Vehicle position detection device and vehicle position detection method

Abstract

To provide a vehicle position detection device and a vehicle position detection method that can detect, with a simple configuration, on which railway track a railway vehicle is located.SOLUTION: A vehicle position detection device comprises: a railway GIS 231 that stores map information including the latitudes and longitudes of respective points on a plurality of railway tracks; a GNSS receiving unit 212 that measures the latitude and longitude of a railway vehicle; and a position calculation unit 24 that calculates on which railway track the railway vehicle is located. The position calculation unit 24 calculates an azimuth in which the railway vehicle travels as a vehicle azimuth, on the basis of the latitude and longitude of the current position of the railway vehicle, and the latitude and longitude of the immediately previous position of the railway vehicle measured by the position calculation unit 24 immediately before the current position, extracts the altitudes and longitudes of two points closer to the current position from the map information for each railway track, calculates an azimuth for every railway track as a track azimuth on the basis of the extracted altitudes and longitudes of the two points for every railway track, and calculates on which railway track the railway vehicle is located on the basis of the vehicle azimuth and the track azimuth for every railway track.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a vehicle position detection device and a vehicle position detection method for detecting the position of a railway vehicle on a railway track. [Background technology]

[0002] Train approach warning systems are used to prevent accidents such as contact between railway vehicles and workers during railway construction work (see, for example, Patent Document 1). The train approach warning system described in Patent Document 1 uses a Global Navigation Satellite System (GNSS) such as a Global Positioning System (GPS) to measure the position of the railway vehicle, and calculates the position (in kilometers) of the railway vehicle traveling on the railway track by referring to a railway Geographic Information System (GIS), which is map information including position information of the railway track. Then, when the railway vehicle approaches within a predetermined distance (warning distance) to a worker, an alarm is generated on an alarm terminal carried by the worker, and the alarm is stopped when the railway vehicle passes the worker's work position. In addition, the worker takes refuge in a position away from the railway track while the alarm is being transmitted. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2003-212121 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, conventional train approach warning systems using GNSS can only detect the position of railway vehicles in the direction of the rails (kilometer direction), but cannot detect or determine lateral directions such as the direction of branching or whether the vehicle is traveling on the reference line or branch line. This is because the distance error from GNSS positioning is larger than the lateral distance between tracks.

[0005] In light of this, the conventional method is to install ID (Identification) tags or ground coils on the railway tracks that record location information (kilometers, line, track number, etc.) and to read these with a receiver mounted on the train to identify the lateral direction. However, this method requires huge costs, including the construction costs for laying the ground equipment, the installation costs for the trains, and the maintenance costs for the ground equipment.

[0006] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a vehicle position detection device and a vehicle position detection method that are capable of detecting, with a simple configuration, on which railway track a railway vehicle is located. [Means for solving the problem]

[0007] In order to solve the above problem, the invention described in claim 1 comprises a map information storage means for storing map information including the latitude and longitude of each point on a plurality of railway tracks, a positioning means for measuring the latitude and longitude of a railway vehicle running on the railway tracks, and a vehicle position calculation means for calculating on which railway track the railway vehicle is located, wherein the vehicle position calculation means calculates the latitude and longitude of the current position of the railway vehicle measured by the positioning means, the latitude and longitude of the immediately preceding position of the railway vehicle measured by the positioning means immediately before the current position, the latitude and longitude of two points closest to the current position for each of the railway tracks from the map information; the latitude and longitude of the two points extracted for each of the railway tracks are used to calculate an azimuth angle for each of the railway tracks as a track azimuth angle; and the vehicle azimuth angle and the track azimuth angle for each of the railway tracks are used to perform a first determination process to determine on which railway track the railway vehicle is located.

[0008] The invention recited in claim 2 is characterized in that, in the vehicle position detection device recited in claim 1, in the first determination process, the vehicle position calculation means sequentially calculates the vehicle azimuth angle and a track azimuth angle for each of the railway tracks as the railway vehicle travels, and accumulates a difference angle between the track azimuth angle and the vehicle azimuth angle for each of the railway tracks, and calculates on which railway track the railway vehicle is located based on an evaluation value calculated from the accumulated value.

[0009] The invention described in claim 3 is characterized in that, in the vehicle position detection device described in claim 2, the vehicle position calculation means determines that the railway vehicle is located on any of the railway tracks when the evaluation value of that railway track reaches a predetermined value in the first determination process.

[0010] The invention described in claim 4 is characterized in that, in the vehicle position detection device described in claim 3, in the first determination process, if the evaluation value of any of the railway tracks does not reach the predetermined value when the railway vehicle has traveled a predetermined distance, the vehicle position calculation means determines that it is impossible to calculate on which railway track the railway vehicle is located.

[0011] The invention described in claim 5 is characterized in that, in the vehicle position detection device described in claim 2, the vehicle position calculation means determines, in the first determination process, that the railway vehicle is located on the railway track with the maximum evaluation value when the railway vehicle has traveled a predetermined distance.

[0012] The invention described in claim 6 is characterized in that, in the vehicle position detection device described in claim 2, the vehicle position calculation means calculates the evaluation value in the first judgment process depending on the surrounding environment in which the railway vehicle is traveling.

[0013] The invention described in claim 7 is characterized in that, in the vehicle position detection device described in claim 1, the positioning means, in the first determination process, calculates satellite positioning coordinates based on a positioning signal received from a positioning satellite, and if the positioning accuracy index is equal to or greater than a predetermined value, sets the satellite positioning coordinates as the latitude and longitude of the railway vehicle, and if the positioning accuracy index is less than the predetermined value, calculates composite coordinates based on the satellite positioning coordinates, the speed of the railway vehicle, and the inertial momentum of the railway vehicle, and sets the composite coordinates as the latitude and longitude of the railway vehicle.

[0014] The invention described in claim 8 is characterized in that, in the vehicle position detection device described in claim 7, the positioning means estimates an amount of error between the satellite positioning coordinates and the composite coordinates in the first judgment process, and uses the estimated amount of error in calculating the composite coordinates.

[0015] The invention recited in claim 9 is characterized in that the vehicle position detection device of claim 1 further comprises angular velocity detection means for detecting an angular velocity indicating an angle of a rotational speed in a horizontal direction of a railway vehicle running on the railway track, and the vehicle position calculation means acquires the angular velocity of the railway vehicle detected by the angular velocity detection means in the vicinity of a junction between a reference line on the railway track and a branch line branching off from the reference line, calculates a distance from the branch point to the current position of the railway vehicle in a direction of the reference line, calculates a perpendicular distance from the reference line to the current position of the railway vehicle based on the acquired angular velocity of the railway vehicle and the calculated distance of the railway vehicle in the direction of the reference line, executes a second determination process to determine on which railway track the railway vehicle is located based on the calculated distance of the railway vehicle in the direction of the reference line and the calculated perpendicular distance to the current position of the railway vehicle, and determines on which railway track the railway vehicle is located based on the first determination process and the second determination process.

[0016] The invention described in claim 10 is characterized in that, in the vehicle position detection device described in claim 9, when the vehicle position calculation means detects, based on the map information, that the railway vehicle is approaching a junction between a reference line on the railway track and a branch line branching off from the reference line in the second determination process, the vehicle position calculation means acquires the angular velocity of the railway vehicle detected by the angular velocity detection means.

[0017] The invention described in claim 11 is characterized in that, in the vehicle position detection device described in claim 9, the vehicle position calculation means, in the second determination process, acquires the angular velocity of the railway vehicle, calculates the distance of the railway vehicle in the direction of the reference line, calculates the perpendicular distance to the current position of the railway vehicle, and repeats the process of determining on which railway track the railway vehicle is located at predetermined intervals.

[0018] The invention described in claim 12 is characterized in that, in the vehicle position detection device described in any one of claims 9 to 11, the vehicle position calculation means, in the second determination process, time-integrates the acquired angular velocity of the railway vehicle to calculate an angular velocity integral value, and calculates a distance in the direction of the reference line from the branch point to the current position of the railway vehicle based on the angular velocity integral value.

[0019] The invention described in claim 13 is characterized in that, in the vehicle position detection device described in claim 9, the vehicle position calculation means, in the second determination process, calculates the perpendicular distance to the current position of the railway vehicle multiple times within a predetermined time, retains maximum and minimum values ​​of the perpendicular distance to the current position of the railway vehicle, and determines on which railway track the railway vehicle is located based on the calculated maximum and minimum values ​​of the perpendicular distance to the current position of the railway vehicle.

[0020] The invention described in claim 14 is characterized in that, in the vehicle position detection device described in claim 13, the vehicle position calculation means determines that the railway vehicle is located on a branch line when the maximum or minimum value of the calculated perpendicular distance to the current position of the railway vehicle reaches a threshold value set for each branch line in the second determination process.

[0021] The invention described in claim 15 is characterized in that, in the vehicle position detection device described in claim 14, the vehicle position calculation means determines in the second determination process that the maximum or minimum value of the calculated perpendicular distance to the current position of the railway vehicle is outside a predetermined range when it reaches a threshold value set for each branch line.

[0022] The invention described in claim 16 is characterized in that, in the vehicle position detection device described in claim 9, the vehicle position calculation means determines that the railway vehicle is located on the reference line when the calculated distance of the railway vehicle in the direction of the reference line reaches a threshold value defined for each reference line in the second determination process.

