Patent Publication Number: US-10308265-B2

Title: Vehicle control system and method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Application No. 62/134,518, which was filed on 17 Mar. 2015. This application is also a continuation-in-part of U.S. application Ser. No. 14/922,787, filed 26 Oct. 2015, which claims priority to U.S. Provisional Application No. 62/134,518. U.S. application Ser. No. 14/922,787 also is a continuation-in-part of U.S. application Ser. No. 14/155,454, filed 15 Jan. 2014 (the “&#39;454 application”), and is a continuation-in-part of U.S. application Ser. No. 12/573,141, filed 4 Oct. 2009 (the “&#39;141 application”). The &#39;454 application is a continuation of International Application No. PCT/US13/54284, which was filed on 9 Aug. 2013, and claims priority to U.S. Provisional Application No. 61/681,843, which was filed on 10 Aug. 2012, to U.S. Provisional Application No. 61/729,188, which was filed on 21 Nov. 2012, to U.S. Provisional Application No. 61/860,469, which was filed on 31 Jul. 2013, and to U.S. Provisional Application No. 61/860,496, which was filed on 31 Jul. 2013. The &#39;141 application is a continuation-in-part of U.S. application Ser. No. 11/385,354, which was filed on 20 Mar. 2006. The entire disclosures of these applications are incorporated herein by reference. 
    
    
     FIELD 
     Embodiments of the subject matter described herein relate to systems and methods for vehicle control. 
     BACKGROUND 
     Vehicle systems, such as automobiles, mining equipment, rail vehicles, over-the-road truck fleets, and the like, may be operated, at least in part, by vehicle control systems. These vehicle control systems may perform under the manual instruction of an operator, may perform partly on manual input that is supplemented with some predetermined level of environmental awareness (such as anti-lock brakes that engage when a tire loses traction), or may perform entirely autonomously. Further, the vehicles may switch back and forth from one operating mode to another. 
     The vehicle system may not be used efficiently if the path over which it travels is in disrepair. For example, a train (including both a locomotive and a series of rail cars) may derail if the rails are not within designated specifications. Railroads may experience many derailments per year. In addition to the repair work to the rails, the resulting costs include network congestion, idled assets, lost merchandise, and the like. At least some derailments may be caused by, at least in part, faults in the track, bridge, or signal and in the mechanical aspects of the rail cars. Contributing aspects to derailments may include damaged or broken rails and wheels. 
     To reduce or prevent derailments, it has been prudent to conduct a periodic visual inspection of the track and of rail cars while in rail yards. Additionally, technology has been introduced that uses ultrasonic detection and lasers that may be mounted on hi-rail vehicles, track-geometry test cars, and wayside detectors (every 24 kilometers to 483 kilometers apart) that monitor freight car bearings, wheel impacts, dragging equipment, and hot wheels. This approach relies on the ability to maintain the track to be within tolerances so that operating a vehicle system on that track can be done in a consistent manner. 
     Various freight movers have introduced the use of unmanned vehicle (“drone”) technology to inspect right of ways or routes. These drones are equipped with at least visible light cameras, but may be equipped with more advanced LIDAR systems if certain technical challenges are overcome. The image payload is delivered to human reviewers for determination of the route status. It may be desirable to have a system that differs from those that are currently available. 
     BRIEF DESCRIPTION 
     In one embodiment of the subject matter described herein, a system is provided that includes a controller and route examination equipment. The route examination equipment obtains a route parameter indicative of a condition of a route over which a vehicle system travels. The controller receives the route parameter, and examines the route parameter to determine the condition of the route. The controller can control at least one operational aspect of the vehicle system in response to the determined condition of the route. 
     In one aspect, the route examination equipment includes one or both of a stationary wayside unit and a mobile route inspection unit. And, can combine the inspection information from multiple sources so as to predict the route condition for a particular route segment at a particular point in time. When the vehicle system is about to enter that segment, the controller can determine, based on the predicted condition of the route segment, the status of the vehicle system, and other factors, a speed ceiling for the vehicle system such that below that speed ceiling the possibility of a undesirable event (e.g., a crash or a derailment) is below a determined confidence threshold level. 
     In one embodiment of the subject matter described herein, a method includes obtaining two or more route parameters indicative of a condition of a segment of a route over which a vehicle system travels. The condition of the segment of the route is determined based on a combination of the two or more route parameters. At least one operational aspect of the vehicle system is controlled in response to the determined condition of the route. 
     In one aspect, controlling the at least one operational aspect of the vehicle system can include slowing, stopping or rerouting the vehicle system in response to the condition of the route segment being below a determined threshold prior to or during the vehicle system traversing the segment. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The subject matter described herein may be understood from reading the following description of non-limiting embodiments, with reference to the attached drawings, wherein: 
         FIG. 1  is a schematic illustration of a vehicle system according to one example of the inventive subject matter; 
         FIG. 2  is a schematic illustration of a vehicle system according to one example of the inventive subject matter; 
         FIG. 3  includes a schematic illustration of an examination system according to one embodiment; and 
         FIG. 4  illustrates a flowchart of one embodiment of a method for examining a vehicle and/or route. 
     
    
    
     DETAILED DESCRIPTION 
     One or more embodiments of the inventive subject matter described herein relate to a vehicle control system, and to associated methods of vehicle control. This “holistic inspection system” may obtain and use information from multiple sources to allow the vehicle control system to operate in a determined manner. While several examples of the inventive subject matter are described in terms of rail vehicles, not all embodiments of the inventive subject matter are limited to rail vehicles. At least some of the inventive subject matter may be used in connection with other vehicles, such as mining equipment, automobiles, marine vessels, airplanes, over the road trucks, or the like. And, where appropriate, the term track may be interchanged with path, road, route, or the like as may be indicated by language or context. Further, the term track (as well as path, road, route, etc.) may include specific segments of such, and further may include features that form a part of the track. For example, reference may be made to a bridge or other infrastructure that forms part of the route. 
     By having route detection (rail and track geometry) mounted on a powered vehicle, with sensors mounted on each car mechanically or logically coupled to the powered vehicle and communicating therewith, the powered vehicle may be “aware” of an operational change, deviation or failure on either or both of the track or the coupled car component, and a vehicle control system of the vehicle can responsively initiate a new operating mode in which the powered vehicle changes its speed, direction, or some other operating parameter. In addition, the track and vehicle system status detection may be more continuous, and less discrete or segmented (either by time or by space, or by both time and space). And, analysis of historical data may provide prognostic information relating to a particular vehicle operating at a particular track location. 
     As used herein, the term continuous means generally without significant interruption. The term discrete means confined to a location/geography or to a period of time. For example, discrete examination of a route may refer to a measurement or other examination of the route that occurs during a finite time period that is separated (in terms of time and/or location) from other discrete examinations by a significantly longer period of time than the finite time period. In contrast, continuous examination may refer to a measurement or other examination of the route that extends over a longer period of time (e.g., during an entire trip of a vehicle system from a starting location to a final destination location of the trip), that is frequently repeated, or the like. In one embodiment, discrete examinations of the route may be separated in time and/or location such that the condition of the route may significantly change between the discrete examinations. For example, a first discrete examination of the route may not identify any crack, pitting, or the like, of the route, but a subsequent, second discrete examination of the route may identify one or more cracks, pits, or the like, at the same location along the route. In contrast, a continuous examination of the route may be frequently repeated and/or non-stop such that the changing condition of the route is detected as the route condition is changing (e.g., the examination may witness the damage to the route). 
     In one embodiment, a system includes route examination equipment and a controller. The route examination equipment can obtain a route parameter indicative of a condition of a route over which a vehicle system travels. The controller receives the route parameter, and examines the route parameter to determine the condition of the route. The controller controls at least one operational aspect of the vehicle system in response to the determined condition of the route. 
