Position calculation device and position calculation method

Abstract

To efficiently calculate a position of a moving body.SOLUTION: A position calculation device includes: an orbit coordinate specification unit 52 for identifying two mutually adjacent facility coordinates from a side closest to positioning coordinates of a moving body by repeating processing of excluding a predetermined number of facility coordinates from a side of facility coordinates which are far from the positioning coordinates; and a kilometer calculation unit 53 for obtaining the kilometers of a position to which the positioning coordinates are assigned as a position of the moving body after correction in which the positioning coordinates are assigned on a line segment connecting the two identified mutually-adjacent facility coordinates.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a technique for calculating the position of a moving object traveling on a predetermined infrastructure such as a railway track or a highway. [Background technology]

[0002] A known device for calculating the position of a railway vehicle is a vehicle position calculation device that includes a positioning means for measuring the position of the railway vehicle using GPS satellites (GPS: Global Positioning System), and a kilometer distance calculation means for calculating the position of the railway vehicle in kilometers from a preset starting point based on map information including track position information and the measured vehicle position (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-186651 Summary of the Invention [Problem to be solved by the invention]

[0004] When calculating the position (specifically, distance in kilometers) of a railcar traveling on a railroad track using latitude and longitude determined by a GNSS receiver (GNSS: Global Navigation Satellite System) and referring to GIS (Geographic Information System; information on the latitude, longitude, and distance in kilometers for each railroad line is compiled), shortening the GNSS positioning interval and the calculation interval for the railcar's position is one way to calculate the position of a fast-moving railcar as quickly as possible. However, because all processing, including application functions that perform various processes based on the calculated railcar position, needs to be completed within the GNSS positioning interval, it is desirable to speed up the calculation of the railcar's position by efficiently searching GIS data and reducing the number of searches.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a position calculation device and a position calculation method that are capable of efficiently calculating the position of a moving object. [Means for solving the problem]

[0006] In order to solve the above problems, a position calculation device according to the present invention includes a positioning unit that measures the position of a moving object and calculates positioning coordinates, and a plurality of areas that are partitioned and set in a mesh shape in a region where facilities on which the moving object travels are laid. An area specifying unit that specifies the area in which the positioning coordinates are located and specifies the facility coordinates at both ends located within the specified area among the plurality of facility coordinates that are connected to represent the shape of the facility in plan view, and a facility coordinate specifying unit that excludes the number of facility coordinates corresponding to 1 / n (where 1 < n) of the number of facility coordinates located within the specified area from the side of the facility coordinate farther from the positioning coordinates among the facility coordinates at both ends, and a kilometer calculation unit that obtains the position of the moving object. The facility coordinate specifying unit repeatedly excludes the number of facility coordinates corresponding to 1 / n of the number of facility coordinates constituting the continuous arrangement of facility coordinates from the side of the facility coordinate farther from the positioning coordinates among the facility coordinates at both ends of the continuous arrangement of facility coordinates remaining after the process of excluding the facility coordinates, and specifies two mutually adjacent facility coordinates closest to the positioning coordinates. The kilometer calculation unit corrects the positioning coordinates so as to be assigned on a line segment connecting the two specified mutually adjacent facility coordinates, and obtains the kilometer of the position where the positioning coordinates are assigned as the position of the moving object.

[0007] The position calculation device according to the present invention may have a database including the association between each of the plurality of areas and the facility coordinates located within each area.

[0008] The position calculation device according to the present invention may be such that the positioning unit, the area specifying unit, the facility coordinate specifying unit, and the kilometer calculation unit are mounted on the moving object.

[0009] The position calculation device according to the present invention may be such that the positioning unit is mounted on the moving object and the area specifying unit, the facility coordinate specifying unit, and the kilometer calculation unit are installed at a location away from the moving object.

[0010] The positioning device according to the present invention may be such that the moving body is a railway vehicle and the facility is a railway track.

[0011] Further, the positioning method according to the present invention includes a process of measuring the position of a moving body and calculating positioning coordinates, a process of identifying an area in which the positioning coordinates are located among a plurality of areas set by partitioning the area where the facility on which the moving body travels is laid out in a mesh shape, a process of identifying the facility coordinates at both ends located within the identified area among a plurality of facility coordinates that are continuous so as to represent the shape of the facility in plan view, a process of excluding the number of facility coordinates corresponding to 1 / n (where 1 < n) of the number of facility coordinates located within the identified area from the side of the facility coordinate farther from the positioning coordinates among the facility coordinates at both ends, a process of obtaining the position of the moving body, and after the process of excluding the facility coordinates, repeating the process of excluding the number of facility coordinates corresponding to 1 / n of the number of facility coordinates constituting the series of facility coordinates from the side of the facility coordinate farther from the positioning coordinates among the facility coordinates at both ends of the remaining series of facility coordinates to identify two mutually adjacent facility coordinates closest to the positioning coordinates, and correcting so as to assign the positioning coordinates on the line segment connecting the two identified mutually adjacent facility coordinates, and then obtaining the number of kilometers of the position where the positioning coordinates are assigned as the position of the moving body. This is the gist of the invention.

