SYSTEM AND METHOD FOR DETERMINING THE POSITION OF A SPECIFIC ITEM OF A VEHICLE SYSTEM

Abstract

A method is provided that involves obtaining a first area zone in which a specific location of a vehicle system can be determined to be present, at least partially, based on a calculated distance from a known position at the front end of the vehicle system, as determined by a front sensor. The front end can be relative to a direction of travel. The method can involve obtaining a second area zone in which the specific location of the vehicle system can be determined to be present using a different, rear sensor located at a distance from the front end of the vehicle system. The method can involve determining the degree of overlap, or lack thereof, between the first and second area zones and responding to a specific degree of overlap.

Description

BACKGROUNDTechnical field

[0001] Examples of the present subject matter relate to methods and systems for determining a position of a particular location in or on a vehicle system. Discussion of the state of the art

[0002] Vehicle systems (for example, rail vehicle systems or other vehicle systems that do not run on rails or tracks) may consist of a single vehicle or multiple vehicles. In multi-vehicle systems, the vehicles may be mechanically coupled (for example, by couplings) or logically coupled but not mechanically coupled. When vehicle systems consist of multiple vehicles, it may be necessary to determine the position of a front end of the vehicle system, a rear end of the vehicle system, and sections of the vehicle system between the front and rear ends.

[0003] Current vehicle systems may include a computer system on board the front end of the vehicle system. The computer system may provide safety, navigation, and other functions for the vehicle system. To perform these functions, it may be useful to determine a rear end position. Currently, the rear end position of the vehicle system may be determined by taking a position associated with the head end position of the vehicle and tracing a known route of the vehicle back to a distance specified by a longitude of the vehicle system, such as that specified by vehicle system personnel. The head end position of the vehicle may be determined using a Global Navigation Satellite System (GNSS) receiver.

[0004] Many current systems may only use this single data source to determine the position of the rear end of the vehicle system. Therefore, when making safety-related decisions due to errors in the data used to determine the rear end position, current systems may consider a margin of safety uncertainty further past the rear end of the vehicle system, where the actual rear end of the vehicle system might be located. The margin of safety may account for errors in the head-end position that may be due to inaccuracies in the GNSS determination of the position of the rear end of the vehicle system. However, the margin of safety cannot account for other sources of error, for example, human error in inputting the length of the vehicle system, normal vehicle dynamics such as compression and extension between vehicles, errors in a track database, or the like.Current systems may not be able to properly account for these error sources without being impractically large, as there is no other source of information about the position of the rear end of the vehicle system. As a result, current systems may not be able to determine the position of the rear end of the vehicle system with a sufficiently high confidence and / or with sufficient precision to perform safety functions (e.g., to prevent another vehicle from colliding with the rear end of the vehicle system, to ensure that the rear end of the vehicle system has cleared a railroad crossing, intersection, or switch, etc.), and it may be necessary to involve vehicle personnel to confirm the position of the rear end of the vehicle system. It may be desirable to have a system and procedure different from those currently available. SHORT DESCRIPTION

[0005] According to one example or aspect, a method is provided that includes obtaining a first range zone in which a particular location (e.g., a rear end) of a vehicle system may be determined to be present based at least in part on a calculated distance from a known position at a front end of the vehicle system determined by a front sensor. The front end may be relative to a direction of travel. The method may include obtaining a second range zone in which the particular location of the vehicle system may be determined to be present using a different, rear sensor that may be located at a distance from the front end of the vehicle system.The method may include determining the degree of overlap or lack of overlap of the first range zone and the second range zone and responding to a determined degree of overlap.

[0006] According to another example or aspect, a system is provided that includes a first sensor, a second sensor, and a controller having one or more processors. The first sensor can detect a position of a reference location of a vehicle system. The processors can calculate a first range zone in which a particular location of the vehicle system can be determined to exist based at least in part on a calculated distance from the position of the reference location determined by the first sensor. The second sensor can detect a second range zone in which the particular location of the vehicle system can be determined to exist. The controller can compare the first range zone and the second range zone and can respond to an overlap or lack of overlap of the first range zone and the second range zone.

[0007] According to one example or aspect, a method is provided that includes detecting a front or first position of a first vehicle system using a first or front sensor. The method may include adding a determined distance to the front or first position to identify a calculated range of positions of a particular location of the first vehicle system. The method may include obtaining a detected position of the particular location of the first vehicle system using a rear or second sensor.The method may include comparing the calculated range of potential positions of the particular location with an uncertainty range of the detected position of the particular location to determine whether the detected position of the particular location and the calculated range of potential positions of the particular location overlap or are within a threshold distance of each other. The method may include identifying a safety boundary at or within a rearmost portion of the calculated range and the uncertainty region in response to the calculated range and the uncertainty region overlapping or being within the threshold distance of each other, or identifying the safety boundary at or within the calculated range in response to the calculated range and the uncertainty region not overlapping and not being within the threshold distance of each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The subject matter can be understood by reading the following description of non-limiting examples with reference to the accompanying drawings, in which: Fig. 1 illustrates an example of a positioning system capable of determining a position of a particular location of a vehicle system; Fig. 2 illustrates an example of a positioning system that can determine a position of a particular location of a vehicle system based on outputs from a front sensor; Fig. 3 illustrates an example of a positioning system that can determine a position of a particular location of a vehicle system based on outputs from a rear sensor; Fig. 4 illustrates an example of a positioning system that can determine a position of a particular location of a vehicle system based on outputs from a front sensor and a rear sensor; Fig. 5 illustrates an example of a positioning system that can determine a position of a particular location of a vehicle system; and Fig. 6 illustrates an example flowchart of a method for determining a position of a particular location of a vehicle system. DETAILED DESCRIPTION

[0009] Embodiments of the subject matter described herein may relate to methods and systems for determining a position of a particular location (e.g., a rear end location) of a vehicle system. The methods and systems may use more than one source of information when determining or calculating the position of the particular location (or other location) of the vehicle system. The methods and systems may increase the confidence and reliability in determining where various locations of the vehicle system are located. This may increase the safety of the operation of the vehicle system because having more precise positions (e.g., geographical positions) of various locations (e.g.,a rear end or tail, or the last vehicle in a convoy of vehicles) of the vehicle system can help ensure that other vehicles will not collide with the vehicle system, that the vehicle system has cleared an intersection, railroad crossing, barrier, or switch, and the like. While one or more embodiments or examples described herein relate to determining the positions of the rear end of a mechanically coupled vehicle system, not all embodiments or examples may be limited to determining the positions of this location. Other embodiments or examples may relate to determining a location in a vehicle system other than the rear end, such as a location several feet from the rear end, a mid-range position, a forward position, or the like in the vehicle system.Other embodiments may further include a vehicle in a vehicle group that is remote from the lead or first vehicle.

[0010] The vehicles and vehicle systems described here extend to several types of vehicles or vehicle systems. Suitable vehicle types may include motor vehicles, trucks (with or without trailers), rail vehicles or rail vehicle systems, buses, ships, aircraft, mining vehicles, agricultural vehicles, or other off-road vehicles. The vehicle systems described here (rail vehicle systems or other vehicle systems that do not travel on rails or tracks) may consist of a single vehicle or multiple vehicles. In multi-vehicle systems, the vehicles may be mechanically coupled (for example, by couplings) or logically coupled but not mechanically coupled. For example, vehicles may be logically but not mechanically coupled if the individual vehicles communicate with each other to coordinate vehicle movements so that the vehicles travel together as a group.Vehicle systems can also be referred to as vehicle groups, convoys, formations, swarms, fleets, columns, platoons, etc.

[0011] Fig. 1 illustrates an example of a positioning system 100 that can determine a position of a particular location 110 of a vehicle system 102. The vehicle system can travel along a route 104. For example, the vehicle system can include a lead vehicle 112 at a front end 114 of the vehicle system, a rear vehicle 116 at a rear end of the vehicle system, and / or one or more intermediate vehicles 118 between the lead vehicle and the rear vehicle. Optionally, the vehicle system can include only the lead vehicle and the rear vehicle, or only the lead vehicle. As used herein, the front end of the vehicle can be a forwardmost portion of the vehicle. However, the front end can be located in a front half of the vehicle without being a forwardmost part (e.g.,The front end may be closer to the front end of the vehicle system than to the opposite end of the vehicle system. Similarly, the rear end of the vehicle may be a rearmost portion of the vehicle. However, the rear end may be located in a rear half of the vehicle without being a rearmost portion (e.g., the rear end may be closer to the rear end of the vehicle system than to the opposite end of the vehicle system).