     The route examination equipment can include one or both of a stationary wayside unit and a mobile route inspection unit. Suitable stationary wayside units may include one or more of a video (visible light) sensor unit, an infrared sensor unit, and an electrical current sensor. The electrical current sensor can determine if an electrical break or an electrical short has occurred in a monitored segment of the route. 
     If the vehicle system is one of a plurality of like vehicle systems, and the mobile route inspection unit includes an inspection system mounted on another, second vehicle system of the plurality of vehicle systems operating over the segment of the route prior to the first vehicle system then the system can use data for a route segment even if it was inspected by a different vehicle system&#39;s equipment. The system can, for example, organize the inspection results by chronology so as to present a trend over time and then can use that trend information predictively. Additionally or alternatively, the system can use a data set from a particular period, and then refer to a table (or the like) to determine what the expected degradation rate would be from the time of the data set until the time the vehicle is expected to travel over the corresponding segment. 
     Other suitable mobile route inspection units may include one or more of a drone or unmanned vehicle, an inspection system secured to the vehicle system as it travels over a segment of the route, or an inspection system mounted on an inspection vehicle having the primary purpose of inspecting the route. A primarily purposed inspection vehicle may include a Hi-Rail vehicle (with respect to rail usage) having gel-filled ultrasound wheels. A mounted inspection system may be secured to (again, with reference to rail usage) the locomotive and/or one or more of the rail cars. For on-road vehicles, the mounted inspection system can be secured to automobiles, tractor-trailers, busses, and the like. 
     Where the route parameters are collected by a drone, the drone can obtain images of the route using one or more of visible light video, infrared, Light Detection and Ranging (Lidar), ultrasound, and radar. Suitable drones can include an aerial drone or a surface vehicle. If the drone is a surface vehicle drone it may be autonomous or semi-autonomous as it travels over the segment of the route. Other suitable surface drones may be remotely piloted. 
     The stationary wayside unit may provide substantially continuous signals indicating the condition of the route, while the mobile route inspection unit may provide substantially periodic signals indicating the condition of the route. To be clear, the signal from the mobile unit may be continuous in its operation, but it may pass over a particular geography periodically. The controller can determine the condition of the route based at least in part on both the substantially continuous signals and on the substantially periodic signals. And, to do so, it may need to pull information from different data sets so that it can match data for a particular route segment. And, as mentioned, it may need to organize the data for a given segment based on the time stamp. 
     With regard to the at least one operational aspect of the vehicle system, in one embodiment the operational aspect is vehicle system speed. The controller can control the vehicle system speed over the route, and particularly the route segments, based on the determined condition relative to a determined threshold value for that condition. If the condition indicates the route is impassible (e.g., for a rockslide or a washout) the controlled vehicle system speed may be zero to stop the vehicle system prior to the vehicle system arriving at a segment of the route. Of note, the signal to stop would not be expected to be applied upon the mere identification of the route hazard. The vehicle system may still be many miles away from the segment in question. It may be slowed, it may be re-routed, or it may be slowed to a stop based on the stopping distance for a particular vehicle type. Additional messages, such as to initiate a fix of the route damage (e.g., repair a broken rail, fill a pot hole, etc.) may be generated and sent to the appropriate agency to remedy the situation. As noted, in one embodiment, the at least one operational aspect of the vehicle system is the route, and the controller can control the vehicle system to change at least a portion of the route from a first route portion to a second route portion, if the first route portion has a segment that has the determined condition below a determined threshold value and if the second route portion does not include the segment with the determined condition. In another embodiment, the operational aspect may be to urge the vehicle relatively left, right, up or down compared to an otherwise unaltered path. 
     Expanding on the determined condition, suitable conditions that may require the controller to respond may include one or more of a broken rail if the vehicle system is a locomotive, a rockslide or mudslide over the route, a washout of the route, a snow drift over the route, pitting, potholes downed power lines, obstacles in an upcoming crossing, loose ties, missing ballast, sinkholes, fissures, heavy fog, ice, and the like. 
     Where the route examination equipment is a drone, and the drone can switch operating modes, the switch is to shift from a first operating mode of identifying the segment of the route having a determined condition to a second operating mode where the drone can signal a location of the segment, signal a type of determined condition, signal a location of the route examination equipment, signal information about the segment of the route, perform additional sensing tests or procedures that are different from those used in the identifying of the segment, and control the route examination equipment movement. Controlling the route examination equipment movement may include one or more of the drone hovering for a determined period proximate to the segment, landing proximate to the segment, parking the route proximate to the segment, changing positions to obtain additional perspectives of the segment, and obtaining higher definition or closer images of the segment. 
     During operation, the system can obtain one or more route parameters indicative of a condition of a segment of a route over which a vehicle system travels; determine the condition of the segment of the route based on the one or more route parameters; and control at least one operational aspect of the vehicle system in response to the determined condition of the route. Controlling at least one operational aspect of the vehicle system may include, for example, slowing, stopping or rerouting the vehicle system in response to the condition of the route segment being below a determined threshold prior to or during the vehicle system traversing the segment. In one embodiment, two or more route parameters may be used. And, in one embodiment, vehicle operating parameters indicating a condition of the vehicle systems may be combined with the condition of the route to further allow the controller to control the operation of the vehicle system. 
     Additionally or alternatively, in one embodiment, the system can obtain a status of the vehicle system, and can control the operational aspect of the vehicle system in response to both the determined condition of the route and to the status of the vehicle system. For example, a vehicle with new tires may not be instructed to slow but a vehicle with worn tires may be instructed to slow when approaching a stretch of road that has an indication of a certain amount of snow or ice relative to a threshold level of snow or ice (using an on-road example). Or, a passenger car might be instructed differently than a tractor-trailer rig under a heavy load. Additional stopping distance or time might be needed, different speed limits might be in play, and so on. 
     With reference to  FIG. 1 , a schematic illustration of an embodiment of an examination system  100  is shown. The system includes a test vehicle  102  disposed on a segment of route  104  leading a vehicle system  106 . The route can be a track, road, or the like. The test vehicle can represent a rail test vehicle and the vehicle system can represent a train. Optionally, the vehicle may be another type of vehicle, the track can be another type of route, and the train can represent a vehicle system formed from two or more vehicles traveling together along the route. The vehicle system includes a lead vehicle  110  and a trail vehicle  112  in consist, and a remote vehicle  114  operating under a distributed power system, such as LOCOTROL Distributed Power available from GE Transportation. Between the trail vehicle and the remote vehicle are a plurality of cars  116 . The vehicles and cars can represent locomotives and rail cars, but optionally can represent other types of vehicles. The vehicles  112 ,  114  may be referred to as propulsion-generating vehicles and the cars  116  may be referred to as non-propulsion-generating vehicles. A wayside unit  118  is disposed proximate to the route. The wayside unit is one of a plurality of such units (not shown) that are dispersed periodically along the route. A drone that can travel down the route is not shown. 
     At least the lead vehicle has communication equipment that allows for data transmission with one or more other equipment sets off-board that vehicle. Suitable off-board equipment may include, as examples, cellular towers, Wi-Fi, wide area network (WAN) and Bluetooth enabled devices, communication satellites (e.g., low Earth orbiting or “LEO” satellites), other vehicles, and the like. These communication devices may then relay information to other vehicles or to a back office location. The information that is communicated may be in real time, near real time, or periodic. Periodic communications may take the form of “when available” uploads, for data storage devices that upload to a data repository when a communication pathway is opened to them. Also included are manual uploads, and the like, where the upload is accomplished by downloading the information to a USB drive or a computing device (smart phone, laptop, tablet and the like), and from that device communicating the information to the repository. 