[0023] The invention described in claim 17 is characterized in that, in the vehicle position detection device described in claim 16, the vehicle position calculation means determines that the calculated distance of the railway vehicle in the direction of the reference line is impossible to determine if it reaches a threshold value defined for each reference line and is outside a predetermined range.

[0024] The invention described in claim 18 is characterized in that, in the vehicle position detection device described in claim 17, the vehicle position calculation means issues a predetermined notification when the position of the railway vehicle cannot be determined in the second determination process.

[0025] The invention described in claim 19 is characterized in that, in the vehicle position detection device described in claim 10, the vehicle position calculation means, in the second determination process, calculates the distance in the direction of the reference line from the branch point to the current position of the railway vehicle based on the map information.

[0026] The invention recited in claim 20 is the vehicle position detection device recited in claim 9, wherein the vehicle position calculation means calculates, in the second determination process, a distance in a direction of the reference line from the branch point to a current position of the railway vehicle based on a moving speed of the railway vehicle detected by a speed detection means provided on the railway vehicle for detecting a moving speed of the railway vehicle. It is characterized by:

[0027] The invention described in claim 21 is a vehicle position detection method to be executed by a computer having a processor and a storage unit, the storage unit stores map information including latitude and longitude of each point on a plurality of railway tracks, and the processor executes a positioning step of measuring the latitude and longitude of a railway vehicle running on the railway tracks, and a vehicle position calculation step of calculating on which railway track the railway vehicle is located, and the vehicle position calculation step calculates the latitude and longitude of the current position of the railway vehicle measured in the positioning step and the latitude and longitude of a position measured immediately before the current position. the latitude and longitude of a position immediately preceding the railway vehicle that has been detected, the latitude and longitude of two points closest to the current position are extracted from the map information for each railway track, the latitude and longitude of the two points extracted for each railway track are calculated, and an azimuth angle for each railway track is calculated as a track azimuth angle based on the latitude and longitude of the two points; and a first determination process is executed to determine on which railway track the railway vehicle is located based on the vehicle azimuth angle and the track azimuth angle for each railway track.

[0028] The invention of claim 22 provides the vehicle position detection method of claim 21, further comprising the processor executing an angular velocity detection step of detecting an angular velocity indicating an angle of a rotational speed in a horizontal direction of a railway vehicle traveling on the railway track, and the vehicle position calculation step includes detecting, based on the map information, that the railway vehicle is approaching a junction between a reference line on the railway track and a branch line branching off from the reference line, acquiring the angular velocity of the railway vehicle detected in the angular velocity detection step, and calculating the angular velocity of the railway vehicle in a direction of the reference line from the branch point to a current position of the railway vehicle. the first determination process calculates a distance from the reference line to the current position of the railway vehicle based on the acquired angular velocity of the railway vehicle and the calculated distance of the railway vehicle in the direction of the reference line; a second determination process is executed to determine on which railway track the railway vehicle is located based on the calculated distance of the railway vehicle in the direction of the reference line and the calculated perpendicular distance to the current position of the railway vehicle; and a second determination process is executed to determine on which railway track the railway vehicle is located based on the calculated distance of the railway vehicle in the direction of the reference line and the calculated perpendicular distance to the current position of the railway vehicle; and Effect of the Invention

[0029] According to the inventions described in claims 1 and 21, in the first determination process, it is calculated which railway track the railway vehicle is located on based on the vehicle azimuth, which is the azimuth angle and direction in which the railway vehicle runs, and the track azimuth, which is the azimuth angle and direction of each railway track. For example, it is calculated that the railway vehicle is located on the railway track close to the vehicle azimuth angle and direction in which the railway vehicle runs among the track azimuth angles and directions of each railway track. In this way, it is possible to detect which railway track the railway vehicle is located on. Moreover, since it is only necessary to measure the latitude and longitude of the railway vehicle and calculate which railway track the railway vehicle is located on based on the positioning result, no large-scale equipment is required on the ground or on the railway vehicle, the configuration is simplified, and it is possible to reduce costs such as equipment costs and maintenance costs.

[0030] According to the invention described in claim 2, in the first determination process, which railway track the railway vehicle is located on is calculated based on an evaluation value based on an integrated value of the difference angle between the track azimuth angle of each railway track and the vehicle azimuth angle. In other words, since the position of the railway vehicle is calculated based on an evaluation value based on an integrated value of the difference angle integrated as the railway vehicle travels, rather than the difference angle between a temporary track azimuth angle and the vehicle azimuth angle, it becomes possible to more appropriately detect which railway track the railway vehicle is located on.

[0031] According to the invention described in claim 3, in the first judgment process, when the evaluation value of any railway track reaches a predetermined value, it is judged that the railway vehicle is located on this railway track, so that it becomes possible to quickly and early detect on which railway track the railway vehicle is located.

[0032] According to the invention described in claim 4, in the first determination process, if the evaluation value of none of the railway tracks reaches a predetermined value even when the railway vehicle has traveled a predetermined distance, it is determined that it is impossible to calculate which railway track the railway vehicle is located on. This makes it possible to prevent the position of the railway vehicle from being erroneously determined and output.

[0033] According to the invention described in claim 5, in the first judgment process, when the railway vehicle has traveled a predetermined distance, it is judged that the railway vehicle is located on the railway track with the maximum evaluation value, so that it is possible to reliably (without omissions) detect which railway track the railway vehicle is located on.

[0034] According to the invention described in claim 6, in the first judgment process, an evaluation value is calculated according to the surrounding environment in which the railway vehicle is traveling, so that it is possible to properly detect on which railway track the railway vehicle is located according to the surrounding environment in which the railway vehicle is traveling.

[0035] According to the invention described in claim 7, in the first determination process, when the positioning accuracy index based on the positioning signal from the positioning satellite is less than a predetermined value, composite coordinates are calculated based on the satellite positioning coordinates, the speed, and the inertial momentum, and are set as the latitude and longitude of the railway vehicle. Therefore, even if the positioning accuracy based on the positioning signal from the positioning satellite is poor because the railway vehicle enters a tunnel or underground, it is possible to detect the position of the railway vehicle with high accuracy.

[0036] According to the invention described in claim 8, in the first determination process, the amount of error between the satellite positioning coordinates and the composite coordinates is used to calculate the composite coordinates, so that it is possible to accurately detect the position of the railway vehicle from measurement values ​​that contain errors and noise, such as the satellite positioning coordinates, speed, and inertial momentum.

[0037] According to the inventions of claims 9 to 11 and 22, in the second determination process, an angular velocity indicating the angle of the horizontal rotational speed of a railway vehicle traveling on a railway track is detected, and a perpendicular distance from the reference line to the current position of the railway vehicle is calculated based on the angular velocity and the distance in the direction of the reference line of the railway vehicle, and on which railway track the railway vehicle is located is determined based on the distance. Therefore, compared to a method using GNSS positioning, for example, it is possible to detect on which railway track the railway vehicle is located without being affected by lateral position errors with respect to the traveling direction of the railway vehicle. Furthermore, compared to a method using a neural network, the amount of calculation is reduced, which can contribute to reducing the cost of the device.

[0038] In addition, according to the inventions described in claims 9 to 11 and claim 22, a first judgment process and a second judgment process are performed, and the position of the railway vehicle can be detected from the judgment result of either the first judgment process or the second judgment process, and it is also possible to detect the position of the railway vehicle by combining the judgment results of both the first judgment process and the second judgment process.Therefore, an appropriate judgment process can be selected according to the route environment and vehicle environment, making it possible to increase the accuracy of the judgment.

[0039] According to the invention described in claim 12, in the second determination process, the acquired angular velocity of the railway vehicle is integrated over time to calculate an angular velocity integral value, a relative angle of the traveling direction of the device with respect to the object is calculated, and a distance in the direction of the reference line from the branch point to the current position of the railway vehicle is calculated. Therefore, the amount of calculation is reduced, which can contribute to reducing the cost of the device.

[0040] According to the invention described in claim 13, in the second determination process, the maximum and minimum values ​​of the perpendicular distance to the current position of the railway vehicle are stored, and the railway track on which the railway vehicle is located is determined based on the calculated maximum and minimum values ​​of the perpendicular distance to the current position of the railway vehicle, thereby enabling more accurate determination of the position on the railway track.

[0041] According to the inventions recited in claims 14 to 18, in the second determination process, if the maximum or minimum value of the perpendicular distance to the current position of the railway vehicle reaches a threshold value defined for each branch line, it is determined that the railway vehicle is located on the branch line. Also, if the distance of the railway vehicle in the direction of the reference line reaches a threshold value defined for each reference line, it is determined that the railway vehicle is located on the reference line. Here, the threshold value can be set based on various laws, regulations, and standards, so that the work related to said setting is easy. Therefore, it is possible to contribute to reducing the cost of setting the threshold value.

