APPARATUS AND METHOD FOR GATHERING DATA FROM SENSORS ORIENTED AT AN OBLIQUE ANGLE RELATIVE TO A RAILWAY TRACK
20190367061 · 2019-12-05
Inventors
Cpc classification
B61K9/08
PERFORMING OPERATIONS; TRANSPORTING
B61L23/00
PERFORMING OPERATIONS; TRANSPORTING
G01S19/50
PHYSICS
B61L2205/04
PERFORMING OPERATIONS; TRANSPORTING
G01S19/48
PHYSICS
G01S19/45
PHYSICS
B61L23/048
PERFORMING OPERATIONS; TRANSPORTING
International classification
B61L23/04
PERFORMING OPERATIONS; TRANSPORTING
B61K9/08
PERFORMING OPERATIONS; TRANSPORTING
G01S19/50
PHYSICS
Abstract
A system and method for inspecting a railway track using sensors oriented at an oblique angle relative to a rail vehicle on which the system is traveling. The orientation of the sensors allows for different data to be gathered regarding a particular rail including rail design specifications (gathered based on manufacturer markings detected and analyzed by the system), rail seat abrasion values based on direct measurement of rails from the oblique angle, and other analysis of rail features including joint bars, rail welds, bond wires, rail holes, and broken rails. The use of an air blower, ducts, and one or more air distribution lids over the sensors helps remove debris from blocking the sensors and structured light generators.
Claims
1. A railway track assessment apparatus for gathering, storing, and processing profiles of one or both rails on a railway track while the apparatus travels on a rail vehicle along the railway track, the apparatus comprising: i. a processor; ii. a system controller in communication with the processor; iii. a data storage device in communication with the processor; iv. a power source for providing electric power to the track assessment apparatus; v. a first sensor pod attached adjacent to an undercarriage of the rail vehicle, the first sensor pod comprising: 1. a first 3D sensor in communication with the system controller wherein the first 3D sensor is oriented at an oblique angle relative to a railway track bed surface supporting rails on which the rail vehicle is moving wherein such orientation provides the first 3D sensor a side view of a first side of a first rail of the railway track so that the first 3D sensor can obtain data from the first side of the first rail; and 2. a first structured light generator in communication with the system controller.
2. The railway track assessment apparatus of claim 1 wherein the first sensor pod is oriented at an oblique angle relative to the undercarriage of the rail vehicle.
3. The railway track assessment apparatus of claim 1 i. wherein the first sensor pod further comprises 1. a first sensor enclosure wherein the first 3D sensor and the first structured light generator are attached adjacent to the first sensor enclosure inside of the first sensor enclosure; 2. a first thermal sensor; and 3. a first heating and cooling device; and ii. wherein the system controller further comprises a temperature controller in communication with the first thermal sensor and the first heating and cooling device wherein the first heating and cooling device is activated or deactivated by the temperature controller based on feedback from the first thermal sensor so that the temperature inside the first sensor enclosure is maintained within a specific range.
4. The railway track assessment apparatus of claim 1 further comprising: i. an encoder engaged with a wheel of the rail vehicle to transmit pulses to the system controller based on the direction and distance travelled of the rail vehicle; ii. a GNSS receiver in communication with the processor for providing position data of the railway track assessment apparatus to the processor; iii. the system controller further comprising a sensor trigger controller; and iv. computer executable instructions stored on a computer readable storage medium in communication with the sensor trigger controller operable to: 1. convert wheel encoder pulses to a desired profile measurement interval; and 2. reference profile scans to geo-spatial coordinates by synchronizing encoder pulses with GNSS receiver position data.
5. The railway track assessment apparatus of claim 1 further comprising: i. a second sensor pod attached adjacent to the undercarriage of the rail vehicle, the second sensor pod comprising: 1. a second 3D sensor in communication with the system controller wherein the second 3D sensor is oriented at an oblique angle relative to a railway track bed surface supporting rails on which the rail vehicle is moving wherein such orientation provides the second 3D sensor a side view of a second side of the first rail of the railway track so that the second 3D sensor can obtain data from the second side of the first rail; and 2. a second structured light generator in communication with the system controller; ii. a third sensor pod attached adjacent to the undercarriage of the rail vehicle, the third sensor pod comprising: 1. a third 3D sensor in communication with the system controller wherein the third 3D sensor is oriented at an oblique angle relative to a railway track bed surface supporting rails on which the rail vehicle is moving wherein such orientation provides the third 3D sensor a side view of a first side of a second rail of the railway track so that the third 3D sensor can obtain data from the first side of the second rail; and 2. a third structured light generator in communication with the system controller; and iii. a fourth sensor pod attached adjacent to the undercarriage of the rail vehicle, the fourth sensor pod comprising: 1. a fourth 3D sensor in communication with the system controller wherein the fourth 3D sensor is oriented at an oblique angle relative to a railway track bed surface supporting rails on which the rail vehicle is moving wherein such orientation provides the fourth 3D sensor a side view of a second side of the second rail of the railway track so that the fourth 3D sensor can obtain data from the second side of the second rail; and 2. a fourth structured light generator in communication with the system controller.
