Track washout detector using track circuit data

Abstract

A railroad track washout detector including a monitor programmed to receive data from a conventional track circuit. The monitor is programmed to determine when there is a simultaneous increase in the transmit current and a decrease in the receive current of the track circuit representative of a rain event. The monitor is further programmed to determine when there is a simultaneous decrease in the transmit current and an increase in the receive current that represents drying out of the ballast and soil or a washout. If the simultaneous decrease in the transmit current and an increase in the receive current occurs too soon after the rain event and occurs too quickly, the monitor determines that a washout has occurred.

Description

TITLETRACK WASHOUT DETECTOR USING TRACK CIRCUIT DATABACKGROUND OF THE INVENTION1. FIELD OF THE INVENTION

[0001] The present disclosure relates to railroad safety systems and, more particularly, to a track washout detector.2. DESCRIPTION OF THE RELATED ART

[0002] One issue facing railroads today is derailment of trains where the supporting structure under the track has been washed out due to flooding. Historical data suggests that in the United States, railroads experience on average 5-7 accidents each year related to track washouts, which costs railroads as much as $6 million USD annually, not to mention the opportunity costs related to train delays from all track washout events (including those that do not cause accidents). This problem is an increasing concern given the climate change occurring globally.

[0003] Railroads currently manage the risk of derailments related to track washouts by performing manual track inspections periodically or when flooding has occurred. Manual track inspections are performed by walking the track or driving a maintenance vehicle at slow speeds over the track. In either case, the railroads usually rely on maintenance personnel to detect potential track washouts. In some cases, railroads may deploy sensors such as those disclosed in US Pat. No. 2,232,379 to detect high water, which then use the signal system to stop trains by automatically setting the track vacancy systems (track circuit, axle counter, etc) to the occupied state. These sensors, however, can only detect a potential washout in the small area covered by the sensor and will often stop trains unnecessarily. In fact, data from a recent study of the Federal Railroad Administration has found that very few track washouts are detected by automated systems, such as high water level sensors, and that track safety is mostly reliant on visual detection from manual track inspections. Accordingly, there is a need for a track washout detection system that can provide continuous coverage over the entire railroad with improved detection success.BRIEF SUMMARY OF THE INVENTION

[0004] The present invention provides a real-time track washout system and method that provides continuous coverage over an entire railroad. The present invention uses data available from existing track circuits, which makes the present invention economically feasible as no additional sensors or equipment are required to be installed. The present122512882. v1 -12 / 9 / 25invention can improve the detection success rate and responsiveness to track washouts, thereby preventing railroad accidents and avoiding unnecessary costs due to false alarms.

[0005] In an embodiment, a railroad track washout detector according to the present invention comprises a monitor programmed to receive data from a track circuit. The monitor determines when there is a simultaneous increase in the transmit current and a decrease in the receive current indicating a rain event followed by a simultaneous decrease in the transmit current and an increase in the receive current indicating a potential washout event depending on the timing of the potential washout event and the timing between the rain event and the potential washout event. The monitor may be included in the existing signal equipment or provided by a separate device located at the wayside or even remotely in a monitoring center. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

[0006] The present invention will be more fully understood and appreciated by reading the following Detailed Description in conjunction with the accompanying drawings, in which:

[0007] FIG. 1 is a schematic of a track washout monitor according to the present invention.

[0008] FIG. 2 is a schematic of a track circuit to which a track washout monitor according to the present invention may be connected to receive transmit and receive current data.

[0009] FIG. 3 is a schematic of a washout monitor according to the present invention.

[0010] FIG. 4 is a graph of the reaction of a standard track circuit to a rain event.

[0011] FIG. 5 is a graph of the reaction of a standard track circuit to a washout event.

[0012] FIG. 6 is a graph showing a comparison of the relative timing of initial and reverse events indicating a rain event and a washout event.

[0013] FIG. 7 is a flowchart of a method of detecting a track washout according to the present invention.DETAILED DESCRIPTION OF THE INVENTION

[0014] Referring to the figures, wherein like numerals refer to like parts throughout, there is seen in FIG. 1, a schematic of a washout detection system 10 according to the present invention. System 10 comprises a washout monitor 12 that is interconnected to a track circuit 14, which may be a conventional track circuit used to detect the presence of a train on a given section of track 16. Washout monitor 12 is configured to receive data collected from track circuit 14 about the signals sent and received by track circuit 14, including the level of the transmit and receive currents versus time.222512882. v1 -12 / 9 / 25

[0015] Referring to FIG. 2, track circuit 14 is comprised of a track section 20 having a pair of rails 22 and 24 supported by crossties 26. Track section 20 is isolated from adjoining sections of track by insulated joints 28 positioned in 22 and 24. Each end of track section 20 may include a monitoring system 30 having a power source 32, a detector 34 with a transceiver 36, and a programmable controller 38 locally interconnected. Monitoring system 30 is coupled to rails 22 and 24 via cables 40 and 42, respectively. One monitoring system 30 (or both) is configured to generate and apply a signal, e.g., a constant or varying AC or DC current, to rails 22 and 24, with the other monitoring system 30 (or both) having a measurement module 44 configured to receive the signal and interpret any changes in the signal to make determinations about the track section 20, such as the presence or absence of a train or a break in one of both of the rails 22 and 24.

