Patent Publication Number: US-11377130-B2

Title: Autonomous track assessment system

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to U.S. Provisional Patent Application Ser. No. 62/848,630 for an “Autonomous Track Assessment System” filed on May 16, 2019, Provisional Patent Application Ser. No. 62/988,630 for an “Autonomous Track Assessment System” filed on Mar. 12, 2020, and Provisional Patent Application Ser. No. 63/016,661 for an “Autonomous Track Assessment System” filed on Apr. 28, 2020, and is a continuation-in-part and claims priority to U.S. application Ser. No. 16/255,928 for an “Apparatus and Method for Gathering Data From Sensors Oriented at an Oblique Angle Relative to a Railway Track” filed on Jan. 24, 2019, which is a continuation-in-part of and claims priority to U.S. application Ser. No. 16/127,956 entitled “APPARATUS AND METHOD FOR CALCULATING WOODEN CROSSTIE PLATE CUT MEASUREMENTS AND RAIL SEAT ABRASION MEASUREMENTS BASED ON RAIL HEAD HEIGHT” which was filed on Sep. 11, 2018, which claims priority to U.S. Provisional Patent Application Ser. No. 62/679,467 entitled “APPARATUS AND METHOD FOR CALCULATING WOODEN TIE PLATE CUT MEASUREMENTS AND RAIL SEAT ABRASION MEASUREMENTS” which was filed on Jun. 1, 2018, the entireties of which are incorporated herein by reference in their respective entireties. 
    
    
     FIELD 
     This disclosure relates to the field of railway track inspection and assessment systems. More particularly, this disclosure relates to a railway track inspection and assessment system and platform that is autonomous and includes various sensors oriented relative to a railway track for gathering data from the railway track. 
     BACKGROUND 
     Railway tracks must be periodically inspected to assess a condition of the railway track and various individual components of the track. Traditional methods and systems of assessing a railway track may require significant labor by on-track workers and require that sections of railway track be obstructed during assessment. Traditional methods of track inspection further enhance risk for on-track workers and may slow or prevent other traffic along a section of railway track during inspection, such as when a section of railway track is occupied by hi-rail based systems. 
     Further, current track assessment systems require significant resources to operate and to review data captured from assessment of a section of railway track. Existing systems may only be able to capture limited stretches of a railway track at a given time, further increasing costs and an amount of time required to assess sections of railway track. Existing systems may further suffer from drawbacks including obstructions to sensors by debris building up on optics of the sensors or by extreme conditions, such as extreme temperatures or temperature variations along a section of railway track. 
     What is needed, therefore, is a railway track inspection and assessment system and platform that is autonomous and that prevents obstruction of sensors, such as by debris on the railway track. 
     SUMMARY 
     Embodiments herein include a railway track inspection and assessment system and platform that is autonomous and that prevents obstruction of sensors, such as by debris on the railway track. In a first aspect, an autonomous railway track assessment apparatus for gathering, storing, and processing profiles of one or both rails on a railway track includes: railway track assessment platform including a boxcar including an enclosed space formed therein; one or more power sources located on the boxcar; a controller in electrical communication with the one or power sources including at least one processor and a data storage device in communication with the processor; a first sensor assembly in electronic communication with the controller, the first sensor assembly including a first sensor enclosure, a light emitting device, and one or more first sensors oriented to capture data from the railway track; an air handling system located on the rail car, the air handling system including an air blower and a heater/chiller; and a set of air ducts in fluid communication with the air handling system and the first sensor assembly for supplying heated or cooled blown air from the air from the handling system to the first sensor assembly. Data from the railway track is autonomously collected by the first sensor assembly controlled by the controller and such data is stored on the data storage device. 
     In one embodiment, the autonomous railway track assessment apparatus further includes: a second sensor assembly in electronic communication with the controller, the second sensor assembly including a second sensor enclosure, a second light emitting device, and one or more second sensors oriented to capture data from the railway track; the set of air ducts in fluid communication with the air handling system, the first sensor assembly, and the second sensor assembly for supplying heated or cooled blown air from the air handling system to the first sensor assembly and the second sensor assembly. Data from the railway track is autonomously collected by both the first sensor assembly controlled by the controller and the second sensor assembly controlled by the controller and such data is stored on the data storage device. 