6. The railway track assessment apparatus of claim 5 further comprising: i. an encoder engaged with a wheel of the rail vehicle to transmit pulses to the system controller based on the direction and distance travelled of the rail vehicle; ii. a GNSS receiver in communication with the processor for providing position data of the railway track assessment apparatus to the processor; iii. the system controller further comprising a sensor trigger controller; and iv. computer executable instructions stored on a computer readable storage medium in communication with the processor operable to: 1. synchronize the repeated activation of the first 3D sensor, the second 3D sensor, the third 3D sensor, and the fourth 3D sensor; 2. combine profile scans from the first 3D sensor and the second 3D sensor into a first combined profile scan, and combine profile scans from the third 3D sensor and the fourth 3D sensor into a second combined profile scan; 3. reference the first combined profile scan and the second combined profile scan to geo-spatial coordinates by synchronizing encoder pulses with GNSS receiver position data.
7. The railway track assessment apparatus of claim 1 further comprising: i. a first sensor enclosure inside which the first 3D sensor and the first structured light generator are attached adjacent to the first sensor enclosure; and ii. a cover plate forming a wall of the first sensor enclosure wherein the cover plate further comprises a first cover plate aperture with a first glass panel covering the first cover plate aperture, and a second cover plate aperture with a second glass panel covering the second cover plate aperture.
8. The railway track assessment apparatus of claim 7 wherein the first glass panel comprises a light transmission band that is compatible with the wavelengths of the first structured light generator, allowing most of any generated light from the first structured light generator to pass through the first glass panel and not be reflected back into the first sensor enclosure by the first glass panel.
9. The railway track assessment apparatus of claim 7 further comprising: i. an air blower in communication with the system controller; and ii. first ducting extending from the air blower to a position proximate to the first glass panel and the second glass panel, wherein the air blower is activated at specified times to blow air through the ducting to dislodge and deflect debris from the first glass panel and the second glass panel.
10. The railway track assessment apparatus of claim 7 further comprising: i. an air distribution lid attached adjacent to the cover plate, the air distribution lid further comprising: 1. a first duct mount; 2. a first walled enclosure adjacent to the first glass panel; 3. a first enclosed channel providing space for air to flow from the first duct mount to the first walled enclosure proximate to the first glass panel; 4. a first air distribution lid first aperture at least partially covering the first glass panel; 5. a second duct mount; 6. a second walled enclosure adjacent to the second glass panel; and 7. a second enclosed channel providing space for air to flow from the second duct mount to the second walled enclosure proximate to the second glass panel; ii. an air blower in communication with the system controller; and iii. first ducting from the air blower to the air distribution lid wherein the first ducting further comprises a first duct attached adjacent to the first duct mount and a second duct attached adjacent to the second duct mount, wherein the air blower is activated by the system controller at specified times and, when activated, the air blower causes air to flow from the air blower, through the ducting, through first duct mount and the second duct mount, through the first enclosed channel and the second enclosed channel, to the first walled enclosure and the second walled enclosure to dislodge debris from the first glass panel and the second glass panel during operation of the railway track assessment apparatus.
11. The railway track assessment apparatus of claim 1 further comprising: i. a first database stored on a computer readable medium in communication with the processor wherein the first database comprises manufacturing data regarding the physical characteristics of specified rails cross-referenced with rail web markings; ii. the system controller further comprising a 3D sensor controller; iii. computer executable instructions stored on a computer readable storage medium in communication with the 3D sensor controller operable to allow the 3D sensor controller to: 1. gather a first scanline of a rail being scanned from the first 3D sensor, such first scanline providing information regarding a physical characteristic of a rail feature shown in the scanline; and 2. gather multiple scanlines to form an elevation map of the rail being scanned; and iv. computer executable instructions stored on a computer readable storage medium in communication with the processor operable to allow the processor to: 1. analyze alpha-numeric markings on a side of the rail being scanned using an optical character recognition algorithm, such alpha-numeric markings analyzed using the elevation map; 2. access the first database; 3. cross-reference alpha-numeric markings in the elevation map with manufacturing data in the first database; 4. measure a first physical characteristic of the rail being scanned using the processor to analyze the first scanline; 5. using a machine vision algorithm, compare the first physical characteristic of the rail being scanned with a same type of physical characteristic of a rail found in the first database, wherein the rail found in the first database matches the alpha-numeric markings that were decoded by the 3D sensor controller applicable to the first scanline; and 6. determine the condition of the first physical characteristic of the rail being scanned based on the comparison between the first physical characteristic of the rail being scanned and the same type of physical characteristic of a rail found in the first database.
12. The railway track assessment apparatus of claim 11 further comprising: i. a wireless transmitter and receiver in communication with the processor; ii. a second database stored on a computer readable medium in communication with the processor but geographically remote from the processor, wherein the second database comprises manufacturing data regarding the physical characteristics of specified rails cross-referenced with rail web markings; and iii. computer executable instructions stored on a computer readable storage medium in communication with the processor operable to allow the processor to: 1. access the second database; 2. cross-reference alpha-numeric markings in the elevation map with manufacturing data in the second database; 3. measure the first physical characteristic of the rail being scanned using the processor to analyze the first scanline; 4. using a machine vision algorithm, compare the first physical characteristic of the rail being scanned with a same type of physical characteristic of a rail found in the second database, wherein the rail found in the second database matches the alpha-numeric markings that were deciphered by the 3D sensor controller applicable to the first scanline; and 5. determine the condition of the first physical characteristic of the rail being scanned based on the comparison between the first physical characteristic of the rail being scanned and the same type of physical characteristic of a rail found in the second database.