[0012] The positioning method according to the present invention may utilize a database including the association between each of the plurality of areas and the facility coordinates located within each area.

[0013] The positioning method according to the present invention may be such that the moving body is a railway vehicle and the facility is a railway track.

Effect of the Invention

[0014] According to the position calculation device and the position calculation method of the present invention, the area in which the positioning coordinates of the moving body are located is identified, and a process of excluding a predetermined number of equipment coordinates within the area that are farthest from the positioning coordinates is repeated to identify the two adjacent equipment coordinates closest to the positioning coordinates, thereby determining the position of the moving body, thereby making it possible to efficiently calculate the position of the moving body.

[0015] According to the position calculation device and the position calculation method of the present invention, when a database including correspondence between each of a plurality of areas and the coordinates of facilities located within each area is used, it becomes possible to calculate the position of a moving object more efficiently.

[0016] The position calculation device according to the present invention may have all of its constituent parts mounted on a moving body, or may have some of its constituent parts mounted on a moving body and the rest installed at a location remote from the moving body, so that the placement of the parts can be adjusted depending on the purpose of calculating the position of the moving body, etc. Therefore, the position calculation device according to the present invention can improve the versatility of its mechanism for calculating the position of a moving body. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a functional block diagram showing a schematic configuration of a position calculation device according to an embodiment of the present invention; [Figure 2] 3 is a flowchart showing the processing procedure in the position calculation device of FIG. 1 and the processing procedure of the position calculation method according to the embodiment of the present invention. [Figure 3] FIG. 1 is a diagram showing an image of mesh settings for railway tracks of a railway line. [Figure 4] 1. FIG. 4 is a diagram illustrating an area identification process in an area identification unit of the position calculation device of FIG. [Figure 5] 1. FIG. 4 is a diagram illustrating a process of identifying a pair of nearest trajectory coordinates in the trajectory coordinate identifying unit of the position calculation device of FIG. [Figure 6] 1. FIG. 4 is a diagram illustrating a process in the final stage of the process of identifying a pair of nearest trajectory coordinates in the trajectory coordinate identifying unit of the position calculation device of FIG. [Figure 7] 1. FIG. 4 is a diagram illustrating a calculation process of the kilometers distance of the position after the positioning coordinates are corrected in the kilometers distance calculation unit of the position calculation device of FIG. [Figure 8] FIG. 10 is a functional block diagram showing a schematic configuration of another aspect of the position calculation device according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] The present invention will be described below based on the illustrated embodiment. In this embodiment, the position calculation device 1 and the position calculation method according to the present invention will be described by taking as an example a case where a railway vehicle traveling on a railway track is used to calculate the position of the railway vehicle. The position calculation device 1 is mounted on the railway vehicle traveling on the railway track.

[0019] Fig. 1 is a functional block diagram showing a schematic configuration of a position calculation device 1 according to an embodiment of the present invention. Fig. 2 is a flowchart showing the processing procedure in the position calculation device 1 according to the embodiment of the present invention and the processing procedure of a position calculation method according to the embodiment of the present invention.

[0020] The position calculation device 1 is a mechanism that is mounted on a railway vehicle and calculates and outputs the distance in kilometers from a starting point (in other words, the departure station) that is set for each railway line as the current position of the railway vehicle, and mainly comprises a control unit 2, a memory unit 3, a positioning unit 4, a position calculation unit 5, an interface unit 6, and a display unit 7. The components that make up the position calculation device 1 are connected so that they can transmit and receive signals via a bus and communicate information with each other.

[0021] The positioning device 1 according to the embodiment includes a positioning unit 4 that measures the position of a moving body (in this embodiment, a railway vehicle) and calculates positioning coordinates, and a plurality of areas that are partitioned and set in a mesh shape in a region where facilities (in this embodiment, railway tracks) on which the moving body travels are laid. An area specifying unit 51 that specifies the area in which the positioning coordinates are located and specifies the two end facility coordinates (in this embodiment, track coordinates) located within the specified area among the plurality of facility coordinates (in this embodiment, track coordinates) that are continuous so as to represent the shape of the facility in plan view; A facility coordinate specifying unit (in this embodiment, a track coordinate specifying unit 52) that excludes the number of facility coordinates corresponding to 1 / n (where 1 < n) of the number of facility coordinates located within the area specified from the side of the facility coordinate farther from the positioning coordinates among the two end facility coordinates; and a kilometer calculation unit 53 that obtains the position of the moving body. The facility coordinate specifying unit (track coordinate specifying unit 52) repeatedly excludes the number of facility coordinates corresponding to 1 / n of the number of facility coordinates constituting the continuous line of facility coordinates from the side of the facility coordinate farther from the positioning coordinates among the two end facility coordinates of the continuous line of facility coordinates remaining after the process of excluding the facility coordinates, and specifies two mutually adjacent facility coordinates from the side closest to the positioning coordinates. The kilometer calculation unit 53 corrects the positioning coordinates so as to allocate them on the line segment connecting the two specified mutually adjacent facility coordinates, and then obtains the kilometer of the position where the positioning coordinates are allocated as the position of the moving body.