     In another embodiment, the first sensor assembly is oriented at a substantially perpendicular angle relative to the railway track. In yet another embodiment, the second sensor assembly is oriented at an oblique angle α relative to the undercarriage of the rail vehicle. 
     In one embodiment, the autonomous railway track assessment apparatus further includes a first LiDAR sensor configured to gather data of a rail corridor along a first scan plane and a second LiDAR sensor configured to gather data of a rail corridor along a second scan plane wherein the first LiDAR sensor and the second LiDAR sensor are in electrical communication with the controller and are physically connected to on an outer rear surface of the boxcar. 
     In another embodiment, the autonomous railway track assessment apparatus further includes a temperature controller in communication with the air handling system wherein the blower and heater/chiller are activated or deactivated by the temperature controller based on environmental conditions of the autonomous railway track assessment apparatus. 
     In yet another embodiment, the autonomous railway track assessment apparatus further includes one or more valves within ducts between the air handling system and each of the first sensor assembly and the second sensor assembly. 
     In a second aspect, an air handling system for an autonomous track assessment apparatus includes: a railroad data gathering assembly including a sensor and a light emitter inside a sensor enclosure wherein the railroad data gathering assembly is operable to gather data from a railroad track using the sensor and the light emitter; an air blower; a heater/chiller in fluid communication with the air blower; a temperature controller in electronic communication with the air blower and the heater/chiller; a temperature sensor in communication with the temperature controller. The temperature controller activates and deactivates the air blower and heater/chiller to provide conditioned air to the railroad data gathering assembly based on data received from the temperature sensor wherein the conditioned air is blown out of the sensor enclosure proximate to the sensor and the light emitter to divert debris or precipitation from the sensor and the light emitter. 
     In one embodiment, the air handling system for an autonomous track assessment apparatus further includes: at least one sensor assembly comprising a LiDAR sensor mounted on an outer surface of a rail car; the air handling system further including at least one duct formed through a side of the rail car for communicating air from the air blower and heater/chiller to the at least one sensor assembly. 
     In another embodiment, the LiDAR sensor further including a LiDAR sensor housing having a plurality of apertures formed therethrough for emitting air from the air handling system towards a sensor surface of the LiDAR sensor. In yet another embodiment, the plurality of apertures are arranged radially around the LiDAR sensor housing. 
     In one embodiment, the LiDAR sensor housing further includes at least one camera located on the LiDAR sensor housing, wherein air flowing through the LiDAR sensor housing towards the plurality of apertures passes proximate to a lens of the at least one camera. 
     In another embodiment, air from the air blower passes through a computer hardware rack prior to passing through the sensor enclosure. 
     In a third aspect, an air handling system for an autonomous track assessment apparatus includes: a railroad data gathering assembly including a LiDAR sensor mounted on a LiDAR sensor housing on a boxcar, the LiDAR sensor housing including a plurality of apertures formed therethrough proximate to sensors of the LiDAR sensor; an air blower; a heater/chiller in fluid communication with the air blower; a temperature controller in electronic communication with the air blower and the heater/chiller; a temperature sensor in communication with the temperature controller. The temperature controller activates and deactivates the air blower and heater/chiller to provide conditioned air to the railroad data gathering assembly based on data received from the temperature sensor wherein the conditioned air is blown out of the sensor enclosure proximate to the sensor and the light emitter to divert debris or precipitation from the sensor and the light emitter. 