[0012] The position of the specific location being determined can be a geocode, for example, a geographic coordinate (for example, a longitude, latitude, and / or altitude), UTM (Universal Transverse Mercator) coordinates, MGRS (Military Grid Reference System) coordinates, or another grid position. The position of the specific location can be an absolute position (for example, a precise and specific geographic position of a particular location on, above, or below the Earth's surface, providing a precise reference point for locating the specific location on the planet). Optionally, the position can be a relative position, for example, a position that is at a calculated distance from another position.

[0013] The vehicle system may include a controller 142. The controller may include hardware circuitry that may include and / or be coupled to one or more processors (e.g., one or more microprocessors, integrated circuits, microcontrollers, field-programmable gate arrays, etc.). The controller may represent one or more control units or devices that may be operatively coupled to perform the operations described herein. In one embodiment, the one or more processors may be arranged in a single, integral control unit or controller. In another embodiment, the controller may include a plurality of different control units, and the processors may be distributed among the control units. The controller may be associated with a tangible and non-transitory computer-readable storage medium (e.g.,The controller may include and / or be coupled to a memory (data storage device), referred to herein as memory. The memory may store program instructions (e.g., software) that are executed by one or more processors of the controller to perform the operations described herein. The program instructions may include one or more algorithms used by one or more processors of the controller to generate one or more outputs. In one example, one or more processors of the controller may implement machine learning or artificial intelligence (AI) systems to generate the one or more outputs. The program instructions may provide functions, models, and / or neural networks used to generate the outputs.The program instructions can also specify actions to be performed by a controller with one or more processors. While the instructions in . Fig. 1 may be shown in the vehicle system, in other examples the controller may be remote from the vehicle system.

[0014] In one example, the controller may include an on-board computer. The on-board computer may be part of a PVC system (PVC, positive vehicle control). In one example, the controller may be separate from the PVC system. The PVC system may be a subsystem on the vehicle system that can communicate with an off-board PVC system. The controller can communicate with the PVC system. A PVC system may be a control system in which a vehicle system only moves in response to the receipt or continued receipt of one or more signals (e.g., received from outside the vehicle) that meet certain criteria, e.g., the signals have certain properties (e.g.,a specific waveform and / or content) and / or are received at specific times (or according to other specific time criteria) and / or under specific conditions, may move and / or may move outside of a certain restricted manner (such as above a certain penalty speed limit). The PVC system may include information about the route or the vehicle system, for example, an intended itinerary, a route database, a length of the route, a gradient of the route, a curvature of the route, a number of vehicles in the vehicle system, a length of the vehicle system, a speed of the vehicle system, a type of vehicle in the vehicle system, a weight of the vehicle system, or the like. In one example, the on-board computer may include a Negative Vehicle Control (NVC) system.The NVC can allow a vehicle to move unless a signal (movement restriction) is received.

[0015] The system may determine a length 130 of the vehicle system. In one example, the length may be calculated by adding the lengths of the vehicles and the estimated distance(s) between vehicles. The length may be summed in a direction of movement of the vehicle system. Optionally, the length may be determined or entered by an operator or other crew member of the vehicle system, may be obtained from one or more sensors, may be received from one or more control systems, may be obtained from a vehicle database, may be learned from a vehicle manifest, or the like. Optionally, the length may be a default value or a distance. In one example, the length of the vehicle system may be determined by measuring a distance between the front end and the rear end of the vehicle system.In one embodiment, a network-level vehicle coordination and management system may use the position data to ensure that a particular block portion of a route is clear of a first vehicle before another vehicle is allowed to enter the block.

[0016] The system may include one or more sensors. A front sensor 140 may be positioned at a reference location, for example, on the front vehicle. In one example, the front sensor may be located on another vehicle of the vehicle system. The front sensor may include a navigation system or a positioning system, for example, a GNSS receiver such as a Global Positioning System (GPS) receiver, a dead reckoning mechanism using a wheel tachometer or other speed sensor, another wireless triangulation system, an inertial measurement unit that may include a digital accelerometer and a gyroscope, or the like. The front sensor may output data to the controller, and the controller may use the output to calculate a position of the vehicle system's reference location, or the front sensor itself may determine this position.This position may be or include a geographic coordinate (e.g., longitude, latitude, and / or altitude or elevation) or a position expressed in another grid. The position may be an absolute position (e.g., a geographic coordinate or a coordinate in another system) or a relative position (e.g., a distance from a specific position).

[0017] In one example, the front sensor may include another positioning system, such as a proximity sensor, that can determine or assist in determining the position by detecting the presence of a destination along the route and providing the position at which the destination was read as the position. As another example, the front sensor may be or include an optical sensor (e.g., an infrared sensor, a camera, a proximity detector, etc.) that can scan, read, or otherwise identify an identifying mark. This identifying mark may be indicia printed on a sign, a wayside device, a building, a signaling device, a barrier, or the like. The identifying mark may be associated with a position along the route.When the optical sensor scans or reads the identification mark, the position of the identification mark can be used as the position of the optical sensor.

[0018] The controller may calculate a position 111 of the particular location of the vehicle system by taking the position of the front sensor and tracing the known route (e.g., a length of the route, an elevation of the route, a curve of the route, etc.) of the vehicle system back to a distance specified as the length of the vehicle system. The controller may use inputs from the PVC system to trace the route back to the distance specified as the length of the vehicle system. In another example, the controller may use inputs from an operator or another control system to trace the route back to the distance specified as the length of the vehicle system. In one example, route information (e.g., the length, grade, shape, contour, elevation, etc.) may be output from the PVC system to the controller.In other examples, the route information may be determined from one or more sensors, one or more databases, or the like. The length of the vehicle system may be output to the controller by the PVC system, an operator, or a crew member of the vehicle system. In other examples, the length of the vehicle system may be determined based on the output of one or more sensors, one or more databases, or the like.

[0019] The position of the front sensor can be an absolute position and / or a relative position of the front sensor. The absolute position can be a geographic coordinate of the reference location, for example, the front end of the vehicle system.

[0020] The position of the front sensor may be based on a relative position. The relative position may be determined based on a proximity of the front sensor to the route or a proximity of the front sensor to a section of the route, for example, a route block. A given route may consist of multiple route blocks. The route blocks may divide the route into smaller sections, where each route block may have a known position that may be contained in the route database. In one example, an identification of the route and the route block may be stored in the route database and may be accessible to the vehicle system or operators or components thereof. An identification of the positions along the route and the route block may be stored in the route database.The route block may include wayside devices, for example, a switch with a marker (for example, a QR code or a label) that can be read by the front sensor. The front sensor may, for example, be a proximity sensor that can read and identify the marker in the wayside device when the front sensor is within a predetermined distance of the marker. When the front sensor reads the wayside device marker, the front sensor may communicate the wayside device marker to the controller of the vehicle system. The wayside device marker may have a position that may be stored in the route database. The controller or front sensor may retrieve this wayside device position from the database using the identified marker.The front sensor can transmit a signal indicating the identification of the marker of the wayside device directly to the controller. The controller can use the position information associated with the marker stored in the route database to determine the position of the marker. The controller can use the position of the marker as the position of the vehicle system's reference point.

[0021] In one example, the front sensor may communicate the determined position of the reference point to the controller via a communication device 144. However, in one example, the front sensor may communicate directly with the controller. The communication device may communicate with one or more other vehicle systems and / or other remote systems located outside the vehicle system, such as an off-board controller, a back-office control system, an off-board crew member, or the like. The off-board controller may receive updates on the position of the vehicle system and may communicate the position to other vehicle systems.The communication device may include or represent an antenna (along with associated transceiver hardware circuitry and / or software applications) for wireless communication with other vehicle systems and / or remote locations. Optionally, the communication device may communicate via one or more wired connections, such as a multiple unit (MU) cable, a train line, an electrically controlled pneumatic (ECT) brake line, or the like.