13. The railway track assessment apparatus of claim 1 further comprising: i. the system controller further comprising a 3D sensor controller; ii. computer executable instructions stored on a computer readable storage medium in communication with the 3D sensor controller operable to allow the 3D sensor controller to gather an elevation map of the first side of the first rail using the first 3D sensor; and iii. computer executable instructions stored on a computer readable storage medium in communication with the processor operable to allow the processor to: 1. determine whether there is an elevation variation in the elevation map; 2. if there is an elevation variation in the elevation map, a. determine the likely cause of the elevation variation based on the size and shape of the elevation variation; b. assign a specific type of rail component identity to that elevation variation; c. analyze the elevation variation under the presumption that the elevation variation coincides with the assigned specific type of rail component; and d. save the elevation map, the identity of the assigned rail component, and the measurements made during the analysis of the elevation variation to the data storage device.
14. The railway track assessment apparatus of claim 1 further comprising: i. the system controller further comprising a 3D sensor controller; ii. computer executable instructions stored on a computer readable storage medium in communication with the 3D sensor controller operable to allow the 3D sensor controller to gather a scanline of the first side of the first rail using the first 3D sensor; iii. computer executable instructions stored on a computer readable storage medium in communication with the processor operable to allow the processor to: 1. calibrate the first 3D sensor to determine the real world unit width of a pixel in a scanline; 2. locate a pixel representing a rail base bottom using a horizontal edge detection machine vision algorithm 3. determine whether a tie is present in the scanline by detecting a generally smooth planar surface in proximity to and below the first rail using a machine vision algorithm; 4. if a tie is present in the scanline, locate a pixel representing the top of the tie surface using a machine vision algorithm; 5. calculate the difference in elevation between the bottom of the rail and the top of the tie surface representing the thickness of a pad under the first rail; and 6. based on the calculated thickness of the pad, determine the amount of rail seat abrasion on the tie under the first rail.
15. The railway track assessment apparatus of claim 1 further comprising: i. the system controller further comprising a 3D sensor controller; ii. computer executable instructions stored on a computer readable storage medium in communication with the 3D sensor controller operable to allow the 3D sensor controller to gather a scanline of the first side of the first rail using the first 3D sensor; iii. computer executable instructions stored on a computer readable storage medium in communication with the processor operable to allow the processor to: 1. calibrate the first 3D sensor to determine the real word unit width of a pixel in a scanline; 2. locate a pixel representing a rail base bottom using a horizontal edge detection machine vision algorithm; 3. determine whether a tie is present in the scanline by detecting a generally smooth planar surface in proximity to and below the first rail using a machine vision algorithm; 4. if a tie is present in the scanline, locate a pixel representing the top of the tie surface using a machine vision algorithm; and 5. calculate the difference in elevation between the bottom of the rail and the top of the tie surface representing the amount of plate cut in the first rail.
16. The railway track assessment apparatus of claim 1 wherein the system controller further comprises: i. a laser power controller in communication with the first structured light generator and the processor; and ii. computer executable instructions stored on a computer readable storage medium in communication with the laser power controller operable to allow the laser power controller to adjust the power to the structured light generator based on the light intensity of the most recent profile scan made by the first 3D sensor.
17. A method for analyzing the side of a rail of a railway track comprising: i. scanning the first side of a first rail of a railway track with an optical scanning system using a first sensor that is attached adjacent to a rail vehicle and oriented at an oblique angle relative to a railway track bed surface supporting rails on which the rail vehicle is moving wherein the first sensor obtains data regarding the first side of the first rail; ii. generating a first 3D profile of the first side of the first rail based on the data gathered by the first sensor using a system controller; and iii. analyzing the first 3D profile using a processor, such processor operating using a machine vision algorithm.
18. The method of claim 17 further comprising: i. generating a 3D elevation map of the first side of the first rail by combining a plurality of 3D profiles including the first 3D profile using a processor; ii. analyzing alpha-numeric markings on the first side of the first rail shown in the 3D elevation map using the processor operating an optical character recognition algorithm; iii. referencing the 3D elevation map to geo-spatial coordinates using the processor by synchronizing the plurality of 3D profiles forming the 3D elevation map with the location of the rail vehicle when those 3D profiles were generated using a GNSS receiver; and iv. storing the referenced 3D elevation map to a data storage device using a processor.
19. The method of claim 18 further comprising: i. accessing a database stored on a computer readable using a processor wherein the first database includes manufacturing data regarding the physical characteristics of specified rails cross-referenced with alpha-numeric rail markings located on the sides of the specified rails; ii. cross-referencing the alpha-numeric markings in the elevation map with manufacturing data in the database using the processor; and iii. measuring a physical characteristic of the first side of the first rail using the processor to analyze the first 3D profile; iv. comparing the physical characteristic of the first side of the first rail shown in the first 3D profile with a same type of physical characteristic of a rail found in the database matching the alpha-numeric markings that were detected by the processor; and v. determining the condition of the first physical characteristic of the first side of the first rail being scanned based on the comparison between the first physical characteristic of the first side of the first rail being scanned and the same type of physical characteristic of the specified rails found in the database.
20. The method of claim 17 further comprising controlling the temperature of the inside of a first sensor enclosure in which the first sensor is located using a temperature controller in communication with a thermal sensor and a heating and cooling device.
