the region or track segment, and/or the like. The operator information may include the identification of the train or other entity that detects and reports the track defect  110  to the back office system  104 . Trend information may include, for example, historical data for the location of the track defect  110  including past defect magnitudes, past repairs, and/or the like. Additionally, the track defect data  108  may include the vertical, lateral, or angular acceleration, tilt, movement, train velocity, and location, such that the magnitude of the detected track defect  110  can be calculated at a later time by the back office system  104 . 
     Referring now to  FIG. 2 , a further non-limiting embodiment of a track defect detection system  1000  is shown. In this example, the defect sensor  101  is located on or is otherwise part of an end-of-train device  118  at the rear of the train  116 . The end-of-train device  118  is in communication with the locomotive computer  109  via the train line  117 , wireless communications system, or other form of communication. Defect sensor output from the defect sensor  101 , resulting from the train  116  traveling over a track defect  110 , is communicated from the end-of-train device  118  to the locomotive computer  109 . The magnitude of the track defect  110  may be determined with a controller of the end-of-train device  118  or the locomotive computer  109 . Location information and other identifying data may also be received from wayside equipment  115  associated with the track  112 . 
     Referring to  FIGS. 1 and 2 , it will be appreciated that, in non-limiting embodiments, the defect sensor  101  may be part of a device adapted to be attached or installed in a locomotive  114 , railcar, cab car, end-of-train device  118 , head-of-train device, and/or other portions of the train  116 . Further, the defect sensor  101  may be part of a device or system already existing on the train such as, for example, a component of a positive train control (PTC) system. For example, the system  1000  may use an accelerometer that is part of a navigation system, the locomotive computer  109 , an end-of-train  118  or head-of-train device, a mobile device in communication with the locomotive computer  109 , application computing devices on or in a railcar, and/or any other device or system that has capabilities for measuring, sensing, and/or detecting a vertical or lateral acceleration, tilt, or other movement of the train or portion of the train. 
     With continued reference to  FIGS. 1 and 2 , the locomotive computer  109  is in communication with the back office system  104  and, in particular, the server computer  105 . The server computer  105  may receive the track defect data  108  from the locomotive computer  109  and store it in the track defect database  107 . The track defect database  107  may include the track defect data  108  formatted or arranged in any number of data structures. It will further be appreciated that the track defect database  107  may also be located onboard the train  116  and may be part of, for example, an event recording system, the locomotive computer  109 , and/or the track data  106 . 
     Referring now to  FIG. 3   a , a process is shown for detecting and reporting track defects  110  according to one preferred and non-limiting embodiment. The process starts at step  301 , during which an acceleration is detected with a defect sensing device  101  while the train is in motion. At step  303 , the system  1000  determines whether the acceleration, or a magnitude determined based at least partially on the acceleration, is greater than or equal to a predetermined threshold. If the acceleration and/or the magnitude of the track defect  110  does not equal or exceed the threshold amount, the process starts again at step  301 . If the acceleration and/or magnitude of the track defect  110  does equal or surpass the threshold, at step  305 , a track defect  110  is identified and associated with the current location of the train  116  to generate track defect data  108 . At a next step  307 , the track defect data  108  is communicated to the back office system  104  and the process continues to detect subsequent defect sensor outputs at step  301 . 
     Referring now to  FIG. 3   b , a process is shown for detecting and reporting track defect data according to another preferred and non-limiting embodiment. At a first step  311 , an acceleration is detected. The train  116  velocity is detected at a next step  312  based on, for example, a tachometer. Based on the velocity and the acceleration, a magnitude of a track defect  110  is calculated at step  313 . At a next step  315 , the track defect  110  magnitude is compared to a predetermined threshold and, if the magnitude is greater than or equal to the threshold, the process continues to step  317 . If the defect magnitude is below the threshold and therefore not great enough to be identified as a track defect  110 , the process starts over at step  311  and continues monitoring the defect sensor output. 
     Still referring to  FIG. 3   b , at step  317 , it is determined if milepost or block location data is available. Milepost or block location data may specifically identify a portion of track  112  or region of a track network based on landmarks or identifiers such as, but not limited to, milepost markers or other landmarks, authority blocks, identified track segments, and/or other features. As an example, a location may be expressed in terms of a distance into a particular authority block or from a given milepost marker. The milepost or block location data may be part of the track data  106  and identified based on a real-time location. If milepost or block location data is available, the method proceeds to step  321  where the location of the track defect  110  is determined relative to the milepost marker, authority block, or other like attribute or feature. If milepost or block location data is not available, at step  319  a longitude and latitude is determined from a Global Positioning System (GPS) or other onboard navigation system. At step  323 , track defect data  108  is generated based on the magnitude of the track defect  110  calculated in step  313  and the location data. In some examples, the track defect data  108  may be in the form of a track defect report or other data structure. At step  325 , the track defect data  108  is transmitted to the back office system  104 . 
     Referring now to  FIG. 4 , a track network interface  400  is shown according to one non-limiting embodiment. Track defects  403 ,  405 ,  407  are mapped to specific locations of the tracks  401  and are identified by varying graphical symbols, colors, or icons to signify different types and/or magnitudes of track defects. The track network interface  400  is a visualization of at least a portion of the track defect data  108  and/or the track defect database  107 . In some non-limiting embodiments, the track network interface  400  may be provided for repair crews, train operators, government agencies, and/or the like. Through the track network interface  400 , a user may be able to view and examine the track defects  403 ,  405 ,  407  by selecting the corresponding icons. In an embodiment, a selection of a particular track defect  407  displays an information window  408  including track defect data  410 . It will be appreciated that various other ways of visualizing and/or interacting with the track defect data  410  may be used, and that the track network interface  400  may be accessed and viewed by a variety of devices and systems such as, for example, a back office system server  105  or other computer, a mobile device, or the locomotive computer  109  (not shown). 