[0022] The controller may consider an uncertainty margin 160 when calculating the position of the particular location of the vehicle system. The uncertainty margin may represent a margin of error in the position of the particular location being calculated. This uncertainty margin may indicate various spaces in which the particular location may actually be located (where the calculated position is inaccurate or imprecise). In one example, the uncertainty margin may be a unique point. In another example, the uncertainty margin may be two or more points, resulting in an uncertainty range. For example, the uncertainty margin may be a distance, such as 10 meters, 15 meters, 100 meters, or the like. The uncertainty range may be a space between the two or more points, a range encompassing the two or more points, a volume encompassing the two or more points, or the like.In one example, the uncertainty margin can be expressed as a percentage, which can represent a confidence level for calculating the position of the determined location. The uncertainty margin can be determined as an estimated error standard deviation for each reported geographic position. The uncertainty margin can be calculated by the controller and can account for potential errors (e.g., errors in sensor accuracy) in the inputs (e.g., the determined positions) of the front sensor. The uncertainty margin can be based on the accuracy of the GNSS position.

[0023] In one example, the uncertainty margin may be located behind the calculated position of the particular location of the vehicle system along a direction of travel of the vehicle system. For example, the uncertainty margin may extend further behind the particular location of the vehicle system. This may allow the uncertainty margin to be communicated to the off-board control system and used as a barrier or boundary to prevent other vehicles or other vehicle systems from coming too close and colliding with the rear end of the vehicle system. Optionally, the uncertainty margin may be used to ensure that the particular location of the vehicle system has passed through or is no longer located within a railroad crossing, intersection, switch, barrier, or the like. In one example, the uncertainty margin may be located ahead of the calculated position of the particular location along a direction of travel of the vehicle system.

[0024] The errors used to determine uncertainty may include errors in the accuracy of the front sensor, for example, a margin of error in the accuracy of the GNSS position. Errors may also include errors in determining the length of the vehicle system, the length and / or curvature of the route, or the like.

[0025] In one example, the uncertainty margin can be a standard value. The standard value can be determined based on historical data indicating an uncertainty of historical positions determined for the specific location of the vehicle system compared to the actual positions of the specific location of the vehicle system. If the historical positions deviate greatly from the actual positions or if there are large errors associated with the historical positions, the uncertainty margin can be larger. If the historical positions deviate less from the actual positions or if there are smaller errors associated with them, the front and rear position uncertainty can be smaller. The standard values ​​of the front and rear position uncertainty can be determined based on a formula derived based on the historical data.

[0026] In one example, the uncertainty margin may be manually entered by a crew member of the vehicle system. In one example, the uncertainty margin may be calculated based on a vehicle system speed. In one example, the uncertainty margin may be larger when the vehicle system speed is higher. When the vehicle system speed is slower, the uncertainty margin may be smaller. This may be due to the fact that the measured positions of the specific location change more quickly during fast movement, which may lead to greater uncertainty in the measurement of the geographic position of the specific location (compared to slower movement).

[0027] Another source of uncertainty in determining the position of the specific point based on the front sensor can be vehicle dynamics uncertainty. Vehicle dynamics uncertainty can be variations in the length of the vehicle system, which can be used to calculate the position of the specific point from the measured position of the front sensor. Vehicle dynamics uncertainty can be changes in the length of the vehicle system due to movements permitted between vehicle couplings, for example, extension or compression. Vehicle dynamics uncertainty can increase or change against the direction of movement when the vehicles of the vehicle system pull apart. Vehicle dynamics uncertainty can decrease or change in the direction of movement when the vehicles of the vehicle system compress.The vehicle dynamics uncertainty can estimate an average distance between vehicles of the vehicle system.

[0028] In one example, the estimated distance between vehicles may be between 6 inches and 75 inches. The average distance between vehicles may be multiplied by the number of vehicles in the vehicle system. This may provide an estimate of a total distance or length between the vehicles of the vehicle system. In one example, the vehicle system may be commanded to operate in a compress mode to reduce the gaps between adjacent vehicles of the vehicle system. In one example, the vehicle system may be commanded to operate in a stretch mode to increase the gaps between adjacent vehicles of the vehicle system. The controller may receive the operating mode of the vehicle system (e.g., compress, stretch, etc.) and may change the calculated position of the determined location based on the operating mode.Vehicle dynamics can change during a trip, so it may be useful to use vehicle dynamics uncertainty. Vehicle dynamics uncertainty can specify a range based on whether the vehicle is in a fully compressed or fully extended position, for example. By determining vehicle dynamics uncertainty, the length of the vehicle system can be estimated more accurately, potentially allowing the controller to more accurately calculate the position of the specific location.

[0029] The vehicle dynamics uncertainty can be calculated as a predetermined percentage of the total length of the vehicle system. For example, the vehicle dynamics uncertainty can be between 0.3% and 5% of the total length of the vehicle system. The vehicle dynamics uncertainty can be validated when the vehicle system is stopped to ensure that the length of the vehicle system has not changed by more than the predetermined percentage of the total length of the vehicle system. When the vehicle system is potentially stopped, the length can be measured by the one or more sensors. This measurement and validation when the vehicle system is potentially stopped can increase confidence in the vehicle dynamics uncertainty while the vehicle system is moving.

[0030] In one example, the uncertainty margin may be calculated or measured by the controller by considering the distance between vehicles (e.g., distances between vehicles). The distance between vehicles may be measured or calculated using sensors that measure the distance between vehicles, default values ​​based on the number of vehicles of the vehicle system, types of couplings, the route, and vehicle characteristics (e.g., the curve of the route, the speed of the vehicle system, the compression / stretch of the vehicle system, or the like). The controller may use the vehicle dynamics uncertainty to calculate the position of the particular location of the vehicle system. In particular, the controller may use the vehicle dynamics uncertainty as a factor to calculate the uncertainty margin or to adjust the uncertainty margin.

[0031] The uncertainty margin may include an additional distance behind the calculated position of the specific location of the vehicle system to ensure that the current position of the specific location of the vehicle system can be covered by the uncertainty margin. The uncertainty margin may ensure that there is sufficient distance behind the specific location of the vehicle system, if necessary. An additional safety margin may be added to the uncertainty margin. The additional safety margin may be a distance behind the expected position of the specific location. The additional safety margin may be a safety measure to ensure that the safety margin can be sufficiently far behind the specific location of the vehicle system to perform a specific operation, for example, a safety operation.

[0032] The uncertainty margin may provide a spatial buffer to ensure that the particular location of the vehicle system, for example, the rear end, can be detected by the calculated position of the particular location. The uncertainty margin may be used by the operator and / or control system in making safety-related decisions related to the particular location of the vehicle system. For example, the uncertainty margin may be used in deciding whether another vehicle system can safely pass behind the particular location of the vehicle system. The uncertainty margin may be determined regularly during a journey, for example, every ten seconds. In one example, the uncertainty margin may be determined in response to an operational or safety command by the operator.

[0033] A rear sensor 150 may be positioned on the rear vehicle. The rear sensor may be positioned on another vehicle of the vehicle system, for example, at any position on the vehicle system that may be behind the front sensor in a direction of travel. In one example, the rear sensor may be positioned on a driven vehicle of the vehicle system. The rear sensor may include a navigation system or a positioning system, for example, a GNSS transceiver, another wireless triangulation system, or the like. The rear sensor may include one of the sensors discussed above with respect to the front sensor.

[0034] The rear sensor may determine a measured position 170 of the particular location of the vehicle system. In one example, the measured position may be a distance spaced a fixed distance from the particular location, for example, 10 feet, 100 feet, 500 feet, or the like. The controller may use information from the rear sensor, the PVC system, and other inputs to calculate the position of the particular location of the vehicle system. As discussed further below, the other inputs may include route information, vehicle speed, communication data, or the like. In one example, the position may be a single point, but in other examples, the position may be an area consisting of two or more points.The area may be a space between the two or more points, a region encompassing the two or more points, a volume encompassing the two or more points, or the like. The rear sensor may transmit the determined position of the rear end of the vehicle system to the vehicle system controller.