21. The method of claim 17 further comprising: i. scanning the second side of the first rail of the railway track with the optical scanning system using a second sensor that is attached adjacent to the rail vehicle and oriented at an oblique angle relative to the undercarriage of the rail vehicle wherein the second sensor obtains data regarding the second side of the first rail; ii. generating a second 3D profile of the second side of the first rail based on the data gathered by the second sensor using the system controller; iii. scanning the first side of a second rail of the railway track with the optical scanning system using a third sensor that is attached adjacent to the rail vehicle and oriented at an oblique angle relative to the undercarriage of the rail vehicle wherein the third sensor obtains data regarding the first side of the second rail; iv. generating a third 3D profile of the first side of the second rail based on the data gathered by the third sensor using the system controller; v. scanning the second side of the second rail of the railway track with the optical scanning system using a fourth sensor that is attached adjacent to the rail vehicle and oriented at an oblique angle relative to the undercarriage of the rail vehicle wherein the fourth sensor obtains data regarding the second side of the second rail; vi. generating a fourth 3D profile of the second side of the second rail based on the data gathered by the fourth sensor using the system controller; and vii. analyzing the first 3D profile using the processor, such processor operating using a machine vision algorithm.
22. The method of claim 21 further comprising: i. synchronizing activation of the first sensor, the second sensor, the third sensor, and the fourth sensor using the system controller in communication with an encoder; ii. combining the first 3D profile from the first sensor, the second 3D profile from the second sensor, the third 3D profile from the third sensor and the fourth 3D profile from the fourth sensor into a single combined 3D profile scan; and iii. referencing the combined 3D profile scan to geo-spatial coordinates by synchronizing encoder pulses with GNSS receiver position data from a GNSS receiver.
23. The method of claim 17 further comprising: i. generating a 3D elevation map of the first side of the first rail by combining a plurality of 3D profiles including the first 3D profile using the processor; ii. determining whether there is an elevation variation in the 3D elevation map using the processor operating a machine vision algorithm; and iii. if there is an elevation variation in the elevation map, 1. determining the likely cause of the elevation variation based on the size and shape of the elevation variation using the processor operating a machine vision algorithm; 2. assigning a specific type of rail component identity to that elevation variation using the processor; 3. analyzing the elevation variation under the presumption that the elevation variation coincides with the assigned specific type of rail component using the processor; and 4. saving the elevation map, the identity of the assigned rail component, and any measurements made during the analysis of the elevation variation to a data storage device using the processor.
24. The method of claim 17 further comprising: i. calibrating the first sensor to determine the real word unit width of a pixel in a 3D profile; ii. locating a pixel representing a rail base bottom using the processor operating a machine vision algorithm; iii. determining whether a tie is present in the 3D profile using the processor operating a machine vision algorithm; and iv. if a tie is present in the 3D profile: 1. locating a pixel representing the top of the tie using the processor operating a machine vision algorithm; 2. calculating the thickness of a pad under the first rail using the processor; and 3. determining the amount of rail seat abrasion on the tie under the first rail based on the calculated thickness of the pad using the processor.
25. The method of claim 17 further comprising: i. calibrating the first sensor to determine the real word unit width of a pixel in a 3D profile; ii. locating a pixel representing a rail base bottom using the processor operating a machine vision algorithm; iii. determining whether a tie is present in the 3D profile using the processor operating a machine vision algorithm; and iv. if a tie is present in the 3D profile: 1. locating a pixel representing the top of the tie using the processor operating a machine vision algorithm; and 2. calculating the plate cut under the first rail using the processor.
26. The method of claim 17 further comprising adjusting the power to a structured light generator based on the light intensity of the most recent 3D profile scan made by the first sensor using the processor and a laser power control controller.
27. A method of clearing debris from the view of a sensor of a railway track assessment system, the method comprising: i. blowing air from an air blowing device on a rail vehicle wherein such air is blown through a duct to an exit location wherein the exit location is proximate to a sensor enclosure comprising a transparent window through which a sensor has a field of view; and ii. clearing the transparent window of debris using the air exiting the duct at the exit location.
28. A sensor pod for use with a railway track assessment system, the sensor pod comprising: i. a sill mount attached adjacent to an undercarriage of a rail vehicle; ii. a first side bracket attached adjacent to a first side of the sill mount; iii. a second side bracket attached adjacent to a second side of the sill mount; and iv. a sensor enclosure wherein a first side of the sensor enclosure is attached adjacent to the first side bracket and a second side of the sensor enclosure is attached adjacent to the second side bracket.
29. The sensor pod of claim 28 further comprising: i. the first side bracket comprising a plurality of elongate first side bracket apertures; ii. the second side bracket comprising a plurality of second side bracket apertures; and iii. the sensor enclosure further comprising: 1. a first plurality of tapped holes for receiving fasteners located along a first side of the sensor enclosure that align with the plurality of elongate first side bracket apertures; and 2. a second plurality of tapped holes for receiving fasteners located along a second side of the sensor enclosure that align with the plurality of elongate second side bracket apertures, wherein the sensor enclosure can be selectively fastened to the first side bracket at different angles using first fasteners extending through the plurality of elongate first side bracket apertures into the first plurality of tapped holes and wherein the sensor enclosure can be selectively fastened to the second side bracket at different angles using second fasteners extending through the plurality of elongate second side bracket apertures into the second plurality of tapped holes.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0050] Further features, aspects, and advantages of the present disclosure will become better understood by reference to the following detailed description, appended claims, and accompanying figures, wherein elements are not to scale so as to more clearly show the details, wherein like reference numbers indicate like elements throughout the several views, and wherein:
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DETAILED DESCRIPTION
[0115] Various terms used herein are intended to have particular meanings. Some of these terms are defined below for the purpose of clarity. The definitions given below are meant to cover all forms of the words being defined (e.g., singular, plural, present tense, past tense). If the definition of any term below diverges from the commonly understood and/or dictionary definition of such term, the definitions below control.