[0042] According to the invention described in claims 19 and 20, in the second determination process, the distance in the direction of the reference line from the junction to the current position of the railway vehicle is calculated based on map information. Also, the distance in the direction of the reference line from the junction to the current position of the railway vehicle is calculated based on the travel speed of the railway vehicle detected by a speed detection means provided in the railway vehicle. Therefore, it is possible to realize a more accurate determination process. [Brief description of the drawings]

[0043] [Figure 1] 1 is a schematic configuration diagram showing a vehicle approach warning system 1 according to first and second embodiments of the present invention. [Diagram 2]2 is a schematic configuration block diagram showing an on-board device according to a first embodiment in the vehicle approach warning system 1 of FIG. [Diagram 3] 3 is a diagram showing a calculation concept relating to a first determination process of a position calculation unit in the on-board device of FIG. 2. [Figure 4] 3 is a flowchart showing a calculation procedure for a first determination process of a position calculation unit in the on-board device of FIG. 2. [Diagram 5] 5 is a flowchart showing a calculation procedure of a branch determination process in the flowchart of FIG. 4. [Figure 6] FIG. 2 is a schematic configuration block diagram showing an on-board device according to a second and fourth embodiments in the vehicle approach warning system of FIG. [Figure 7] 7 is a diagram showing a calculation concept relating to a second determination process of a position calculation unit in the on-board device of FIG. 6. [Figure 8] 7 is a flowchart showing a calculation procedure for a second determination process of a position calculation unit in the on-board device of FIG. 6. [Figure 9] 9 is a flowchart showing a calculation procedure of the branch determination process in the flowchart of FIG. 8. [Figure 10] 7 is a diagram showing a determination result obtained by combining the determination results of the first determination process and the second determination process, among the determination results obtained by the on-board device in FIG. 6. FIG. [Figure 11] FIG. 11 is a schematic configuration diagram showing a vehicle approach warning system 1A according to an embodiment 3 of the present invention. [Figure 12] FIG. 11 is a schematic configuration diagram showing a vehicle approach warning system 1B according to an embodiment 4 of the present invention. [Figure 13] 13 is an explanatory diagram showing a method of calculating a composite coordinate by an on-board device according to embodiment 5 of the present invention; FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0044] Hereinafter, the present invention will be described based on the illustrated embodiment.

[0045] (Embodiment 1) 1 is a schematic diagram showing a vehicle approach warning system 1 using a vehicle position detection device and a vehicle position detection method according to a first embodiment of the present invention. This vehicle approach warning system 1 comprises an on-board device (vehicle position detection device) 2 mounted on a railway vehicle Tr, a warning terminal 3 carried by a worker W engaged in railway construction work, and a server 4, which are connected to each other so as to be able to communicate with each other via a communication network NW. Here, the communication network NW is, for example, a communication network such as a mobile phone communication network or the Internet.

[0046] The on-board device 2 is mounted on the railway vehicle Tr and, as described below, detects the position of the railway vehicle Tr on the railway track R (for example, kilometers indicating the distance from the starting point set for each railway line) and detects which railway track R the railway vehicle Tr is located on, and transmits train information including these detection results to the server 4.

[0047] The warning terminal 3 has a function of receiving a GNSS signal (e.g., a GPS signal) from a GNSS satellite (e.g., a positioning satellite such as a GPS satellite) St, and detecting the position of the warning terminal 3, i.e., the position of the worker W, based on the received GNSS signal, a function of receiving train information of the railway vehicle Tr from the server 4, a function of generating an alarm using sound, light, etc. when the position of the railway vehicle Tr approaches within an alarm distance from the position of the worker W, and a function of stopping the alarm when the position of the railway vehicle Tr passes the position of the worker W.

[0048] Here, the alarm terminal 3 can detect and input the railway track R (work line) on which the worker W is working, and the train information from the on-board device 2 includes which railway track R the railway vehicle Tr is located on. For this reason, an alarm is issued when the position of the railway vehicle Tr approaches within an alarm distance from the position of the worker W, and the railway track R on which the railway vehicle Tr is running is the same as the railway track R on which the worker W is working. The function of issuing an alarm also includes a function of displaying the approaching distance and speed of the railway vehicle Tr by text information, or displaying the work position and an icon of the railway vehicle Tr on a track diagram, allowing the user to intuitively grasp the positional relationship.

[0049] Thus, in this embodiment, the alarm terminal 3 is configured to determine whether to issue and stop an alarm, but the server 4 may also be configured to do so. In this case, the server 4 collects train information from the on-board device 2, and collects worker information (information including the location of the worker W, the work route, the line type, etc., and the location may be in kilometers or may be latitude and longitude) from the alarm terminal 3. When the railroad vehicle Tr approaches within the alarm distance of the worker W and they are on the same railroad track R, the server 4 transmits an alarm signal to the alarm terminal 3 to issue an alarm, and when the railroad vehicle Tr passes the worker W, the server 4 transmits an alarm stop signal to the alarm terminal 3 to stop the alarm.

[0050] 2 is a schematic block diagram showing the configuration of the on-board equipment 2 according to this embodiment. The on-board equipment 2 mainly includes a GNSS antenna 211, a GNSS receiving unit 212, a communication unit 22, a storage unit 23, and a position calculation unit (vehicle position calculation means) 24.

[0051] The GNSS antenna 211 receives GNSS signals, which are positioning signals, from multiple GNSS satellites St, and outputs them to the GNSS receiver 212. The GNSS receiver 212 calculates GNSS coordinates (satellite positioning coordinates) based on the GNSS signals, calculates and positions the position (kilometers) of the railway vehicle Tr, that is, the latitude and longitude of the railway vehicle Tr traveling on the railway track R, based on the GNSS coordinates, and outputs the position to the position calculator 24. Here, the method of positioning using GNSS is a well-known technology, so a detailed description will be omitted.

[0052] Thus, in this embodiment, the positioning means of the present invention is constituted by the GNSS antenna 211 and the GNSS receiver 212, but may be constituted by other elements. For example, the latitude and longitude of the railway vehicle Tr may be determined by transmitting radar waves from the railway vehicle Tr and receiving reflected waves of the radar waves to measure the speed of the railway vehicle Tr, or by measuring the inertial momentum of the railway vehicle Tr with an inertial sensor (angular velocity sensor 251 and acceleration sensor 252 described later) mounted on the railway vehicle Tr.

[0053] The communication unit 22 is a communication interface for performing wired or wireless communication with the server 4 via the communication network NW, and any communication protocol may be used as long as mutual communication can be performed. Specifically, the communication unit 22 includes a communication antenna 221 and a communication module 222, and the communication antenna 221 transmits the train information output from the communication module 222 to the server 4 via the communication network NW.

[0054] The storage unit 23 stores programs for executing various control processes and functions in the position calculation unit 24, input data, etc., and is composed of memories including RAM, ROM, etc., and storages including HDD, SSD, flash memory, etc. The storage unit 23 stores a railway GIS (map information storage means) 231. The storage unit 23 also temporarily stores data communicated with the server 4.

[0055] The railway GIS 231 is a geographic information system that stores map information including the latitude and longitude of each point on a plurality of railway tracks R. That is, it is a database in which map information of each railway track R and information on the latitude, longitude, and kilometres of each railway track R are recorded. Specifically, for each railway track R, identification information for identifying a plurality of points (track coordinates) on the railway track R, the latitude and longitude of each point (including branch points), and kilometres indicating the distance from the starting point (in other words, the starting station) of the railway track R to each point are stored in association with the map information of the railway track R.

[0056] The position calculation unit 24 is programming software that calculates on which railway track R the railway vehicle Tr is located, and in this embodiment, it performs a first determination process. First, the first determination process will be described with reference to Figs. 3 to 5. Here, in this embodiment, a case where a reference line R1, which is a reference railway track, branches into two railway tracks, a branch line R2 which is a branch railway track at a branch point, and the reference line R1, will be mainly described, but it can also be applied to a case where the railway track branches into three or more tracks.

[0057] <First Determination Process> The calculation concept of the first determination process will be described with reference to Fig. 3. In Fig. 3, the black dots are the latitude and longitude (positioned position) of the railway vehicle Tr measured as described above, the white dots are the latitude and longitude of each point on the reference line R1 stored in the railway GIS 231, and the double dots are the latitude and longitude of each point on the branch line R2 stored in the railway GIS 231. Then, for example, when the railway vehicle Tr approaches a branch point, the azimuth angle and direction in which the railway vehicle Tr travels are calculated as the vehicle azimuth angle θP based on the latitude and longitude P1 of the current (latest) position of the railway vehicle Tr measured by the GNSS receiver 212 and the latitude and longitude P0 of the previous position of the railway vehicle Tr measured by the GNSS receiver 212 immediately before the latitude and longitude P1 of the current position.

[0058] Specifically, for example, the calculation is performed based on the following formula. θP = arctan((cos(yp0)*tan(yp1)-sin(yp0)*cos(xp1-xp0)) / sin(xp1-xp0)) xp1: X coordinate value of current location latitude, longitude P1 yp1: Y coordinate value of latitude and longitude P1 of the current location xp0: X coordinate value of the previous position's latitude and longitude P0 yp0: Y coordinate value of latitude and longitude P0 of the previous position π=3.141592654

[0059] Also, the latitude and longitude of two points close to the latitude and longitude P1 of the current position are extracted from the railway GIS 231 for each of the railway tracks R1 and R2, and the azimuth and direction of each of the railway tracks R1 and R2 are calculated as track azimuth angles θM and θB based on the latitude and longitude of the two points extracted for each of the railway tracks R1 and R2. That is, from the points on the reference line R1 stored in the railway GIS 231, the latitude and longitude of two points close to the latitude and longitude P1 of the current position, that is, the latitude and longitude of the point M0 on the starting point side and the point M1 on the end point side, are extracted. Then, based on the latitude and longitude of these two points M0 and M1, the azimuth of the reference line R1 is calculated as the track azimuth angle θM. Similarly, from the points on the branch line R2 stored in the railway GIS 231, the latitude and longitude of two points close to the latitude and longitude P1 of the current position, that is, the latitude and longitude of the point B0 on ​​the starting point side and the point B1 on the end point side, are extracted. Then, based on the latitude and longitude of these two points B0 and B1, the azimuth angle of the branch line R2 is calculated as the orbit azimuth angle θB.

