On-board device and control method

Abstract

On a track (5) on which a vehicle (3) travels, N (N≥2) magnets (7) are installed at positions separated from each other along the track (5), in order to indicate reference information (387) for travel of the vehicle (3) based on a combination of the types and installation intervals of the installed magnets (7). An on-board control device (30) comprises: a magnetic sensor unit (10) that, when passing the installation position of a magnet (7), detects the magnetic field generated by the magnet (7); a determination unit (355) that, on the basis of the detection result of the magnetic sensor unit (10), determines whether the installation position of the detected magnet has been passed and determines the type of the detected magnet; and an acquisition unit (357) that acquires reference information (387) on the basis of the interval that has been to determined to have been passed according to the determination unit (355) and the type determination result.

Description

On-vehicle device and control method

[0001] The present invention relates to an on-vehicle device mounted on a vehicle traveling on a track and the like.

[0002] A technique is known in which magnetic markers (permanent magnets) are installed along a track and the position of a vehicle is detected by detecting them on the vehicle side (see Patent Document 1).

[0003] Japanese Unexamined Patent Application Publication No. 2022-170810

[0004] However, in the conventional technology, when trying to increase the amount of information transmitted from the ground to the vehicle, there was no way other than increasing the types of magnets to be installed. That is, the amount of information that can be transmitted was limited to the types of magnets.

[0005] The problem to be solved by the present invention is to provide a technique capable of increasing the amount of information that can be transmitted.

[0006] A first invention is an on-vehicle device mounted on a vehicle traveling on a track, wherein N (N≧2) magnets are installed at positions separated from each other along the track in order to indicate reference information for traveling of the vehicle based on a combination of the type of magnet to be installed and the installation interval; different types of the magnets have different sizes, installation directions, or magnetization patterns; a magnetic sensor unit that detects the magnetic field generated by the magnet when passing through the installation position of the magnet; a determination unit that performs a passing determination of the installation position of the detected magnet and a type determination of the detected magnet based on the detection result of the magnetic sensor unit; and an acquisition unit that acquires the reference information based on the interval in which the passing determination is made by the determination unit and the result of the type determination.

[0007] According to the first invention, N magnets are installed at separate positions along the track to indicate reference information for vehicle movement based on a combination of the type of magnets to be installed and the spacing between them. While the vehicle is in motion, the magnetic field generated by the magnets is detected by a magnetic sensor unit, and based on the detection result, a determination is made as to when the vehicle passes the installation position of the detected magnet and the type of the detected magnet is determined. Based on the spacing at which the vehicle has passed and the result of the type determination, reference information is acquired. This makes it possible to dramatically increase the amount of information that can be transmitted by changing the combination of the type of magnets to be installed and the spacing between them.

[0008] The second invention is an on-board device in the above invention, wherein the combination differs depending on the order of the types of magnets installed along the track, and the acquisition unit acquires the reference information by determining the combination using the order of the types of the detected magnets for which the passage determination has been made.

[0009] According to the second invention, the amount of information that can be transmitted can be further increased by combining the type of magnets to be installed, the spacing between them, and the order in which the types of magnets are installed.

[0010] The third invention is an on-board device in the above invention, wherein N is 3 or more.

[0011] According to the third invention, three or more magnets are placed in the track to indicate one piece of reference information.

[0012] The fourth invention is an on-board device in the above invention, comprising: a speed measuring unit for measuring the driving speed; and an acquisition unit which calculates a distance corresponding to the interval time based on the driving speed at the time the pass determination was made by the determination unit and the interval time between the previous and current pass determinations, and acquires the reference information based on the distance and the result of the type determination.

[0013] According to the fourth invention, the distance corresponding to the interval time is calculated based on the travel speed at the time the passage determination is made and the interval time between the previous passage determination and the current passage determination, and reference information can be obtained based on the calculated distance and the result of the type determination.