     In one embodiment, air from the air blower passes through a computer hardware rack prior to passing through the sensor enclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       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: 
         FIG. 1  shows a side view of an autonomous track assessment system according to one embodiment of the present disclosure; 
         FIG. 2  shows a schematic view of an autonomous track assessment system according to one embodiment of the present disclosure; 
         FIG. 3  shows a bottom view of an autonomous track assessment system according to one embodiment of the present disclosure; 
         FIG. 4  shows a sensory assembly of an autonomous track assessment system according to one embodiment of the present disclosure; 
         FIG. 5  shows a schematic diagram of a sensor assembly of an autonomous track assessment system including sensors oriented at an oblique angle which are capable of gathering data from rail webs and sides of rails; 
         FIG. 6  shows a schematic of a 3D sensor and light emitter oriented at an oblique angle, gathering data from the side of a rail; 
         FIG. 7  shows a sensor enclosure including a sensor and a light emitter attached adjacent to an internal frame inside the sensor enclosure as well as a heating and cooling device for maintaining the operating temperature inside the sensor enclosure to within specific temperature limits; 
         FIG. 8  shows the sensor enclosure of  FIG. 7  including a cover plate covering the sensor and the light emitter and enclosing the sensor enclosure; 
         FIG. 9A  shows a side view of the internal frame from  FIG. 7  which is located inside the sensor enclosure; 
         FIG. 9B  is a plan view of the internal frame shown in  FIG. 9A ; 
         FIG. 9C  shows an end view of the internal frame shown in  FIGS. 9A and 9B ; 
         FIG. 9D  shows a frame base which forms the base of the internal frame shown in  FIGS. 9A-9C ; 
         FIG. 10  shows a sensor pod including the sensor enclosure confined therein; 
         FIG. 11A  shows a first side bracket of the sensor pod; 
         FIG. 11B  shows a second side bracket of the sensor pod; 
         FIG. 12  shows a sill mount of the sensor pod which is used to engage sensor pod with the undercarriage of a rail vehicle; 
         FIG. 13  shows a pair of sensor pods oriented at oblique angles α on either side of a rail so that data can be gathered from both sides of the rail; 
         FIG. 14A  shows a perspective view of an air distribution lid for covering the cover plate from  FIG. 10  and providing air flow to such cover plate to remove debris from cover plate glass panels through which the sensor has a field of view and through which the light emitter emits light; 
         FIG. 14B  shows a plan view of the air distribution lid from  FIG. 14A ; 
         FIG. 14C  shows an end view of the air distribution lid shown in  FIGS. 14A-14B ; 
         FIG. 14D  shows a bottom view of the air distribution lid shown in  FIGS. 14A-14C ; 
         FIG. 15  shows a sensor pod including the air distribution lid from  FIGS. 14A-14D  attached adjacent to the cover plate of the sensor enclosure from  FIG. 10  wherein ducts are attached adjacent to the air distribution lid; 
         FIG. 16  shows an array of four sensor pods, each pod including an air distribution lid, wherein each air distribution lid is receiving air flow through a plurality of ducts originating from an air blower; 
         FIG. 17  shows a schematic of the air blower from  FIG. 16  and the plurality of ducts leading to the various air distribution lids; 
         FIG. 18  shows a close-up bottom view of an autonomous track assessment system according to one embodiment of the present disclosure; 
         FIG. 19  shows a side view of a sensor assembly of an autonomous track assessment system according to one embodiment of the present disclosure; 
         FIGS. 20 and 21  show a first sensor assembly, a second sensor assembly, and a blower of an autonomous track assessment system according to one embodiment of the present disclosure; 
         FIG. 22  shows a cross-sectional side view of a LiDAR sensor enclosure according to one embodiment of the present disclosure; 
         FIG. 23  shows an end view of a LiDAR sensor enclosure according to one embodiment of the present disclosure; and 
         FIG. 24  shows a cross-sectional side view of an air blower and conduits of an autonomous track assessment system according to one embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     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. 
     “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. 
     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. 
     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). 
     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. 
     Referring to  FIG. 1 , embodiments herein include an autonomous track assessment platform  10  for inspecting railway track  12  and components thereof. The autonomous track assessment platform  10  provides for a fully integrated autonomous platform capable of inspecting sections of a railway track. The autonomous track assessment platform  10  is capable of inspecting and gathering data from long stretches of the railway track  12  and high speeds and of providing real-time reporting and archiving of data collected from the railway track  12 . 