[0022] Further, the position calculation method according to the embodiment includes a process of measuring the position of a moving object and calculating the measured position coordinates (step S1), a process of identifying the area in which the measured position coordinates are located among a plurality of areas that are partitioned and set in a mesh-like manner in the area where the facility on which the moving object travels is laid (step S2), a process of identifying the facility coordinates at both ends located within the identified area among a plurality of facility coordinates (in this embodiment, track coordinates) that are continuous so as to represent the shape of the facility in a plan view (step S3), a process of excluding the number of facility coordinates corresponding to 1 / n (where 1 < n) of the number of facility coordinates located within the area identified from the side of the facility coordinate farther from the measured position coordinates among the facility coordinates at both ends (step S4), and a process of obtaining the position of the moving object (step S5). After the process of excluding the facility coordinates, the process of excluding the number of facility coordinates corresponding to 1 / n of the number of facility coordinates constituting the continuous line of the facility coordinates from the side of the facility coordinate farther from the measured position coordinates among the facility coordinates at both ends of the continuous line of the remaining facility coordinates is repeated to identify two mutually adjacent facility coordinates from the side closest to the measured position coordinates, and after correcting so as to assign the measured position coordinates on the line segment connecting the two identified mutually adjacent facility coordinates, the kilometer of the position where the measured position coordinates are assigned as the position of the moving object is obtained.

[0023] (Overall configuration of the position calculation device) The control unit 2 has a function of controlling the operations of each part constituting the position calculation device 1, and is configured, for example, as a mechanism having a central processing unit (CPU: abbreviated as Central Processing Unit) that performs arithmetic processing related to the calculation of the position (specifically, the kilometer) of a railway vehicle.

[0024] The control unit 2 controls the start, content, and end of the processing of each part constituting the position calculation device 1 according to the program by causing the central processing unit to execute the program (not shown) stored in the storage unit 3 for controlling the operation of the position calculation device 1.

[0025] The memory unit 3 has the function of serving as a memory area for storing and storing programs, various information, and data used by the central processing unit when performing arithmetic processing related to calculating the position of a railway vehicle (specifically, kilometers), and as a working area for temporarily storing data and information generated when the central processing unit performs the arithmetic processing, and is configured as a mechanism having, for example, at least one of a ROM (short for Read Only Memory), which is a read-only memory device, a RAM (short for Random Access Memory), which is a readable and writable memory device, and a hard disk.

[0026] The storage unit 3 stores a track coordinate database 31 and an area coordinate correspondence database 32.

[0027] Information on the shape of the railway track in a plan view (in other words, location information) and kilometer distance information are stored for each railway line in the track coordinate database 31. The position coordinates (specifically, latitude and longitude) of multiple points that are connected along the shape of the railway track in a plan view (in other words, connected to represent the shape), which constitute the information on the shape of the railway track in a plan view, are called "track coordinates."

[0028] Specifically, the track coordinate database 31 accumulates and stores, for each railway line, a combination of track coordinate numbers as identification numbers for distinguishing between multiple track coordinates, the latitude and longitude of each track coordinate, and the distance in kilometers from the starting point of the railway line (in other words, the starting station) to each track coordinate (see Table 1 below).

[0029] [Table 1]

[0030] The track coordinate numbers in the combination data stored in the track coordinate database 31 are given as ordinal numbers (in other words, consecutive natural numbers) starting from the starting point of the railway line. The track coordinate with track coordinate number 1 is the track coordinate corresponding to the starting point of the railway line (in other words, the starting station), and the track coordinate with the largest track coordinate number (J in the example shown in Table 1 above) is the track coordinate corresponding to the end point of the railway line (in other words, the terminal station).

[0031] The latitude and longitude of the track coordinates in the combined data stored in the track coordinate database 31 are, for example, the latitude and longitude of the position coordinates of the railway track in GIS (Geographic Information System) data.

[0032] The kilometres in the combined data stored in the track coordinate database 31 may be, for example, the value obtained by calculating the distance between each two adjacent track coordinates and adding the distance from the starting point to the track coordinate, or the value of the distance from the starting point to the track coordinate determined by the railway operator.

[0033] The area coordinate correspondence database 32 stores information on the shape of areas partitioned into meshes and information on the coordinates of orbits located within the areas.

[0034] The area is set by dividing the area where the railroad tracks are laid from the starting point to the end point of the railroad line into a mesh (see FIG. 3). The area may be divided into a mesh according to a unique rule, or may be set according to an existing method for the range corresponding to the area where the railroad tracks are laid. The area may be divided according to Geohash, which is geocoding based on longitude and latitude.