[0014] The fifth invention is a control method for an on-board device mounted on a vehicle traveling on a track to acquire reference information for the vehicle's movement, wherein N (N≧2) magnets are installed at separate positions along the track, the magnets are of different types, differing in size, installation orientation, or magnetization pattern, and the on-board device performs the following: a magnetic sensor unit detects the magnetic field generated by a magnet when it passes the installation position of the magnet; a determination of the passage of the installation position of the detected magnet and a determination of the type of the detected magnet based on the detection result of the magnetic sensor unit; and the acquisition of the reference information based on the interval at which the passage determination was made and the result of the type determination.

[0015] According to the fifth invention, a control method that produces the same effects as the first invention can be realized.

[0016] A diagram illustrating an example of the application of the on-board device. A diagram showing an example of the configuration of the magnetic sensor section. A diagram explaining an example of magnet installation. A diagram showing an example of magnet type. A diagram showing another example of magnet type. A diagram showing another example of magnet type. A diagram showing another example of magnet type. A block diagram showing an example of the functional configuration of the on-board control device. A diagram showing an example of the data configuration of magnet group data. A flowchart showing the processing flow performed by the on-board control device.

[0017] Preferred embodiments of the present invention will be described below with reference to the drawings. However, the present invention is not limited to the embodiments described below, nor are the applicable forms of the present invention limited to the embodiments described below. Furthermore, the same parts are denoted by the same reference numerals in the drawings.

[0018] Figure 1 is a schematic diagram illustrating an example of the application of the on-board device in this embodiment. As shown in Figure 1, the on-board device 1 is mounted on a railway vehicle 3 that travels on a track 5 and comprises a magnetic sensor unit 10 and an on-board control device 30.

[0019] N (N≧2) magnets 7 are installed at separate positions along the track 5 to indicate reference information for the operation of the railway vehicle 3 based on the combination of the type of magnets (permanent magnets) 7 to be installed and the installation interval. In this embodiment, the magnets 7 are installed between the left and right rails. The magnets 7 come in different types, differing in size, installation orientation, or magnetization pattern.

[0020] The magnetic sensor unit 10 is installed on the bottom or bogie of the railway vehicle 3 in a position where it can detect the magnet 7 when passing over the installation location of the magnet 7. Preferably, the magnetic sensor unit 10 is installed in a position where it faces the magnet 7 when passing over the installation location of the magnet 7.

[0021] Figure 2 is a diagram showing an example configuration of the magnetic sensor unit 10, and is a schematic plan view of the magnetic sensor unit 10 as seen from above. As shown in Figure 2, the magnetic sensor unit 10 has a plurality of magnetic sensor elements 12 arranged in a planar manner facing the track 5. In the example in Figure 2, the magnetic sensor unit 10 is shown having a total of 16 magnetic sensor elements 12 arranged in a planar manner, with four rows in the left-right direction and four rows in the front-rear direction (travel direction) of the railway vehicle 3. The spacing between adjacent magnetic sensor elements 12 is such that they do not overlap, and it is preferable that the distance between the centers of the magnetic sensor elements 12 in both the left-right and front-rear directions is within 150 mm.

[0022] The arrangement of magnetic sensor elements 12 in the magnetic sensor unit 10 is not limited to the example arrangement of 16 elements in total: 4 rows in the left-right direction and 4 rows in the front-back direction (travel direction). For example, it could be an arrangement of 9 elements in 3 rows x 3 columns, or 16 elements in 4 rows x 4 columns, or an arrangement of 12 elements in 4 rows x 3 columns with different numbers for left-right and front-back. It can be set as appropriate. In addition, the magnetic sensor unit 10 may be configured with multiple magnetic sensor elements 12 arranged only in the left-right direction.

[0023] The magnetic sensor element 12 is an element that detects a magnetic field and outputs a current or voltage as a detected value corresponding to the magnitude and direction of the magnetic field. In this embodiment, the magnetic sensor element 12 is a three-axis sensor having three detection axes (X-axis, Y-axis, and Z-axis), with the X-axis aligned with the front-rear direction of the railway vehicle 3, the Y-axis aligned with the left-right direction of the railway vehicle 3, and the Z-axis aligned with the up-down direction of the railway vehicle 3. For example, the magnetic sensor element 12 is a Hall element, a magnetoresistive element (MR element), a magnetoimpedance element (MI element), a flux-gate sensor, etc. The detected value of the magnetic sensor element 12 is output to the on-board control device 30.