     Embodiments of the autonomous track assessment platform  10  include a boxcar  14  on which a plurality of sensor systems are installed as discussed in greater detail below. The boxcar  14  includes an enclosed space  16  located within the boxcar  14  for housing various sensor components and hardware discussed in greater detail below. The boxcar  14  may have dimensions substantially similar to a common boxcar or a hi-roof boxcar typically used to carry freight or other items. The boxcar  14  is preferably suspended on bogies  18  including pairs of wheels  20  that allow the boxcar  14  to travel along the railway track  12 . The boxcar  14  further preferably includes couplings  22  located at opposing ends of the rail car  14  such that the railcar  14  may be secured at either or both ends to a locomotive or other railcars of a train. The boxcar  14  may include ballast, such as a ballast concrete slab, to improve stability of the rail car  14 . 
     Referring now to  FIG. 2 , the autonomous track assessment platform  10  preferably includes a plurality of sensor assemblies mounted on the boxcar  14  for capturing data for the assessment of a condition of the railway track  12  as the boxcar  14  travels along the railway track  12 . In one embodiment, a plurality of sensor assemblies and other hardware components are installed on the autonomous track assessment platform  10  for automatically capturing data related to conditions of the railway track  12  and a surrounding environment without requiring substantial human intervention or labor to assess the railway track  12 . 
     In one embodiment, the autonomous track assessment platform  10  includes an onboard power supply for powering various sensors and hardware components of the autonomous track assessment platform  10 . A power supply is preferably onboard the track assessment platform  10  such that the autonomous track assessment platform  10  may be operated independent of a train to which the boxcar  14  is connected. For example, an electrical generator  24  may be located on the boxcar along with a fuel source  26  for powering the electrical generator  24 . Additional power supply components may be included such as one or more batteries  28 . The one or more batteries  28  may be in electrical communication with the electrical generator  24 . One or more solar panels  30  may be mounted on the rail car  14  and in electrical communication with the one or more batteries  28 . A power controller  32  is in electrical communication with the electrical generator  24 , one or more batteries  28 , and the one or more solar panels  30  for managing generation, storage, and distribution of electricity to components of the autonomous track assessment platform  10 . 
     The autonomous track assessment platform  10  preferably includes a plurality of sensors and sensor assemblies for gathering data from the railway track  12  for further assessment and determination of a condition of the railway track  12  and surrounding objects. Various sensor assemblies may be mounted below the boxcar  14  and oriented towards the railway track  12  such that the sensor assemblies capture data from the railway track  12 . Sensors may further be mounted on other external surfaces of the boxcar  14  for capturing data from the railway track  12  and a rail corridor including objects located around the railway track. 
     In one embodiment, a first sensor assembly  34  is mounted on the boxcar  14  for assessing a condition of the railway track  12  on which the boxcar  14  is travelling. The first sensor assembly  34  preferably includes a 3D Track Assessment System or “3DTAS” available from Tetra Tech, Inc. and disclosed in U.S. Patent Application Publication Number 2016/0249040 for a “3D Track Assessment System and Method,” the contents of which are incorporated herein by reference in their entirety. The first sensor assembly  34  is directed straight down towards the railway track  12  and components thereof. 
     Referring to  FIG. 3 , the first sensor assembly  34  includes a sensor housing  36  including a shroud  37  mounted underneath the boxcar  14  containing one or more sensors that are oriented to capture the railway track  12  as the boxcar  14  moves along the railway track  12 . As shown in  FIG. 4 , the first sensor assembly may include components of a track assessment system  200  preferably including a processor  202 , an onboard computer readable storage medium  204 , a data storage device  206  in communication with the processor  202 , computer executable instructions stored on one of the onboard computer readable storage medium  204  or the data storage device  206 , optionally one or more light emitters  208  (e.g., a laser line emitter) via an optional light emitter interface  210 , one or more sensors  212  in communication with the processor  202  via a sensor interface  214 , and an optional wheel mounted shaft encoder  216  in communication with the processor  202  via an optional encoder interface  220 . In a preferred embodiment, the one or more sensors  212  are Time of Flight (“ToF”) sensors. However, it is also understood that various other suitable sensors including three-dimensional or “3D” sensors  212  may be used. The track assessment system  200  further preferably includes a display and user interface  218  in communication with the processor  202  to display data to or receive input from an operator. Components of the track assessment system  200  are preferably mounted on the boxcar  14  of the autonomous track assessment system  10 . The track assessment system  200  may be powered by the boxcar  14  or may be powered by a battery or other local power source. The data storage device  206  may be onboard the boxcar  14  or may be remote from the vehicle, communicating wirelessly with the processor  202 . 