[0035] The shape of each mesh area may be set to a square or a rectangle. The size of each mesh area is not limited to a specific size, but may be set to an appropriate value taking into consideration, for example, the following points A and B. The size of each mesh area may be set to, for example, about 2 to 3 km on a side. a) The smaller each area is, the fewer the number of trajectory coordinates included in each area is, and the shorter the processing time per area is; on the other hand, the more areas there are, and the longer the area search time is. a) As each area is larger, the number of areas decreases and the area search time becomes shorter, but the number of trajectory coordinates included in each area increases and the processing time per area becomes longer.

[0036] The shape and size of each mesh area may be set to be the same throughout the entire area in which a railway track is laid from the starting point to the end point of a certain railway line, or may be set to be different depending on the part of the area. For example, if the shape of the railway track in a plan view is (partially) folded or meandering, the shape and size of each area may be adjusted and set for each part of the area so that the railway track does not once exit a certain area and then make a U-turn and re-enter the certain area.

[0037] Specifically, the area coordinate correspondence database 32 accumulates and stores, for each railway line, combined data of area numbers as identification numbers for distinguishing between multiple areas, the minimum and maximum latitude values ​​of each area, the minimum and maximum longitude values ​​of each area, and the start and end track coordinate number values ​​of the track coordinates located within each area (see Table 2 below).

[0038] [Table 2]

[0039] In the combination data stored in the area coordinate correspondence database 32, the starting value of the trajectory coordinate number of the trajectory coordinates located within each area is the smallest value of the trajectory coordinate number among the trajectory coordinates located within that area (in other words, the value of the trajectory coordinate number of the trajectory coordinate closest to the starting point), and the ending value of the trajectory coordinate number of the trajectory coordinates located within that area is the largest value of the trajectory coordinate number among the trajectory coordinates located within that area (in other words, the value of the trajectory coordinate number of the trajectory coordinate closest to the ending point).

[0040] The positioning unit 4 is equipped with an antenna, receives radio waves (in other words, GNSS signals) transmitted from GNSS (Global Navigation Satellite System) satellites, and uses the received radio waves (GNSS signals) to calculate / measure the position coordinates (specifically, latitude and longitude; referred to as "positioning coordinates") of the positioning unit 4 and output them as positioning data. The method of positioning using GNSS is a well-known technology, so a detailed description will be omitted.

[0041] The trajectory coordinates in the combined data stored in the trajectory coordinate database 31 and the positioning coordinates in the positioning data output from the positioning unit 4 are organized, calculated / positioned as position coordinates in a common coordinate system, or converted into position coordinates in a common coordinate system.

[0042] The position calculation unit 5 has a function of calculating the distance in kilometers from a starting point (in other words, the starting station) set for each railway line as the position of the positioning unit 4 (and therefore the position of the railway vehicle) using the positioning data output from the positioning unit 4. The processing by the position calculation unit 5 is performed at a predetermined time interval / cycle set in advance.

[0043] The interface unit 6 has a function of providing an input / output interface to the position calculation unit 5, and, for example, receives input data on the position (specifically, distance in kilometers) of the railway vehicle calculated by the position calculation unit 5, and displays and outputs the position (specifically, distance in kilometers) of the railway vehicle on the display unit 7.

[0044] The display unit 7 has a function of displaying various information including the position of the railway vehicle (specifically, the distance in kilometers) output from the interface unit 6, and is configured as a mechanism including, for example, a liquid crystal display.

[0045] (Processing content of the position calculation unit) The position calculation unit 5 is a mechanism for using the positioning data (specifically, the positioning coordinates) output from the positioning unit 4 to calculate the position of the positioning unit 4 (and therefore the position of the railway vehicle) in kilometers from the starting point (in other words, the starting station) set for each railway line, and has an area identification unit 51, a track coordinate identification unit 52, and a kilometer calculation unit 53.

[0046] The positioning unit 4 calculates / measures the position coordinates (specifically, latitude and longitude; i.e., positioning coordinates) of the positioning unit 4 using radio waves (in other words, GNSS signals) transmitted from GNSS satellites and outputs them (step S1).

[0047] The area specifying unit 51 specifies the area in which the positioning coordinates acquired in the processing of step S1 are located (step S2).

[0048] Specifically, the area identification unit 51 receives the positioning coordinates (specifically, latitude and longitude) output from the positioning unit 4 and refers to the area coordinate correspondence database 32 to compare the values ​​of the positioning coordinates with the minimum and maximum values ​​of latitude and the minimum and maximum values ​​of longitude for each area stored in the area coordinate correspondence database 32 to identify the area in which the positioning coordinates are located.

[0049] For example, in the example shown in FIG. 3, the positioning coordinate M (the position indicated by the ▼ mark in the figure) is located within the area with area number 6, and therefore the area specifying unit 51 specifies the area with area number 6.

[0050] When the positioning coordinates are located on the periphery of each area, the area identification unit 51 may identify not only the area in which the positioning coordinates are located, but also areas adjacent to the periphery of the area.