[0024] The on-board control device 30 uses the detection of magnetism by the magnetic sensor unit 10 to determine when the railway vehicle 3 has passed the location where the magnet 7 is installed, and also determines the type of magnet 7 that was detected. Then, the on-board control device 30 acquires reference information based on the interval at which the passage was determined and the result of the type determination.

[0025] [Details] Figure 3 is a diagram illustrating an example of the placement of magnets 7 on the track 5. In this embodiment, N magnets 7 (3 in the example of Figure 3) that indicate reference information are considered to be a set of magnet groups 70 (70-1, 70-2, ...).

[0026] For example, magnet group 70-1 is a magnet group in which three types of magnets 7b, 7n, and 7m are installed in this order along the direction of travel of the railway vehicle 3, with the installation distance between magnet 7b and magnet 7n being D11, and the installation distance between magnet 7n and magnet 7m being D13. Also, magnet group 70-2 is a magnet group in which two types of magnets 7a and 7g are installed in the order of magnet 7a, 7g, and 7a along the direction of travel of the railway vehicle 3, with the installation distance between the first magnet 7a and magnet 7g being D21, and the installation distance between magnet 7g and the third magnet 7a being D23.

[0027] In this embodiment, reference information is pre-set for each combination of magnet type 7, installation order, and installation interval (i.e., for each type of magnet group 70) (see magnet group data 380 in Figure 10). Therefore, each magnet group 70 is installed at a location corresponding to the reference information. For example, if the reference information is the distance to a speed limit ahead, the magnet group 70 indicating that reference information is installed at a location that is the corresponding distance before the speed limit. In other words, three magnets 7 are installed in a combination of type, installation order, and installation interval corresponding to the reference information.

[0028] The on-board control device 30 determines the passage of the installation position of the magnet 7 and determines the type of the magnet 7. Next, it identifies the magnet group 70 based on the interval at which the passage was determined and the result of the type determination. Then, it obtains reference information that indicates the combination of the type of magnet 7, installation order, and installation interval related to the identified magnet group 70.

[0029] According to this, information on the combination of the type of magnet 7, the installation order, and the installation interval can be transmitted from the ground to the vehicle, and the amount of information that can be transmitted can be dramatically increased by changing the combination. For example, suppose there are 16 types of magnets 7, and the installation interval (resolution) detectable by the magnetic sensor unit 10 is 10 cm, and the installation interval is set in 16 steps from 50 cm to 200 cm. If a magnet group 70 consisting of three magnets 7 is constructed, the number of combinations of 16 types of three magnets 7 and 16 steps of spacing between adjacent magnets 7 is 16^3 × 16^2 = 1,048,576.

[0030] Furthermore, the number of magnets 7 constituting one magnet group 70 is not limited to the three shown in the example; it may be two, four or more, or any number of magnets. Also, the spacing between adjacent magnets may be less than or greater than 16 levels. In addition, instead of having the same number of magnets 7 constituting each magnet group 70, cases where different numbers of magnets 7 are used to constitute the magnet group 70 are also included.

[0031] 1. Types of Magnets Magnets 7 are available in multiple types (for example, 16 types) that differ in size, orientation, magnetization pattern, and combinations thereof. Figures 4 to 8 show examples of the types of magnets 7 (7a to 7e). Magnets 7a to 7e are all formed in a thin, rectangular shape that is roughly square when viewed from above. Note that the shape of the magnet 7 is not limited to a rectangular shape, and may be other shapes such as round.

[0032] Figures 4 and 5 show examples of two types of magnets 7a and 7b that differ in size and orientation. Magnet 7a, shown in Figure 4, has a length of 100 mm in both the front-to-back and left-to-right directions, and is installed with the north pole at the top and the south pole at the bottom. On the other hand, magnet 7b, shown in Figure 5, has a length of 800 mm in both the front-to-back and left-to-right directions, and is installed with the south pole at the top and the north pole at the bottom. The magnetization pattern is the same, with the magnetization pattern applied in the vertical direction (thickness direction).