[0035] In one example, the controller may be located at the front end of the vehicle system. The rear sensor may communicate with the controller repeatedly, for example, once per minute, once every two minutes, or the like. In another example, the controller may be located at the rear end of the vehicle system. In another example, both the rear end and the front end of the vehicle system may have on-board controllers. In some cases, the rear sensor may not be able to communicate with the controller, and thus the controller may not be able to calculate the position of the particular vehicle system location based on the rear sensor. If the controller cannot receive output from the rear sensor, the controller may rely on the front sensor to determine the position of the particular vehicle system location.However, if the controller receives an output from the rear sensor, the controller may determine whether the calculated position of the particular location and the measured position of the particular location determined using inputs from the rear sensor are correlated. The positions may be correlated if the positions are within a threshold distance of each other. If the positions are within the threshold distance, this may indicate that both sensors determined the particular location in a similar general area, thus providing greater confidence in the position of the particular location. If the positions determined by the front sensor and the rear sensor are correlated, the controller may use the output from the rear sensor, the output from the front sensor, outputs from the PVC system, outputs from crew members, and the like to determine the position of the particular location of the vehicle system.

[0036] The controller may determine a rear sensor uncertainty 172 behind the measured position to account for potential expected errors in the measurement from the rear sensor. In one example, the rear sensor uncertainty behind the measured position may account for communication delays from the rear sensor to the controller. There may be a delay in delivering the output from the rear sensor to the controller, and the controller may account for this delay when determining the rear sensor uncertainty. For example, the rear sensor uncertainty may be changed to a direction opposite to motion in response to a larger communication delay. In one example, the rear sensor uncertainty may be determined by the controller and account for a speed of the vehicle system.The speed of the vehicle system may be a current speed of the rear end of the vehicle system, the front end of the vehicle system, an average speed of the vehicle system, or the like.

[0037] The controller may multiply the vehicle system's speed by the communication delay to determine the rear sensor's uncertainty. For example, the communication delay may be two seconds, and the controller may multiply the communication delay by the vehicle system's speed to account for the communication delay and calculate the rear sensor's uncertainty. In one example, the rear sensor's uncertainty may be lower when the vehicle system's speed is slower. This may be because the measured positions of the particular spot change more quickly during fast movement, which may result in greater uncertainty in the measurement of the particular spot's geographic position (compared to slower movement).In one example, the front sensor data may be stored with timestamps in the front section of the vehicle system, and the rear sensor data may be sent to the front section of the vehicle system. The rear sensor data is received at the front section of the vehicle system with a delay, and the delay may be compared to the corresponding front sensor data based on the data timestamps.

[0038] In one example, the rear sensor uncertainty may be a default value that may be determined by the controller based on historical data from the rear sensor compared to historical data of an actual position of the particular location of the vehicle system. If the historical data from the rear sensor and the actual position may vary greatly or may have large associated errors, the rear sensor uncertainty may be larger. If the historical data from the rear sensor and the actual position may vary less greatly or may have smaller associated errors, the rear sensor uncertainty may be smaller.

[0039] The controller may determine the rear sensor uncertainty to account for errors in sensor accuracy (e.g., GNSS error margin), communication delay, the PVC system, the operating characteristics of the vehicle system, and the like. The rear sensor uncertainty may represent a margin of error in the position of the particular location measured using the rear sensor. This uncertainty margin may indicate various spaces in which the particular location may actually be located (where the measured position is inaccurate or imprecise). In one example, the rear sensor uncertainty may be a single point. In another example, the rear sensor uncertainty may be two or more points that form an uncertainty region.The uncertainty range can be a space between the two or more points, a region encompassing the two or more points, a volume encompassing the two or more points, or the like. The uncertainty of the rear sensor can be calculated by the controller and can account for potential errors (e.g., sensor accuracy errors) in the inputs (e.g., measured positions) from the rear sensor.

[0040] The rear sensor uncertainty can provide a more conservative estimate for the position of the specific location of the vehicle system. This can be useful when making safety decisions that affect the specific location of the vehicle system. The rear sensor uncertainty can be determined by the controller using the rear sensor output and multiplied by an uncertainty factor for the output. In one example, the rear sensor uncertainty factor can be determined by the controller or by machine learning based on historical data or based on a formula. In one example, the rear sensor uncertainty factor can be a standard value. The rear sensor uncertainty factor can then be added to the position output by the rear sensor to arrive at the rear sensor uncertainty point behind the position of the specific location.The uncertainty of the rear sensor behind the position of the specific location may provide a position that may be further behind the position of the specific location determined with the rear sensor.

[0041] The rear sensor uncertainty may be used as a buffer to ensure that the specific location of the vehicle system can be detected. In one example, the rear sensor uncertainty factor for a GNSS position may be approximately 99.9999999%. In one example, the rear sensor uncertainty margin may be expressed as a percentage, which may represent the confidence level for calculating the position of the specific location. The rear sensor uncertainty margin may be determined as an estimated error standard deviation for each reported geographic position. The rear sensor uncertainty factor may be determined repeatedly during a trip, for example, once per minute. In one example, the rear sensor uncertainty factor may be determined in response to an operational or safety command from the operator.In one example, the rear sensor uncertainty factor may be determined each time the rear sensor outputs data to the controller. Suitable methods for calculating, determining, or expressing the uncertainty factor may include a numerical value, a categorization (high / medium / low, etc.), and the like.

[0042] In one example, the controller may compare the uncertainty margin and the rear sensor uncertainty to determine a verified position uncertainty 180 behind the particular location of the vehicle system. Using the front sensor and the rear sensor, the controller may calculate the verified position uncertainty based on a most conservative location (e.g., the furthest rearward position in the direction of travel) possible between the two correlated positions of the particular location. In the Fig. 1, the rear sensor uncertainty may be the most conservative position and may therefore be used as the verified position uncertainty. Therefore, the uncertainty margin may be updated to a new uncertainty margin 162 to match the verified uncertainty margin. In another example, the uncertainty margin may be the most conservative position and may be used as the verified position uncertainty. In this scenario, the rear sensor uncertainty may be updated based on the verified position uncertainty. In one example, the verified position uncertainty behind the specific location of the vehicle system may be a single point. In one example, the verified position uncertainty behind the specific location may be two or more points.

[0043] The verified position uncertainty behind the specific location of the vehicle system may be a conservative, or worst-case scenario, for where the specific location of the vehicle system may be located. This may help facilitate safety decisions related to the specific location of the vehicle system. By using the outputs from multiple sensors at multiple locations of the vehicle control system, the controller may be able to determine the specific position of the specific location of the vehicle system with higher confidence. The verified position uncertainty may be determined repeatedly during a trip, for example, every ten seconds. In one example, the verified position uncertainty may be determined in response to an operator operational or safety command.

[0044] Fig. 2 illustrates an example of a positioning system 200 that can determine a position of a particular location of a vehicle system 202 based on outputs from a front sensor. Fig. 2 may contain substantially similar components (e.g. vehicle system, sensors, control) as in Fig. 1. For the sake of brevity, the components are included in the discussion of Fig. 2 included. The system of Fig. 2 can primarily use the position information calculated by the controller using the front sensor, the length of the vehicle system, and the route database. In the Fig. In the example illustrated in Figure 2, the particular location may be the rear end of the vehicle system, but the particular location may also be located elsewhere in the vehicle system. The particular location may have an actual position 210. The actual position of the particular location may be the position at which the particular location actually exists and which the positioning system may attempt to determine.

[0045] The controller may determine a forward position uncertainty 260 of the determined location of the vehicle system and a rearward position uncertainty 262 of the determined location of the vehicle system. The forward position uncertainty of the determined location may be a forward-most position, in the direction of travel, of the calculated position of the determined location. The forward position uncertainty may be based on a forward portion of the calculated position of the determined location, incorporating the uncertainty margin. The rearward position uncertainty may be a rearward-most position, in the direction of travel, of the calculated position of the determined location. The rearward position uncertainty may be based on a rearward portion of the calculated position of the determined location, incorporating the uncertainty margin.