[0051] For example, in the example shown in FIG. 4, which is an enlarged view of a portion of the example shown in FIG. 3, the area specification process may be performed as in a or b below. a) When the positioning coordinate M is located on the northern edge En of the area with area number 3, in addition to the area with area number 3, the area with area number 4, which is the area north of the area with area number 3, may also be identified. b) When the positioning coordinate M is located in the northeast corner Ene of the area with area number 3, in addition to the area with area number 3, at least one of the area with area number 4, which is the area north of the area with area number 3, and the area with area number 5, which is the area northeast of the area with area number 3, may also be identified.

[0052] The area identification unit 51 then refers to the area coordinate correspondence database 32 and acquires the start and end values ​​of the trajectory coordinate numbers associated with the area number of the area identified in the processing of step S2 (step S3). That is, the area identification unit 51 identifies the trajectory coordinates at both ends of the series of trajectory coordinates located within the area in which the positioning coordinates are located, and acquires the trajectory coordinate number values ​​of each of the trajectory coordinates at both ends.

[0053] When the area identification unit 51 identifies multiple areas in the processing of step S2 by identifying not only the area in which the positioning coordinates are located but also the areas adjacent to the peripheral parts of the area, it acquires the start value and end value of the trajectory coordinate number associated with the area number of each of the multiple areas, and as a result of the processing of step S3, it sets the smallest value among the acquired multiple start values ​​as the start value of the trajectory coordinate number and the largest value among the acquired multiple end values ​​as the end value of the trajectory coordinate number.

[0054] Then, the area identification unit 51 outputs the positioning coordinates (specifically, latitude and longitude) output from the positioning unit 4 and received as input, as well as the starting value and ending value of the track coordinate number obtained above to the track coordinate identification unit 52.

[0055] The track coordinate identification unit 52 identifies two adjacent track coordinates from the track coordinates from the starting value of the track coordinate number obtained in the process of step S3 to the ending value of the track coordinate number, which are the closest to the positioning coordinates obtained in the process of step S1 (step S4). The two adjacent track coordinates identified in the process of step S4 are referred to as the "pair of nearest track coordinates".

[0056] Specifically, the track coordinate identification unit 52 receives the input of the positioning coordinate M output from the area identification unit 51 and the starting value Js and ending value Je of the track coordinate number, calculates the distance Ds between the positioning coordinate M and the track coordinate of the starting value Js of the track coordinate number, and calculates the distance De between the positioning coordinate M and the track coordinate of the ending value Je of the track coordinate number (see Fig. 5(A)) (step S4-1). The track coordinate identification unit 52, that is, calculates the distances between the positioning coordinate M and the track coordinates at both ends of the sequence of track coordinates located within the area where the positioning coordinate M is located. Note that Fig. 5 is an image diagram for explaining the identification process of the pair of nearest track coordinates, and the shape in the plan view of the railway track is not considered.

[0057] Subsequently, the track coordinate identification unit 52 compares the distance Ds and the distance De calculated in the process of step S4-1, and designates the side of the track coordinate with the larger value (that is, the track coordinate with the longer and farther distance) as the 《exclusion side》 (step S4-2). In the example shown in Fig. 5(A), Ds < De, and the side of the track coordinate of the ending value Je of the track coordinate number is designated as the 《exclusion side》.

[0058] When the distances Ds and De calculated in the process of step S4-1 are hypothetically the same value, for example, the side of the orbit coordinate with the larger orbit coordinate number (in other words, the orbit coordinate on the end point side) is designated as the 《excluded side》.

[0059] The orbit coordinate specifying unit 52 also calculates the number T of orbit coordinates from the orbit coordinate of the starting value Js to the orbit coordinate of the ending value Je from the input starting value Js and ending value Je of the orbit coordinate number according to the following formula 1 (step S4-3). (Equation 1) T = Je - Js + 1

[0060] Next, the orbit coordinate specifying unit 52 excludes the number of orbit coordinates corresponding to 1 / n (where 1 < n) of the number T of orbit coordinates calculated in the process of step S4-3 from the 《excluded side》 specified in the process of step S4-2 from the candidates of the nearest pair of orbit coordinates (step S4-4).

[0061] The value of n that determines the number (in other words, the ratio) of orbit coordinates to be excluded is not limited to a specific value (however, 1 < n). For example, as an example only, it is set to any value within the range of about 2.5 to 5. The value of n may be set to be the same in all of the mesh-shaped areas into which the area where the railway track is laid is divided after considering the shape of the railway track in plan view from the starting point to the ending point of a certain railway line, or may be set to be different depending on the mesh-shaped areas.

[0062] Regarding the decimal part of the value of T×(1 / n), which is the number of orbit coordinates to be excluded, it may be either rounded up or rounded down, but when the value of T×(1 / n) is less than 1, it is set to 1.

[0063] Furthermore, if excluding 1 / n of the number T of trajectory coordinates from the candidates for the nearest pair of trajectory coordinates results in only one candidate for the nearest pair of trajectory coordinates, the number of candidates to be excluded from the candidates is adjusted so that two candidates for the nearest pair of trajectory coordinates remain.