[0033] Here, assuming that the magnetic sensor elements 12 are arranged with a center spacing of 150 mm, the size of the magnetic sensor unit 10 is approximately 500 mm in both the front-to-back and left-to-right directions. Therefore, the size of the magnet 7a is smaller than the size of the magnetic sensor unit 10. In other words, the magnet 7a is such that, when the railway vehicle 3 passes over its installation location, the entire magnet 7a is covered by the magnetic sensor unit 10 in a top view. In contrast, the size of the magnet 7b is larger than the size of the magnetic sensor unit 10. In other words, the magnet 7b is such that, when the railway vehicle 3 passes over its installation location, only a portion of the magnet 7b is covered by the magnetic sensor unit 10 in a top view.

[0034] Figures 6 to 8 show examples of three types of magnets 7c to 7e with different magnetization patterns. Magnets 7c to 7e are the same size. Specifically, their length in both the front-to-back and left-to-right directions is 100 mm. Therefore, the size relationship between magnets 7c to 7e and the magnetic sensor unit 10 is the same as the size relationship between magnet 7a and the magnetic sensor unit 10.

[0035] The magnetization pattern of the magnet 7c shown in Figure 6 is such that the magnetization pattern is such that the magnetic fields in a top view are of the same polarity diagonally. Furthermore, the orientation of the magnet 7c is such that the upper left and lower right of the top view are north poles, and the upper right and lower left are south poles.

[0036] Here, since magnet 7 generates a magnetic flux moving from the north pole to the south pole, even if the magnetization pattern is the same, if the installation orientation is different, the magnetic field distribution detected by the magnetic sensor unit 10 (detected magnetic field distribution) will be different. For this reason, magnets 7 with the same magnetization pattern but different installation orientations can be treated as different types of magnets 7. For example, a magnet 7 with the same magnetization pattern as magnet 7c, but installed with the upper left and lower right of the top surface being the south poles and the upper right and lower left being the north poles, will be treated as a different type from magnet 7c.

[0037] The magnet 7d shown in Figure 7 has a magnetization pattern in which two magnet pieces with different magnetization patterns in the vertical direction are arranged side by side, and the orientation of the top surface is such that the left side is the north pole and the right side is the south pole. Similarly, with respect to this magnet 7d, magnets with the same magnetization pattern but different orientations can be treated as different types from magnet 7d. For example, an orientation where the right side of the top surface is the north pole and the left side is the south pole is treated as a different type. Likewise, magnets 7 with orientations where the top surface is the north pole at the top and the south pole at the bottom, or where the top surface is the north pole at the bottom and the south pole at the top, are also treated as different types from magnet 7d.

[0038] The magnet 7e shown in Figure 8 has a magnetization pattern that is magnetized in the front-to-back direction, and is installed with the front as the south pole and the back as the north pole when viewed from above. Similarly, magnets with the same magnetization pattern as magnet 7e but with different installation orientations can be treated as different types from magnet 7e. For example, magnets 7 with installation orientations where the back is the south pole and the front is the north pole when viewed from above, or where the right is the north pole and the left is the south pole, or where the left is the north pole and the right is the south pole, are all treated as different types from magnet 7e.

[0039] 2. Determination of Passage to Installation Location and Type Determination As described above, the type of magnet 7 is determined by its size, installation orientation, and magnetization pattern. Different sizes, installation orientations, and magnetization patterns result in different generated magnetic fields. In other words, if the type of magnet 7 is different, the magnetic field distribution detected by the magnetic sensor unit 10 when the railway vehicle 3 passes over its installation location will be different. The onboard control device 30 uses this to determine passage and type, and determines that the railway vehicle 3 has passed over the installation location of the magnet 7 and the type of magnet 7 that has passed over.

[0040] In this embodiment, a reference magnetic field distribution is prepared in advance for each type of magnet 7. The reference magnetic field distribution is a reference for the magnetic field distribution detected when passing through the installation location of the corresponding type of magnet 7. For example, the reference magnetic field distribution can be determined based on the magnetic field distribution detected by the magnetic sensor unit 10 when the railway vehicle 3 actually runs on the track 5 after the magnets 7 have been installed on the track 5. Alternatively, since the magnetic field distribution detected by the magnetic sensor unit 10 is determined by the relative positional relationship between the magnet 7 and the magnetic sensor unit 10, the reference magnetic field distribution can also be determined by experimental results in a laboratory or factory, or by computer simulations.

