JP7108083B1 - On-board device and judgment method - Google Patents

Abstract

An on-board device (1) of a train capable of detecting a magnet installed on a track. A magnetic sensor unit (10) has a plurality of magnetic sensor elements (12) arranged in a predetermined positional relationship to detect a magnetic field generated by a permanent magnet (7). The on-vehicle control device 30 detects a magnetic field distribution based on the detection values of the magnetic sensor elements 12, and detects a reference magnetic field distribution as a reference for the magnetic field distribution detected when passing through the installation position of the permanent magnet 7. By comparing with the magnetic field distribution, it is determined whether or not the installation position of the permanent magnet 7 has been passed. [Selection drawing] Fig. 1

Description

The present invention relates to an on-board device and the like.

2. Description of the Related Art Train position detection devices, which are components of a train control system for railways, include a type that detects the position of the train with a ground device and a type that recognizes the position of the own train with an on-board device.

As the ground equipment of the former type, track circuits are most commonly used, and in recent years, axle detectors and the like are also being widely used. These devices have a high level of safety, but when trying to increase the positional resolution for detection, there is a problem that a large amount of equipment is required accordingly.

As for the latter type, it is common to calculate the distance traveled by accumulating the speed information of the own train obtained using a tachometer or pulse generator, and to recognize the position of the own train. This method has the advantage of not requiring a large amount of equipment. , it is necessary to detect the absolute position in some way and periodically reset the error. As a method of detecting an absolute position, a method of detecting ground equipment such as a ground coil installed on a track is generally used. However, since the track on which the train runs is long, it is necessary to install a large number of ground facilities for position detection, and there is a problem that the installation and maintenance costs are high.

By the way, in the field of automatic driving technology for automobiles, there is a known technology that recognizes the relative position of the vehicle with respect to the magnet by embedding a permanent magnet in the road surface and detecting the magnet with a magnetic sensor mounted on the vehicle ( For example, see Patent Document 1).

Japanese Patent No. 6355607

A method of applying the technology of Patent Document 1 above to the railway field is conceivable. Specifically, there is a method in which a magnet is installed on the track as wayside equipment for detecting the position of the train, and an on-board device detects the magnet to reset the train position error. However, in order to realize this method, it is necessary to solve the following problems.

In other words, magnets are detected by magnetic sensors mounted on trains, but in railways, there are huge magnetic sources that generate magnetic fields, such as iron bridges. It is necessary to distinguish between such a magnetic source and the magnet for position detection. For example, the change in the magnetic field strength against the distance traveled (train position) is obtained from the time-series change in the detected magnetic field strength and the time-series change in the train speed. By estimating, a method of distinguishing whether it is a magnet for position detection or another magnetic source is conceivable. Since the magnetic field strength detected at a given distance depends on the size of the magnetic source and the distance from the magnetic source, the change in magnetic field strength with respect to the distance traveled will result in different shapes of graphs depending on the size of the magnetic source. . However, as described above, since the speed information acquired by the on-board device includes errors due to slipping, skidding, etc., the traveling distance recognized by the on-board device also includes errors. For this reason, the change in the magnetic field intensity with respect to the running distance also includes an error, and it is difficult to say that this is a reliable detection method.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to enable an on-board device of a train to detect a magnet installed on a track.

A first invention for solving the above problems is
An on-board device mounted on a vehicle running on a track in which a magnet is installed at a predetermined installation position,
a magnetic sensor unit having a plurality of magnetic sensor elements arranged in a predetermined positional relationship for detecting the magnetic field generated by the magnet when passing through the installation position;
a detection unit that detects a magnetic field distribution based on the detection value of each of the magnetic sensor elements;
By comparing a reference magnetic field distribution, which is a reference of the magnetic field distribution detected by the detection unit when passing through the installation position, with the magnetic field distribution detected by the detection unit, it is possible to determine whether or not the installation position has been passed. a determination unit that determines
An on-vehicle device comprising

Another invention is
An on-vehicle device mounted on a vehicle running on a track in which a magnet is installed at a predetermined installation position, the device being located at a predetermined position for detecting the magnetic field generated by the magnet when passing through the installation position. A determination method for determining whether an on-vehicle device having a magnetic sensor unit having a plurality of magnetic sensor elements arranged in a relationship has passed through the installation position,
Detecting a magnetic field distribution based on the detection value of each of the magnetic sensor elements;
determining whether or not the installation position has been passed by comparing the detected magnetic field distribution with a reference magnetic field distribution that is a reference of the magnetic field distribution detected when passing the installation position; ,
You may configure a determination method including