     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 boxcar  14  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. 
     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. 
     Referring again to  FIG. 2 , a second sensor assembly  36  is mounted on the rail car  14  for assessing a condition of the railway track  12  on which the rail car  14  is travelling. The second sensor assembly  36  preferably includes one or more sensors oriented at an oblique angle relative to the railway track  12  to capture side view of the railway track. An exemplary embodiment of the second sensor assembly  36  is shown in  FIG. 5 , which may include components of a 3D track assessment system  500  and can be used as shown schematically in  FIG. 5  which includes a plurality of 3D sensors  502  wherein the system  500  and sensors  502  are attached adjacent to a rail vehicle  504  configured to move along a railway track. The sensors  502  are oriented downward from the rail vehicle  504  but at an oblique angle looking at a rail from the side as shown in  FIG. 5 . Suitable sensors may include commercially available 3D sensors and cameras, such as Ranger cameras manufactured by SICK AG based in Waldkirch, Germany. The 3D track assessment system  500  further includes a plurality of structured light generators  506  (similar or identical to light emitters  208 ). The 3D track assessment system uses a combination of sensors  502 , structured light generators  506 , a specially configured processor  508 , a data storage device  510 , a power supply  512 , a system controller  514 , an operator interface  516 , and a Global Navigation Satellite System (GNSS) receiver  518 . Although single components are listed, it is understood that more than one of each component may be implemented in the 3D track assessment system  500  including, for example, more than one processor  508  and more than one controller  514 . These and other system components help provide a way to gather high resolution profiles of the sides of rails including the heads, the bases and rail webs of rails  520  (including a first rail  520 A and a second rail  520 B) on a railway track. The 3D sensors  502  are preferably configured to collect four high resolution substantially vertical profiles at programmable fixed intervals as the system  500  moves along a railway track. The current implementation can collect 3D profiles (or scanlines) every 1.5 millimeters (mm) while the autonomous track assessment system  10  is moving along the railway track  12  at speeds up to 70 miles per hour. The system autonomously monitors sensor  502  operation, controls and configures each sensor  502  independently, and specifies output data storage parameters (directory location, filename, etc.). The system  500  further provides rail web manufacturer mark inventory capabilities, and various rail features inventory, exception identification and reporting capabilities. Typical exceptions include rail head and joint bar defects or dimensional anomalies. When identified, these exceptions can be transmitted based on specific thresholds using exception prioritization and reporting rules. 
     In a preferred embodiment, the 3D track assessment system  500  includes a first sensor  502 A, a first structured light generator  506 A, a first heating and cooling device  522 A (e.g., solid state or piezo electric), and a first thermal sensor  524 A all substantially sealed in a first enclosure  526 A forming part of a first sensor pod  528 A; a second sensor  502 B, a second structured light generator  506 B, a second heating and cooling device  522 B, and a second thermal sensor  524 B all substantially sealed in a second enclosure  526 B forming part of a second sensor pod  528 B; a third sensor  502 C, a third structured light generator  506 C, a third heating and cooling device  522 C, and a third thermal sensor  524 C all substantially sealed in a third enclosure  526 C forming part of a third sensor pod  528 C; and a fourth sensor  502 D, a fourth structured light generator  506 D, a fourth heating and cooling device  522 D, and a fourth thermal sensor  524 D all substantially sealed in a fourth enclosure  526 D forming part of a fourth sensor pod  528 D.  FIG. 6  shows an image of the first sensor  502 A and the first light generator  506 A (without the first enclosure  526 A for illustrative purposes) oriented at an oblique angle to the plane of the railway track bed surface allowing a view of the side of the first rail  520 A.  FIG. 7  shows the first sensor  502 A, the first light generator  506 A, and the first heating and cooling device  522 A inside the first enclosure  526 A. 
     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  537  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. 
     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 . 