[0016] Washout monitor 12 may be directly connected to track circuit 14, be coupled to a local or remote host monitoring system that receives the data from track circuit 14, or be connected wirelessly to a source of data that is being or has been collected from track circuit 14. Washout monitor 12 is programmed to evaluate the data from track circuit 14 to determine any simultaneous changes in the transmit current and the receive current as well as the timing of such changes. As an example, track circuit data can be obtained from systems such as the ElectroLogIXS product platform (VPM-3, VTI-2S or VTI-2E modules) as well as from other conventional track circuits or track circuit monitoring systems.

[0017] Referring to FIG. 3, an exemplary washout monitor 12 includes a track circuit interface 50 for receiving data from track circuit 14. A controller 52 is programmed to monitor the data received by track circuit interface 50 from track circuit 14 and can optionally store the data in memory 54. As explained herein, controller 52 may be programmed to evaluate the magnitude of the transmit current and the receive current from track circuit 14 over time and make decisions about track conditions based on changes the magnitude of the transmit current and the receive current from track circuit 14 over time. In an embodiment, controller 52 may include electronic monitoring devices, such as current and voltage sensors, to process raw signal information provided by track circuit 14 and extract the desired signal characteristics over time. If track circuit 14 includes the equipment for performing those evaluations, controller 52 need only be programmed to evaluate the transmit current and the receive current as determined by track circuit 14. In another embodiment, washout monitor 12 software or firmware in programmable controller 38, or even as a software upgrade to programmable controller 38 of a legacy track circuit 14.322512882. v1 -12 / 9 / 25

[0018] During a rain event, track circuit 14 will continue to conduct current between the rails. More specifically, water in the track substructure, such as collected rain, will lead to a simultaneous increase in the transmit current and a decrease in the receive current in track circuit 14, seen in FIG. 4. The timing and magnitude of the reaction of track circuit 14 to rain will depend on the amount of rainfall and the contamination level of the track structure supporting the rails, such as the ballast and soil. The reaction of track circuit 14 generally stabilizes in several minutes or hours after the start of the rain as the ballast and soil become saturated with water. Once it stops raining, the ballast and soil supporting the rails begins to dry out, thereby resulting in an opposite reaction of the track circuit currents to produce a simultaneous decrease in transmit current and increase in receive current, as further seen in FIG. 4. The opposite reaction generally takes a matter of hours or even days, depending on the prevailing weather conditions and the ability of the ballast and soil supporting the rails to drain and dry out.

[0019] In the event of a washout, the data received from track circuit 14 will initially show a reaction similar to that of a rain event where there is a simultaneous increase in the transmit current and a decrease in the receive current. The reaction from a simulated washout is seen in FIG. 5. The timing and magnitude of the initial reaction is very similar to the beginning of a rain event. As the ballast and soil supporting the rails is washed away, however, the opposite reaction will occur at a much faster rate (such as seconds or minutes) as compared to hours or days of drying out after a typical rain event. The accelerated opposite reaction is due to the fact that an area within the monitored location of the track circuit that is saturated with water is completely and rapidly removed by the washout rather than drying out slowly over time.

[0020] A rain event may be first identified based on an initial reaction by track circuit 14 that reflects that the ballast and soil have become saturated with water. The durational of the initial reaction and the occurrence and duration of the reverse reaction can help identify whether the rain event resulted in a track washout or whether ordinary drying of the ballast and soil has occurred. If the reverse event does not occur for an extended period of time, such as several hours or days (e.g., 4 hours to 2 days), it is most likely that the ballast and soil have simply dried out. If the reverse event occurs within minutes or a few hours (30 minutes to 4 hours), a track washout is more likely to have occurred. The occurrence of a track washout can be further discriminated from mere drying out based on the length of time of the reverse event. Mere drying out will produce a reverse event that extends over a longer period of time, such as several hours or days (seen as 8 hours in FIG. 4). By comparison, a washout will422512882. v1 -12 / 9 / 25produce a reverse reaction that is completed within minutes, if not faster. For example, as seen in FIG. 5, the reverse reaction took place in less than 1 minute. Thus, even though there may be an overlap between the timing between the initial event and the reverse event, e.g., 4 to 12 hours might be consistent with both a short rain event and a slowing dry time as well as a washout, the amount of time between the commencement and end of the reverse even can confirm whether it was merely a rain event versus a washout event, as seen in FIG. 6. It should be recognized that additional analytics may be used to learn the typical drying out reaction timing and magnitude for a given track circuit so that monitor 12 can be configured accordingly to discriminate between rain and washout events based on the particular track conditions of the location being monitored. It should also be recognized that providing the monitor 12 with additional information such as real time weather conditions, may also further support the ability to determine if a washout were possible.