[0046] The leading and trailing position uncertainty may be calculated by the controller and may account for potential errors (e.g., errors in sensor accuracy) in the inputs (e.g., the determined positions) from the leading sensor. The leading position uncertainty may be based on the accuracy of the GNSS position, which may be 99.9999999%. In one example, the leading position uncertainty margin may be expressed as a percentage, which may represent the confidence level for calculating the position of the determined location. The leading position uncertainty margin may be determined as an estimated error standard deviation for each reported geographic position. In one example, the leading and trailing position uncertainties may be a standard value.The default value can be calculated based on historical data indicating the uncertainty of historical positions determined for a particular vehicle system location compared to the actual positions of that particular vehicle system location. The default values ​​for the leading and trailing position uncertainty can be determined based on a formula derived from the historical data. In one example, the position uncertainty can be entered manually by a vehicle system crew member.

[0047] The controller may calculate a verified position uncertainty behind 282 the determined location of the vehicle system, as well as a verified position uncertainty in front 280 of the determined location of the vehicle system. Using the front sensor and the rear sensor, the controller may calculate the verified position uncertainty based on the most conservative location (e.g., the furthest rearward position) possible between the two correlated positions of the determined location, as discussed above. The verified position uncertainty may include outputs from the rear sensor to confirm or reject the position determined based on the outputs of the front sensor. For example, the controller may use the verified position uncertainty to determine whether the outputs from the rear sensor can be within the determined position uncertainty of the front sensor.If the outputs from the rear sensor can be within the determined position uncertainty of the front sensor, the positioning system can have higher confidence regarding the position of the specified location, because both sensors can provide a position within a threshold of each other. In other words, both sensors can provide a position that can be correlated with each other, thereby increasing the confidence level that positions are accurate.

[0048] A range between the verified position uncertainty behind and the verified position uncertainty in front may be a first range zone 220 in which the particular location of the vehicle system may be located. The first range zone may be calculated by the controller based on the inputs from the front sensor and may be the range that the positioning system has calculated as the one in which the particular location of the vehicle system is located. The first range zone may be the range that the controller calculates, taking uncertainty into account, as the one in which the particular location may be located. The controller may use the first range zone as the expected range of the particular location, and the controller may use the first range zone in safety decisions or navigation decisions related to the particular location of the vehicle system.

[0049] Fig. 3 illustrates an example of a positioning system 300 that can determine a position of a particular location of a vehicle system 302 based on outputs from the rear sensor. Fig. 3 may contain substantially similar components (e.g. vehicle system, sensors, control) as in Fig. 1. For the sake of brevity, the components are included in the discussion of Fig. 3 included. The system in Fig. 3 can primarily use the position information calculated by the control system using the rear sensor. In the Fig. In the example illustrated in Figure 3, the specific location may be the rear end of the vehicle system, but the specific location may also be another portion of the vehicle system. The specific location of the vehicle may have a position 370 measured by the rear sensor. The position measured by the rear sensor may be a position at which the rear sensor may expect the presence of the specific location of the vehicle system.

[0050] The controller may calculate a rear sensor position uncertainty 372 to account for potential expected errors in the rear sensor measurement, communication delay, vehicle speed, and the like, as explained above. The rear sensor uncertainty may account for errors in the sensor measurement, communication delays, vehicle speed, and the like. The rear sensor uncertainty may provide a more conservative estimate for the position of the particular location of the vehicle system.

[0051] The controller may determine a verified forward position uncertainty 360 of the rear sensor of the particular location of the vehicle system and a verified rear position uncertainty 362 of the rear sensor of the particular location of the vehicle system. The verified forward uncertainty of the rear sensor and the verified forward uncertainty of the rear sensor may be calculated by the controller by incorporating outputs from the forward sensor to confirm or reject the position measured by the rear sensor. For example, the controller may use the verified forward position uncertainty of the rear sensor to determine whether the outputs from the forward sensor may be within the determined position uncertainty from the rear sensor.If the outputs from the front sensor can be within the determined position uncertainty of the rear sensor, the positioning system can have higher confidence regarding the position of the specified location, because both sensors can provide a position within a threshold of each other. In other words, both sensors can provide a position that can be correlated with each other, thereby increasing the confidence level that positions are accurate.

[0052] The verified forward position uncertainty of the rear sensor may be a forward-most position at which the positioning system can expect the presence of the specific vehicle system location based on the outputs of the rear sensor. The verified rearward position uncertainty of the rear sensor may be a rearward-most position at which the positioning system can expect the presence of the specific vehicle system location based on the outputs of the rear sensor. The verified forward and rearward position uncertainties of the rear sensor may form a range within which the rear sensor can determine the specific vehicle system location. In one example, the verified rearward position uncertainty of the rear sensor may be the same as the rear sensor uncertainty discussed above.The controller may determine a second range zone 320 between the verified forward position uncertainty of the rear sensor and the verified rear position uncertainty of the rear sensor. The second range zone may provide an expected range that may include the particular location of the vehicle, as determined by the controller based on the output of the rear sensor. The second range zone may be the range that the controller calculates, taking uncertainty into account, as where the particular location may be located. The controller may use the second range zone as the expected range of the particular location, and the controller may use the second range zone in safety decisions or navigation decisions related to the particular location of the vehicle system.

[0053] In one example, the controller may receive multiple outputs of the position of the particular location measured by the rear sensor, particularly when the vehicle system may be stopped. The controller may average the multiple outputs as well as average the position uncertainty of the multiple outputs. The controller may use the average position and the average position uncertainty to determine the particular location based on the rear sensor outputs. In an example where the vehicle system may be stopped, additional weight may be given to the average position. For example, if the vehicle system may be stopped and multiple position readings from the rear sensor indicate that the particular location of the vehicle system is within a certain range, the average position may be used as a heavily weighted factor for the position of the particular location.Additionally, the controller can use the mean position to calculate the distance between adjacent vehicles when the vehicle system is stopped. The controller can use this information to validate vehicle dynamics uncertainty, as discussed above.

[0054] The output of the rear sensor may be compared to a position of a wayside device 380 positioned along the route traveled by the vehicle system when the particular location of the vehicle system potentially passes the wayside device. The particular location of the vehicle system may include a tag reader 382, ​​for example, a radio frequency identification (RFID), that can read a tag or signal from the wayside device. In one example, the wayside device may be a switch in the traveled route. If the output from the rear sensor is potentially determined to be within a predetermined threshold of the wayside device, the controller may give more weight to the output from the rear sensor.If the output from the rear sensor may be outside the predetermined threshold of the wayside device, the controller may give less weight to the output from the rear sensor.

[0055] Fig. 4 illustrates an example of a positioning system 400 that can determine a position of a particular location of a vehicle system 402 based on outputs from the front sensor and the rear sensor. The controller can compare the first range zone and the second range zone determined by the controller. The controller can detect if an overlap 418 may exist between the first range zone and the second range zone. The overlap may indicate higher confidence in the first range zone and the second range zone, allowing certain safety functions to be requested or performed without further input from the operator or crew member. The overlap may indicate higher confidence because both range zones produced positions that can be correlated with each other.

[0056] In the case of a possible overlap, the controller may determine a third range zone 420 in which the particular location of the vehicle system may be located. The third range zone may be based on a rearmost portion 362 of the overlap. Fig. In the embodiment illustrated in Figure 4, the rearmost portion of the overlap may be the rearward position uncertainty of the rear sensor. In another example, the rearmost portion of the overlap may be the rearward position uncertainty of the front sensor. The third range zone may be used as a safety uncertainty distance behind the particular location of the vehicle system. The third range zone may be used by the system when more conservative decisions need to be made, for example, when making a safety decision, for example, whether another vehicle system can pass behind the particular location of the vehicle system.The third range zone may not be associated with the most probable position of the particular location, but the third range zone may provide a furthest back position in which the particular location may be located to accommodate a safety uncertainty position.