[0116] Track, Railway track, track bed, rail assembly, or railway track bed is defined herein to mean a section of railway including the rails, crossties (or ties), components holding the rails to the crossties, components holding the rails together, and ballast material.
[0117] A processor is defined herein to include a processing unit including, for example, one or more microprocessors, an application-specific instruction-set processor, a network processor, a vector processor, a scalar processor, or any combination thereof, or any other control logic apparatus now known or later developed that is capable of performing the tasks described herein, or any combination thereof.
[0118] The phrase in communication with means that two or more devices are in communication with one another physically (e.g., by wire) or indirectly (e.g., by wireless communication).
[0119] When referring to the mechanical joining together (directly or indirectly) of two or more objects, the term adjacent means proximate to or adjoining. For example, for the purposes of this disclosure, if a first object is said to be attached adjacent to a second object, the first object is either attached directly to the second object or the first object is attached indirectly (i.e., attached through one or more intermediary objects) to the second object.
[0120] Embodiments of the present disclosure provide methods and apparatuses for determining plate cut and rail seat abrasion values without requiring the upper surface of a crosstie plate for wooden crossties or rail base for concrete crossties to be visible to sensors located in proximity of a rail assembly. Methods described herein enable determination of plate cut and rail seat abrasion values when all or portions of the rail assembly are obscured by ballast or other debris, and only require that a top of the rail head and a portion of an underlying crosstie surface to be visible to sensors passing overhead.
[0121] As shown in
[0122] For embodiments employing one or more light emitters 208, such light emitters 208 are used to project a light, preferably a laser line, onto a surface of an underlying rail assembly to use in association with three-dimensional sensors to three-dimensionally triangulate the rail assembly. In a preferred embodiment, a camera 224 in communication with the processor 202 via a camera interface 226 is oriented such that a field of view 228 of the camera 224 captures the rail assembly including the light projected from the light emitter 208. The camera 224 may include a combination of lenses and filters and using known techniques of three-dimensional triangulation a three-dimensional elevation map of an underlying railway track bed can be generated by the processor 202 after vectors of elevations are gathered by the camera 224 as the rail vehicle 222 moves along the rail. Elevation maps generated based on the gathered elevation and intensity data can be interrogated by the processor 202 or other processing device using machine vision algorithms. Suitable cameras and sensors may include commercially available three-dimensional sensors and cameras, such as three-dimensional cameras manufactured by SICK AG based in Waldkirch, Germany.
[0123] ToF sensors are preferably based on pulsed laser light or LiDAR technologies. Such technologies determine the distance between the sensor and a measured surface by calculating an amount of time required for a light pulse to propagate from an emitting device, reflect from a point on the surface to be measured, and return back to a detecting device. The ToF sensors may be a single-point measurement device or may be an array measurement device, commonly referred to as a ToF camera, such as those manufactured by Basler AG or pmdtechnologies AG.
[0124] Referring to
[0125] Referring again to
[0126] In a preferred embodiment, data from the camera 224 and one or more sensors 212 is combined, and a calibration process is preferably performed between the camera 224 and one or more sensors 212 using a known dimensional calibration target such that the camera 224 and one or more sensors 212 combine to generate a 3D elevation map as described in greater detail below.
[0127] The encoder 216 is located at a wheel 230 of the rail vehicle 222 and is in communication with the processor 202 via the encoder interface 220. The encoder 216 preferably operates at a rate of at least 12,500 pulses per revolution of the wheel 230 with a longitudinal distance of approximately 0.25 mm per pulse. Measurements from sensors 212 of the track assessment system are preferably synchronized with data from the encoder 216 to determine locations of measurements of the track assessment system and a generated three-dimensional elevation map. In one embodiment, the track assessment system further includes a GPS antenna 232 in communication with the processor 202 via a GPS interface 234 to further provide geo-position synchronization data during measurement of a rail assembly.
[0128] In order to extend the ability to estimate plate cut measures in areas with obscured crosstie plates (
[0129] Methods disclosed herein determine a difference between a wooden crosstie surface elevation 300 and an estimated tie plate base elevation 302. The improved rail head surface elevation method described herein measures a rail head surface elevation 304 as a reference elevation and calculates a vertical offset from the rail head surface elevation 304 to establish the estimated tie plate base elevation 302. This vertical offset is calculated as the sum of an estimated rail height 306 and an estimated tie plate thickness 308. The total height of the entire rail is the sum of both the estimated rail height 306 (which includes the distance from the rail head surface elevation 304 to a rail base surface elevation 310) plus the estimated tie plate thickness 308. A plate cut measurement 312 based on rail head surface elevation (which is insensitive to the presence of rail base surface debris) may be determined, for example, as follows:
Plate Cut Measurement=Crosstie Surface Elevation(Rail Head Surface Elevation (Rail Height Estimate+Estimated Crosstie Plate Thickness))Equation 3:
[0130] Estimated rail height 306 may be determined, for example, from a) the specifications of known rail sizes and types, b) by using a representative fixed elevation estimate, or c) by calculating the elevation difference between the rail head and rail base top surface at regular intervals along the length of the track.