     With regard to the test vehicle, the test vehicle may be run over the route at a certain frequency or in response to certain trigger conditions. Route examination equipment  314  (shown in  FIG. 3 ) onboard the test vehicle includes sensors that measure one or more parameters. The parameters can include route parameters, structure parameters, and/or environmental parameters. The route parameters may include level, grade, condition, spalling, gauge spread, and other forms of damage to the route. Structure parameters may further include information about the route bed and ballast, joints, the health of ties or sleepers, fasteners, switches, crossings, and the sub-grade. Environmental parameters may include information relating to proximate surroundings (such as brush or trees), or other such conditions on or near the route, grease or oil, leaves, snow and ice, water (particularly standing or flowing water on the tracks), sand or dirt build up, and the like. 
     The test vehicle may be land based on rails (as in the illustrated embodiment), but may be a hi-rail vehicle, may travel alongside the route (that is, wheeled), or may be airborne in the form of a drone, for example. The test vehicle may be a self-propelled vehicle, or the test vehicle may be manually run along the route such as, for example, the Sperry B-Scan Single Rail Walking Stick (available from Sperry Rail Service, a Rockwood Company) or pulled by a powered vehicle. The route examination equipment  314  onboard the test vehicle may use video, laser, x-ray, electric induction, and/or ultrasonics to test the route or a catenary line for faults, defects, wear, damage, or other conditions. For ease of discussion, all references to route will include a reference to catenary lines as appropriate. The test vehicle may include a location device (such as a global positioning system receiver) so that the segment of the route being tested at a discrete point in time and location can result in a route profile. 
     The locomotive may include a location device and sensors that detect operational information from the locomotive. In such a way, for example, an impact sensor on the locomotive may record an impact event at a known time and location. This may indicate, among other things, a fault, defect, wear or damage (or another condition) of the track. Alternatively, the detected event may be associated with, for example, a wheel and not the track. A wheel with a flat spot, or that is out of alignment, or that has some other defect associated with it may be identified by sensors on board the locomotive. The locomotive may include the communication device that allows such information to be communicated to a back office, and may include a controller that may analyze the information and may suggest to the locomotive operator or may directly control the operation of the locomotive in response to an analysis of the information. 
     The rail car may include sensors that, like the locomotive, detect events associated with the track, a catenary line, the rail car, or both. Further, communication devices may be mounted on or near the rail car sensors. In one embodiment, these communication devices may be powerful enough to communicate over a distance and directly port sensor data to an off-board receiver. In another embodiment, the rail car communication devices are able to feed data to one or more locomotives. The communication feed through may be wired (for example, the Ethernet over multiple unit (eMU) product from GE Transportation) or wireless. The locomotive may then store and/or transmit the data as desired. 
     The wayside detectors may include sensors that measure impact force, weight, weight distribution and the like for the passing train. Further, other sensors (e.g., infrared sensors) may track the bearings health and/or brake health, and the health and status of like propulsion components. In one example, a locked axle for an AC combo may heat up and the heat may be detected by a wayside monitor. 
     With reference to  FIG. 2 , a segment of track  200  is occupied by a first train set  300  that includes a lead vehicle having an inductance based broken rail detection system  206  and a trail vehicle that has an impact sensor  220  that can sense the health of the rail tracks over which it runs. A second train set  302  is traveling on a different portion of the same track as the segment with the first train set. A wayside device  304  is disposed proximate to the track. A back office facility  306  is remote from the first train set, the second train set and the wayside device. 
     During operation, the broken rail detection system and the impact sensor can sense discontinuities in the track and/or in the wheels. That information is supplied to the locomotive powering the first train set (not shown), and is reported to the facility. The information from the wayside notes the health of the wheels and combos of the first train set as it passes the wayside device. The wayside device reports that information to the facility. There may be a period of time and/or distance prior to which the health of the wheels and combos of the first train set are not monitored by a wayside device. This may be due to the spacing of the wayside devices relative to each other along the route. Of note, just as the wayside devices may provide health information at discrete distances, if the route is checked by rail test vehicles periodically such health information is provided at discrete times. Further, the accuracy and reliability of the periodic rail test vehicle will diminish and degrade over time. 
     The locomotive, or powered vehicle, may be informed of the information from on-board sensors, as well as the historic data about the upcoming track from a rail test vehicle from one or more previous surveys of the track segment, and further with information from the wayside device or devices about the track segment and/or the wheel and/or combo health of the rail cars coupled to the locomotive. With this information, a controller in the locomotive may alter the operation of the locomotive in response to encountering a section of track in which there is a concern about the health or quality of the track, or in response to the health of a wheel or combo on a rail car in the train powered by the locomotive. 
     In one embodiment, the train may be traveling along the route according to a trip plan that designates operational settings of the train as a function of one or more of distance along the route or time. For example, the trip plan may dictate different speeds, throttle positions, brake settings, etc., for the train at different locations along the route. A locomotive pulling the first train set illustrated in  FIG. 2  communicates with the facility and downloads data (learns) to the effect (for example) that the three previous rail test cars passing through a curve in an upcoming rail section detected that there were signs of the beginnings of cracks in the rails. The rails were still “in spec” when tested, but just barely, and further, there had been heavy traffic over that segment in the previous days since the last test. Further, the last wayside device noted rather severe flat spots on a damaged rail car towards the end of the mile-long first train set. The locomotive controller may then alter the trip plan in response to the information received from the various information sources. For example, the locomotive may slow down the entire first train set to navigate the curve in the track segment, and when the damaged rail car is set to enter the curve the locomotive may slow the first train set down to an even slower speed. The impact from the flat wheel spots at the slower speed may have a correspondingly lower chance of damaging the track at the curve, or of breaking either the track or the wheel set. After the first train set has cleared the curve and the track health is improved relative to the curve the locomotive may accelerate back to normal speed or to a third speed that is determined to be an efficient speed based on the health of the damaged rail car&#39;s wheel and the health of the track. 
     Using a different example, the combination of discrete information sources (geographically discrete and temporally discrete) with continuous monitoring by an on-board rail health monitor and/or broken rail detector allows for the controller in the locomotive to provide real time control over the speed and operation of the train. In one embodiment, information from a wayside detector can inform a locomotive that there is a problem or potential problem with a wheel and/or combo. The locomotive may then switch operating modes based on that information. One potential operating mode involves slowing or stopping the train. Another potential operating mode involves monitoring the train set for indications that the wheel and/or combo are exhibiting the problem. For example, if a wayside detector indicates that there is a hot axle, the locomotive can monitor the train for increased drag. If an axle seizes up, the increased resistance (or increased coupler force if there is a coupler sensor) can be detected as increased drag and an on-board the rail car sensor can alert the locomotive controller. The controller can then implement a determined action in response to detecting the increased drag. 
     Suitable other operating modes may include the use or prevention of the use of adhesion modifiers. Adhesion modifiers may be materials applied to a section of the track, such as lubricants or traction enhancers. Naturally, the lubricants may reduce friction and grip, while the traction enhancers increase it. Suitable traction enhancers may include blasted air (under defined conditions) as well as sanding and other traction enhancing techniques. Yet another operating mode may include engaging or disabling a dynamic weight management (DWM) system. The DWM system may lift or drop one or more axles to affect the weight distribution of a vehicle or vehicle system. And, another operating mode may reduce or increase wheel torque, may engage or prevent one or the other of dynamic braking or air braking, or may control the rate at which a vehicle may change its rate of acceleration or deceleration (for locomotives, that may be the rate at which notch levels may be changed). 
     In one embodiment, the combination of information from the plurality of discrete sources and the continuous source(s) is used to reduce or prevent derailment due to a broken wheel. In one embodiment, the combination of information from the plurality of discrete sources and the continuous source(s) is used to prevent derailment due to a locked axle. In one embodiment, the combination of information from the plurality of discrete sources and the continuous source(s) is used to prevent derailment due to a broken rail. In various embodiments, other sources of information may provide additional information. For example, weather services may provide data about the current, previous, or upcoming weather events. 