[0060] Specifically, for example, the calculation is performed based on the following formula. "Orbit azimuth angle θM of reference line R1" θM = arctan((cos(ym0)*tan(ym1)-sin(ym0)*cos(xm1-xm0)) / sin(xm1-xm0)) xm1: X coordinate value of end point M1 ym1: Y coordinate value of the end point M1 xm0: X coordinate value of point M0 on the starting point side ym0: Y coordinate value of point M0 on the starting point side "Orbit azimuth angle θB of branch line R2" θB = arctan((cos(yb0)*tan(yb1)-sin(yb0)*cos(xb1-xb0)) / sin(xb1-xb0)) xb1: X coordinate value of end point B1 yb1: Y coordinate value of the end point B1 xb0: X coordinate value of point B0 on ​​the starting point side yb0: Y coordinate value of point B0 on ​​the starting point side

[0061] Then, based on the vehicle azimuth angle θP of the railroad vehicle Tr calculated and calculated in this manner and the track azimuth angles θM, θB for each of the railroad tracks R1, R2, it is calculated which railroad track R1, R2 the railroad vehicle Tr is located on. In other words, it is determined that the railroad vehicle Tr is located on the reference line R1 or the branch line R2 of the track azimuth angles θM, θB that are closer to the vehicle azimuth angle θP. As a result, for example, it is determined that the railroad vehicle Tr is located on the reference line R1 in the reference line angle area AM shown in Fig. 3, and that the railroad vehicle Tr is located on the branch line R2 in the branch line angle area AB. In addition, in other areas AQ, it is determined that determination is impossible / abnormal.

[0062] Next, a specific calculation method of the first determination process based on such a calculation concept will be described with reference to the flowcharts shown in FIGS.

[0063] First, the latitude and longitude of the railroad vehicle Tr are measured as described above (positioning step, step S1), and compared with map information (information on each point and branch point) of the railroad GIS 231 (step S2). Then, if the railroad vehicle Tr is not approaching a branch point on the railroad track R (if "N" in step S3), the process returns to step S1 and repeats the same process. On the other hand, if the railroad vehicle Tr is approaching a branch point on the railroad track R (if "Y" in step S3), a branch determination process is performed to determine which railroad track R the railroad vehicle Tr is located on (vehicle position calculation step, step S4). Then, when the branch determination process is completed and the railroad track on which the railroad vehicle Tr is located is determined (step S5), the process returns to step S1 and repeats the same process. Here, the distance for determining whether the railroad vehicle Tr has approached a branch point or not is preset according to the surrounding environment and environmental factors for each branch point, which will be described later.

[0064] Meanwhile, in the branch judgment process, as the railcar Tr travels, as described in the above calculation concept, the vehicle azimuth angle θP and the track azimuth angles θM, θB for each of the railroad tracks R1, R2 are sequentially calculated, and the difference angles between the track azimuth angles θM, θB and the vehicle azimuth angle θP for each of the railroad tracks R1, R2 are integrated. Then, based on the evaluation value calculated using this integrated value, it is calculated which of the railroad tracks R1, R2 the railcar Tr is located on.

[0065] Specifically, first, as described above, the vehicle azimuth angle θP of the latitude and longitude of the current position of the railway vehicle Tr is calculated (step S11), and the latitude and longitude of two points close to the latitude and longitude of the current position for each railway track R1, R2 are extracted from the railway GIS 231 (step S12). Next, the track azimuth angles θM, θB are calculated based on the latitude and longitude of the two extracted points for each railway track R1, R2 (step S13). Next, the difference angle between the track azimuth angle θM of the reference line R1 and the vehicle azimuth angle θP, and the difference angle between the track azimuth angle θB of the branch line R2 and the vehicle azimuth angle θP are calculated (step S14).

[0066] Next, an evaluation process is performed based on each calculated angle difference (step S15). At this time, in order to properly evaluate a variety of branch points with different angles, etc., a function that can be expressed in terms of probability is used, and the evaluation and judgment are standardized. First, the integrated values ​​f1n and f2n of each angle difference are calculated using the following formula. Here, as will be described later, the calculation and integration of the angle difference are repeated every time the latitude and longitude of the current position of the railway vehicle Tr change (every time the position is measured at a predetermined cycle) until a termination condition is met. The integrated value of the reference line R1, f1n = Σ(w1 × |θM-θP|), (n = 0, 1, 2, ...) The integrated value of branch line R2, f2n = Σ(w1 × |θB-θP|), (n = 0, 1, 2, . . .) Here, the weighting coefficient w1 is set in advance according to the surrounding environment and environmental factors for each branch point, such as the track environment (curving branches, continuous branches, gradients, etc.), railway structures (railroad crossings, station premises, tunnels, etc.), and vehicle structures (bogies, car bodies, springs, etc.). As a result, the evaluation values ​​F1 and F2, which will be described later, are calculated (adjusted) according to the surrounding environment in which the railway vehicle Tr runs.

[0067] Next, evaluation values ​​F1 and F2 expressed as probabilities for the reference line R1 and the branch line R2 are calculated using the following formula based on the integrated values ​​f1n and f2n. Evaluation value of reference line R1 F1=exp(f2n-C) / {exp(f1n-C)+exp(f2n-C)} Evaluation value of branch line R2 F2=1-F1 C: Constant for overflow prevention (the larger of the n-th integrated values ​​f1n and f2n)

[0068] If the termination condition is satisfied ("Y" in step S16), the evaluation process, i.e., the branch determination process, is terminated, and if the termination condition is not satisfied ("N" in step S16), the process returns to step S11 and the same process is repeated. Here, the termination condition may be any condition as long as it can be properly determined on which of the railway tracks R1 and R2 the railway vehicle Tr is located, and examples of the termination condition include the following conditions:

[0069] As a first termination condition, the process is terminated when (at) the time when the evaluation values ​​F1, F2 of either of the railway tracks R1, R2 reach a predetermined value (predetermined threshold value), and it is determined that the railway vehicle Tr is located on the railway tracks R1, R2 whose evaluation values ​​F1, F2 have reached the predetermined value. Here, the predetermined value is set in advance according to the surrounding environment and environmental factors for each branch point.

[0070] As a second termination condition, the process is terminated when the travel of the railroad vehicle Tr reaches a predetermined distance. In other words, the process is terminated when the railroad vehicle Tr travels a predetermined distance from the start of the branch judgment process (when the railroad vehicle Tr passes the branch). In this case, the predetermined distance is set in advance according to the surrounding environment and environmental factors at each branch point, and the position of the railroad vehicle Tr is determined as follows.

[0071] As judgment (1), it is judged that the railroad vehicle Tr is located on the railroad tracks R1, R2 whose evaluation values ​​F1, F2 are the largest at that time. As judgment (2), it is judged that the railroad vehicle Tr is located on the railroad tracks R1, R2 whose evaluation values ​​F1, F2 have reached the above-mentioned predetermined values ​​at that time. In this case, if the evaluation values ​​F1, F2 of neither of the railroad tracks R1, R2 reach the above-mentioned predetermined values, it is judged that it is impossible to calculate (impossible to judge) which railroad track R1, R2 the railroad vehicle Tr is located on, and a notification to that effect is output / notified.

[0072] Here, the fact that the judgment is impossible may be notified to a preset user to warn him / her, or the railway vehicle Tr may be stopped to manually set the track, or if another on-track detection means is possessed, the information may be used to make corrections. In addition, in order to detect incorrect setting or incorrect track when manually setting the track, the angle difference between the railway GIS 231 and the positioning vector (azimuth angle) may be checked after setting to evaluate the validity of the set track. Alternatively, this evaluation and judgment of validity may be performed constantly, and may be used to increase the accuracy of the judgment even if the branch judgment is successful.

[0073] Also, the first and second termination conditions may be mixed. For example, if the evaluation values ​​F1, F2 of either of the railroad tracks R1, R2 reach a predetermined value before the railway vehicle Tr travels a predetermined distance, the process may be terminated at that point, and if the evaluation values ​​do not reach the predetermined value, the process may be terminated according to the second termination condition. Also, whether the first or second termination condition is used for termination, or whether a mixed termination condition is used, or whether the second termination condition is used for judgment (1) or judgment (2) may be determined for each branch point according to the surrounding environment and environmental factors, or may be set for each branch point or for all branch points by the user's selection.