[0131] Exemplary methods of determining the estimated rail height 306 can include analyzing data collected on the track assessment system 200, including location data from one or both of the encoder 216 and GPS antenna 232 to determine a position at which measurements of the rail assembly are taken. Location data may be used to determine a particular type of rail used based on data provided by an owner or operator of a particular railway, such data accessed directly from an onboard data storage device (e.g., the data storage device 206) or wirelessly from a remote data storage device. For example, an owner or operator of a railway may provide data regarding the manufacturer and size of a rail used at particular locations of the railway, and the estimated rail height 306 may be determined based on known dimensions of the rail available from the manufacturer.
[0132] In another exemplary method, data collected from the track assessment system 200 may be analyzed to detect visual marks or indicators 314 located on the rail, as shown in
[0133] In yet another exemplary method, the estimated rail height 306 (
[0134] The estimated tie plate thickness 308 shown in
[0135] Referring to
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Field Rail Height=Rail Head ElevationField Rail Base ElevationEquation 4:
Gauge Rail Height=Rail Head ElevationGauge Rail Base ElevationEquation 5:
[0137] Various sensors and technologies may be employed to determine elevations of components of the track and to provide additional measurements when calculating rail height, rail base thickness, or tie plate thickness estimates. These technologies can include fixed point or LiDAR based Time of Flight ToF range sensors referenced to 3D triangulation elevation measurement systems.
[0138] In order to extend the ability to estimate rail seat abrasion (RSA) measurement in areas with obscured rail base surfaces, the rail base seat elevation measures can be referenced to the top surface of the rail head 110, the surface on which the wheels travel, is an area of the track structure which is never obscured. Rail seat abrasion measurements referenced from the rail head elevation produce valid RSA measures, even in conditions where the presence of ballast, debris or foliage in and around the track obscures all but the top surface of the rail head and a small portion of the crosstie surface.
[0139] Methods and embodiments of the present disclosure are further capable of determining a rail seat abrasion (RSA) value of a section of track. Referring to
Equation 6: Rail Seat Abrasion=Crosstie Surface Elevation(Rail Head Elevation(Rail Height Estimate+Rail Base Thickness Estimate)).
[0140] With further reference to
[0141] Referring now to
Field Side Total Rail Height=Rail Head Elevation(Field Side Crosstie Elevation+Pad Thickness)Equation 7:
Gauge Side Total Rail Height=Rail Head Elevation(Gauge Side Crosstie Elevation+Pad Thickness)Equation 8:
[0142] The combined rail height and rail base thickness (collectively, the total rail height), plus pad thickness can be determined by calculating a running maximum of a difference of the rail head surface elevation 304 to the concrete crosstie surface elevation 328, as shown in
[0143] The calculation of the rail seat elevation based on the difference in rail head elevation and combined rail height and rail base thickness measurement allows calculating RSA measurements in situations where the rail base is obscured with track debris, such as ballast stones. The presence of track debris, and ballast stones in particular, on the top surface of the rail base (e.g., the rail foot and crosstie plates) is a common occurrence.
Rail Seat Abrasion=Crosstie Surface Elevation(Rail Head Elevation(Rail Height Estimate [including rail head and rail web]+Rail Base Thickness Estimate))Equation 9:
[0144] The method described above is insensitive to the presence of debris on the rail base surface. For example,
[0145] Referring now to
[0146] The fixed-point Time of Flight or LiDAR sensors can be positioned to provide measurements for rail base, rail head and crosstie surface elevations for both the field and gauge side of each rail. These systems would be capable of providing real-time rail seat abrasion measures in both clear rail base and obscured rail base scenarios.
[0147] In operation, the track assessment system 200 scans an underlying track, and the track assessment system 200 preferably moves along the track to gather data at various points along the track. Data from the track assessment system includes elevational data corresponding to an elevation of the rail head and an elevation of a top surfaces of crossties. Elevation data may be stored on the data storage device 206 (
[0148] Embodiments of the present disclosure refer to an elevation or surface elevation of various components of a rail assembly, such as the concrete crosstie surface elevation 320, rail head surface elevation 304, and other surface elevations. As shown in
[0149] Methods and embodiments described herein advantageously allow for the detection and measurement of plate cut and rail seat abrasion in environments where all or portions of crosstie plates and other components of the rail assembly are obscured by debris such as ballast stones. One embodiment as shown in
[0150] In certain embodiments a 3D track assessment system 500 can be used as shown schematically in
[0151] In a preferred embodiment, the 3D track assessment system 500 includes a first sensor 502A, a first structured light generator 506A, a first heating and cooling device 522A (e.g., solid state or piezo electric), and a first thermal sensor 524A all substantially sealed in a first enclosure 526A forming part of a first sensor pod 528A; a second sensor 502B, a second structured light generator 506B, a second heating and cooling device 522B, and a second thermal sensor 524B all substantially sealed in a second enclosure 526B forming part of a second sensor pod 528B; a third sensor 502C, a third structured light generator 506C, a third heating and cooling device 522C, and a third thermal sensor 524C all substantially sealed in a third enclosure 526C forming part of a third sensor pod 528C; and a fourth sensor 502D, a fourth structured light generator 506D, a fourth heating and cooling device 522D, and a fourth thermal sensor 524D all substantially sealed in a fourth enclosure 526D forming part of a fourth sensor pod 528D.