     The 3D sensors  502  and structured light generators  506  are housed in the substantially sealed watertight 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. 
       FIG. 8  shows the first enclosure  526 A including a cover plate  542  forming one side of the first enclosure  526 A. The cover plate  542  includes a first cover plate aperture  543 A through which the first sensor  502 A views outside of the first enclosure  526 A and a second cover plate aperture  543 B through which the light generator casts light outside of the first enclosure  526 A. The first cover plate aperture  544 A is covered by a first glass panel  544 A and the second cover plate aperture  544 B is covered by a second glass panel  544 B. The glass panels  544  are preferably impact resistant and have optical transmission characteristics that are compatible with the wavelengths of the light generators  506 . This helps avoid broken aperture glass and unnecessary heat buildup inside the enclosures  526  from light reflected back into the enclosures  526  during operation. The first sensor  502 A and the first light generator  506 A are preferably mounted to an internal frame  545  preferably using bolts. The frame  545  is shown in  FIG. 9A-9C  and such frame is preferably bolted to the inside of the first enclosure  526 A. The frame  545  includes a frame base  546  (shown by itself in  FIG. 9D ), a laser alignment panel  547  to which the first structured light generator  506 A is attached, and a sensor alignment panel  548  to which the first 3D sensor  502 A is attached. Each additional enclosure ( 526 B,  526 C, and  526 D) includes a cover plate (like the cover plate  542 ) with apertures (like the apertures  544 ) as well as a frame (like the frame  545 ) for attaching and optically aligning sensors and light generators together inside the enclosures. 
       FIG. 10  shows the first sensor pod  528 A including the first enclosure  526 A. The first sensor pod  528  includes a sill mount  548  and side brackets  550  (including a first side bracket  550 A shown in  FIG. 11A  and a second side bracket  550 B shown in  FIG. 11B ). The sill mount  548  is shown by itself in  FIG. 12 . The sill mount  548  is preferably attached adjacent to the undercarriage of the rail vehicle  504  by mechanical fastening using bolts or welding the sill mount  548  directly to the rail vehicle undercarriage. The first side bracket  550 A is attached adjacent to the sill mount  548  preferably by bolts through a first side bracket first aperture  552 A, and the second side bracket  550 B is attached adjacent to the sill mount  548  preferably by bolts through a second side bracket first aperture  554 A. The first enclosure  526 A is attached adjacent to the side brackets  550  preferably using bolts through first side bracket second apertures  552 B and second side bracket second apertures  554 B extending into tapped holes on the sensor enclosure. As an example, the first side bracket second apertures  552 B are elongated so that the first enclosure  526 A can be rotated plus or minus up to about 5° relative to the side brackets  550  before being bolted, screwed or otherwise attached tightly adjacent to the side brackets  550 . The flexibility to slightly rotate the first enclosure  526 A inside the first pod  528 A is helpful to compensate for mounting height variations which can occur from rail vehicle to rail vehicle since not all vehicles are the same height.  FIG. 13  shows the first sensor pod  528 A and the second sensor pod  528 B attached adjacent to the undercarriage of the rail vehicle  504  in a configuration that allows for data to be gathered from both sides of the first rail  520 A using a combination of the first sensor  502 A and the second sensor  502 B. In  FIG. 13 , the first side bracket  550 A is removed to show the first enclosure  526 A. The orientation of the sensor pods  528  is at an angle α relative to the undercarriage of the rail vehicle  504 . Angle α preferably ranges from about 10° to about 60°, more preferably from about 25° to about 55°, and most preferably from about 40° to about 50°. The value for a in  FIG. 13  is about 45°. The lowest point of the first sensor pod is preferably at least 75 mm above the rail being scanned by the first sensor  502 A. The first sensor  502 A is oriented at an oblique angle θ relative to the railway track bed surface  555  wherein angle θ preferably ranges from about 30° to about 60° and more preferably from about 40° to about 50°. 