     In other contemplated embodiments, logically coupled or remote controlled vehicles may be used rather than locomotives. Logically coupled groups of vehicles include those that are not mechanically coupled (as are locomotives, multi-unit over-the-road trucks, and the like) but rather have a control system that operates the vehicle (speed, direction, and the like) relative to another vehicle that is nearby or relative to a stationary object. In that manner, a lead vehicle may have a human operator with a trail vehicle that is otherwise driverless and is controlled by the lead vehicle so that it, for example, follows behind and mirrors the movement and speed of the lead vehicle. 
       FIG. 3  includes a schematic illustration of vehicle examination equipment  310  of the examination system  100  according to one embodiment. The vehicle examination equipment  310  is shown as being disposed onboard the test vehicle, but optionally may be disposed onboard another vehicle and/or may be distributed among two or more vehicles in the vehicle system  106  shown in  FIG. 1 . The vehicle examination equipment  310  includes communication equipment  312  (“Communication Device” in  FIG. 3 ) that allows for data transmission with one or more other equipment sets off-board that vehicle. The communication equipment  312  can represent transceiving circuitry, such as modems, radios, antennas, or the like, for communicating data signals with off-board locations, such as other vehicles in the same vehicle system, other vehicle systems, or other off-board locations. The communication equipment can communicate the data signals to report the parameters of the route as measured by the examination system. The communication equipment can communicate the data signals in real time, near real time, or periodically. 
     The route examination equipment  314  can include one or more electrical sensors  316  that measure one or more electrical characteristics of the route and/or catenary as parameters of the route and/or catenary. The electrical sensor may be referred to as a broken rail monitor because the electrical sensor generates data representative of whether the rail of a route is broken. The electrical sensors  316  can include conductive and/or magnetic bodies such as plates, coils, brushes, or the like, that inject an electrical signal into the route (or a portion thereof) and that measure one or more electrical characteristics of the route in response thereto, such as voltages or currents conducted through the route, impedances or resistances of the route, etc. Optionally, the electrical sensors  316  can include conductive and/or magnetic bodies that generate a magnetic field across, though, or around at least part of the route and that sense one or more electrical characteristics of the route in response thereto, such as induced voltages, induced currents, or the like, conducted in the route. 
     In one aspect, the electrical sensor  316  and/or a controller  320  of the examination system  100  can determine structure parameters and/or environmental parameters of the route based on the electrical characteristics that are measured. For example, depending on the voltage, current, resistance, impedance, or the like, that is measured, the route bed and/or ballast beneath the route may be determined to have water, ice, or other conductive materials (with the voltage or current increasing and the resistance or impedance decreasing due to the presence of water or ice and the voltage or current decreasing and the resistance or impedance increasing due to the absence of water or ice) and/or damage to joints, ties, sleepers, fasteners, switches, and crossings can be identified (with the voltage or current increasing and the resistance or impedance decreasing for less damage and the voltage or current decreasing and the resistance or impedance increasing due to the increasing damage). 
     The route examination equipment  314  can include one or more optical sensors  318  that optically detect one or more characteristics of the route and/or catenary as parameters of the route and/or catenary. The optical sensor may be referred to as a broken rail monitor because the optical sensor generates data representative of whether the rail of a route is broken. The optical sensor  318  can include one or more cameras that obtain images or videos of the route, LIDAR (light generating devices such as lasers and light sensitive sensors such as photodetectors) that measure reflections of light off various portions of the route, thermographic cameras that obtain images or videos representative of thermal energy emanating from the route or catenary, etc. Optionally, the optical sensor  318  can include one or more x-ray emitters and/or detectors that generate radiation toward the route and/or the areas around the route and detect reflections of the radiation off of the route and/or other areas. These reflections can be representative of the route and/or damage to the route. 
     The optical sensor  318  can represent hardware circuitry that includes and/or is connected with one or more processors (e.g., microprocessors, field programmable gate arrays, integrated circuits, or other electronic logic-based devices) that examine the data measured by the optical sensor  318  to generate parameters of the route. For example, the optical sensor  318  can examine the images, videos, reflections of light, etc., to determine parameters such as geometries of the route (e.g., curvature of one or more rails, upward or downward bends in one or more rails, grade of the route, etc.), damage to the route (e.g., cracks, pits, breaks, holes, etc. in the route), a type of the route (e.g., a track, a road, etc.), or other information about the route. Alternatively, the optical sensor  318  may obtain the images, videos, reflections, etc., and report this data to the controller  320 , which examines the data to determine the parameters of the route. In one aspect, the optical sensor and/or the controller can determine route parameters, structure parameters, and/or environmental parameters of the route using the optical data that is obtained by the optical sensor. 
     The vehicle examination equipment  310  can include one or more impact sensors  322  that detect impacts of the vehicle during movement along the route. The impact sensor may be referred to as a broken rail monitor because the impact sensor generates data representative of whether the rail of a route is broken. Optionally, the impact sensor may be referred to as an asset health monitor because the impact sensor generates data representative of the condition of the vehicle or vehicle system. The impact sensor  322  can represent an accelerometer that generates data representative of accelerations of the vehicle, such as those accelerations that can occur when one or more wheels of the vehicle travel over a damaged portion of the route, wheels travel over a gap between neighboring sections of the route, a wheel of the vehicle has a flat spot, a wheel is not aligned with the route (e.g., with a rail of the route), or a wheel has some other defect associated with it, etc. The impact sensor  322  can represent hardware circuitry that includes and/or is connected with one or more processors (e.g., microprocessors, field programmable gate arrays, integrated circuits, or other electronic logic-based devices) that examine the accelerations measured by the impact sensor  322  to generate parameters of the route. For example, the impact sensor  322  can examine the accelerations to determine whether the vehicle traveled over a gap in the route, such as may occur when the route is broken into two or more neighboring sections. Alternatively, the impact sensor  322  may measure the accelerations and report the accelerations to the controller  320 , which examines the accelerations to determine the parameters of the route. 
     The route examination equipment  314  can include one or more acoustic sensors  324  that detect sounds generated during movement of the vehicle along the route. The acoustic sensor may be referred to as a broken rail monitor because the acoustic sensor generates data representative of whether the rail of a route is broken. In one embodiment, the acoustic sensor includes one or more ultrasound or ultrasonic transducers that emit ultrasound waves or other acoustic waves toward the route and detect echoes or other reflections of the waves off the route and/or locations near the route (e.g., the surface beneath the route, objects or debris on top of the route, etc.). The detected echoes or reflections represent acoustic data of the route, which may be used to determine parameters of the route. Optionally, the acoustic sensor can represent an acoustic pick up device, such as a microphone, that generates data representative of sounds generated by the vehicle traveling over the route. Sounds may be generated when one or more wheels of the vehicle travel over a damaged portion of the route, a gap between neighboring sections of the route, etc. The acoustic sensor can represent hardware circuitry that includes and/or is connected with one or more processors (e.g., microprocessors, field programmable gate arrays, integrated circuits, or other electronic logic-based devices) that examine the sounds detected by the acoustic sensor to generate parameters of the route. For example, the acoustic sensor can examine the sounds to determine whether the vehicle traveled over a gap in the route, such as may occur when the route is broken into two or more neighboring sections. Alternatively, the acoustic sensor may detect the sounds and report the sounds to the controller, which examines the sounds to determine the parameters of the route. 