[0152] The controller 514 further includes a 3D sensor controller 530 in communication with the 3D sensors 502, a sensor trigger controller 532 in communication with the 3D sensors 502, a structured light power controller 534 in communication with the structured light generators 506, and a temperature controller 536 in communication with the heating and cooling devices 522 and the thermal sensors 524. The system controller 514 further includes a network interface 538 in communication with the processor 508 and the 3D sensor controller 530, sensor trigger controller 532, structured light power controller 534, and the temperature controller 536. The triggering for the 3D sensors 502 is generated by converting pulses from an encoder 538 (e.g., a quadrature wheel encoder attached adjacent to a wheel 540 on the survey rail vehicle 504 wherein the encoder 538 is capable of generating 12,500 pulses per revolution, with a corresponding direction signal) using the dedicated sensor trigger controller 532, a component of the dedicated system controller 514, which allows converting the very high resolution wheel encoder pulses to a desired profile measurement interval programmatically. For example, the wheel 540 could produce encoder pulses every 0.25 mm of travel and the sensor trigger controller 532 would reduce the sensor trigger pulse to one every 1.5 mm and generate a signal corresponding to the forward survey direction, or a different signal for a reverse survey direction.
[0153] The configuration of the four 3D sensors 502 and light generators 506 ensure that the complete rail profile is captured by combining the trigger synchronized left and right 3D sensor profiles of both rails 520 on a railway track simultaneously to produce a single combined scan for each rail. These scans can be referenced to geo-spatial coordinates using the processor 508 by synchronizing the wheel encoder 538 pulses to GNSS receiver positions acquired from the GNSS satellite network (e.g., GPS). This combined rail profile and position reference information can then be saved in the data storage device 510.
[0154] The 3D sensors 502 and structured light generators 506 are housed in the substantially sealed water tight enclosures 526. Because of the heating and cooling devices 522, thermal sensors 524, and the dedicated temperature controller 536, the inside of the enclosures 526 can be heated when the ambient temperature is below a low temperature threshold and cooled when the ambient air temperature is above a high temperature threshold. The thermal sensors 524 provide feedback to the temperature controller 536 so that the temperature controller can activate the heating function or the cooling function of the heating and cooling devices on an as-needed basis. These sealed and climate-controlled enclosures 526 ensure the correct operation and extend the operational life of the sensitive sensors 502 and light generators 506 by maintaining a clean and dry environment within acceptable ambient temperature limits. The temperature control function is part of the system controller 514 with a dedicated heating and cooling device interface inside each enclosure.
[0155]
[0156]
[0157]
[0158] Sensor pod 528 structural components such as the sides of the enclosures 526, internal frames 546, the sill mount 549, the side brackets 550, and the air distribution lids 556 are preferably made of impact resistant and non-corrosive materials including, for example, aluminum or stainless steels. Although metal is preferred, other materials could be used instead of metal including, for example, polycarbonate or ABS plastics. The power supply 512 can be different types of power sources such as, for example, electricity from the rail vehicle 504 originating from a liquid fuel to propel the rail vehicle 504 and being output as electricity, a generator burning a fuel and outputting electricity, solar panels and outputting electricity or a battery source. Power is preferably fed to the system controller 514 and from there is fed to other components of the system 500 in communication with or otherwise electrically tied to the system controller 514. For example, power is fed from the system controller 514 to the processor 508, components in communication with the processor 508, and the sensor pods 528 (including all electrical hardware in the sensor pods 528). The operator interface 516 can come in the form of different devices including, for example, an onboard computer with a monitor and input device (e.g., a keyboard), a computing tablet, a computing cellular device, or other similar device known to a person having ordinary skill in the art.
[0159] Each 3D sensor profile gathered from operating the 3D sensors is analyzed by the system controller 514 and the light intensity from the light generators 506 is adjusted to optimize the exposure levels. Low intensity profile scans result in an increase of structured light generator power and over exposed profile scans reduces the structured light generator drive power level. The laser power controller 534 also monitors structured light source temperature and current and is able to shutdown each individual light source in the event that safe operating limits are exceeded.
[0160] Computer executable instructions stored on a computer readable storage medium in communication with the system controller 514 are used to run an algorithm to control the amount of power supplied to the structured light generators 506. The structured light generators 506 are preferably laser line generators and are referred to below as lasers. An example of this algorithm is shown in the flowchart in
[0161] On system 500 initialization, each 3D sensor 502 is configured with required operational parameters by the 3D sensor controller 530. These parameters can include; exposure times, region of interest, gain levels, and sensor processing algorithms. The 3D sensor controller 530 is programmed with the specific 3D sensor operational parameters from a configuration file for each sensor by the processor 508 to allow external changes to the sensor parameters as required.
[0162] During operation of the system 500, 3D sensor scan data is streamed from the system controller 514 to the processor 508 for storage in the data storage device 510, linear referencing (wheel encoder based), geo-spatial referencing (GNSS receiver based), processing, and analysis. The processor 508 is programmed with algorithms for real-world profile coordinate correction (converting the oblique scan angle profile data to real-world coordinates), and feature detection and assessments. Features can include the recognition of rail web manufacturer markings (including both branded (raised) and stamped (recessed) marks). These marks are repeated (typically every 4 to 8 feet) on a rail web of a rail on one or both sides of the rail. These marks include the weight of rail (115, 136, 140 lb/yard rail), heat treating information, manufacturer, and year and lot/month of manufacture. Examples of 3D rail web elevation profile-based rail manufacturer marks are shown in
[0163]
[0164] After the alphanumeric markings are processed and recorded, in real time or near real time, the system 500 can access the onboard database 576A or the cloud-based database 576B via a wireless transmitter/receiver 578 in communication with the processor 508. By accessing the database(s) 576, the system 500 is then informed on the specific design specifications for that specific section of rail being analyzed. Current measurements of this section of rail made by the system 500 can then be compared to design specifications for the section of rail to determine changes that have occurred to that rail section over time. The system uses various rail processing steps for this analysis and it preferably processes the data streams from all four 3D sensors simultaneously or substantially simultaneously.