[0064] The trajectory coordinate specifying unit 52 then determines whether or not the number of trajectory coordinates remaining after the processing of step S4-4 is two (step S4-5).

[0065] If the number of trajectory coordinates remaining after the processing of step S4-4 is not two (step S4-5: No), the trajectory coordinate identification unit 52 returns to the processing of step S4-1 and repeats the processing up to step S4-5.

[0066] At this time, the trajectory coordinate identification unit 52 sets the smallest value among the trajectory coordinate numbers of the trajectory coordinates remaining after the processing of step S4-4 as a start value Js and the largest value as an end value Je, and calculates the distance Ds between the positioning coordinate M output from the area identification unit 51 and the trajectory coordinate of the newly set start value Js, and also calculates the distance De between the positioning coordinate M and the trajectory coordinate of the newly set end value Je (see FIG. 5(B)) (step S4-1). That is, the trajectory coordinate identification unit 52 calculates the distance between the positioning coordinate M and each of the trajectory coordinates at both ends of the series of trajectory coordinates remaining after the processing of step S4-4.

[0067] Then, the orbit coordinate specifying unit 52 compares the distance Ds and the distance De calculated in the process of step S4-1, designates the side of the orbit coordinate with the larger value (that is, the orbit coordinate with the longer and farther distance) as the 《exclusion side》 (step S4-2), calculates the number T of orbit coordinates from the orbit coordinate of the newly set starting value Js to the orbit coordinate of the ending value Je according to the above formula 1 (step S4-3), excludes the number of orbit coordinates corresponding to 1 / n of the number T of orbit coordinates calculated in the process of step S4-3 from the 《exclusion side》 specified in the process of step S4-2 from the candidates for the pair of nearest orbit coordinates (step S4-4), and determines whether the number of orbit coordinates remaining after the process of step S4-4 is two (step S4-5).

[0068] When the value of the number T of orbit coordinates calculated in the process of step S4-3 is 3, as the process of step S4-4, the orbit coordinate specifying unit 52 excludes one orbit coordinate with the larger value (that is, the orbit coordinate with the longer and farther distance) by comparing the distance Ds and the distance De calculated in the process of step S4-1 from the candidates for the pair of nearest orbit coordinates (see Fig. 6(A)). In the example shown in Fig. 6(A), Ds < De, and the orbit coordinate of the ending value Je of the orbit coordinate number is excluded. The remaining two orbit coordinates become the pair of nearest orbit coordinates.

[0069] Also, when the value of the number T of orbit coordinates calculated in the process of step S4-3 is 3 and the distance Ds and the distance De calculated in the process of step S4-1 have the same value, as the process of step S4-4, the orbit coordinate specifying unit 52 excludes, for example, one orbit coordinate with the larger orbit coordinate number (in other words, the orbit coordinate closer to the end point; in this case, the orbit coordinate of the ending value Je of the orbit coordinate number) from the candidates for the pair of nearest orbit coordinates (see Fig. 6(B)). The remaining two orbit coordinates become the pair of nearest orbit coordinates.

[0070] On the other hand, if the number of trajectory coordinates remaining after processing step S4-4 is two (step S4-5: Yes), the trajectory coordinate identification unit 52 outputs the trajectory coordinate numbers of the two trajectory coordinates (i.e., the pair of nearest trajectory coordinates) to the kilometer distance calculation unit 53.

[0071] The kilometre calculation unit 53 calculates the kilometre distance as the current position of the railway vehicle using the positioning coordinates acquired in the process of step S1 and the pair of nearest track coordinates identified in the process of step S4 (step S5).

[0072] Here, if the positioning data is error-free and the positioning coordinates are accurate, and if the railway track position information (e.g., GIS data) is sufficiently accurate and the track coordinates are accurate, the positioning coordinates will be located on the line segment connecting the nearest pair of track coordinates, i.e., on the railway track. However, in reality, if the positioning data contains errors or the railway track position information is insufficiently accurate, the positioning coordinates may indicate a position that is off the line segment connecting the nearest pair of track coordinates (i.e., on the railway track).

[0073] Therefore, in order to correct the positioning coordinates to a position on the line segment connecting the nearest pair of track coordinates, the kilometer distance calculation unit 53 allocates the positioning coordinates to the line segment connecting the nearest pair of track coordinates. The kilometer distance calculation unit 53 then calculates the kilometer distance of the allocated position. Note that it is assumed that the track coordinates are arranged at an interval / distance such that the shape of the railway track between two adjacent track coordinates can be considered to be a straight line, and the shape of the railway track between two adjacent track coordinates is treated as being a straight line.

[0074] Specifically, the kilometer distance calculation unit 53 receives an input of the positioning coordinate M output from the area identification unit 51 and an input of the track coordinate numbers of the nearest pair of track coordinates A and B output from the track coordinate identification unit 52, draws a perpendicular line from the positioning coordinate M to a line segment AB between the nearest pair of track coordinates A and B, and corrects the positioning coordinate M by setting the position of the intersection P of the line segment AB and the perpendicular line as the position of a railway vehicle on the railway track (see FIG. 7). It is assumed that the track coordinate A is closer to the starting point than the track coordinate B.