     With reference to  FIG. 5   a , a defect determination chart  501  is shown according to one preferred and non-limiting embodiment. The defect determination chart  501  is illustrative of a function or algorithm that determines whether a track defect has been detected. A defect magnitude  503 , indicative of the defect sensor output including, for example, a vertical, lateral, or angular acceleration, is shown as a function of time. Threshold levels  505 ,  507  are associated with predetermined threshold amounts of different types or classifications of track defects. For example, threshold  505  indicates a severe defect and threshold  507  indicates a moderate defect. When the magnitude  503  exceeds or equals the thresholds  505 ,  507 , the track defect  110  is determined to be significant enough to be reported and logged. It will be appreciated that the thresholds may be configured, selected, predetermined, descriptive, based on a sliding scale or percentage, varied based on track  112  or location, and/or the like. 
     Referring now to  FIG. 5   b , a defect magnitude chart  502  is shown according to one preferred and non-limiting embodiment. The defect magnitude chart  502  illustrates acceleration as a function of increasing train velocity. A defect region  504  illustrates corresponding accelerations (e.g., vertical, lateral, and/or angular acceleration) and train velocities that would indicate a track defect  110  significant enough to report (i.e., equal to or greater than a predetermined threshold). The defect magnitude chart  502  is illustrative of a function or algorithm that, based on at least an acceleration and a train velocity, calculates a defect magnitude. Thus, a given acceleration may indicate a track defect  110  at a slow train velocity (i.e., the left side of chart  502 ), but not at a more rapid velocity (i.e., the right side of the chart  502 ). In this manner, the faster a train is moving, the greater the acceleration necessary to indicate that a track defect  110  exists. 
     Referring now to  FIG. 6 , a track defect report  601  is shown according to one preferred and non-limiting embodiment. The track defect report  601  includes a data structure with track defect data  603  including track defect magnitudes  605  associated with locations  607  of those track defects  110  and a date and time  609  that the track defects  110  were detected. As can be seen, the locations  607  of two of the recorded track defects  110  are measured from milepost landmarks, and the third recorded track defect  110  is measured by longitude and latitude coordinates. The magnitudes  605  may be expressed as a level or classification (e.g., moderate or severe), or as numerical values. As explained herein, different ways for specifying a location may be used based on the data available or determined to be the most accurate when the defect is detected. 
     In one preferred and non-limiting embodiment, the system  1000  generates and communicates alerts to the back office system  104  when a certain number of track defects  110  have been detected in a particular region or portion of track network. In this manner, repair and maintenance crews can be allocated to repair the defects efficiently. The alerts may be generated based at least partially on the proximity between the track defects  110 , the magnitudes of the track defects  110 , and/or the like. Alerts may also be generated if, for example, the magnitude of a single track defect  110  is significant enough to pose immediate threat to the safety of other trains. 
     In one preferred and non-limiting embodiment, the system  1000  may generate or initiate speed restriction bulletins based on detected track defects to help prevent derailments or other accidents. The speed restriction bulletins may be automatically triggered and/or generated by the system  1000  including, for example, the back office system  104  or locomotive computer  109 . Because the exact locations of the track defects  110  are known, the speed restriction bulletins can be issued selectively such that they do not cover more portions of track  112  than necessary. Selective speed restriction bulletins minimize the amount of time that a train velocity has to be reduced for problematic track segments. The speed restriction bulletins may be enforced by locomotive speed control units on subsequent trains traversing the track  112  having the detected track defect  110 . 
     The system  1000  may also be configured to detect when a track defect  110  has been repaired or otherwise becomes less problematic, by comparing a defect magnitude detected in a location with a previously recorded magnitude for that location, resulting in the withdrawal of the associated speed restriction bulletin and/or removal of the track defect from the track defect database  107 . For example, if a train  116  is traveling over a track  112  that has been previously determined by the system  1000  to have a track defect  110  of a magnitude significant enough to report and log, the acceleration and/or train velocity may be used to calculate a new magnitude of the track defect  110 . Therefore, if the track defect  110  has been repaired, or has otherwise become less problematic over time, the train  116  can verify that the track defect  110  does not exist or that the magnitude has decreased by comparing the new magnitude to the previous magnitude. If the new magnitude is negligible or non-existent, or if the new magnitude is less than a predetermined threshold and therefore less than the previous magnitude, the locomotive computer  109  may communicate a message to the back office system  104  to indicate that the track defect  110  has been repaired or has otherwise become insignificant. Multiple detections of a track defect  110  may also allow the back office system  104  to monitor trends in the track defect  110  so that a repair can be made before the magnitude of the track defect  110  reaches a critical level. 
     In this manner, and according to non-limiting embodiments, track defects  110  may be detected and measured while a train  116  is in motion and associated with the locations of those track defects  110  to form track defect data  108 . The track defect data  108  may be compiled in a track defect database  107  and used to efficiently dispatch repair crews, issue selective speed restriction bulletins, monitor trends in track defect  110  magnitudes, and for other purposes. The track defects are detected at least partially on defect sensor output, which may include but is not limited to a vertical, angular, or lateral acceleration of a train  116  or part of a train  116  and, in some examples, a velocity of the train  116 . 
     Although the invention has been described in detail for the purpose of illustration based on what is currently considered to be the most practical and preferred embodiments, it is to be understood that such detail is solely for that purpose and that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover modifications and equivalent arrangements that are within the spirit and scope of the appended claims. For example, it is to be understood that the present invention contemplates that, to the extent possible, one or more features of any embodiment can be combined with one or more features of any other embodiment.