[0165] With additional reference to
[0166] The processor 508 can also determine rail cant angle by determining the angle that the vertical centerline of the combined field and gauge rail profile (the calculated centerline of the measured rail cross-section) makes with the plane of the tie surfaces to which the rails are fastened (Step 822).
[0167] The processor 508 can also locate tie surface pixels if a particular scanline includes a tie (Step 824) by identifying regions of the profile where the surface normal variation (or the profile gradient variation) is low, representing a smooth region of the correct dimension (8 to 10 inches wide typically) and placement (next to both rails. This information can be used to help determine pad thickness between a rail base and a tie under the rail base (Step 826). More details regarding these steps are discussed below and shown in
[0168] The processor 508 can also determine rail web surface elevation variations (or anomalies) (Step 828) by determining the difference between the localized rail web surface profile and the extended rail web median profile (a profile derived by calculating the median profile elevation at each point of the profile over a rail length of from about 5 meters to about 6 meters). If a large localized surface elevation difference of a minimum length (anomaly) is detected, the processor 508 presumes that the anomaly represents a rail joint bar and that joint is then analyzed (Step 830). This step can further include sub-steps such as linear and geospatial referencing of the joint, taking inventory of the joint bar (including size and type), determining the joint condition (e.g., whether it is broken or has missing bolts), the width of any gap detected between the joined rail segment ends (rail joint gap) and whether the joint is compliant with any required specifications from the railroad owner. An image reproduced from the combination of multiple scanlines of a joint bar is shown in
[0169] If a small localized surface elevation anomaly is detected, the processor 508 will presume it is a rail weld which can be visually analyzed by the processor 508 (Step 832) and data recorded on the data storage device 510 related to this feature. If a wire based localized elevation anomaly is detected, the processor 508 presumes it is a bond wire which can be analyzed by the processor (Step 834) and data recorded on the data storage device 510 related to this feature. If a hole based localized elevation anomaly is detected, the processor 508 will presume that it represents a rail hole which can be analyzed by the processor 508 (Step 836) and data recorded to the data storage device 510 related to this feature. If a crack or gap based localized elevation anomaly is detected, the processor 508 presumes it represents a broken rail which can be analyzed by the processor 508 (Step 838) and data recorded to the data storage device 510 related to this feature. The processor 508 can also determine elevation anomalies related to manufacturer markings (Step 840) discussed above in association with
[0170] The system 500 can also be used to locate railhead surface elevation variations (Step 842). If the processor 508 detects what it believes is a rail joint based on visual analysis (Step 844), the processor 508 can then visually analyze crushed railheads (Step 846), visually analyze battered railheads joints (Step 848), visually analyze misaligned rails (Step 850), and visually analyze rail height transitions (Step 852). For all of the features that are analyzed in steps 800-852, the system 500 can record and keep track of data associated with that particular location on the rail being interrogated, such information including time, linear referencing (wheel encoder based), and geo-spatial referencing (GNSS receiver based). Such information can be stored in the data storage device 510. Not all of the rail processing steps described above (800-852) have to occur together or in the specific order as listed.
[0171] Because of the unique orientation of the sensors 502 relative to rails being interrogated, the system 500 also can be used to make direct determinations of rail seat abrasion or plate cut. Computer executable instructions stored on a computer readable storage medium in communication with the processor 508 are used to run this algorithm shown in a flowchart in
[0172] If the system 500 is detecting plate cut values, a slightly different algorithm is used because the estimated thickness of the tie plate must be accounted for. Computer executable instructions stored on a computer readable storage medium in communication with the processor 508 are used to run this algorithm shown in a flowchart in
[0173] One of the advantages of the embodiments described herein is that some of the embodiments represent the first non-contact 3D measurement/analysis of rail webs for the purposes of rail manufacturing mark inventory (required for accurate rail asset management not currently possible) at the network level. The ability to take this type of inventory allows regulatory compliance assessments for rail at the network level (right rail type for the place/use it has been installed). Certain embodiments herein also represent the first 3D measurement/analysis of other side-of-rail hardware (joints, welds, bond wires, rail pads thickness for PCC ties) not previously possible at the network level. These embodiments augment emerging downward looking 3D track assessment technologies with the ability to look at the side of the rails which are one of the most critical components of the overall track structure. Such embodiments produce for the first time a more complete 3D view of the track surface including such side views.
[0174] The foregoing description of preferred embodiments of the present disclosure has been presented for purposes of illustration and description. The described preferred embodiments are not intended to be exhaustive or to limit the scope of the disclosure to the precise form(s) disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments are chosen and described in an effort to provide the best illustrations of the principles of the disclosure and its practical application, and to thereby enable one of ordinary skill in the art to utilize the concepts revealed in the disclosure in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the disclosure as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.