[0074] According to the vehicle approach warning system 1 using the vehicle position detection device and vehicle position detection method configured as above, by performing the first determination process, it is calculated which railway track R1, R2 the railway vehicle Tr is located on based on the vehicle azimuth angle θP, which is the azimuth angle and direction in which the railway vehicle Tr runs, and the track azimuth angles θM, θB, which are the azimuth angles and directions of each of the railway tracks R1, R2. For example, it is calculated that the railway vehicle Tr is located on the railway track R1, R2 that is close to the vehicle azimuth angle θP on which the railway vehicle Tr runs, among the track azimuth angles θM, θB of each of the railway tracks R1, R2. In this way, it is possible to detect which railway track R1, R2 the railway vehicle Tr is located on. Moreover, since it is only necessary to measure the latitude and longitude of the railway vehicle Tr and calculate which railway track R1, R2 the railway vehicle Tr is located on based on the positioning result, no large-scale equipment is required on the ground or on the railway vehicle Tr, the configuration is simplified, and it is possible to reduce costs such as equipment costs and maintenance costs.

[0075] Further, which railway track R1, R2 the railway vehicle Tr is located on is calculated based on evaluation values ​​F1, F2 based on integrated values ​​f1, f2 obtained by integrating the difference angle between the track azimuth angles θM, θB of each railway track R1, R2 and the vehicle azimuth angle θP. In other words, the position of the railway vehicle Tr is calculated based on the evaluation values ​​F1, F2 based on the integrated values ​​f1, f2 of the difference angle integrated as the railway vehicle Tr travels, rather than the difference angle between the temporary track azimuth angles θM, θB and the vehicle azimuth angle θP. This makes it possible to more appropriately detect which railway track R1, R2 the railway vehicle Tr is located on.

[0076] Then, when the evaluation values ​​F1, F2 of either of the railway tracks R1, R2 reach a predetermined value, it is determined that the railway track R1, R2 that has reached the predetermined value is on which the railway vehicle Tr is located, making it possible to quickly and early detect which railway track R1, R2 the railway vehicle Tr is located on.

[0077] Furthermore, by determining that the railway vehicle Tr is located on the railway tracks R1, R2 with the largest evaluation values ​​F1, F2 at the point in time when the railway vehicle Tr has traveled a predetermined distance, it becomes possible to reliably (without omission even when the predetermined values ​​are not reached) detect which railway tracks R1, R2 the railway vehicle Tr is located on. On the other hand, if the evaluation values ​​F1, F2 of none of the railway tracks R1, R2 reach the predetermined values ​​even when the railway vehicle Tr has traveled a predetermined distance, it is determined that it is impossible to calculate which railway track R1, R2 the railway vehicle Tr is located on, making it possible to prevent the position of the railway vehicle Tr from being erroneously determined and output.

[0078] In addition, since the evaluation values ​​F1, F2 are calculated according to the surrounding environment and environmental factors in which the railway vehicle Tr is running, it is possible to properly detect which railway track R1, R2 the railway vehicle Tr is located on according to the surrounding environment and environmental factors in which the railway vehicle Tr is running.

[0079] (Embodiment 2) Next, a vehicle approach warning system 1 using a vehicle position detection device and a vehicle position detection method according to embodiment 2 of the present invention will be described. Note that the same components as those in embodiment 1 are designated by the same reference numerals and detailed descriptions thereof will be omitted.

[0080] In the first embodiment, if a position error due to GNSS positioning occurs in a lateral direction relative to the traveling direction of the railcar, it may not be possible to accurately determine on which railroad track the railcar is located. In addition, in the first embodiment, the latitude and longitude of two points close to the latitude and longitude of the current position for each of the railroad tracks R1 and R2 are extracted from the railroad GIS 231 each time, but this process involves a large amount of calculation, which is costly. Furthermore, in cases where positioning data from GPS satellites cannot be used, such as inside a tunnel, a position detection device using a neural network is used (see, for example, JP 2014-100963 A), but in the case of a method using a neural network, it is necessary to build a necessary neural network, which is problematic in that a device with high calculation capabilities is required.

[0081] In order to solve the above problem, in this embodiment, the position calculation unit 24 executes a second determination process in addition to the first determination process, and an appropriate determination result is obtained based on the first determination process and the second determination process. In this respect, this embodiment differs from the first embodiment.

[0082] 6 is a schematic block diagram showing the configuration of the on-board equipment 2 according to this embodiment. In this embodiment, the on-board equipment 2 further includes an angular velocity sensor 251 (angular velocity detection means), and the position calculation unit 24 performs not only the first determination process but also the second determination process.

[0083] The angular velocity sensor 251 is a sensor for detecting the angle (angular velocity) of the rotational speed in the horizontal direction of the on-board equipment 2 (railroad car Tr), and is provided in the sensor unit 25. The sensor unit 25 also includes an acceleration sensor 252, and can measure the inertial momentum of the on-board equipment 2 (railroad car Tr).

[0084] <Second Determination Process> The second determination process will be described with reference to Figs. 7 to 9. First, Fig. 7 is a diagram showing a calculation concept related to the second determination process. The railway vehicle Tr shown in Fig. 7 travels on a railway track R, and detects that it is approaching and passing a branch point M0 between a reference line R1 and a branch line R2 branching from the reference line R1 by checking the current position against the railway GIS 231. Alternatively, the position calculation unit 24 may detect that the railway vehicle Tr is approaching the branch point M0 when the railway vehicle Tr is located at a predetermined distance from the branch point M0. Then, the position calculation unit 24 acquires the angle of the rotational speed in the horizontal direction of the on-board equipment 2 (railroad vehicle Tr), that is, information on the angular speed, from the angular speed sensor 251. Then, the position calculation unit 24 time-integrates the acquired angular speed to calculate an angular speed integral value θ. The angular speed integral value θ indicates the rotation angle in the horizontal direction of the on-board equipment 2 (railroad vehicle Tr).

[0085] The position calculation unit 24 calculates the distance d from the branch point M0 to the current position of the railway vehicle Tr in the direction of the reference line R1. Fig. 7 shows the distance d when the railway vehicle Tr is located at point CP1 when it is located on the branch line R2, and when it is located on the reference line R1, the distance d when it is located at point CP2. At this time, the position calculation unit 24 may calculate the distance d based on the result of matching with the railway GIS 231 at the current position of the railway vehicle Tr, or may calculate the distance d based on the movement speed of the railway vehicle Tr detected by a speed detection means for detecting the movement speed of the railway vehicle Tr provided on the railway vehicle Tr, specifically, a radar speedometer 26.

[0086] The position calculation unit 24 calculates the perpendicular distance g from the reference line R1 to the current position of the railway vehicle Tr based on the angular velocity integral value θ (rotation angle) and the distance d of the railway vehicle Tr in the direction of the reference line R1. Fig. 7 shows the perpendicular distance g when the railway vehicle Tr is located at point CP1 when the railway vehicle Tr is located on the branch line R2. At this time, the position calculation unit 24 may calculate the perpendicular distance g multiple times within a predetermined time or while the railway vehicle Tr is located at a predetermined distance from the branch point M0, hold the maximum value g1 and the minimum value g2 of the perpendicular distance g to the current position of the railway vehicle Tr each time they are calculated, and calculate the maximum value g1 and the minimum value g2 of the perpendicular distance to the calculated current position of the railway vehicle Tr.

[0087] In this case, the perpendicular distance g and its maximum value g1 and minimum value g2 are expressed by the following formula.

number

[0088] Then, the position calculation unit 24 determines on which railroad track the railroad vehicle Tr is located, i.e., on which of the reference line R1 or the branch line R2 it is located, based on the calculated distance d and the calculated perpendicular distance g. At this time, the determination may be made based on either the maximum value g1 or the minimum value g2 of the perpendicular distance. For example, the position calculation unit 24 may determine that the railroad vehicle Tr is located on the branch line R2 when the maximum value g1 or the minimum value g2 of the perpendicular distance reaches a threshold value determined for each branch line R2. For example, this threshold value is set to a dashed line L1 shown in FIG. 7, and when the railroad vehicle Tr passes through an intersection IP1 between the dashed line L1 and the branch line R2, the maximum value g1 or the minimum value g2 of the perpendicular distance exceeds the perpendicular distance g at the intersection IP1, so that it is determined that the railroad vehicle Tr is located on the branch line R2. The reason for making the determination based on either the maximum value g1 or the minimum value g2 of the perpendicular distance is that the sign of the perpendicular distance g changes depending on the rotation direction of the railroad vehicle Tr.

[0089] Furthermore, the position calculation unit 24 may determine that the railcar Tr is located on the reference line R1 when, for example, the distance d of the railcar Tr in the direction of the reference line R1 reaches a threshold value determined for each reference line R1. For example, this threshold value is set to a dashed line L2 shown in Fig. 7, and when the railcar Tr passes an intersection IP2 between the dashed line L2 and the reference line R1, the distance d exceeds the distance d at the intersection IP2, and therefore it is determined that the railcar Tr is located on the reference line R1.