     The acoustic sensor and/or controller can determine route parameters, structure parameters, and/or environmental parameters from the sounds that are detected. For example, the echoes that are detected by the acoustic sensor may be examined to identify cracks, pits, or other damage to the route. These echoes may represent areas inside the route that are damaged, which may not be visible from outside of the route. Optionally, designated sounds and/or sounds having one or more designated frequencies may indicate damage to the route that indicates changes in the level, grade, condition, grade, or the like of the route, changes in the route bed or ballast, damage to joints, damage to ties or sleepers, damage to fasteners, damage to or improperly functioning switches, improperly functioning crossings, changes to the sub-grade, the presence of brush or trees near the route (e.g., when the vehicle contacts the brush or trees), travel of wheels over segments of the route having grease or oil disposed on the route, the presence of leaves of the route, the presence of snow, ice, or water on the route, sand or dirt build up on the route, and the like. 
     The vehicle examination equipment  310  can include one or more car sensors  332  that detect characteristics of the test vehicle or another vehicle in the same vehicle system. The car sensor may be referred to as an asset health monitor because the car sensor generates data representative of the health of the vehicle or vehicle system. The car sensor  332  can include one or more speed sensors (e.g., tachometers), accelerometers, thermal sensors (e.g., infrared sensors that detect heat given off of bearings, axles, wheels, or the like), or other sensors that detect characteristics of the vehicle. The car sensor and/or controller can determine car parameters of the test vehicle and/or another vehicle in the vehicle consist. For example, the speeds that are detected by the car sensor may be rotational speeds of one or more wheels of the vehicle, and can be used to measure wheel creep or other characteristics representative of adhesion between the wheels and the route. The car sensor can measure accelerations of the vehicle to determine impacts of the vehicle on the route and/or with another vehicle in order to determine how much force is imparted on the vehicle and/or route. The car sensor can measure temperatures of bearings, axles, wheels, or the like, in order to determine if the bearings, axles, wheels, or the like, are overheating (and possibly indicative of a stuck axle or wheel). 
     While the test vehicle is illustrated as including wheels for land-based travel, as described above, the test vehicle optionally may travel on land using other components, may fly alongside or above the route (e.g., as an aerial vehicle), or the like. The test vehicle may include a propulsion system  326  that performs work to propel the test vehicle. The propulsion system can represent one or more engines, alternators, generators, batteries, capacitors, motors, or the like, that generate and/or receive energy (e.g., electric current) in order to power vehicle and propel the vehicle along the route. Alternatively, the test vehicle may not include the propulsion system. For example, the test vehicle may be pulled and/or pushed along the route by one or more other vehicles having propulsion systems, or may be manually pulled and/or pushed along the route. 
     While the preceding description focuses on the sensors onboard the test vehicle examining the route, optionally, one or more of the sensors may examine a catenary from which the test vehicle or the vehicle system that includes the test vehicle obtains electric current (e.g., for powering the vehicle system). For example, the electrical sensor may sense the current supplied from the catenary in order to identify surges or drops in the current (which may be indicative of damage to the catenary or equipment onboard the vehicle that receives current from the catenary). As another example, the optical sensor may obtain images of the catenary, videos of the catenary, or x-ray reflections off of the catenary in order to identify damage to the catenary. 
     The test vehicle includes a location device  328  (“Locator” in  FIG. 3 ) that determines locations of the test vehicle or the vehicle system along the route at one or more times. The location device optionally may be disposed onboard another vehicle of the vehicle system that includes the test vehicle. The location device can include a global positioning system receiver, a wireless antenna, a reader that communicates with roadside transponders, or the like. Based on signals received from one or more off-board sources (e.g., satellites, cellular signals from cellular towers, wireless signals from transponders, etc.), the location device can determine the location of the location device (and, consequently, the test vehicle or vehicle system). Optionally, the location device can represent hardware circuitry that includes and/or is connected with one or more processors (e.g., microprocessors, field programmable gate arrays, integrated circuits, or other electronic logic-based devices) and/or a speed sensor (e.g., a tachometer). The location device can determine the location of the test vehicle or vehicle system by integrating speeds measured by the speed sensor over time from a previously known or determined location in order to determine a current location of the test vehicle and/or vehicle system. 
     The controller of the test vehicle represents hardware circuitry that includes and/or is connected with one or more processors (e.g., microprocessors, field programmable gate arrays, integrated circuits, or other electronic logic-based devices) that may examine the data measured by the route examination equipment  314  to determine parameters of the route (e.g., route parameters, environmental parameters, structure parameters, etc.). Optionally, the examination system  100  may determine one or more of these parameters. The controller may communicate with an input/output device  330  and/or the propulsion system to control movement of the test vehicle and/or vehicle system (that includes the test vehicle) based on the parameters that are determined. For example, the controller may automatically change operation of the propulsion system to stop or slow movement of the vehicle system responsive to determining that a parameter indicates damage to the route, damage to the vehicle (e.g., damage to a wheel), debris on the route, or other unsafe operating conditions. Alternatively, the input/output device can represent one or more displays, touchscreens, speakers, or the like, that the controller can cause to present instructions or warnings to an operator of the vehicle system. The controller may cause the instructions or warnings to be displayed to cause the operator to change operation of the vehicle or vehicle system in response to determining that one or more of the parameters indicates an unsafe operating condition. The input/output device optionally can represent one or more input devices, such as levers, buttons, touchscreens, keyboards, steering wheels, or the like, for receiving input into the controller from an operator of the vehicle system. 
     In one embodiment, responsive to determining that a parameter indicates damage or deteriorating conditions of the route, the controller may communicate a warning signal to an off-board location, such as the facility  306  shown in  FIG. 2 . This warning signal may report the parameter that is indicative of the route damage or deteriorating condition, and the location at which the damage or deteriorating condition is identified. The deteriorating condition may include debris on the route, shifted or decreased ballast material beneath the route, overgrown vegetation on the route, damage to the route, a change in geometry of the route (e.g., one or more rails have become bent or otherwise changed such that the shape of one segment of the route is different from a remainder of the route), etc. The warning signal may be communicated automatically responsive to determining the parameter, and may cause the off-board location to automatically schedule additional inspection, maintenance, or repair of the corresponding portion of the route. In one embodiment, communication of the warning signal may cause the off-board location to change the schedules of one or more other vehicle systems. For example, the off-board location may change the schedule of other vehicle systems to cause the vehicle systems to travel more slowly or to avoid the location with which the parameter is associated. Optionally, the warning signal may be broadcast or transmitted by the communication device to one or more other vehicles to warn the vehicles, without being first communicated to the off-board location. 
     In one example of operation of the test vehicle, the vehicle can operate as a self-aware vehicle that continuously monitors itself and/or the route during movement of the vehicle or vehicle system along the route. Some known rail safety systems and methods consist of visual inspections of a track (e.g., hi-rail systems) and cars (e.g., such as visual inspections that occur in rail yards) combined with periodic inspections of the track and inspection of the cars by stationary wayside units. One significant drawback with these known systems and methods is that the inspections of the route and vehicles are discrete in time and space. With respect to time, the track and/or cars may only be inspected periodically, such as every three weeks, every six months, and the like. Between these discrete times, the track and/or cars are not inspected. With respect to location, the cars may be inspected as the cars move past stationary wayside units disposed at fixed locations and/or portions of the track that are near stationary wayside units may be inspected by the units, but between these locations of the wayside units, the track and/or cars are not inspected. 
     The examination system  100  described herein can operate using the test vehicle as a hub (e.g., a computer center) that is equipped with broken route inspection equipment (e.g., the route examination equipment  314 ) for detecting damage or deteriorating conditions of the route during movement of the test vehicle. The parameters of the route that are generated by the examination system  100  can be used to identify damaged sections of the route or sections of the route that require repair or maintenance. Optionally, the controller of the test vehicle can examine both the parameters provided by the examination system  100  and historical parameters of the route. The historical parameters of the route can include the parameters determined from data measured by the examination system  100  onboard the test vehicle and/or one or more other test vehicles during a previous time or trip. For example, the historical parameters may represent the condition or damage of the route as previously measured by the same or a different examination system. The historical parameters may be communicated from an off-board location, such as the facility  306  shown in  FIG. 2 , and based on the data measured by and provided from the examination systems onboard the same and/or different vehicles. 