       FIG. 14A  shows the cover plate  542  with a first air distribution lid  556 A attached adjacent to the cover plate  542  preferably by bolts or screws.  FIG. 14B-14D  show different views of the first air distribution lid  556 A by itself. The first air distribution lid  556 A includes a first duct mount  557 A which directs air through a first enclosed channel  558 A to a first walled enclosure  559 A at an area proximate to a first air distribution lid first aperture  560 A which overlaps the first cover plate aperture  544 A. The first air distribution lid  556 A includes a second duct mount  557 B which directs air through a second enclosed channel  558 B to a second walled enclosure  559 B at an area proximate to a second air distribution lid second aperture  560 B which overlaps the second cover plate aperture  544 B.  FIG. 15  shows a perspective view of the first sensor pod  528 A including the cover plate  542  and the first air distribution lid  556 A. A first air duct  562 A is engaged with the first duct mount  557 A to supply air to the first walled enclosure  559 A. A second air duct  562 B is engaged with the second duct mount  557 B to supply air to the second walled enclosure  559 B.  FIG. 16  shows a full array of the sensor pods  528  and shows an air blower  564  supplying air through a plurality of ducts  566 .  FIG. 17  shows schematically how air is supplied from the air blower  564  to the first air distribution lid  556 A, a second air distribution lid  556 B, a third air distribution lid  556 C, and a fourth air distribution lid  556 D. The air blower  564  is in communication with the system controller  514  so that when the 3D sensors  502  are activated, the system controller  514  causes the air blower  564  to be activated also. The air flowing through the plurality of ducts  566  to the air distribution lids  556  is used to clear debris from the area proximate to the enclosure cover plate apertures through which the sensors  502  view rails and through which the light generators  506  shine light. As the rail vehicle  504  moves along a railway track, debris that would otherwise cover the view of the sensors  502  or block the light of the light generators  506  is dislodged by the air flow through the air distribution lids  556 . 
     Referring now to  FIG. 18 , one or more of the plurality of air ducts  566  are further in fluid communication with the first sensor assembly  34  for directing air from the air blower  564  towards sensors of the first sensor assembly  34 . The plurality of air ducts  566  in fluid communication with the first sensor assembly  34  are connected to a plurality of duct mounts  40 A and  40 B of the first sensor assembly  34 . As shown in  FIGS. 18-19 , the plurality of duct mounts  40  are in fluid communication with enclosed channels  42 . Enclosed channels  42  are in fluid communication with walled ducts  44 . Walled ducts  44  are located proximate to windows or lenses of the sensors on the enclosure  48  containing the one or more light emitters  208  and the camera  224  of the first sensor assembly  34  such that air flowing through the enclosed channels  42  the walled ducts  44  is substantially directed towards the sensors of the first sensor assembly  34 . 
     The air blower  564  preferably includes a plurality of outlets  50  for connecting the plurality of ducts  566  to the air blower  564 . For example, the air blower  564  may include a number of outlets  50  corresponding to a number of sensors on both the first sensor assembly  34  and the second sensor assembly  36  such that air from the air blower  564  is imparted proximate to sensors of the first sensor assembly  34  and the second sensor assembly  36 . The air blower  564  preferably includes a blower motor  52  located within a blower housing  54 . The blower motor  52  is in fluid communication with the plurality of outlets  50 . 
     The air blower  564  further preferably includes a chiller/heater  58  ( FIG. 2 ) for heating or cooler air through the air blower  564 . The chiller/heater  58  is preferably in fluid communication with the air blower  564  such that air from the air blower  564  provided to the first sensor assembly  34  and the second sensor assembly  36  may be heated or cooled depending on external environmental conditions. The chiller/heater  58  may be in electronic communication with a controller, such as the temperature controller  536  ( FIG. 5 ) for controlling a heated or cooled temperature of air through the air blower  564 . 
     As shown in  FIGS. 2 and 23-24 , the first sensor assembly  34 , the second sensor assembly  36 , and the blower  564  are preferably located proximate to each other underneath the rail car  14  to minimize a required length of the plurality of air ducts  566 . The first sensor assembly  34  and the second sensor assembly  36  are preferably arranged underneath the rail car  14  such that sensors of the first sensor assembly  34  and the second sensor assembly  36  are oriented to capture data from the railway track  12  at multiple angles. 