[0021] Washout monitor 12 is therefore programmed to monitor track circuit 14 and evaluate the timing of the initial and opposite reactions of the transmit current and the receive current to discriminate between a rain event and a washout event. More specifically, although the combination of the initial and opposite reactions due to the initial rain event and the washout are similar, the specific timing of the initial and opposite reactions can be used to detect, identify and alert of a track washout. For example, washout monitor 12 may be programmed to implement a washout detection method 60 to detect a track washout such as the illustrative method seen in FIG. 7. First, washout monitor 12 monitors the track circuit data 62 for any changes in currents. Next, washout monitor 12 performs a check 64 to determine a rain event based on the initial reaction of a simultaneous increase in the transmit current and a decrease in the receive current over a predetermined duration. Check 64 could include a magnitude evaluation as well as a timing check. If no event is detected at check 64, washout monitor 12 continues monitoring the track circuit data 62. If a rain event has been detected at check 64, washout monitor 12 then checks 66 the track circuit data to determine whether a washout event may have occurred, such as by measuring the timing of the opposite reaction, i.e., the timing of a simultaneous decrease in transmit current and increase in receive current. Check 66 could include a magnitude evaluation as well as a timing check. While the transmit and receive current will return to normal after a rain event, the beginning of the return to normal usually takes several hours or days. Thus, the timing of the beginning of the opposite reaction, i.e., the beginning of the return of the transmit and receive currents to normal, is faster than a first time period, such as several hours or days (e.g., 4 hours to 2 days), a track washout may have occurred. If no washout event has been detected at check 66,522512882. v1 -12 / 9 / 25washout monitor 12 can continue to evaluate check 66 for a washout event and / or continue monitoring the track circuit data 22 for a new rain event.

[0022] If the timing of the beginning of the opposite reaction indicates a potential washout at check 66, washout monitor 12 then checks 68 whether the duration of the opposite reaction is less than a second time period. The second time period represents a minimum amount of time for the track to dry out normally. Thus, evaluating the amount of time the opposite reaction takes reveals whether the opposite reaction happened unreasonably fast, i.e., the amount of time for the transmit currents and receive current to return to normal is shorter than the minimal amount of time that a normal drying out period (such as hours or days) would take to occur after a rain event. If not, washout monitor 12 continues monitoring the track circuit data 62. If check 68 indicates that the drying out period represented by the decrease in transmit current and increase in receive current was too rapid to represent a normal drying out time period, washout monitor 12 can reach the determination that a track washout has occurred and send an appropriate alert of a potential track washout, such as an electronic notification to a central server or remote track or train monitoring system. Thus, washout monitor 12 relies first upon initial reaction to a rain or flooding event as indicated by simultaneous increase in transmit current and decrease in receive current. Washout monitor 12 then considers whether the transmit and receive currents returned to normal too quickly to reflect normal drying out. Washout monitor 12 then confirms that the track is not experiencing normal drying out by evaluating how quickly the drying out takes.

[0023] It should be recognized that the first time period and second time period may be established when configuring washout monitor 12 according to local conditions, i.e., some geographic locations will experience different weather patterns, have track ballasts that dry at different rates, etc. Thus, the suggested time periods here may be customized for particular locations or environments. The time periods may also be adjusted based on past experience in particular locations or environments and be adjustable in the field after installation of washout monitor 12. The time periods may also be automatically determined by algorithms within the monitor 12. Finally, the time periods can be correlated with a real time weather data source.

[0024] As an example, washout monitor 12 may be implemented in software in the Wayside System Data Management Module (WSDMM) comprising an edge analytics processor that consumes track circuit data via an Ethernet port. Data could also be acquired by a data acquisition system that monitors voltage and / or current, such as the Data Acquisition Unit (DAU). It should be noted that monitor 12 could be included in the existing622512882. v1 -12 / 9 / 25signal equipment, or provided by a separate device located at the wayside or even remotely in a monitoring center.