[0041] While the railway vehicle 3 is in motion, the on-board control device 30 compares the magnetic field distribution detected by the magnetic sensor unit 10 (detected magnetic field distribution) with the reference magnetic field distribution for each type of magnet 7. For example, the on-board control device 30 calculates a correlation coefficient between the detected magnetic field distribution and each of the reference magnetic field distributions. The correlation coefficient is calculated as a value between "-1" and "1", and a larger absolute value (closer to "1") indicates a stronger correlation (higher similarity), while a smaller absolute value indicates a weaker correlation (lower similarity). The on-board control device 30 determines that a reference magnetic field distribution whose calculated correlation coefficient is equal to or greater than a predetermined threshold (for example, "0.9") is a match with the detected magnetic field distribution. If the on-board control device 30 determines that any of the reference magnetic field distributions is a match, it determines that the vehicle has passed the installation location of a magnet 7 of the type corresponding to that reference magnetic field distribution.

[0042] 3. For the interval for which passage determination has been made, the on-vehicle control device 30 calculates a distance corresponding to the installation interval from the interval for which passage determination has been made in order to identify the magnet group 70 related to the magnet at the installation position for which passage determination has been made. In the present embodiment, the on-vehicle control device 30 measures and uses the traveling speed of the railway vehicle 3 to calculate a distance (hereinafter also referred to as "corresponding distance") corresponding to the interval time between the previous and current passage determinations.

[0043] Here, in the magnetic sensor unit 10 when the railway vehicle 3 passes through the installation position of the magnet 7, the time-series data of the detection value of the magnetic sensor element 12 changes in the relative position between the magnet 7 and the magnetic sensor unit 10 as the installation position is passed. Therefore, it becomes a waveform in which the magnetic flux density changes according to time (more precisely, the traveling position).

[0044] Focus on a combination (sensor pair) of two magnetic sensor elements 12 arranged along the traveling direction of the railway vehicle 3 among the magnetic sensor elements 12 included in the magnetic sensor unit 10. Then, the waveforms of the magnetic flux density, which are the time-series data of the respective detection values, become substantially the same waveforms although there is a time shift in the detection time. From the time-direction difference (time shift) Δt between these two waveforms and the arrangement interval d along the traveling direction of each magnetic sensor element 12, the traveling speed v of the railway vehicle 3 at the time of passage determination can be calculated by the formula (1). v = d / Δt ... (1)

[0045] Therefore, the on-vehicle control device 30 calculates the traveling speed of the railway vehicle 3 at the time of passage determination by the formula (1) and measures the traveling speed. Then, the on-vehicle control device 30 calculates a distance (corresponding distance) corresponding to the interval time based on the obtained traveling speed and the interval time from the previous passage determination to the current passage determination. Thereby, the installation interval between the magnet 7 related to the previous passage determination and the magnet 7 related to the current passage determination is obtained.

[0046] The two magnetic sensor elements 12 used for calculating the traveling speed may be appropriately selected. For example, the on-vehicle control device 30 selects a combination (sensor set) of the magnetic sensor elements 12 that are the farthest apart along the traveling direction. In the example of FIG. 2, the magnetic sensor unit 10 has four rows of magnetic sensor elements 12 arranged in the front-rear direction of the railway vehicle 3. Therefore, four combinations (A, M), (B, N), (C, O), (D, P) of the combination of the magnetic sensor elements 12 in the first row (frontmost row) and the magnetic sensor elements 12 in the fourth row (rearmost row) are selected.

[0047] Then, for each selected combination (sensor set), the on-vehicle control device 30 obtains the time shift Δt of the waveforms of the magnetic flux density, which are the time-series data of the detection values of the two magnetic sensor elements 12 belonging to the sensor set. From the time shift Δt and the arrangement interval d along the traveling direction of the two magnetic sensor elements 12 belonging to the sensor set, the traveling speed v is calculated according to Equation (1). Then, a predetermined statistical operation (for example, calculation of the average value) is performed on the traveling speed v calculated for each sensor set to finally determine the traveling speed of the railway vehicle 3.

