Abstract:
A system for determining the capability of a railroad track to safely carry railroad vehicles over the track by sensing changes in the environment proximate the track, the system including a sensor for detecting a magnetic field proximate the railroad track and generating data indicative of the magnetic field, a processor for processing data from the sensor to identify changes in the magnetic field proximate the track, and a communication device in communication with the processor for transmitting indicia indicative of changes in the environment proximate the track affecting the capability of the track to safely carry railroad vehicles.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to rail transportation and, more particularly, to sensing railway washout, a shifted railway, pumping ties, and/or an automobile stationary on a railway crossing.  
       BACKGROUND OF THE INVENTION  
       [0002]     A railway track typically has a pair of steel rails supported by a plurality of perpendicularly disposed ties that rest on a ballast material. Many railway tracks are located in remote areas where readily accessing the condition of a track may not occur if no known incident has occurred which may cause damage to the track. For example, railway tracks, or railways, may become damaged from storms or other natural occurrences, such as earthquakes, where the tracks may shift position. The shift can be caused by shifting ties and/or displacement of the ballast material. In other instances, such as where tracks are located adjacent to bodies of water, the ballast may shift or wash away resulting in the ties and hence the tracks shifting position. A track can also experience a shift due to a man-made accident, for example, a barge hitting a pillar or pillars supporting a bridge.  
         [0003]     Similarly, with excessive pumping ties, in particular cement ties, can become damaged from beating against the ballast. Pumping ties are a condition caused by poorly maintained ballast material (rocks) under railroad ties. When a train wheel passes over the tie, the tie is driven down into the rocks. Once the wheel rolls over the tie, the tie rises out of the rock. The lowering and then rising of the tie can be many inches of travel. Wood ties allow for quite a bit of movement. However, when concrete ties are used, this pumping into the rocks causes the cement tie to chip away slowly on the bottom of the tie, which ultimately leads to early failure of the concrete tie.  
         [0004]     Another occurrence that leads to train derailments and/or deaths is when automobiles (cars, trucks, buses, etc) stop on railroad crossings. Though locomotive engineers can visibly see when a vehicle is on a railroad track prior to reaching the vehicle, in some situations not enough time is available for the train to slow down and/or stop. When a vehicle is trapped by a crossing arm, situations result where the only way the vehicle can free itself is by running into and breaking the crossing arm. However, most drivers usually do not take such action.  
         [0005]     If a train has a dragging car, caused by the wheels on the car malfunctioning or where the wheels have jumped the track due to a shifted rail, such incidences are not always immediately noticed. Failure to notice such an incident could result in a train derailment.  
         [0006]     Such damage to a railway, blocking of a railway, and/or malfunction of a car on a train, can result in derailment of the train. With respect to railway damage, currently the best option to identify railway changes is by visual inspections. Even when visual inspections are performed, depending on the damage already occurred and/or frequency of the inspections, it is possible that existing or pending railway shifting may be missed or not identified timely enough.  
       BRIEF DESCRIPTION OF THE INVENTION  
       [0007]     The present invention is directed to a system and method for sensing railway washout, a shifted railway, pumping ties, and/or an automobile stationary on a railway crossing. When such occurrences happen, information regarding these occurrences are reported to a location so as to prevent a train from encountering the railroad track at these locations.  
         [0008]     Towards this end a system for determining the capability of a railroad track to safely carry railroad vehicles over the track by sensing changes in the environment proximate the track is disclosed. The system comprises a sensor for detecting a magnetic field proximate the railroad track and generating data indicative of the magnetic field. A processor for processing data from the sensor to identify changes in the magnetic field proximate the track is also part of the system. Another part of the system is a communication device in communication with the processor for transmitting indicia indicative of changes in the environment proximate the track affecting the capability of the track to safely carry railroad vehicles.  
         [0009]     A method of determining the capability of a railroad track to safely carry railroad vehicles over the track by sensing changes in the environment proximate the track is also disclosed. The method comprises a step of detecting a magnetic field proximate the railroad track. Generating data indicative of the magnetic field, and identifying changes in the magnetic field proximate the track are also steps in the method. The method also comprises transmitting indicia indicative of changes in the environment proximate the track affecting the capability of the track to safely carry railroad vehicles. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]     The features and advantages of the present invention will become apparent from the following detailed description of the invention when read with the accompanying drawings in which:  
         [0011]      FIG. 1  is an illustration of an exemplary embodiment of the present invention;  
         [0012]      FIG. 2  is an illustration of exemplary embodiments of the present invention in communication with a service facility and a train; and  
         [0013]      FIG. 3  is an illustration of exemplary embodiments of the present invention being used for a plurality of purposes at different locations along a railway.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0014]      FIG. 1  is an illustration of an exemplary embodiment of the present invention. As illustrated, a sensor package  10  has a sensor  12  with an embedded processor  14 . The sensor  12  is a three-axis magnetic sensor  12 , such as a Honeywell HMC2003 three-axis magnetometer. The sensor  12  measures low magnetic field strengths along an X-axis, a Y-axis, and a Z-axis wherein changes outside of a given range in the magnetic field around the sensor can be detected. In a preferred embodiment, the sensor provides an analog signal and the ground, or earth, is used as the magnetic field reference.  
         [0015]     The processor  14  is provided to allow for communication of magnetic field readings between a sensor  12  connected to the processor, a plurality of sensors  12  and a wayside unit, or communication device,  16  and/or a locomotive  18 . Communication can occur over industry standard networks such as, but not limited to, a Controller Area Network (“CAN”). CAN is an electronics industry standard vital protocol used for communication between embedded processors. Communication also can occur between the wayside unit  16 , a train  20 , and a service facility, or depot,  22 , as illustrated in  FIG. 2 . Though not illustrated, communication can also occur between the wayside unit  16  and railway equipment operable to prevent train movement towards the railway where the change in magnetic field has been detected.  