[0090] That is, for example, when the railroad vehicle Tr is located in the branch line angle area A1 shown in FIG. 7, the position calculation unit 24 determines that the railroad vehicle Tr is located on the branch line R2, and when the railroad vehicle Tr is located in the reference line angle area A2, the position calculation unit 24 determines that the railroad vehicle Tr is located on the reference line R1. Note that when the railroad vehicle Tr is located in the other area A3 shown in FIG. 7, the position calculation unit 24 determines that the railroad vehicle Tr is indeterminable / abnormal. When the maximum value f1 or the minimum value f2 of the perpendicular distance reaches the above threshold value and the railroad vehicle Tr is located in the other area A3, the position calculation unit 24 may determine that the railroad vehicle Tr is indeterminable / abnormal, and when the distance d reaches the above threshold value and the railroad vehicle Tr is located in the other area A3, the position calculation unit 24 may determine that the railroad vehicle Tr is indeterminable / abnormal. Furthermore, when the railroad vehicle Tr is determined to be indeterminable / abnormal, a predetermined notice may be sent to the user. This allows the user to recognize the abnormality and take action such as stopping the vehicle or manually setting the position.

[0091] Next, a specific calculation method of the second determination process based on such a calculation concept will be described with reference to the flowcharts shown in FIGS.

[0092] Fig. 8 is a flow chart showing a calculation procedure for the second determination process of the position calculation unit 24 in the on-board device 2 in Fig. 6. First, the current position of the railway vehicle Tr is acquired (step S31) and compared with map information (information on each point and branch point) of the railway GIS 231 (step S32). Then, it is determined whether the railway vehicle Tr is approaching a branch point on the railway track R (vehicle position calculation step, step S33). If the railway vehicle Tr is not approaching a branch point on the railway track R ("N" in step S33), the process returns to step S31 and the same process is repeated.

[0093] On the other hand, if the railroad vehicle Tr approaches a branch point on the railroad track R (if "Y" in step S33), a branch determination process is performed to determine which railroad track R the railroad vehicle Tr is located on (step S34). Then, when the branch determination process is completed and the railroad track on which the railroad vehicle Tr is located is determined (step S35), the process returns to step S31 and the same process is repeated. Here, the distance for determining whether the railroad vehicle Tr has approached a branch point is preset according to the surrounding environment and environmental factors for each branch point, which will be described later.

[0094] Next, the branch determination process shown in step S34 will be described.

[0095] Fig. 9 is a flowchart showing the calculation procedure of the branch determination process in the flowchart of Fig. 8. First, as described above, the angle of the rotational speed in the horizontal direction of the on-board equipment 2 (railroad vehicle Tr), i.e., angular speed information is acquired from the angular speed sensor 251 (angular speed detection step and vehicle position calculation step, step S41), and the acquired angular speed is integrated with respect to time to calculate the angular speed integral value θ, i.e., the rotational angle in the horizontal direction of the on-board equipment 2 (railroad vehicle Tr) (vehicle position calculation step, step S42).

[0096] Next, a distance d in the direction of the reference line R1 from the branch point M0 to the current position of the railcar Tr is calculated (a vehicle position calculation step, step S43). At this time, in step S43, the distance d may be calculated based on a result of matching with the railcar GIS 231 at the current position of the railcar Tr, or the distance d may be calculated based on the moving speed of the railcar Tr detected by a speed detection means provided on the railcar Tr, specifically, the radar speedometer 26.

[0097] Next, based on the angular velocity integral value θ (rotation angle) calculated in step S42 and the distance d of the railway vehicle Tr in the direction of the reference line R1 calculated in step S43, a perpendicular distance g from the reference line R1 to the current position of the railway vehicle Tr is calculated (vehicle position calculation step, step S44). In step S44, the perpendicular distance g is calculated multiple times within a predetermined time or while the railway vehicle Tr is located a predetermined distance from the branch point M0, and the maximum value g1 and minimum value g2 of the perpendicular distance g to the current position of the railway vehicle Tr are stored each time they are calculated, and the maximum value g1 and minimum value g2 of the perpendicular distance to the calculated current position of the railway vehicle Tr are calculated.

[0098] Next, an evaluation process is performed based on each calculated angle difference (vehicle position calculation step, step S45). In step S45, for example, a threshold value (perpendicular distance g indicated by dashed line L1 in FIG. 7) is set for the maximum value g1 or minimum value g2 of the perpendicular distance for each branch line R2, and when the railroad vehicle Tr passes an intersection IP1 between the dashed line L1 and the branch line R2, the maximum value g1 or minimum value g2 of the perpendicular distance exceeds the perpendicular distance g at the intersection IP1, so that it is determined that the railroad vehicle Tr is located on the branch line R2.

[0099] In addition, in step S45, for example, a threshold value (the distance in the direction of the reference line R1 indicated by the dashed line L2 shown in Figure 7) is set for each reference line R1, and when the railway vehicle Tr passes through the intersection IP2 between the dashed line L2 and the reference line R1, the distance d exceeds the distance in the direction of the reference line R1 at the intersection IP2, so it is determined that the railway vehicle Tr is located on the reference line R1.

[0100] If the termination condition is satisfied ("Y" in step S46), the evaluation process, i.e., the branch determination process, is terminated, and if the termination condition is not satisfied ("N" in step S46), the process returns to step S41 and the same process is repeated. Here, the termination condition may be any condition as long as it can be properly determined on which railway track R the railway vehicle Tr is located, i.e., whether it is located on the reference line R1 or the branch line R2, and may be, for example, a case where the determination result in step S45 is output by the position calculation unit 24.

[0101] <Determination Based on First Determination Process and Second Determination Process> In this embodiment, the position calculation unit 24 executes a first determination process and a second determination process, and selects whether to detect the position of the railway vehicle from the determination result of either the first determination process or the second determination process, or to detect the position of the railway vehicle by combining the determination results of both the first determination process and the second determination process, depending on the route environment and vehicle environment.

[0102] Fig. 10 is a diagram showing a determination result obtained when the determination results of both the first and second determination processes are combined in the on-board device 2 according to this embodiment. The example shown in Fig. 10 shows a determination result obtained when the determination result of the first and second determination processes are ORed. In this example, if one determination result is the "base line" and the other determination result is the "branch line" and they do not match, and if both determination results are "undeterminable", it is determined that the vehicle is located on the base line or on the branch line, and in all other cases it is determined that the vehicle is located on the base line or on the branch line.

[0103] When the results of the first and second determination processes are combined to determine the position of the railway vehicle, the position of the railway vehicle may be detected by AND operation. In this case, the vehicle is determined to be located on the reference line or the branch line only when the results of both processes match, and is determined to be "undeterminable" in other cases.

[0104] According to this embodiment, a first judgment process and a second judgment process are performed, and the position of the railway vehicle can be detected from the judgment result of either the first judgment process or the second judgment process, and the position of the railway vehicle can also be detected by combining the judgment results of both the first judgment process and the second judgment process. Therefore, an appropriate judgment process can be selected depending on the route environment and vehicle environment, making it possible to increase the accuracy of the judgment.

[0105] In addition, by performing the second determination process, in the railway vehicle Tr traveling on either the reference line R1 on the railway track R or the branch line R2 branching off from the reference line R1, an angular velocity indicating the angle of the rotational speed of the railway vehicle Tr in the horizontal direction is detected and acquired at the branch point M0 between the reference line R1 and the branch line R2, and the acquired angular velocity is integrated over time to calculate an angular velocity integral value θ. A distance d in the reference line R1 direction from the branch point M0 to the current position of the railway vehicle Tr is calculated. Based on the angular velocity integral value θ (rotation angle) and the distance d, a perpendicular distance g from the reference line R1 to the current position of the railway vehicle Tr is calculated. Then, based on the distance d and the perpendicular distance g, it is determined on which railway track the railway vehicle Tr is located, that is, on which of the reference line R1 or the branch line R2 it is located. In this way, it is possible to detect on which of the reference line R1 or the branch line R2 the railway vehicle Tr is located. Moreover, it is possible to detect on which railway track the railway vehicle is located without being affected by a lateral position error with respect to the traveling direction of the railway vehicle Tr. Furthermore, since the database is accessed only to obtain the threshold parameters, the amount of calculation is reduced compared to other methods that access the database multiple times, which can contribute to reducing the cost of the device.Furthermore, the amount of calculation is reduced compared to methods that use neural networks, which can contribute to reducing the cost of the device.

[0106] In addition, the maximum value g1 and the minimum value g2 of the perpendicular distance g to the current position of the railroad vehicle Tr are stored, and the railroad track on which the railroad vehicle Tr is located is determined based on either the maximum value g1 or the minimum value g2 of the perpendicular distance, which allows for more accurate determination of the position on the railroad track.

[0107] Furthermore, when the maximum value g1 or minimum value g2 of the perpendicular distance g to the current position of the railway vehicle Tr reaches a threshold value determined for each branch line R2, it is determined that the railway vehicle Tr is located on the branch line R2. Furthermore, when the distance d of the railway vehicle Tr in the direction of the reference line R1 reaches a threshold value determined for each reference line R1, it is determined that the railway vehicle Tr is located on the reference line R1. Therefore, the amount of calculation for the determination process is reduced, which can contribute to reducing the cost of the device. Furthermore, since the threshold value can be set based on various laws, regulations, and standards, the work related to the setting is simplified, which can contribute to reducing the cost of setting the threshold value.

[0108] In addition, the perpendicular distance g is calculated from the angular velocity detected by the angular velocity sensor 251, and the angular velocity is converted to distance, which is used to determine the position of the railway vehicle Tr. This makes it easy to build a database.