[0057] If there is a possible overlap between the first and second range zones, the controller may determine a position of the particular location based on the overlap, wherein the position of the particular location may be a position range 422 that is most likely associated with the particular location of the vehicle. Fig. In the example illustrated in Figure 4, the position range most likely associated with the particular location of the vehicle may be a position between the forward position uncertainty of the rear sensor and the verified position uncertainty behind the particular location of the vehicle system. These positions may be selected as fully overlapping portions of the first and second range zones. In one example, the position of the particular location may be an average of the first range zone and the second range zone. In another example, the first range zone and the second range zone may be weighted based on a confidence level associated with the range zone. The position of the particular location may be calculated based on the weight of the first range zone and the second range zone.The position of the specific location may be used for non-safety purposes, for example, to indicate on a map where the specific location of the vehicle system may be, where an accurate estimate may be more valuable than a conservative estimate.

[0058] If an overlap could exist, this may indicate an area where there may be a higher confidence of the presence of the particular vehicle system location. The higher confidence may be due to the fact that the multiple input sources (e.g., at least the front sensor and the rear sensor) indicate that the particular vehicle system location may be in the same general vicinity. The higher confidence may result in actions being requested or taken without additional input from the vehicle system operator or crew to verify the position of the particular location. For example, safety decisions, such as whether another vehicle system can pass behind the particular vehicle system location, may be made without additional input if the higher confidence may exist due to the overlap.

[0059] Fig. 5 shows an example of a positioning system 500 that can determine a position of a particular location of a vehicle system 502. The particular location (e.g., the rear end position) of the vehicle system can have an actual position 510. The actual position can be the position where the particular location of the vehicle system can actually be located. The first range zone can have a rearward position uncertainty 262 of the particular location of the vehicle system. The second range zone 320 can be located entirely outside the first range zone 220 and behind the rearward position uncertainty. In one example, the controller can determine a time at which the first range zone and the second range zone were calculated based on a timestamp of the outputs from the front and rear sensors, respectively.This can ensure that the first range zone and the second range zone are evaluated within a predetermined time period of each other. The predetermined time period can be between 5 seconds and 5 minutes after the determination of the first range zone and the second range zone. Determining that the first range zone and the second range zone are determined within the predetermined time can ensure that the range zones can predict the position of the specific location close enough in time and space that a correlation between the ranges can be expected.

[0060] If the first range zone and the second range zone do not overlap, the controller can take a response action. The lack of overlap between the first range zone and the second range zone may indicate problems with the vehicle system, such as a lack of vehicle system integrity. The response action may include modifying the operation of the vehicle system by slowing or stopping the vehicle system to prevent damage to the vehicle system or another vehicle system, sending a notification to the vehicle system operator indicating the potential problem, sending a notification to an off-board controller or the operator, performing an inspection of the vehicle system or route, raising an alarm, or the like.

[0061] In one example, the controller may use the first range zone and discard the second range zone if no overlap can be present. The controller may use the first range zone because the front sensor may provide more frequent communication with the controller and thus be more reliable. In one example, the controller may use the second range zone and discard the first range zone if no overlap can be present. The controller may slow or stop the vehicle system if no overlap is determined between the first range zone and the second range zone. The second range zone being greater than a threshold distance from the first range zone may indicate that the particular location of the vehicle may no longer be moving with the front end of the vehicle.If the second range zone is potentially greater than a threshold distance from the first range zone, the controller may take a responsive action. The controller may request an inspection of a portion of the vehicle system that includes the rear sensor. The inspection may be used to determine whether the portion of the vehicle system that includes the rear sensor has broken away from the rest of the vehicle system (e.g., a first vehicle 512 that is separated from the front portion of the vehicle system).

[0062] As explained above, the rear sensor may need to communicate an output from the particular location 514 (e.g., the rear end) of the vehicle system to the controller, in one example, at the front end of the vehicle system. For some vehicle systems, this may be a large distance, which may result in a delay in communication from the rear sensor to the controller. As such, in one example, a particular speed of the particular location of the vehicle system may be determined and may be multiplied by a communication delay of the particular location. In one example, the speed of a front end of the vehicle system may be multiplied by the communication delay of the particular location.By multiplying the speed by the communication delay, the controller may be able to account for the difference between the determined position and the actual position due to the reporting delay for a moving vehicle system. The communication delay for the determined location may include the time required to relay a message from the determined location of the vehicle system to the front end of the vehicle system. The determined location communication delay, in one example, may be between 0.1 seconds and 5 seconds. The rear sensor uncertainty may be added to the product of the determined location speed and the determined location communication delay to provide the second range zone.

[0063] Fig.6 shows an example of a flowchart of a method for determining a position of a specific location of a vehicle system.

[0064] In step 602, the method may include obtaining a first range zone in which a particular location of a vehicle system is determined to exist based at least in part on a calculated distance from a known position at a front end of the vehicle system determined by a front sensor. The front sensor may include a navigation system or a positioning system, for example, a GNSS, a dead reckoning mechanism using a wheel tachometer or other speed sensor, or the like. The front sensor may determine a position of the front end of the vehicle system. The position may be determined based on an absolute position or a relative position. The relative position may be determined based on a proximity of the front sensor to the route or a portion of the route, such as a route block, as discussed above.

[0065] In step 604, the method may include obtaining a second range zone in which the particular location of the vehicle system is determined to be present using a different, rear sensor that may not be located at the front end of the vehicle system. The rear sensor may include a navigation system or a positioning system, for example, a GNSS or the like.

[0066] In step 606, the method may include comparing the first range zone and the second range zone and responding to an overlap or lack of overlap of the first range zone and the second range zone. The overlap may indicate higher confidence in the first range zone and the second range zone, so that certain safety functions may be requested or performed without further input from the operator or crew member. If an overlap exists, the controller may determine a third range zone in which the particular location of the vehicle system may be located. In one example, the third range zone may be based on a rearmost portion of the overlap to provide a more conservative estimate of the position of the particular location.In another example, the third range zone may be an average of the first range zone and the second range zone, where the third range zone may be the most likely area in which the particular location of the vehicle may be located.

[0067] The controller may compile the information received from the front sensor, the rear sensor, the vehicle system, and the control systems, as well as the determined positions based on these inputs. The controller may implement a machine learning system to evaluate the determined positions over time. In particular, the controller may categorize the inputs and evaluate the determined positions based on the categorized inputs. For example, the controller may evaluate the determined positions based on the length of the vehicle system, the number of vehicles, the route position, or the like. This may allow the controller to use machine learning to evaluate the determined positions based on various inputs. For example, the machine learning system may indicate a greater compression along a given route, resulting in a less accurate position of the determined location.The machine learning system can compensate for past errors in future determinations.

[0068] As discussed above, the specific location determination and system may operate autonomously without user input. Furthermore, the specific location determination system may catalog previously executed and collected data. In one embodiment, the specific location determination system may include a local data acquisition system that may use machine learning to enable inference-based learning. The controller may learn from a data set (including data provided by the various sensors) and make decisions by making data-driven predictions and adapting according to the data set. In embodiments, machine learning may involve the performance of multiple machine learning tasks by machine learning systems, such as supervised learning, unsupervised learning, and reinforcement learning.Supervised learning may involve presenting a set of sample inputs and desired outputs to the machine learning system. Unsupervised learning may involve the learning algorithm structuring its input through techniques such as pattern recognition and / or feature learning. Reinforcement learning may involve the machine learning system operating in a dynamic environment and then providing feedback on correct and incorrect decisions. For example, machine learning may involve several other tasks based on an output of the machine learning system. In examples, the tasks may be machine learning problems such as classification, regression, clustering, density estimation, dimensionality reduction, anomaly detection, and the like. For example, machine learning may involve several mathematical and statistical techniques.The many types of machine learning algorithms include, for example, decision tree-based learning, association rule learning, deep learning, artificial neural networks, genetic learning algorithms, inductive logic programming, support vector machines (SVMs), Bayesian networks, reinforcement learning, representation learning, rule-based machine learning, sparse dictionary learning, similarity and metric learning, LCS (Learning Classifier Systems), logistic regression, random forest, K-means, gradient boosting, K-nearest neighbors (KNN), a priori algorithms, and the like. In embodiments, certain machine learning algorithms may be used (for example, to solve both constrained and unconstrained optimization problems, which may be based on natural selection).In one example, the algorithm can be used to solve mixed-integer programming problems where some components are restricted to integer values. Machine learning algorithms, techniques, and systems can be used in computational intelligence systems, computer vision, natural language processing (NLP), recommendation systems, reinforcement learning, graphical model building, and the like. In one example, machine learning can be used for analyzing vehicle performance and behavior, and the like.