[0048] Note that the method for calculating the distance is not particularly limited. For example, based on the detection signal of a rotation detector such as a pulse generator or a tachogenerator that detects the rotation of a wheel or an axle, the traveling distance of the railway vehicle 3 from the previous passage determination to the current passage determination may be calculated.

[0049] 4. Regarding the identification of the magnet group In this embodiment, the magnet group 70 is configured by three magnets. Therefore, every time the passage determination of the three magnets 7 is made, the magnet group 70 (a combination of the types, installation order, and installation intervals of the three magnets 7) of the magnet 7 related to the passage determination is identified from the corresponding distance obtained from the interval during which the passage determination was made and the result of the type determination.

[0050] Furthermore, in order to correctly identify a single magnet group 70, the magnet group 70 may be configured to include additional magnets indicating the beginning and end of the magnet group 70. In that case, in addition to the three magnets 7 that indicate the content of the original transmission information, two more magnets 7 are included in one magnet group 70. The on-board control device 30 identifies the magnet group 70 based on the corresponding distance between each pass detection determination from the detection of the pass detection of the beginning magnet to the detection of the pass detection of the end magnet, and the result of the type determination.

[0051] Alternatively, a configuration may be used to identify one magnet group 70 using a predetermined unit distance consisting of the maximum length of the magnet group 70. For example, when the passage of the first magnet 7 is determined, the magnet group 70 is identified based on the corresponding distance related to the interval between each passage determination during the subsequent unit distance traveled, and the result of the type determination. The unit distance is predetermined based on the maximum distance among the installation ranges D1 and D2 (see Figure 3) determined for each magnet group 70.

[0052] [Functional Configuration] Figure 9 is a block diagram showing an example of the functional configuration of the on-board control device 30. As shown in Figure 9, the on-board control device 30 comprises an operation unit 310, a display unit 320, a communication unit 330, a processing unit 350, and a storage unit 370, and is configured as a type of computer system.

[0053] The operation unit 310 is implemented by an input device such as a button switch or a touch panel, and outputs an operation signal to the processing unit 350 in accordance with the operation input. The display unit 320 is implemented by a display device such as an LCD (Liquid Crystal Display) or a touch panel, and displays various information in accordance with the display signal from the processing unit 350. The communication unit 330 is implemented by a wired or wireless communication device, and communicates with a predetermined external device.

[0054] The processing unit 350 is implemented, for example, by an arithmetic circuit such as a CPU (Central Processing Unit) or a control board including such an arithmetic circuit, and controls the operation of the on-board device 1 by performing various arithmetic processes based on programs and data stored in the storage unit 370. In this embodiment, the processing unit 350 includes a speed measurement unit 351, a detection unit 353, a determination unit 355, and an acquisition unit 357. Each of these functional units may be an arithmetic processing block implemented as software by executing a program, or it may be a circuit block implemented by a signal processing circuit. In this embodiment, the processing unit 350 is described as an arithmetic processing block implemented as software by executing a predetermined program.

[0055] The speed measurement unit 351 uses the detection of magnetism by the magnetic sensor unit 10 to calculate (measure) the running speed of the railway vehicle 3 according to equation (1).

[0056] The detection unit 353 continuously detects the magnetic field distribution (detected magnetic field distribution) based on the detection values ​​of each magnetic sensor element 12 of the magnetic sensor unit 10 while the railway vehicle 3 is in motion.

[0057] The determination unit 355 compares a reference magnetic field distribution, which serves as a reference for the magnetic field distribution detected by the detection unit 353 when passing the installation position of the magnet 7, with the detected magnetic field distribution detected by the detection unit 353, thereby determining whether the vehicle has passed the installation position of the magnet 7 and determining the type of the magnet 7.

[0058] The acquisition unit 357 identifies the magnet group 70 based on the interval and type determination result of the determination unit 355, and reads and acquires reference information from the magnet group data 380 of the identified magnet group 70.