[0075] In the example shown in FIG. 7, the following formulas 2A and 2B hold true based on Pythagoras' theorem. (Number 2A) D MA 2 = a 2 +m 2 (Number 2B) D MB 2 = b 2 +m 2 Here, D MA : Distance between positioning coordinate M and orbit coordinate A D MB : Distance between positioning coordinate M and orbit coordinate B a: Distance between orbital coordinate A and perpendicular intersection point P b: Distance between orbital coordinate B and perpendicular intersection point P m: Distance between the positioning coordinate M and the perpendicular intersection point P

[0076] Formula 2A and Formula 2B are used to calculate the coordinates (x M ,y M ), the coordinates of the nearest pair of orbital coordinates A (x A ,y A ) and the coordinates of orbital coordinate B (x B ,y B ), and the coordinates of the intersection point P between the line segment AB and the perpendicular line (x P ,y P ), the coordinates of the perpendicular line intersection point P, which is the unknown coordinate, (x P ,y P ) is required.

[0077] The values ​​of each coordinate in the calculation by the kilometer distance calculation unit 53 may be latitude and longitude values ​​(i.e., values ​​in a longitude-latitude coordinate system, for example, values ​​in the WGS84 coordinate system or the ITRF coordinate system), or values ​​obtained by converting the latitude and longitude values ​​into a specified planar rectangular coordinate system may be used.

[0078] The kilometer distance calculation unit 53 then calculates the kilometer distance K of the intersection point P of the perpendicular lines according to the following formula 3: P The following formula 3 is the kilometer distance K of the orbital coordinate A. A This is equivalent to finding the kilometre distance of the assigned position of positioning coordinate M by adding the kilometre distance between orbit coordinate A and intersection point P of the perpendicular line to the above. (Number 3) K P = K A +(K B -K A )×a / (a+b) Here, K P :The distance in kilometers from the intersection point P of the perpendicular lines K A :Kilometers of orbital coordinate A K B :Kilometers of orbital coordinate B a: Distance between orbital coordinate A and perpendicular intersection point P b: Distance between orbital coordinate B and perpendicular intersection point P

[0079] According to the position calculation device 1 and the position calculation method of the embodiment, the area in which the positioning coordinates of the moving body are located is identified, and a process of excluding a predetermined number of equipment coordinates farther from the positioning coordinates among the equipment coordinates in the area is repeated to identify the nearest pair of trajectory coordinates and obtain the position of the moving body, thereby making it possible to efficiently calculate the position of the moving body.

[0080] According to the position calculation device 1 and the position calculation method of the embodiment, the area coordinate correspondence database 32 containing correspondence between each of a plurality of areas and the trajectory coordinates located within each area is used, so that the position of the moving object can be calculated more efficiently.

[0081] The above describes an embodiment of the present invention, but the specific configuration is not limited to the above embodiment, and even if there are design changes or the like within the scope of the gist of the present invention, they are included in the present invention.

[0082] For example, in the above embodiment, the position calculation device 1 and the position calculation method according to the present invention are used to calculate the position of a railway vehicle traveling on a railway track, but the application of the position calculation device 1 and the position calculation method according to the present invention is not limited to calculating the position of a railway vehicle. The position calculation device 1 and the position calculation method according to the present invention may also be used to calculate the position of an automobile traveling on a highway, or even to calculate the positions of various mobile objects traveling on a predetermined infrastructure. In this case, a database corresponding to the track coordinate database 31 in the above embodiment stores position coordinates (specifically, latitude and longitude) of a plurality of points that are connected along the shape of the infrastructure in a planar view (in other words, connected to represent the shape) and that constitute information on the shape of the infrastructure in a planar view, as facility coordinates corresponding to the track coordinates in the above embodiment.

[0083] Furthermore, in the above embodiment, each component of the position calculation device 1 is mounted on a railway vehicle as a moving body, but it is not essential for this invention that all of the components of the position calculation device 1 be mounted on a moving body, and some of the components of the position calculation device 1 may be installed in a location away from the moving body.

[0084] For example, as shown in Fig. 8, a positioning unit 4 may be mounted on a mobile body, and a memory unit 3, a position calculation unit 5, an interface unit 6, and a display unit 7 may be installed at a location remote from the mobile body. The set of units installed at a location remote from the mobile body (in other words, a device including the units installed at a location remote from the mobile body) is referred to as a "management device 8." Note that even when the units that calculate the position of a mobile body (specifically, kilometers) are mounted on the mobile body at a distance from each other or installed at a location remote from the mobile body, the mechanism that calculates the position of the mobile body, which is composed of the units that are separate from each other, is referred to as a "position calculation device 1."