[0069] In one embodiment, the system for determining the particular location may include a policy engine that can apply one or more policies. These policies may be based at least in part on the characteristics of a particular piece of equipment or environment. With respect to control policies, a neural network may receive a number of environment- and task-related parameters as input. These parameters may include a front sensor output, a rear sensor output, a speed of the vehicle system, a length of the vehicle system, a route characteristic, or the like. The neural network may be trained to generate an output based on these inputs, wherein the output represents an action or sequence of actions that the controller should perform to activate or deactivate the converter.During operation of one embodiment, a determination may be made by processing the inputs through the neural network parameters to generate a value at the output node that designates this action as the desired action. This action may be translated into a signal that determines the position of the particular location of the vehicle system. This may be achieved through backpropagation, feedforward processes, closed-loop feedback, or open-loop feedback. Alternatively, instead of backpropagation, the control machine learning system may use evolution strategy techniques to optimize various parameters of the artificial neural network. The controller may use neural network architectures whose functions are not always solvable by backpropagation, for example, nonconvex functions.In one embodiment, the neural network has a set of parameters that represent the weights of its node connections. A number of copies of this network are generated, and then various adjustments are made to the parameters and simulations are performed. Once the output from the various models is available, they can be evaluated for their performance using a specific success metric. The best model is selected, and the controller executes this plan to achieve the desired input data, thus reflecting the predicted best outcome scenario. Additionally, the success metric can be a combination of the optimized results, which can be weighted relative to each other.

[0070] In one embodiment, a method is provided that may include obtaining a first range zone in which a particular location of a vehicle system is determined to be present based at least in part on a calculated distance from a known position at a front end of the vehicle system determined by a front sensor. The front end may be relative to a direction of travel. The method may include obtaining a second range zone in which the particular location of the vehicle system may be determined to be present using a different, rear sensor that may be located at a distance from the front end of the vehicle system. The method may include determining a degree of overlap or lack of overlap of the first range zone and the second range zone and responding to a determined degree of overlap.

[0071] In one example, the method may include determining the first range zone based at least in part on one or more of a length of the vehicle system, a number of vehicles in the vehicle system, a speed of the vehicle system, a vehicle type in the vehicle system, or a stretch or compression between vehicles of the vehicle system. The second range zone may be determined using a GNSS receiver located closer to the determined location of the vehicle system than the front end of the vehicle system, as the rear sensor.

[0072] In one example, the method may include determining that the first range zone and the second range zone overlap, and responding by using a rearmost portion of the overlap as a third range zone in which to determine the particular location of the vehicle. The third range zone may be used as a safety margin of uncertainty behind the particular location of the vehicle system. In another example, the method may include determining that the first range zone and the second range zone overlap, and then determining a location of the particular location based on the overlap between the first range zone and the second range zone. The location of the particular location may be a location most likely associated with the particular location of the vehicle system.

[0073] The first range zone may be modified based at least in part on multiple vehicles in the vehicle system being in a compression mode. The compression mode may reduce a gap between adjacent vehicles of the multiple vehicles.

[0074] If the first range zone and the second range zone do not overlap, the method may include modifying operation of the vehicle system to slow or stop the vehicle system. If the second range zone is greater than a threshold distance from the first range zone, the method may include requesting an inspection of a portion of the vehicle system that includes the rear sensor. In one example, the rear sensor may be positioned at a rear end of the vehicle system or in a vehicle in a group of vehicles farthest from the lead vehicle. In one example, the rear sensor may be positioned on a driven vehicle of the vehicle system.

[0075] The second range zone determined by the rear sensor may be compared to a position of a wayside device positioned along a route traveled by the vehicle system when the determined location of the vehicle system passes the wayside device. The method may include confirming that at least one of the first range zone or the second range zone may be positioned on a track block corresponding to the track block in which the front end of the vehicle system may be located.

[0076] In one embodiment, a system is provided that may include a first sensor, a second sensor, and a controller having one or more processors. The first sensor may detect a position of a reference location of a vehicle system. The controller may calculate a first range zone in which a particular location of the vehicle system may be determined to exist based at least in part on a calculated distance from the position of the reference location determined by the first sensor. The second sensor may detect a second range zone in which the particular location of the vehicle system may be determined to exist. The controller may compare the first range zone and the second range zone and may respond to an overlap or lack of overlap of the first range zone and the second range zone.

[0077] In one example, the second sensor may be positioned in a portion of the rear end of the vehicle system. In one example, the second sensor may be positioned on a wayside device located along a route of the vehicle system. One or more processors of the controller may determine the first range zone based at least in part on one or more of a length of the vehicle system, a number of vehicles in the vehicle system, a speed of the vehicle system, a type of vehicle in the vehicle system, or a stretch or compression between vehicles of the vehicle system. The second range zone may be determined using a GNSS receiver as the second sensor.

[0078] In one example, when the first range zone and the second range zone overlap, one or more processors of the controller may determine a third range zone in which the particular vehicle system location may be determined to exist based on a rearmost portion of the overlap. The third range zone may be used as a safety margin of uncertainty behind the particular vehicle system location. In one example, when the first range zone and the second range zone overlap, one or more processors of the controller may determine a position of the particular location based on the overlap between the first range zone and the second range zone. The position of the particular location may be a position most likely associated with the particular vehicle system location.

[0079] The first range zone may be modified based on multiple vehicles in the vehicle system being in a crush mode. The crush mode may reduce a gap between adjacent vehicles of the multiple vehicles. If the first range zone and the second range zone do not overlap, in one example, a rearmost range of the first range zone and the second range zone may be used as a position of the particular location of the vehicle system. The rearmost range may be communicated to wayside devices located along a route traveled by the vehicle system. If the first range zone and the second range zone do not overlap, in one example, one or more processors of the controller may modify operation of the vehicle system to decelerate or stop the vehicle system.

[0080] In one embodiment, a method is provided that may include sensing a first position of a first vehicle system using a first sensor. The method may include adding a determined distance to the first position to identify a calculated range of potential positions of a determined location of the first vehicle system. The method may include obtaining a sensed position of the determined location of the first vehicle system using a second sensor. The method may include comparing the calculated range of potential positions of the determined location to an uncertainty range of the sensed position of the determined location to determine whether the sensed position of the determined location and the calculated range of potential positions of the determined location overlap or are within a threshold distance of each other.The method may include identifying a safety boundary at or within a rearmost portion of the calculated region and the uncertainty region in response to the calculated region and the uncertainty region overlapping or being within the threshold distance from each other, or identifying the safety boundary at or within the calculated region in response to the calculated region and the uncertainty region not overlapping and not being within the threshold distance from each other.

[0081] In one example, the method may further include slowing or stopping at least a second vehicle system to prevent the at least second vehicle system from crossing a safety boundary. The method may include modifying one or more of the detected position of the particular location or the calculated range of potential positions of the particular location using one or both of a speed of movement of the first vehicle system or a route layout in response to the first position and the detected position of the particular location not being detected within a threshold time period of each other.

[0082] The first position may be detected by identifying a switch on a route traveled by the first vehicle system or identifying a wayside device located along the route. In one example, the first position of the first vehicle system may be detected using a first GNSS receiver located closer to a forward end of the first vehicle system than to an opposite end of the first vehicle system than the first sensor. The detected position of the particular location of the first vehicle system may be detected using a second GNSS receiver located closer to the opposite end of the first vehicle system than the second sensor.The detected position of the particular location determined by the second sensor may be compared to a position of a wayside device positioned along a route traveled by the first vehicle system when a particular location of the first vehicle system passes the wayside device.

[0083] The method may include calculating the determined distance using one or more of a length of the first vehicle system, a number of vehicles in the first vehicle system, a speed of the first vehicle system, a type of vehicle in the first vehicle system, or a stretch or compression between vehicles of the first vehicle system.