     The examination system  100  onboard a test vehicle can use a combination of the currently determined parameters (e.g., the parameters determined by the examination system onboard the test vehicle during movement of the test vehicle) and previously determined parameters (e.g., the parameters determined by the examination system onboard the same test vehicle or another test vehicle during a previous traversal over the same route or section of the route and/or parameters previously determined by one or more wayside units) to control operation of the vehicle system. As one example, if previously determined parameters indicate that damage to a segment of the route is increasing (e.g., a size of a crack in the rail is increasing), but is not yet sufficiently severe to cause the vehicle system to avoid the segment of the route, to warn other vehicle systems of the damage, or to request inspection, repair, and/or maintenance of the route, then the controller may activate one or more of the route examination equipment  314  (e.g., where not all of the examination equipment is constantly activated) for continuous monitoring of the parameters of the route during movement over the same segment of the route. 
     The vehicle examination equipment  310  onboard a test vehicle can use a combination of the currently determined parameters of the vehicle and previously determined parameters of the vehicle to control operation of the vehicle system. As one example, if a warm or hot bearing is detected by a wayside unit on a particular car in a vehicle system, then the examination system  100  can direct the car sensor  332  onboard that car to measure the temperature of the bearing more frequently and/or at a finer resolution in order to ensure that the bearing temperature does not increase exponentially between wayside units. 
     The vehicle system that includes the test vehicle optionally may include an adhesion control system  334 . Although the adhesion control system is shown in  FIG. 3  as being onboard the test vehicle, optionally, the adhesion control system may be disposed onboard another vehicle of the same vehicle system. The adhesion control system represents one or more components that apply one or more adhesion-modifying substances to the route in order to change adhesion between the vehicle system (or a portion thereof) and the route. The adhesion control system can include one or more sprayers or other application devices that apply the adhesion-modifying substances and/or one or more tanks that hold the adhesion-modifying substances. The adhesion-modifying substances can include air, lubricants, sand, or the like. The controller may direct the adhesion control system as to when to apply the adhesion-modifying substances, which adhesion-modifying substances to apply, and how much of the adhesion-modifying substances are to be applied. 
     Based on the parameters of the route and/or vehicle that are determined by the examination system  100 , the operating mode of the controller may change to use or prevent the use of adhesion-modifying substances. If the parameters indicate that wheels of the vehicle system are slipping relative to the route, then the controller may prevent the adhesion control system from applying substances that reduce adhesion of the wheels to the route or may direct the adhesion control system to apply one or more substances that increase adhesion. If the parameters indicate that debris or other substances are on the route, then the controller may direct the adhesion control system to apply one or more substances that remove the debris (e.g., by directing air across the route). 
     The vehicle system that includes the test vehicle optionally may include the DWM system  336 . Although the DWM system is shown in  FIG. 3  as being onboard the test vehicle, optionally, the DWM system may be disposed onboard another vehicle of the same vehicle system. The DWM system includes one or more motors, gears, and the like, that are interconnected with axles of the vehicle on which the DWM system is disposed and may lift or drop one or more axles (relative to the route). The raising or lowering of axles can change the weight distribution of the vehicle or vehicle system on the route. Based on the parameters of the route and/or vehicle that are determined by the examination system  100 , the operating mode of the controller may change to raise or lower one or more axles of the vehicle system. If the parameters indicate that significant impact forces are being caused by wheels of the vehicle system, then the controller may direct the DWM system to raise those axles relative to the route or to lower multiple axles toward the route (and thereby reduce the force imparted by any single axle). 
     The controller may examine the parameters determined from the discrete sources (e.g., the manual and/or wayside unit inspection of the vehicle and/or route) to determine when to begin monitoring parameters of the vehicle and/or route using one or more continuous sources. For example, responsive to determining that a parameter of the vehicle or route (as determined from a wayside unit) indicates potential damage or deteriorating health (e.g., a damaged or bent rail, a hot bearing, etc.), the controller may direct the vehicle and route examination equipment  310 ,  314  to begin continually monitoring parameters of the vehicle and/or route. The continuous monitoring may be for purposes of confirming the potential damage, identifying deteriorating health (changes in damage over time), quantifying or characterizing a nature or aspect of the damage, determining information relevant to vehicle control based on detected damage, etc. With respect to the route, this can involve the controller directing the route examination equipment  314  to continually measure data and determine parameters of the route during travel over a segment of the route associated with a parameter determined by a discrete source that indicates damage or a deteriorating condition of the route. The controller may stop the continual examination of the route and/or vehicle responsive to exiting a segment of the route identified by a discrete source as being problematic, responsive to receiving one or more additional parameters from a discrete source indicating that another segment of the route is not problematic, or once the parameter of the vehicle is identified as no longer indicating a problem with the vehicle. The discrete sources of route parameters and/or vehicle parameters can include the wayside units, results of a manual inspection, or the like. In one embodiment, a weather service may provide data about the current, previous, or upcoming weather events as a discrete source of route parameters. 
     In one embodiment, the controller may use a combination of parameters from one or more discrete sources and one or more continuous sources to identify a broken wheel, locked axle, broken rail, or the like. For example, the parameters of the vehicle obtained from one or more wayside units may indicate that a wheel has a relatively small crack, flat spot, or other minor damage. The parameters may not be significant enough to cause the vehicle system to stop moving along the route. The controller may receive these parameters and then begin continually monitoring the wheel using one or more sensors of the vehicle examination equipment  310 . The continually monitored parameter or parameters of the wheel may identify a decreasing trend in the health of the wheel. For example, the parameter that is continually monitored by the vehicle examination equipment  310  may demonstrate that the crack is growing in size, that the flat spot is growing in size, or that other damage to the wheel is getting worse with respect to time. The controller can examine the changes in the continually monitored parameter(s) of the wheel with respect to time and, responsive to the changes exceeding one or more limits or approaching one or more limits, the controller can slow down or stop movement of the vehicle system before the wheel breaks, automatically request a change in the schedule of the vehicle system to obtain inspection and/or repair of the wheel, automatically request maintenance or repair of the wheel, etc. This can result in the wheel being continually monitored in response to the discrete source of information (e.g., the wayside unit) determining that the wheel may have a problem that otherwise would not prevent the vehicle system from proceeding. Due to the continual monitoring of the wheel, derailment of the vehicle system may be avoided prior to a subsequent discrete examination of the wheel. 
     In another example, the parameters of the vehicle obtained from one or more wayside units may indicate that an axle may be at least partially stuck (e.g., the parameters may indicate elevated temperatures of bearings and/or a wheel connected with the axle). The controller may receive these parameters and then begin continually monitoring the axle using one or more sensors of the vehicle examination equipment  310 . The continually monitored parameter or parameters of the axle may indicate an increasing temperature of the bearings. The controller can examine the changes in the continually monitored parameter(s) of the axle with respect to time and, responsive to the increasing temperatures exceeding one or more limits or approaching one or more limits, the controller can slow down or stop movement of the vehicle system before the axle locks up, automatically request a change in the schedule of the vehicle system to obtain inspection and/or repair of the axle, automatically request maintenance or repair of the axle, etc. This can result in the axle being continually monitored in response to the discrete source of information (e.g., the wayside unit) determining that the axle may have a problem that otherwise would not prevent the vehicle system from proceeding. Due to the continual monitoring of the axle, derailment of the vehicle system may be avoided prior to a subsequent discrete examination of the axle. 