[0109] (Embodiment 3) 11 is a schematic diagram showing a vehicle approach warning system 1A according to a third embodiment, which uses the vehicle position detection device and vehicle position detection method of the present invention. This embodiment differs from the first embodiment in that the external device 6 includes a railway GIS 231 and a position calculation unit 24. Components equivalent to those in the first embodiment are denoted by the same reference numerals and will not be described.

[0110] That is, the external device 6 connected to the on-board equipment 2 is mounted on the railway vehicle Tr, and the external device 6 includes a railway GIS 231 and a position calculation unit 24. In the first determination process, the GNSS coordinates (latitude and longitude of the railway vehicle Tr) measured by the GNSS receiving unit 212 are transmitted from the on-board equipment 2 to the external device 6, and the position calculation unit 24 of the external device 6 detects on which railway tracks R1, R2 the railway vehicle Tr is located, and in the second determination process, the angle of the rotational speed (angular velocity) detected by the angular velocity sensor 251 is transmitted from the on-board equipment 2 to the external device 6, and the position calculation unit 24 of the external device 6 detects on which railway tracks R1, R2 the railway vehicle Tr is located. In this way, in this embodiment, the on-board equipment 2 and the external device 6 configure a vehicle position detection device.

[0111] According to such an embodiment, for example, by using a computer capable of high-speed calculation processing as the external device 6, the position of the railway vehicle Tr can be calculated at high speed, and the calculated position information can be used to operate application software that supports the operation of the railway vehicle Tr. In addition, the processing load of the on-board device 2 can be reduced, and power consumption can be suppressed.

[0112] (Embodiment 4) 12 is a schematic diagram showing a vehicle approach warning system 1B according to a fourth embodiment using the vehicle position detection device and vehicle position detection method of the present invention. This embodiment differs from the first embodiment in that a railway GIS 231 and a position calculation unit 24 are provided in a location other than the railway vehicle Tr, and the same components as those in the first embodiment are denoted by the same reference numerals and will not be described.

[0113] That is, in this embodiment, the server 4 includes a railway GIS 231 and a position calculation unit 24. In the first determination process, the GNSS coordinates (latitude and longitude of the railway vehicle Tr) measured by the GNSS receiving unit 212 are transmitted from the on-board equipment 2 to the server 4, and the position calculation unit 24 of the server 4 detects on which railway tracks R1, R2 the railway vehicle Tr is located, and in the second determination process, the angle of the rotational speed (angular velocity) detected by the angular velocity sensor 251 is transmitted from the on-board equipment 2 to the server 4, and the position calculation unit 24 of the server 4 detects on which railway tracks R1, R2 the railway vehicle Tr is located. In this way, in this embodiment, the on-board equipment 2 and the server 4 configure a vehicle position detection device.

[0114] According to this embodiment, the positions of many railway cars Tr are detected by the position calculation unit 24 of the server 4, so that it is possible to reduce the cost of the on-board equipment 2 mounted on many railway cars Tr. Furthermore, since the position detection of many railway cars Tr can be collectively processed by the server 4, it is possible to reduce the processing load of the on-board equipment 2 installed on each railway car Tr and reduce power consumption. Furthermore, when updating the function of the position calculation unit 24, it is only necessary to change the position calculation unit 24 of the server 4, so that the function can be easily updated.

[0115] (Embodiment 5) 6 is a schematic block diagram showing the on-board device 2 in this embodiment. In this embodiment, the configuration is different from that of the first embodiment in that in the first determination process, the latitude and longitude of the railway vehicle Tr are measured based on the speed and inertial momentum of the railway vehicle Tr in addition to the satellite positioning coordinates, and the same components as those in the first embodiment are denoted by the same reference numerals and will not be described.

[0116] That is, the railway vehicle Tr is equipped with a radar speedometer 26, an acceleration sensor (inertial sensor) 252, and an angular velocity sensor (inertial sensor) 251. The radar speedometer 26 transmits radar waves in the direction of the rails, receives reflected waves reflected by a railway track on which rails, sleepers, etc. are laid, measures the speed of the railway vehicle Tr, and outputs the measurement result to the position calculation unit 24. In addition, the acceleration sensor 252 and the angular velocity sensor 251 measure the acceleration and angular velocity (inertial momentum) generated when the railway vehicle Tr is traveling, and outputs the measurement result to the position calculation unit 24.

[0117] Then, when the positioning accuracy index of the satellite positioning coordinates based on the GNSS signal from the GNSS satellite St is equal to or greater than a predetermined value, the position calculation unit 24 sets the satellite positioning coordinates as the latitude and longitude of the railway vehicle Tr. On the other hand, when the positioning accuracy index is less than the predetermined value, the position calculation unit 24 calculates a composite coordinate based on the satellite positioning coordinates, the speed of the railway vehicle Tr, and the inertial momentum of the railway vehicle Tr, and sets the composite coordinate as the latitude and longitude of the railway vehicle Tr. Note that the positioning accuracy index indicating the positioning accuracy of the GNSS coordinates is included in the GNSS signal.

[0118] Here, a description will be given of the composite positioning unit 241 that calculates composite coordinates in the position calculation unit 24 that also functions as a positioning means. As shown in Fig. 13, the composite positioning unit 241 includes an inertial calculation unit 2411 that calculates and outputs composite positioning information including the composite coordinates, and an error estimation unit 2412 that estimates and outputs an amount of error between the GNSS coordinates and the composite coordinates.

[0119] The composite positioning unit 241 constantly calculates composite coordinates when the railway vehicle Tr starts operation. The GNSS receiving unit 212 initializes the initial position and initial orientation before the railway vehicle Tr starts operation. The initial position is initialized based on the GNSS coordinates calculated from the GNSS signal, and the initial orientation is initialized based on the moving orientation of the railway vehicle Tr at the time of starting operation. The GNSS receiving unit 212 outputs the GNSS positioning information (latitude, longitude, orientation, and speed) calculated after the initialization to the error estimating unit 2412.

[0120] The inertia calculation unit 2411 initializes an initial attitude angle before the railcar Tr starts to operate. Specifically, the acceleration of the stopped railcar Tr is resolved into three axial directions of x, y, and z and initialized. The inertia calculation unit 2411 calculates composite positioning information (latitude, longitude, direction, attitude, speed) including composite coordinates based on the speed of the railcar Tr measured by the radar speedometer 26, the acceleration and angular acceleration of the railcar Tr measured by the acceleration sensor 252 and the angular velocity sensor 251, and the amount of error input from the error estimation unit 2412, and outputs the information to the error estimation unit 2412. The error estimation unit 2412 estimates the amount of error between the GNSS coordinates and the composite coordinates, and outputs the information to the inertia calculation unit 2411.

[0121] In this way, the composite positioning unit 241 outputs more accurate positioning coordinates by repeatedly calculating the composite coordinates based on the speed of the railway vehicle Tr measured by the radar speedometer 26, the acceleration and angular acceleration of the railway vehicle Tr measured by the acceleration sensor 252 and the angular velocity sensor 251, and the amount of error between the GNSS coordinates and the composite coordinates input from the error estimation unit 2412.

[0122] According to this embodiment, when the positioning accuracy index based on the GNSS signal from the GNSS satellite St is less than a predetermined value, composite coordinates are calculated based on the satellite positioning coordinates, the speed, and the inertial momentum, and are set as the latitude and longitude of the railway vehicle Tr. Therefore, even if the railway vehicle Tr enters a tunnel or underground and the positioning accuracy based on the GNSS signal from the GNSS satellite St is poor, it is possible to accurately detect the position of the railway vehicle Tr.

[0123] In addition, since the error amount between the satellite positioning coordinates and the composite coordinates is used to calculate the composite coordinates, it is possible to accurately detect the position of the railway vehicle Tr from measurement values ​​that have errors and noise, such as the satellite positioning coordinates, speed, and inertial momentum.

[0124] Although the embodiment of the present invention has been described above, the specific configuration is not limited to the above embodiment, and the present invention includes design changes and the like that do not deviate from the gist of the present invention. For example, in the above embodiment, the railroad GIS 231 and the position calculation unit 24 are provided as a pair, but the railroad GIS 231 may be provided in a separate computer server.

[0125] In addition, although the vehicle position detection device and vehicle position detection method of the present invention have been described as being applied to the vehicle approach warning systems 1, 1A, and 1B, they may be applied to other systems and devices. For example, they may be applied to a system that determines whether the left or right door of a railway vehicle Tr should be opened depending on which track (railroad track R) the railway vehicle Tr is entering at a station, or to a system that monitors and issues an alarm about the approach of multiple railway vehicles Tr depending on which railroad track R the multiple railway vehicles Tr are running on.