[0084] As used herein, a singular reference to an element or step preceded by the word "a," does not exclude the plural of such elements or acts unless such exclusion is expressly stated. Furthermore, references to "one embodiment" of the invention do not preclude the existence of additional embodiments incorporating the recited features. Unless expressly stated to the contrary, embodiments that "comprise," "include," "have," or "have" one or more elements having a particular property may include additional such elements that do not possess that property. In the appended claims, the terms "include" and "in which" are used as the plain English equivalents of the respective terms "comprising" and "wherein." Otherwise, in the following claims, the terms "first," "second," and "third," etc.used merely as labels and are not intended to impose numerical requirements on their objects. Furthermore, the limitations of the following claims are not written in the mean-plus-function format and are not intended to be interpreted based on 35 USC § 112(f) unless and until such claim limitations expressly use the phrase "means of" followed by a statement of the function without further structure.

[0085] The above description is illustrative and not restrictive. For example, the above-described embodiments (and / or aspects thereof) may be used in combination with one another. Furthermore, many changes 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 define the parameters of the inventive subject matter, they are exemplary embodiments. Other embodiments will be apparent to one of ordinary skill in the art upon review of the above description.

[0086] The use of phrases such as "one or more of ... and," "one or more of ... or," "at least one of ... and," and "at least one of ... or" is intended to encompass that only one of the elements used in connection with the phrase, at least one of each of the elements used in connection with the phrase, or multiple of each of the elements used in connection with the phrase may be included. For example, "one or more of A, B, and C," "one or more of A, B, or C," "at least one of A, B, and C," and "at least one of A, B, or C" may each mean: (1) at least one A, (2) at least one B, (3) at least one C, (4) at least one A and at least one B, (5) at least one A, at least one B, and at least one C, (6) at least one B and at least one C, or (7) at least one A and at least one C.

Claims

[1] Method comprising: Obtaining a first range zone in which a particular location of a vehicle system is determined to be present based at least in part on a calculated distance from a known position at a front end of the vehicle system determined by a front sensor, the front end being relative to a direction of travel; Obtaining a second range zone in which the particular location of the vehicle system is determined to be present using another rear sensor located at a distance from the front end of the vehicle system; and Determining a degree of overlap or lack of overlap of the first range zone and the second range zone and responding to a determined degree of overlap. [2] The method of claim 1, further comprising one of the following: Determining the first range zone based at least in part on one or more of a length of the vehicle system, a number of vehicles in the vehicle system, a speed of the vehicle system, a type of vehicle in the vehicle system, or a stretch or compression between vehicles of the vehicle system; determining the second range zone using a Global Navigation Satellite System (GNSS) receiver that is closer to the determined location of the vehicle system than the front end of the vehicle system than the rear sensor; Determining an intersection of the first range zone and the second range zone and responding by using a rearmost portion of the intersection as a third range zone in which to determine the particular location of the vehicle system, the third range zone configured to be used as a safety uncertainty distance behind the particular location of the vehicle system; Responding to a particular overlap of the first range zone and the second range zone by determining a position of the particular location based on the overlap between the first range zone and the second range zone, wherein the position of the particular location is configured to be a position most likely associated with the particular location of the vehicle system; or Modifying the first range zone based at least in part on a plurality of vehicles in the vehicle system being in a crush mode, the crush mode configured to reduce a gap between adjacent vehicles of the plurality of vehicles. [3] The method of claim 1, further comprising: Determining that the first range zone and the second range zone do not overlap; Responding by using a rearmost region of the first range zone and the second range zone as the position for the particular location of the vehicle system; and Communicating the rearmost area to a wayside device located along a route traveled by the vehicle system. [4] The method of claim 1, further comprising: Determining that the first range zone and the second range zone do not overlap and responding by changing the operation of the vehicle system to slow or stop the vehicle system; and Determining that the second range zone is greater than a threshold distance from the first range zone by requesting an inspection of a portion of the vehicle system that includes the rear sensor. [5] The method of claim 1, wherein the rear sensor is positioned at a rear end of the vehicle system, or in a vehicle in a group of vehicles farthest from the lead vehicle, or on a driven vehicle of the vehicle system. [6] The method of claim 1, further comprising: Determining the second range zone by the rear sensor by comparing a position of a wayside device positioned along a route traveled by the vehicle system when the determined location of the vehicle system passes the wayside device; or Confirm that at least one of the first range zone or the second range zone is positioned on a track block that corresponds to the track block in which the front end of the vehicle system is located. [7] System comprising: a first sensor configured to detect a position of a reference point of a vehicle system; a controller comprising one or more processors configured to calculate a first range zone in which a particular location of the vehicle system is determined to be present based at least in part on a calculated distance from the position of the reference location determined by the first sensor; a second sensor configured to detect a second range zone in which the particular location of the vehicle system is determined to be present, wherein the second range zone is determined using a Global Navigation Satellite System (GNSS) receiver as the second sensor; and the controller is further configured to compare the first range zone and the second range zone and to respond to an overlap or lack of overlap of the first range zone and the second range zone. [8] The system of claim 7, wherein the one controller is further configured to: determine the first range zone based at least in part on one or more of a length of the vehicle system, a number of vehicles in the vehicle system, a speed of the vehicle system, a type of vehicle in the vehicle system, or a stretch or compression between vehicles of the vehicle system. [9] The system of claim 7, wherein, when the first range zone and the second range zone overlap, the controller is further configured to: to determine a third range zone in which the particular location of the vehicle system is determined based on a rearmost portion of the overlap, wherein the third range zone is configured to be used as a safety uncertainty distance behind the particular location of the vehicle system; or determine a position of the particular location based on the overlap between the first range zone and the second range zone, wherein the position of the particular location is a position most likely associated with the particular location of the vehicle system. [10] The system of claim 7, wherein the first range zone is modified based at least in part on a plurality of vehicles in the vehicle system being in a crush mode, the crush mode being configured to reduce a gap between adjacent vehicles of the plurality of vehicles. [11] The system of claim 15, wherein if the first range zone and the second range zone do not overlap: the controller is further configured to change the operation of the vehicle system to slow down or stop the vehicle system; the controller is further configured to use a rearmost area of ​​the first range zone and the second range zone as a position of the determined location of the vehicle system, wherein the rearmost area is communicated to wayside devices along a route traveled by the vehicle system. [12] Method comprising: Detecting a first position of a first vehicle system using a first sensor; Adding a certain distance to the first position to identify a calculated range of potential positions of a certain location of the first vehicle system; Obtaining a detected position of the determined location of the first vehicle system using a second sensor; Comparing the calculated range of potential positions of the specific location with an uncertainty range of the detected position of the specific location to determine whether the detected position of the specific location and the calculated range of potential positions of the specific location overlap or are within a threshold distance of each other; and Identifying a safety boundary at or within a rearmost part of the calculated area and the uncertainty area in response to the calculated area and the uncertainty area overlapping or being within the threshold distance of each other, or identifying the safety boundary at or within the calculated area in response to the calculated area and the uncertainty area not overlapping and not being within the threshold distance of each other. [13] The method of claim 12, further comprising one of the following Slowing down or stopping at least one second vehicle system to prevent the at least one second vehicle system from crossing a safety boundary; Modifying one or more of the detected position of the particular location or the calculated range of potential positions of the particular location using one or both of a speed of movement of the first vehicle system or a route layout in response to the first position and the detected position of the particular location not being detected within a threshold period of each other; or Calculating the determined distance using one or more of a length of the first vehicle system, a number of vehicles in the first vehicle system, a speed of the first vehicle system, a type of vehicle in the first vehicle system, or a stretch or compression between vehicles of the first vehicle system. [14] The method of claim 12, wherein the first position is detected by identifying a switch in a route traveled by the first vehicle system or by identifying a wayside device along the route. [15] The method of claim 12, wherein detecting the first position of the first vehicle system using a Global Navigation Satellite System (GNSS) receiver that is closer to a front end of the first vehicle system than an opposite end of the first vehicle system than the first sensor; and wherein the detected position of the specific location of the first vehicle system: using a second GNSS receiver located closer to the opposite end of the first vehicle system than the second sensor; or detected by the second sensor is compared with a position of a wayside device positioned along a route traveled by the first vehicle system when a certain position of the first vehicle system passes the wayside device.

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