     In another example, the parameters of the route obtained from one or more wayside units may indicate that a segment of the route is damaged (e.g., the parameters may indicate cracks in the route). The controller may receive these parameters prior to travel over the route segment and begin continually monitoring the route using one or more sensors of the route examination equipment  314 . The continually monitored parameter or parameters of the route may indicate increasing damage to the route. The controller can examine the changes in the continually monitored parameter(s) of the route and, responsive to the increasing damage exceeding one or more limits or approaching one or more limits, the controller can slow down or stop movement of the vehicle system before the route is impossible to be traveled upon (e.g., a rail breaks), automatically request a change in the schedule of the vehicle system to avoid traveling over the route segment, automatically request maintenance or repair of the route segment, etc. This can result in the route being continually monitored in response to the discrete source of information (e.g., the wayside unit) determining that the route is at least partially damaged (but still able to be traveled upon). Due to the continual monitoring of the route, derailment of the vehicle system may be avoided prior to a subsequent discrete examination of the route. 
       FIG. 4  illustrates a flowchart of one embodiment of a method  400  for examining a vehicle and/or route. The method  400  may be performed by one or more embodiments of the vehicle systems, vehicles, and examination systems described herein. In one embodiment, the method  400  may represent or be used to generate a software program that directs at least some operations of the controller and/or examination system described herein. 
     At  402 , one or more parameters of a route and/or vehicle are obtained from one or more discrete sources. The route and/or vehicle parameters may be obtained from a wayside unit, from a manual inspection, or another type of inspection of the route and/or vehicle that is not continuous in time and/or is not continuous in location. For example, the parameters may result from the periodic examination of the route and/or vehicle and/or from examination of the route and/or vehicle in a single location (but not other locations). 
     At  404 , a determination is made as to whether the parameter obtained from the discrete source indicates that the vehicle should not travel along the route. For example, the obtained parameter may indicate that the damage to the route and/or vehicle is so severe that the vehicle cannot safely proceed with travelling beyond the location where the discrete examination of the route or vehicle occurred. As a result, flow of the method  400  can proceed toward  406 . On the other hand, if the parameter from the discrete source indicates that continued travel of the vehicle is safe the flow of the method  400  can proceed toward  410 . 
     At  406 , travel of the vehicle is prevented. This system might cooperate with an existing vehicle control overlay, such as a positive train control (PTC) system. In one embodiment, the controller of the vehicle or vehicle system may prevent further movement of the vehicle or vehicle system over the portion of the route that is too badly damaged to safely travel over (as opposed to the PTC system that determines if the route is occupied with a preceding vehicle). At  408 , one or more remedial actions can be implemented. These remedial actions alternatively can be referred to as control actions, and may include slowing or stopping movement of the vehicle system, automatically requesting inspection, maintenance, or repair of the vehicle system and/or route, communicating with an off-board location of the location of the damaged route and/or vehicle, communicating warnings to other vehicle systems of the damaged route, etc. Flow of the method  400  may terminate or return to  402 . In an alternative embodiment, an existing PTC system may be the mechanism engaged so as to slow or stop the vehicle. 
     At  410 , a determination is made as to whether the parameter from the discrete source indicates a deteriorated condition of the route and/or vehicle. The parameter may indicate a deteriorated condition of the route and/or vehicle when the route and/or vehicle are damaged, but not damaged so significantly that travel is not possible over the route. For example, such a parameter can indicate damage, but not a break, in the route; a bearing with an increased temperature but with an axle that is still able to rotate; a wheel having a non-circular segment along the outer perimeter of the wheel, but not yet a flat spot, etc. The parameter may not indicate a deteriorated condition of the route and/or vehicle when the route and/or vehicle are not damaged. If the parameter does not indicate a deteriorated condition, then flow of the method  400  can proceed toward  412 . If the parameter indicates a deteriorated condition, then flow of the method  400  can proceed toward  414 . 
     At  412 , the vehicle can operate in a normal operating mode. In one embodiment, the normal operating mode includes the route and/or vehicle examination equipment  314 ,  310  not continually examining the route and/or vehicle. For example, one or more of the sensors may deactivate and not collect data representative of parameters of the route and/or vehicle. Flow of the method  400  can return toward  402  where additional parameters of the vehicle and/or route are obtained from another discrete source. This can involve the vehicle traveling to another location of a wayside unit or receiving additional information from a manual inspection of the vehicle and/or route. 
     At  414 , the examination system  100  can increase an intensity at which continuous examination of a deteriorated condition is performed during a continuous operating mode. In one example, if no continuous examining of the route and/or vehicle is being performed prior to  414 , then at  414 , continuous examining may begin in a continuous operating mode. In another example, if at least some continuous examining of the route and/or vehicle is being performed prior to  414 , then at  414 , the intensity at which this continuous examination is occurring is increased. The intensity can be increased by increasing a frequency at which data is measured, by activating and using additional sensors to monitor the route and/or vehicle, by increasing a resolution of the data being measured, etc. 
     The continuous operating mode can include one or more of the vehicle or route examination equipment  310 ,  314  continually monitoring parameters of the vehicle and/or route. The continuous monitoring can include obtaining additional data of the condition or state of the vehicle and/or route from continuous sources (e.g., sources onboard the vehicle) between the discrete sources obtaining the data of the condition or state of the vehicle. Alternatively, the continuous monitoring can include obtaining several data points (or measurements of data) during movement of the vehicle over the route. Alternatively, the continuous monitoring can mean obtaining data representative of conditions of the route and/or vehicle from one or more sensors disposed onboard the vehicle. 
     At  416 , the parameter obtained from the continuous sources is examined to determine if the parameter indicates an unsafe condition. The unsafe condition may indicate increasing severity or magnitude in damage to the route and/or vehicle, as identified by the continuous monitoring of the route and/or vehicle. For example, such a parameter can indicate increasing damage in the route as the vehicle progresses along the route; a bearing with increasing temperature; a wheel having the non-circular segment that is becoming more flat, etc. If the parameter indicates an unsafe condition, such as worsening damage of the vehicle and/or route, then flow of the method  400  can proceed toward  418 . Otherwise, flow of the method  400  can return toward  402 . 
     At  418 , one or more control actions (e.g., remedial actions) can be implemented. These control actions can include slowing or stopping movement of the vehicle system, automatically requesting inspection, maintenance, or repair of the vehicle system and/or route, communicating with an off-board location of the location of the damaged route and/or vehicle, communicating warnings to other vehicle systems of the damaged route, etc. Flow of the method  400  may terminate or return to  402 . 
     In one embodiment, a system (e.g., an examination system) includes a controller that is operable to receive information from a plurality of discrete information sources and from a continuous information source on-board a vehicle system. The controller also is operable to control one or both of speed and operation of the vehicle system based on the information received from the discrete information sources and the continuous information source. 
     In one embodiment, a system (e.g., an examination system) includes a controller and examination equipment. The controller is configured to obtain one or more of a route parameter or a vehicle parameter from discrete examinations of one or more of a route or a vehicle system. The route parameter is indicative of a health of the route over which the vehicle system travels. The vehicle parameter is indicative of a health of the vehicle system. The discrete examinations of the one or more of the route or the vehicle system are separated from each other by one or more of location or time. The controller also is configured to examine the one or more of the route parameter or the vehicle parameter to determine whether the one or more of the route or the vehicle system is damaged. The examination equipment is configured to continually monitor the one or more of the route or the vehicle system responsive to determining that the one or more of the route or the vehicle is damaged. 
     In one aspect, the controller is operable to receive at least a portion of the one or more of the route parameter or the vehicle parameter from a stationary wayside unit disposed alongside the route being traveled by the vehicle system. 