     Referring again to  FIG. 1 , the autonomous track assessment system  10  further preferably includes a weather station  60  mounted on exterior of the rail car  14  for detecting external environmental conditions around the autonomous track assessment system  10  such as precipitation, temperature, and other environmental conditions. One or more telemetry components  62 A and  62 B are also preferably mounted on the rail car  14  and may include, for example, cellular or WiFi antennas for communicating data collected on the autonomous track assessment system  10  to a location that is remote from the rail car  14 . The one or more telemetry components  62 A and  62 B are preferably in communication with a telemetry controller  63  ( FIG. 2 ). One or more cameras  64  may be mounted to record the enclosed space of the rail car  14  for security. 
     The autonomous track assessment system  10  further preferably includes one or more LiDAR sensors  66  located on an exterior of the rail car  14  for capturing data including a corridor through which the rail car  14  is travelling along the railway track  12 . The one or more LiDAR sensors  66  are preferably mounted towards an upper portion of a rear side of the boxcar  14  and are preferably mounted in an enclosure  68 . A plurality of digital cameras  70  are also located in the enclosure  68 . The autonomous track assessment system  10  preferably includes at least two LiDAR sensors  66  mounted on opposing sides of ends of the rail car, as shown in  FIG. 22 . 
       FIG. 22  shows a side cross-sectional view of the sensor enclosure  68  wherein the one or more LiDAR sensors  66  are exposed to collect data. The sensor enclosure  68  includes a sensor enclosure outer cap  72  including a plurality of cap apertures  74  ( FIGS. 22 and 23 ) through which blown air may exit the enclosure  68  to prevent dirt, debris, or precipitation from interfering with the one or more LiDAR sensors  66  as explained in greater detail below. As shown in  FIG. 24 , a blower  76  is included for blowing air through the enclosure cap  72  and out of the plurality of cap apertures  74 . A heater/chiller  78  is provided to heat or cool air from the blower  76  to the one or more LiDAR sensors  66 . Air from the blower  76  flows through one or more ducts  80  in the boxcar  14  and through ducts formed through exterior of the boxcar  14 , the ducts being in alignment with the sensor enclosure  68  when the sensor enclosure  68  is mounted on the boxcar  14 . In one embodiment, air from the blower  76  flows through a computer rack  84  ( FIG. 24 ) located within the rail car  14  for cooling or heating components installed on the computer rack  84 . Further, air from the blower  76  may be heated as it passes through the computer rack  84  prior to passing through the enclosure cap  72 . 
     Embodiments further include controlling desirable environmental conditions within the enclosed space of the rail car  14 . For example, when various components of controllers including processors and other hardware are located within the rail car  14 , conditions such as temperature and humidity may be monitored and a desirable temperature may be maintained using the blower  76  and heater/chiller  78 . 
     Although reference herein is made to the blower  564  shown mounted beneath the rail car  14  proximate to the first sensor assembly  34  and the second sensor assembly  36  and the blower  76  installed within the rail car  14 , in one embodiment a single blower may be utilized for heating or cooling the first sensor assembly  34 , the second sensor assembly  36 , and the one or more LiDAR sensors  66 . 
     The autonomous track assessment system  10  provides for autonomous collection of data from the railway track  12  and a surrounding environment on a platform that is readily compatible with existing railway vehicles. For example, the autonomous track assessment system  10  may be located along an existing train that is transporting freight or other goods without compromising operation of the train. The autonomous track assessment system  10  provides for autonomous collection of data 24 hours per day each day of the year using various sensor assemblies without requiring manual operation or control of the sensor assemblies. Embodiments of the autonomous track assessment system  10  described herein further preferably enable operation of the autonomous track assessment system  10  in harsh environments, such as in extreme cold or heat, without compromising an ability of sensor assemblies of the autonomous track assessment system  10  from capturing data during extreme weather conditions. For example, in extreme cold, it s not uncommon for ice to form on various sensor assemblies. Using the blowers described herein blowing warm air across the outer surfaces of the various sensor assemblies allows the system  10  to keep operating when other systems would be rendered ineffective because of ice build-up or, in the case of extreme hot weather, overheating. 
     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.