[0025] When coupled to or implemented with track circuit 14, measurements needed for washout monitor 12 can be measured at just one end of track circuit 14 to minimize the amount of equipment required. On the other hand, washout monitor 12 could be implemented at both ends of track circuit 14, which would allow for an identification of the approximate location of a washout that has been detected by washout monitor 12. As seen in FIG. 3, washout monitor 12 could also be provided with a feed containing weather data 56, such as from a remote host or local weather station, to help eliminate false positive washout detections by comparing the determination made by washout monitor 12 with actual weather data. Washout monitor 12 could also communicate with a local or remote alert system 58 so that the results of a washout detection can be communicated to the appropriate operators of the track so that the track is taken out of use. The location of a washout may be identifiable based on a comparison of data from monitors 12 positioned at each end of track section 20. The size of any washout could also be determined by looking at the magnitude of the opposite reaction compared to the magnitude of the original reaction.

[0026] It should be noted that in order to differentiate the changes observed during the washout test from changes observed during normal operation, as well as to improve the probability of detection, various data analytics methods may be used. The system and method described above thus provides an approach that can provide continuous, real-time detection of track washouts over an entire railroad using data from existing track circuits, while improving the accuracy of detection over existing manual methods of inspection, thereby reducing or eliminating train delays and derailments related to operational practices for track washouts. The system and method of the present invention therefore provide increased reliability and safety compared with existing methods which rely on physical sensors (which have a limited detection range) or humans visually inspecting track (which are less reliable).

[0027] The present invention may thus be a system, a method, and / or a computer program associated therewith and is described herein with reference to flowcharts and block diagrams of methods and systems. The flowchart and block diagrams illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer programs of the present invention. It should be understood that each block of the flowcharts and block diagrams can be implemented by computer readable program instructions in software, firmware, or dedicated analog or digital circuits. These computer readable program instructions may be implemented on the processor of a general purpose722512882. v1 -12 / 9 / 25computer, a special purpose computer, or other programmable data processing apparatus to produce a machine that implements a part or all of any of the blocks in the flowcharts and block diagrams. Each block in the flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical functions. It should also be noted that each block of the block diagrams and flowchart illustrations, or combinations of blocks in the block diagrams and flowcharts, can be implemented by special purpose hardware-based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions.822512882. v1 -12 / 9 / 25

Claims

CLAIMSWhat is claimed is:

1. A track washout detector, comprising: an interface for receiving signal data from a track circuit over time; and a controller coupled to the interface and programmed to determine whether a track associated with the track circuit has experienced a track washout based on changes in the signal data.

2. The track washout detector of claim 1, wherein the controller is programmed to determine whether the track washout has occurred based on changes in a transmit current sent by the track circuit and a receive current received by the track circuit.

3. The track washout detector of claim 2, wherein the controller is programmed to determine whether a rain event has occurred if there has been a simultaneous increase in the transmit current and a decrease in the receive current.

4. The track washout detector of claim 3, wherein the controller is programmed to determine whether the track washout has occurred based on a decrease in the transmit current along with an increase in the receive current that occurs within a first time period after any determination that the rain event has occurred.

5. The track washout detector of claim 4, wherein the first time period is no more than four hours.

6. The track washout detector of claim 5, wherein the controller is programmed to determine whether the track washout has occurred based on a decrease in the transmit current along with an increase in the receive current after any determination that the rain event has occurred.

7. The track washout detector of claim 6, wherein the controller is programmed to determine whether the track washout has occurred based on whether the decrease in the transmit current along with the increase in the receive current occurs overs a second time period.

8. The track washout detector of claim 7, wherein the second time period represents a minimum amount of time that the track structure associated with the track circuit would require to dry after experiencing the rain event.

9. The track washout detector of claim 8, wherein the second time period is no more than an hour.

10. A method of detecting a track washout, comprising the steps of: providing an interface for receiving signal data from a track circuit; and922512882. v1 -12 / 9 / 25using a controller coupled to the interface to determine whether a track washout has occurred on a track associated with the track circuit by evaluating any changes in the signal data over time.

11. The method of claim 10, wherein the step of using the controller to determine whether a track washout has occurred comprises evaluating changes in a transmit current sent by the track circuit and a receive current received by the track circuit over time.

12. The method of claim 11, wherein the step of using the controller to determine whether a track washout has occurred further comprises determining if a rain event has occurred if there has been an increase in the transmit current along with a decrease in the receive current.

13. The method of claim 12, wherein the step of using the controller to determine whether a track washout has occurred further comprises determining whether there has been a decrease in the transmit current along with an increase in the receive current within a first time period after any determination that the rain event has occurred.

14. The method of claim 13, wherein the step of using the controller to determine whether the track washout has occurred if the decrease in the transmit current along with the increase in the receive current occurs within a second time period.

15. The method of claim 14, wherein the first time period is no more than four hours and the second time period is no more than an hour.1022512882. v1 -12 / 9 / 25

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