[0059] A magnet group data set 380 is prepared for each type of magnet group 70. Figure 10 is a diagram showing an example of the data structure of one magnet group data set 380, and shows an example of the magnet group data set 380 for magnet group 70-1 shown in Figure 3. As shown in Figure 10, the magnet group data set 380 is a data table that associates the magnet group ID 381 with a list of magnets 7 that make up the corresponding magnet group 70 (magnet list) 383, installation interval data 385, and reference information 387.

[0060] The magnet list 383 stores the installation order and type of each magnet 7 that makes up the magnet group 70.

[0061] The installation interval data 385 stores the installation interval of each magnet 7 that makes up the magnet group 70.

[0062] Reference information 387 stores reference information indicating the combination of the types, installation order, and installation intervals of the magnets 7 that constitute the magnet group 70. For example, reference information 387 may include information such as the type of speed restriction location ahead, such as a curved section, a downhill section, a level crossing, or a switch section, as well as the distance to the speed restriction location.

[0063] In identifying the magnet group 70, the acquisition unit 357 calculates the corresponding distance based on the running speed of the railway vehicle 3 when the passing determination unit 355 made a passing determination, and the interval time between the previous and current passing determinations. The acquisition unit 357 then identifies the magnet group 70 based on the corresponding distance related to the passing determination interval and the result of the type determination. In this embodiment, one magnet group 70 consists of three magnets 7, so the acquisition unit 357 calculates the corresponding distance sequentially while counting the number of passing determinations up to three times. The acquisition unit 357 then determines that one magnet group has been passed when the current passing determination is the third passing determination. The acquisition unit 357 identifies the magnet group 70 by comparing the corresponding distance related to the interval of the three passing determinations and the result of the three type determinations with the combination of magnet type, installation order, and installation interval set in each magnet group data 380. The acquisition unit 357 then acquires the reference information 387 of the identified magnet group 70.

[0064] The memory unit 370 is implemented using a storage medium such as an IC memory or a hard disk. The memory unit 370 pre-stores programs for operating the on-board device 1 and realizing the various functions of the on-board device 1, as well as data used during the execution of said programs, or temporarily stores them each time processing is performed. In this embodiment, the memory unit 370 stores magnet group data 380, reference magnetic field distribution data 391, and detection data 393.

[0065] The reference magnetic field distribution data 391 stores reference magnetic field distribution data for each type of magnet 7. The detection data 393 is generated each time the magnetic sensor unit 10 detects something and stores the detected values ​​of each magnetic sensor element 12.

[0066] [Processing Flow] Figure 11 is a flowchart showing the processing flow performed by the on-board control device 30. As shown in Figure 11, first, the detection unit 353 starts detecting the magnetic field distribution using the magnetic sensor unit 10 (step S1), and the determination unit 355 starts determining whether the vehicle has passed the installation location of the magnet 7 and determining the type of magnet 7 (step S3). The determination unit 355 compares the detected magnetic field distribution detected by the detection unit 353 as it is detected with each of the reference magnetic field distributions predetermined for each type of magnet 7, and if there is a reference magnetic field distribution that matches the detected magnetic field distribution, it determines that the vehicle has passed the installation location of a magnet 7 of the type corresponding to that reference magnetic field distribution.

[0067] Then, if the determination unit 355 determines that the vehicle has passed (step S5: YES), the speed measurement unit 351 calculates the running speed of the railway vehicle 3 according to formula (1) based on the detected value of the magnetic sensor element 12 of the predetermined sensor set at the time of the passing determination (step S7).

[0068] Next, the acquisition unit 357 calculates the corresponding distance based on the travel speed calculated in step S7 and the interval time between the previous and current pass judgments (step S9). The acquisition unit 357 then determines that the magnet group 70 has passed. In this embodiment, one magnet group 70 consists of three magnets 7. Therefore, the acquisition unit 357 determines that one magnet group has passed each time a pass judgment is made three times (step S11: YES). The acquisition unit 357 compares the corresponding distance related to the interval of the pass judgment and the result of the type judgment with the combination of magnet 7 type, installation order, and installation interval set in each magnet group data 380 to identify the passed magnet group 70 (step S13). The acquisition unit 357 then reads and acquires the reference information 387 of the identified magnet group 70 from the magnet group data 380 (step S15).