     In one aspect, the controller is operable to receive the at least the portion of the one or more of the route parameter or the vehicle parameter from the wayside unit that includes information relating to whether there is a problem or potential problem with a wheel of the vehicle system. In one aspect, the controller is operable to switch operating modes of the vehicle system based on at least one of the one or more of the route parameter or the vehicle parameter from the discrete examinations or information communicated from the examination equipment from continually monitoring the one or more of the route or the vehicle system. 
     In one aspect, at least one of the operating modes comprises the controller slowing or stopping movement of the vehicle system. In one aspect, at least one of the operating modes comprises the controller monitoring the vehicle system for one or more indications that a wheel is exhibiting a problem with the vehicle system. In one aspect, the controller is operable to receive the one or more of the route parameter or the vehicle parameter as information that is one or both of geographically discrete or temporally discrete. In one aspect, the examination equipment includes one or more of an asset health monitor or a broken rail detector. 
     In one aspect, the controller is configured to prevent or reduce a probability of occurrence of a derailment of the vehicle system due to at least one of a broken wheel, a locked axle, or a broken rail based on the one or more of the route parameter or the vehicle parameter received from the discrete examinations and information received from the examination equipment relative to the controller not receiving the one or more of the route parameter or the vehicle parameter and the information from the examination equipment. 
     In another embodiment, a method (e.g., for examining a route and/or vehicle system) includes obtaining one or more of a route parameter or a vehicle parameter from discrete examinations of one or more of a route or a vehicle system. The route parameter is indicative of a health of the route over which the vehicle system travels. The vehicle parameter is indicative of a health of the vehicle system. The discrete examinations of the one or more of the route or the vehicle system are separated from each other by one or more of location or time. The method also includes examining the one or more of the route parameter or the vehicle parameter to determine whether the one or more of the route or the vehicle system is damaged and, responsive to determining that the one or more of the route or the vehicle is damaged, continually monitoring the one or more of the route or the vehicle system. 
     In one aspect, the one or more of the route parameter or the vehicle parameter is obtained from a stationary wayside unit disposed along the route. In one aspect, continually monitoring the one or more of the route or the vehicle system includes continually monitoring the one or more of the route parameter or the vehicle parameter from examination equipment disposed onboard the vehicle system. In one aspect, continually monitoring the one or more of the route or the vehicle system occurs between plural discrete examinations of the one or more of the route or the vehicle system. 
     In one aspect, the plural discrete examinations of the one or more of the route or the vehicle system one or more of occur during different, non-overlapping time periods or occur at different locations, with the continually monitoring of the one or more of the route or the vehicle system occurring one or more of between the different, non-overlapping time periods or between the different locations. 
     In one aspect, the method also includes implementing a control action responsive to determining that the one or more of the route or the vehicle system is damaged based on continually monitoring the one or more of the route or the vehicle system. The control action includes one or more of automatically slowing or stopping movement of the vehicle system, automatically requesting inspection, repair, or maintenance of the one or more of the route or the vehicle system, applying an adhesion-modifying substance to the route, preventing application of the adhesion-modifying substance to the route, lifting one or more axles of the vehicle system away from the route, or lowering the one or more axles of the vehicle system toward the route. 
     In one aspect, both the route parameter and the vehicle parameter are obtained from the discrete examinations of the route and the vehicle system, respectively. The route parameter and the vehicle parameter can be examined to determine whether the route or the vehicle system is damaged, respectively. The one or more of the route or the vehicle system can be continually monitored, responsive to the determining damage of the one or more of the route or the vehicle, to at least one of confirm or quantify the damage. The method also can include controlling the vehicle system responsive to the damage that is at least one of confirmed or quantified. 
     In one aspect, at least one of the route parameter or the vehicle parameter is obtained from a stationary wayside unit disposed along the route. Continually monitoring the one or more of the route or the vehicle system can include continually monitoring the one or more of the route parameter or the vehicle parameter from examination equipment disposed onboard the vehicle system. 
     In one embodiment, a system (e.g., an examination system) includes one or more processors and examination equipment. The one or more processors are configured to obtain one or more of a route parameter or a vehicle parameter from discrete examinations of one or more of a route or a vehicle system. The route parameter is indicative of a health of the route over which the vehicle system travels. The vehicle parameter is indicative of a health of the vehicle system. The one or more processors also are configured to examine the one or more of the route parameter or the vehicle parameter to determine whether the one or more of the route or the vehicle system is damaged. The examination equipment is configured to continually monitor the one or more of the route or the vehicle system responsive to the one or more processors determining that the one or more of the route or the vehicle system is damaged based on the one or more of the route parameter or the vehicle parameter. 
     In one aspect, the one or more processors are configured to receive the one or more of the route parameter or the vehicle parameter from a stationary wayside unit disposed along the route. In one aspect, the examination equipment is configured to be disposed onboard the vehicle system and to continually monitor the one or more of the route or the vehicle system during movement of the vehicle system. 
     In one aspect, the examination equipment includes one or more of a car sensor configured to measure a temperature of the vehicle system, an acoustic sensor configured to measure one or more ultrasound echoes or sounds of the vehicle system or the route, an impact sensor configured to measure one or more accelerations of the vehicle system, an optical sensor configured to one or more of obtain an image or video of the route or measure geometry of the route, or an electrical sensor configured to measure one or more electrical characteristics of the route. In one aspect, the examination equipment is configured to continually monitor the one or more of the route or the vehicle system between plural discrete examinations of the one or more of the route or the vehicle system. 
     In one aspect, both the route parameter and the vehicle parameter are obtained from the discrete examinations of the route and the vehicle system, respectively. The route parameter and the vehicle parameter can be examined to determine whether the route or the vehicle system is damaged, respectively. The examination equipment can continually monitor the one or more of the route or the vehicle system responsive to the determining damage of the one or more of the route or the vehicle to at least one of confirm or quantify the damage. The one or more processors can be configured to control the vehicle system responsive to the damage that is at least one of confirmed or quantified. In one embodiment, the one or more processors are configured to receive at least one of the route parameter or the vehicle parameter from a stationary wayside unit disposed along the route. The examination equipment is configured to be disposed onboard the vehicle system. 
     The above description is illustrative and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the inventive subject matter without departing from its scope. While the dimensions and types of materials described herein are intended to define the parameters of the inventive subject matter, they are by no means limiting and are exemplary embodiments. Many other embodiments will be apparent to one of ordinary skill in the art upon reviewing the above description. The scope of the inventive subject matter should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. Further, the limitations of the following claims are not written in means-plus-function format and are not intended to be interpreted based on 35 U.S.C. § 112(f), unless and until such claim limitations expressly use the phrase “means for” followed by a statement of function void of further structure. 
     As used herein, an element or step recited in the singular and proceeded with the word “a” or “an” should be understood as not excluding plural of said elements or steps, unless such exclusion is explicitly stated. Furthermore, references to “one embodiment” of the inventive subject matter are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Moreover, unless explicitly stated to the contrary, embodiments “comprising,” “including,” or “having” an element or a plurality of elements having a particular property may include additional such elements not having that property. 
     The foregoing description of certain embodiments of the inventive subject matter will be better understood when read in conjunction with the appended drawings. To the extent that the figures illustrate diagrams of the functional blocks of various embodiments, the functional blocks are not necessarily indicative of the division between hardware circuitry. Thus, for example, one or more of the functional blocks (for example, processors or memories) may be implemented in a single piece of hardware (for example, a general purpose signal processor, microcontroller, random access memory, hard disk, and the like). Similarly, the programs may be stand-alone programs, may be incorporated as subroutines in an operating system, may be functions in an installed software package, and the like. The various embodiments are not limited to the arrangements and instrumentality shown in the drawings. 
     This written description uses examples to disclose several embodiments of the inventive subject matter and also to enable a person of ordinary skill in the art to practice the embodiments of the inventive subject matter, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the inventive subject matter is defined by the claims, and may include other examples that occur to those of ordinary skill in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.