         [0016]     With respect to each sensor/processor combination  10 , or package, the processor  14  will also digitize the analog signal provided from the sensor  12 . Depending on the type of application the sensor/processor package  10  is being used for, as will be discussed below in more detail, the processor  14  will apply a specific software filter algorithm  24  to the signal to further reduce noise. Furthermore, based on commands received from the wayside unit  16 , the processor  14  will also function to measure the outputs from the sensor  12  and save the measurements as a zero reference value to be used as a reference for any magnetic field changes detected.  
         [0017]      FIG. 3  is an illustration of exemplary embodiments of how the sensor/processor packages  10  are used with a railway  30 . Depending on the intended purpose, the sensor/processor package  10  is placed either within the ballast material  32 , attached to railway ties  33 , and/or placed within a railroad crossing area  34 . In a preferred embodiment with any application, the packages  10  are placed at fixed intervals which determine an amount of coverage desired.  
         [0018]     As illustrated, the wayside unit  16  interfaces with the sensors  12 , via each respective sensor&#39;s processor  14  via the communication network  40 ,  41 . Communication between the sensor/processor packages  10  and the wayside unit  16  can occur through a wireless network  40 , a wired network  41 , and/or a combination of both. The wayside unit  16  is operable to command the sensors  12  to zero reference output as well as to communicate  45  with a train  20  and/or depot  22  via radio and/or other communication protocols. The type of detection resolution would be determined by how many sensor/processor packages are installed.  
         [0019]     Though the uses of the present invention are numerous, several uses are readily identifiable. By placing a network of the present invention in an automobile crossing area of a railroad track  34 , or railroad crossing, it is possible to detect automobiles present in the crossing area  34  as a train  20  is approaching the crossing area  34 . This is possible due to the sensor(s)  12  detecting a change in the magnetic field over the crossing area  34 . In this application, with respect to an individual sensor/processor combination  10 , the processor  14  applies a low pass filter  47  to the sensor output to eliminate any noise interference. The low pass filter cutoff frequency is high enough to allow detection of objects passing through the crossing area  34 , especially if any objects remain over the crossing area  34 .  
         [0020]     In this application, the wayside unit  16  receives a signal from the crossing sensor (not illustrated) to indicate that the train  20  is approaching and that the crossing guard is activating. The wayside unit  16  communicates to the crossing system if the crossing is clear of automobiles, using the sensor/processing package  10 , and also relays this information to the locomotive  20 . In another preferred embodiment, the wayside unit  16  is configured to constantly supply crossing status to the crossing detector. If an automobile were upon the tracks  30 , a warning is sent, via the wayside unit  16 , to the approaching train  20 . In another preferred embodiment, the sensor/processing package  10  is attached to the crossing guard arm. When the arm  51  lowers into place when a train  20  is approaching, if the magnetic field around it is different, or in other words if a vehicle is detected as being on the tracks, the arm will automatically lift allowing the vehicle to leave the crossing area without having to break the crossing arm  51 .  
         [0021]     Another application for the present invention is for detecting shifted rail and another is for pumping ties. Tie  33  movement in three directions is detectable using the present invention and the earth&#39;s magnetic field for reference. Likewise, a shifted rail is also detectable prior to a train approaching that part of the track. In this application, the wayside unit  16  applies a low pass filter  47  to the sensors at a high enough cutoff frequency to detect tie movement for all train speeds. The wayside unit  16  reports track status to the depot  22 . If a change in track conditions is detected, specifically a change in tie  33  location is detected, in addition to reporting the change to the depot  22 , a warning signal is sent to any locomotives  18  that are approaching that part of the track  30 . The signal  45  reported to any approaching trains  20  can be, but is not limited to, an alarm, voice message, etc. The signal  45  may also be sent to other railway equipment, such as an interlocking (not illustrated) to block train movement towards the detected shifted track.  
         [0022]     In another application, if wheels  52  on one of the cars  54  being pulled by the locomotive  18  consist are malfunctioning, such as if the wheels  52  have jumped the track, the present invention is used to detect this problem. Since the metal of the wheels  52  of the car  54  are likely to contact the ties  33  or drag against the side of the rails  57 , a change in the magnetic field would be realized since the magnetic field around the dragging wheels  52  would change when compared to the other cars  54  that make up the train  20 . Towards this end, the present invention would detect the change in magnetic field caused by the dragging wheels  52 .  
         [0023]     In another application, the present invention is used to detect ballast  32  washout. By using a network of sensor/processor packages  10  buried in the ballast  32  at fixed intervals, it is possible to determine the movement of the railroad ballast  32  based on a change in the magnetic field due to ballast  32  movement. The processor  14  applies a very low frequency low pass filter algorithm  47  to the sensor  12  output to eliminate false signals. The sensor/processor package  10  outputs are monitored by the wayside unit  16  that will command the processors  14 . The processors  14  communicate any changes detected in the magnetic field to the wayside unit  16 . The wayside unit  16  sends a signal warning and/or status report  45  to, via voice message, alarm, etc., approaching trains  20 , a communication to a railroad service facility  22 , or a communication to signal controlling equipment such as an interlocking to block train movement over that stretch of rail.  
         [0024]     While the invention has been described in what is presently considered to be a preferred embodiment, many variations and modifications will become apparent to those skilled in the art. Accordingly, it is intended that the invention not be limited to the specific illustrative embodiment but be interpreted within the full spirit and scope of the appended claims.