[0085] In this case, the mobile body is equipped with a control unit 2A having a central processing unit (CPU) or the like that controls the operation of each part that is mounted on the mobile body among the parts that make up the position calculation device 1, and is also equipped with a mobile body communication unit 9A having a wireless communication module or the like that sends and receives signals between the mobile body and the management device 8 to transmit / communicate information between them.

[0086] The management device 8 is also provided with a control unit 2B having a central processing unit (CPU) or the like that controls the operation of each of the parts that make up the position calculation device 1 and that are provided within the management device 8, and is also provided with a management device communication unit 9B having a wireless communication module or the like that sends and receives signals with a mobile communication unit 9A mounted on the mobile body to transmit / communicate information to / from each other.

[0087] In this case, the positioning coordinates of the positioning unit 4 calculated / measured by the positioning unit 4 mounted on the mobile body are transmitted / communicated as positioning data to the management device 8 via the mobile body communication unit 9A and the management device communication unit 9B, and the position calculation unit 5 provided in the management device 8 uses the positioning data to calculate the position of the positioning unit 4 (and therefore the position of the mobile body). [Explanation of symbols]

[0088] 1 Position calculation device 2. Control Unit 3 Storage section 31 Orbital Coordinate Database 32 Area Coordinate Correspondence Database 4 Positioning unit 5 Position calculation section 51 Area Identification Department 52 Orbit coordinate identification part 53 Kilometer Calculation Unit 6 Interface section 7 Display section 2A Control unit on the moving body side 9A Mobile Communications Department 8 Management device 2B Control section of management device 9B Management device communication department

Claims

1. a positioning unit that measures the position of a moving object and calculates positioning coordinates; an area specifying unit that specifies the area in which the positioning coordinates are located among a plurality of areas that are set by dividing an area in which equipment on which the mobile body travels is installed into a mesh pattern, and that specifies the equipment coordinates of both ends located within the specified area among a plurality of equipment coordinates that are connected to represent the shape of the equipment in a plan view; an equipment coordinate specification unit that excludes equipment coordinates corresponding to 1 / n (where 1<n) of the number of equipment coordinates located within the specified area from the side of the equipment coordinates at both ends that are farther from the positioning coordinates; a kilometer distance calculation unit for calculating the position of the moving object, the facility coordinate identification unit repeats a process of excluding a number of facility coordinates corresponding to 1 / n of the number of facility coordinates constituting the facility coordinate series from the facility coordinates farthest from the positioning coordinates among the facility coordinates at both ends of the facility coordinate series remaining after the process of excluding the facility coordinates, thereby identifying two adjacent facility coordinates from those closest to the positioning coordinates; the kilometer distance calculation unit corrects the positioning coordinates so that they are assigned to a line segment connecting the specified two adjacent facility coordinates, and then calculates the kilometer distance of the position to which the positioning coordinates are assigned as the position of the moving body. A position calculation device characterized by:

2. a database including correspondence between each of the plurality of areas and the coordinates of the equipment located within each area; 2. The position calculation device according to claim 1.

3. The positioning unit, the area specifying unit, the facility coordinate specifying unit, and the kilometer distance calculation unit are mounted on the moving body.

3. The position calculation device according to claim 1 or 2.

4. The positioning unit is mounted on the moving body, and the area specifying unit, the facility coordinate specifying unit, and the kilometer distance calculation unit are installed at a location away from the moving body.

3. The position calculation device according to claim 1 or 2.

5. The moving body is a railway vehicle and the facility is a railway track.

5. The position calculation device according to claim 1, wherein the position calculation device is a position calculation device for calculating a position of a vehicle.

6. A process of measuring the position of a moving object and calculating positioning coordinates; A process of identifying an area in which the positioning coordinates are located among a plurality of areas set by dividing an area in which facilities on which the mobile body travels are laid into a mesh pattern; A process of identifying the coordinates of equipment at both ends located within the identified area from among a plurality of equipment coordinates that are connected to represent the shape of the equipment in a plan view; a process of excluding, from the equipment coordinates at both ends, equipment coordinates corresponding to 1 / n (where 1<n) of the number of equipment coordinates located within the specified area from the equipment coordinates farther from the positioning coordinates; and a process of determining the position of the moving body, repeating a process of excluding a number of equipment coordinates corresponding to 1 / n of the number of equipment coordinates constituting the series of equipment coordinates from the side of the equipment coordinates farthest from the positioning coordinates among the equipment coordinates at both ends of the series of equipment coordinates remaining after the process of excluding the equipment coordinates, thereby identifying two mutually adjacent equipment coordinates from the side closest to the positioning coordinates; correcting the positioning coordinates so that they are assigned to a line segment connecting the specified two adjacent facility coordinates, and then determining the distance in kilometers from the position to which the positioning coordinates are assigned as the position of the moving body; A position calculation method characterized by:

7. Using a database including correspondence between each of the plurality of areas and the coordinates of the equipment located within each area; 7. The method of claim 6, wherein the position is calculated based on the location of the object.

8. The moving body is a railway vehicle and the facility is a railway track.

8. The position calculation method according to claim 6 or 7.

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