[0126] 1, 1A, 1B Vehicle Approach Warning System 2 On-board device (vehicle position detection device) 211 GNSS antenna (positioning means) 212 GNSS receiver (positioning means) 22 Communications Department 221 Communication Antenna 222 Communication Module 23 Memory section 231 Railway GIS (map information storage means) 24 Position calculation unit (vehicle position calculation means) 25 Sensor section 251 Angular velocity sensor (angular velocity detection means) 252 Acceleration Sensor 26 Radar Speedometer 3. Alarm terminal 4 Server Tr Railway Vehicles L1: Dashed line L2: Dashed line M0: Branch point NW: Communication network CP1: point CP2: point IP1: Intersection IP2: Intersection R Railway track R1 Reference Line R2 Branch line W Worker θP Vehicle heading angle θM, θB Orbit azimuth

Claims

1. A map information storage means for storing map information including the latitude and longitude of each point on a plurality of railroad tracks; a positioning means for measuring the latitude and longitude of a railway vehicle running on the railway track; a vehicle position calculation means for calculating on which railroad track the railway vehicle is located, The vehicle position calculation means calculating an azimuth angle in which the railway vehicle travels based on the latitude and longitude of the current position of the railway vehicle measured by the positioning means and the latitude and longitude of a previous position of the railway vehicle measured by the positioning means immediately before the current position, as a vehicle azimuth angle; extracting, for each of the railway tracks, latitudes and longitudes of two points close to the current position from the map information, and calculating an azimuth angle for each of the railway tracks as a track azimuth angle based on the extracted latitudes and longitudes of the two points for each of the railway tracks; executing a first determination process for determining on which railway track the railway vehicle is located based on the vehicle azimuth angle and a track azimuth angle for each railway track; A vehicle position detection device comprising:

2. The vehicle position calculation means, in the first determination process, sequentially calculating the vehicle azimuth angle and a track azimuth angle for each of the railway tracks as the railway vehicle travels, integrating a difference angle between the track azimuth angle and the vehicle azimuth angle for each of the railway tracks, and calculating on which railway track the railway vehicle is located based on an evaluation value calculated from the integrated value; 2. The vehicle position detection device according to claim 1 .

3. In the first determination process, the vehicle position calculation means when the evaluation value of any one of the railway tracks reaches a predetermined value, it is determined that the railway vehicle is located on the railway track.

3. The vehicle position detection device according to claim 2.

4. The vehicle position calculation means, in the first determination process, if the evaluation value of any of the railway tracks does not reach the predetermined value when the railway vehicle has traveled a predetermined distance, it is determined that it is impossible to calculate on which railway track the railway vehicle is located.

4. The vehicle position detection device according to claim 3.

5. The vehicle position calculation means, in the first determination process, When the railway vehicle has traveled a predetermined distance, it is determined that the railway vehicle is located on the railway track having the maximum evaluation value.

3. The vehicle position detection device according to claim 2.

6. The vehicle position calculation means, in the first determination process, calculating the evaluation value according to the surrounding environment in which the railway vehicle runs; 3. The vehicle position detection device according to claim 2.

7. In the first determination process, the positioning means calculating satellite positioning coordinates based on a positioning signal received from a positioning satellite, and when a positioning accuracy index is equal to or greater than a predetermined value, setting the satellite positioning coordinates as the latitude and longitude of the railway vehicle; if the positioning accuracy index is less than the predetermined value, a composite coordinate is calculated based on the satellite positioning coordinate, the speed of the railway vehicle, and the inertial momentum of the railway vehicle, and the composite coordinate is set as the latitude and longitude of the railway vehicle.

2. The vehicle position detection device according to claim 1 .

8. In the first determination process, the positioning means an amount of error between the satellite positioning coordinate and the composite coordinate is estimated, and the estimated amount of error is used in the calculation of the composite coordinate; 8. The vehicle position detection device according to claim 7.

9. and an angular velocity detection means for detecting an angular velocity indicating an angle of a rotational velocity in a horizontal direction of a railway vehicle running on the railway track, The vehicle position calculation means acquiring an angular velocity of the railway vehicle detected by the angular velocity detection means in the vicinity of a branch point between a reference line on the railway track and a branch line branching off from the reference line; Calculating a distance from the branch point to a current position of the railroad vehicle in a direction of the reference line; calculating a perpendicular distance from the reference line to a current position of the railway vehicle based on the acquired angular velocity of the railway vehicle and the calculated distance of the railway vehicle in a direction of the reference line; executing a second determination process for determining on which railroad track the railway vehicle is located based on the calculated distance of the railway vehicle in the direction of the reference line and the calculated perpendicular distance to the current position of the railway vehicle; determining on which railroad track the railcar is located based on the first determination process and the second determination process; 2. The vehicle position detection device according to claim 1 .

10. In the second determination process, the vehicle position calculation means when it is detected based on the map information that the railway vehicle is approaching a junction between a reference line on the railway track and a branch line branching off from the reference line, an angular velocity of the railway vehicle detected by the angular velocity detection means is acquired.

10. The vehicle position detection device according to claim 9.

11. In the second determination process, the vehicle position calculation means acquiring an angular velocity of the railway vehicle, calculating a distance of the railway vehicle in a direction of the reference line, calculating a perpendicular distance to a current position of the railway vehicle, and determining on which railway track the railway vehicle is located, the process of repeating this at predetermined intervals; 10. The vehicle position detection device according to claim 9.

12. In the second determination process, the vehicle position calculation means calculating an angular velocity integral value by integrating the acquired angular velocity of the railway vehicle with respect to time, and calculating a distance in a direction of the reference line from the branch point to a current position of the railway vehicle based on the angular velocity integral value; 12. The vehicle position detection device according to claim 9, wherein the vehicle position detection device is a vehicle position detection device.

13. In the second determination process, the vehicle position calculation means calculating a perpendicular distance to the current position of the railway vehicle a plurality of times within a predetermined time period, retaining maximum and minimum values ​​of the perpendicular distance to the current position of the railway vehicle, and determining on which railway track the railway vehicle is located based on the calculated maximum and minimum values ​​of the perpendicular distance to the current position of the railway vehicle; 10. The vehicle position detection device according to claim 9.

14. In the second determination process, the vehicle position calculation means when the calculated maximum or minimum value of the perpendicular distance to the current position of the railway vehicle reaches a threshold value defined for each of the branch lines, it is determined that the railway vehicle is located on the branch line.

14. The vehicle position detection device according to claim 13.

15. In the second determination process, the vehicle position calculation means when the calculated maximum or minimum value of the perpendicular distance to the current position of the railway vehicle reaches a threshold value determined for each of the branch lines, but is outside a predetermined range, it is determined that the determination is impossible; 15. The vehicle position detection device according to claim 14.

16. In the second determination process, the vehicle position calculation means if the calculated distance of the railway vehicle in the direction of the reference line reaches a threshold value defined for each of the reference lines, it is determined that the railway vehicle is located on the reference line.

10. The vehicle position detection device according to claim 9.

17. The vehicle position calculation means When the calculated distance of the railway vehicle in the direction of the reference line reaches a threshold value determined for each of the reference lines, but is outside a predetermined range, it is determined that the distance is impossible to determine.

17. The vehicle position detection device according to claim 16.

18. In the second determination process, the vehicle position calculation means if the position of the rail vehicle cannot be determined, a predetermined notification is given; 18. The vehicle position detection device according to claim 17.

19. In the second determination process, the vehicle position calculation means calculating a distance from the branch point to a current position of the railway vehicle in a direction of the reference line based on the map information; 11. The vehicle position detection device according to claim 10.

20. In the second determination process, the vehicle position calculation means calculating a distance in a direction of the reference line from the branch point to a current position of the railway vehicle based on a moving speed of the railway vehicle detected by a speed detection means provided in the railway vehicle and detecting a moving speed of the railway vehicle; 10. The vehicle position detection device according to claim 9.

21. A vehicle position detection method to be executed by a computer having a processor and a memory unit, the method comprising: The memory unit stores map information including latitude and longitude of each point on a plurality of railway tracks, a positioning step in which the processor measures latitude and longitude of a railway vehicle traveling on the railway track; a vehicle position calculation step of calculating on which railroad track the railroad vehicle is located; In the vehicle position calculation step, calculating an azimuth angle in which the railway vehicle travels as a vehicle azimuth angle based on the latitude and longitude of the current position of the railway vehicle measured in the positioning step and the latitude and longitude of a previous position of the railway vehicle measured immediately before the current position; extracting, for each of the railway tracks, latitudes and longitudes of two points close to the current position from the map information, and calculating an azimuth angle for each of the railway tracks as a track azimuth angle based on the extracted latitudes and longitudes of the two points for each of the railway tracks; executing a first determination process for determining on which railway track the railway vehicle is located based on the vehicle azimuth angle and a track azimuth angle for each railway track; A vehicle position detection method comprising:

22. The processor further performs an angular velocity detection step of detecting an angular velocity indicating an angle of a rotational velocity in a horizontal direction of a rail vehicle traveling on the rail track; In the vehicle position calculation step, Detecting, based on the map information, that the railroad vehicle is approaching a junction between a reference line on the railroad track and a branch line branching off from the reference line; acquiring an angular velocity of the railway vehicle detected in the angular velocity detection step; Calculating a distance from the branch point to a current position of the railroad vehicle in a direction of the reference line; calculating a perpendicular distance from the reference line to a current position of the railway vehicle based on the acquired angular velocity of the railway vehicle and the calculated distance of the railway vehicle in a direction of the reference line; executing a second determination process for determining on which railroad track the railway vehicle is located based on the calculated distance of the railway vehicle in the direction of the reference line and the calculated perpendicular distance to the current position of the railway vehicle; determining on which railroad track the railcar is located based on the first determination process and the second determination process; 22. The method of claim 21, wherein the vehicle position is detected by the vehicle position detecting means.

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