[0069] As described above, according to this embodiment, a group of magnets 70 determined by a combination of the type, installation order, and installation interval of the magnets 7 to be installed is installed on the track 5 at locations corresponding to the reference information indicated by that combination. While the railway vehicle 3 is in motion, the vehicle determines whether the magnets 7 have passed the installation locations and whether they are of a specific type. Based on the interval at which the vehicle passed and the result of the type determination, the group of magnets 70 related to the magnets 7 that passed the vehicle can be identified, and reference information corresponding to that group of magnets 70 can be obtained. This allows information on the combination of the type, installation order, and installation interval of the magnets 7 to be transmitted to the vehicle, dramatically increasing the amount of information that can be transmitted depending on the combination.

[0070] In the above-described embodiment, the corresponding distance corresponding to the installation interval of the magnets 7 is calculated from the running speed of the railway vehicle 3 when the passage determination is made and the interval time between the previous and current passage determinations. Furthermore, the magnet group 70 of the magnets 7 related to the passage determination is identified from the corresponding distance and the result of the type determination. Alternatively, the system may be configured to identify the magnet group and obtain reference information from the interval time between the previous and current passage determinations. For example, consider a case where the magnet group consists of three magnets. The installation order is such that the installation interval between the first and second magnets is fixed at 100 cm, and the installation interval between the second and third magnets is either 50 cm, which is shorter than the installation interval between the first and second magnets, or 150 cm, which is longer than the installation interval between the first and second magnets. The system may then be configured to identify the type of installation interval depending on whether the interval time between the second and third magnets when the passage determination is made is shorter or longer than the interval time between the first and second magnets when the passage determination is made. According to this method, the amount of information regarding the type of installation interval (number of stages in the installation interval) of the magnets 7 is reduced, but the type of installation interval can be identified from the interval time between the passage detections without having to calculate the corresponding distance corresponding to the installation interval.

[0071] 1...On-board device 10...Magnetic sensor unit 12...Magnetic sensor element 30...On-board control device 350...Processing unit 351...Speed ​​measurement unit 353...Detection unit 355...Determination unit 357...Acquisition unit 370...Storage unit 380...Magnet group data 383...Magnet list 385...Installation interval data 387...Reference information 391...Reference magnetic field distribution data 393...Detection data 3...Railway vehicle 5...Track 7...Magnet 70...Magnet group

Claims

1. An on-board device mounted on a vehicle traveling on a track, wherein N (N≧2) magnets are installed at separate positions along the track to indicate reference information for the vehicle's movement based on a combination of the type of magnets to be installed and the spacing between them, the magnets are of different types, differing in size, orientation, or magnetization pattern, and the on-board device comprises: a magnetic sensor unit that detects the magnetic field generated by a magnet when passing over the installation location of the magnet; a determination unit that determines the passage over the installation location of the detected magnet and the type of the detected magnet based on the detection result of the magnetic sensor unit; and an acquisition unit that acquires the reference information based on the spacing at which the determination unit determined the passage and the result of the type determination.

2. The combination differs depending on the order of the types of magnets installed along the track, and the acquisition unit acquires the reference information by further determining the combination using the order of the types of the detected magnets for which the passage determination has been made. The on-board device according to claim 1.

3. The vehicle-mounted device according to claim 1 or 2, wherein N is 3 or more.

4. An on-board device according to any one of claims 1 to 3, comprising: a speed measuring unit for measuring the speed of travel; and an acquisition unit which calculates a distance corresponding to the interval time based on the speed of travel at the time the pass determination was made by the determination unit and the interval time between the previous and current pass determinations, and acquires the reference information based on the distance and the result of the type determination.

5. A control method for an on-board device mounted on a vehicle traveling on a track to acquire reference information for the vehicle's operation, wherein N (N≧2) magnets are installed at separate positions along the track, the magnets are of different types, differing in size, installation orientation, or magnetization pattern, and the on-board device performs the following: a magnetic sensor unit detects the magnetic field generated by a magnet when it passes the installation position of the magnet; a determination of passage to the installation position of the detected magnet and a determination of the type of the detected magnet based on the detection result of the magnetic sensor unit; and the acquisition of the reference information based on the interval at which the passage determination was made and the result of the type determination.

Images