According to the first invention and the like, the on-board device of the train can detect the magnet installed on the track. In other words, by detecting the magnetic field distribution based on the detection values of multiple magnetic sensor elements and comparing the detected magnetic field distribution with the reference magnetic field distribution that is the reference for the magnetic field distribution detected when passing through the installation position of the magnet. , it is determined that the magnet has passed through the installation position. As a result, the magnet can be detected separately from other magnetic sources, and it can be determined that the magnet has passed through the installation position. Then, the train position detection device using the magnet installed on the track as ground equipment can be constructed at a lower cost than the conventional train position detection device using ground coils or the like as ground equipment.

A second invention is based on the first invention,
The magnetic sensor unit has at least a plurality of magnetic sensor elements arranged in the lateral direction of the vehicle,
It is an on-board device.

According to the second invention, the plurality of magnetic sensor elements of the magnetic sensor section are arranged at least in the left-right direction perpendicular to the front-rear direction, which is the running direction of the vehicle.

A third invention is the first or second invention,
The magnetic sensor unit has at least a plurality of magnetic sensors arranged in a plane along the front, rear, left, and right directions of the vehicle,
on-board equipment

According to the third invention, the plurality of magnetic sensor elements of the magnetic sensor section are arranged in a plane along at least the front, rear, left, and right directions of the vehicle.

A fourth invention is, in any one of the first to third inventions,
The magnet includes a plurality of types of magnets that differ in any one of size, installation orientation, and magnetization pattern,
In the track, the type of the magnet to be installed is predetermined for each installation position where the magnet is installed,
The reference magnetic field distribution includes a reference magnetic field distribution for each type of the magnet,
The determination unit compares the magnetic field distribution detected by the detection unit with each reference magnetic field distribution for each type of the magnet, and determines the type of the magnet installed at the installation position to pass through.
It is an on-board device.

According to the fourth invention, there are a plurality of types of magnets with different sizes, installation directions, and magnetization patterns, and the types of magnets to be installed for each installation position are determined in advance on the track. If the type of magnet is different, the magnetic field generated by the magnet will be different, and thus the magnetic field distribution detected by the on-vehicle device will be different. Therefore, by comparing each reference magnetic field distribution for each type of magnet with the detected magnetic field distribution, it is possible to determine the type of magnet that has passed through the installation position.

A fifth invention is based on the fourth invention,
The reference magnetic field distribution includes a reference magnetic field distribution for each type of the magnet and for each position relative to the installation position,
The determination unit compares the magnetic field distribution detected by the detection unit in time series with each of the reference magnetic field distributions, and determines the type of the magnet installed at the installation position to be passed based on the number of times it is determined to match. do,
It is an on-board device.

According to the fifth invention, in addition to the types of magnets, there are also a plurality of reference magnetic field distributions according to relative positions with respect to the installation positions of the magnets. Then, when a traveling vehicle passes the installation position of the magnet, the magnetic field distribution detected in time series is determined to match each reference magnetic field distribution. Then, when the number of matching times is, for example, a predetermined number of times or more, it is determined that the type of magnet has been detected. This makes it possible to accurately determine the type of magnet installed at the installation position that has passed.

A sixth invention is, in any one of the first to fifth inventions,
The magnetic sensor element has a plurality of detection axes,
The detection unit detects the magnetic field distribution for each detection axis,
The reference magnetic field distribution includes a reference magnetic field distribution for each detection axis,
The determination unit compares, for each detection axis, a reference magnetic field distribution of the detection axis with the magnetic field distribution of the detection axis detected by the detection unit.
It is an on-board device.

According to the sixth invention, since the magnetic field generated by the magnet is a magnetic field distribution in a three-dimensional space, a magnetic sensor element having a plurality of detection axes is used, and the magnetic field distribution detected for each detection axis is compared with the reference magnetic field distribution. Thus, the magnetic field generated by the magnet can be detected more accurately, and it can be determined more accurately whether or not the installation position of the magnet has been passed.

Application example of on-board equipment. Configuration example of the magnetic sensor unit. Explanatory drawing of how to express magnetic field distribution. Explanatory drawing of determination of the kind of permanent magnet. An example of a type of permanent magnet. FIG. 6 is a positional relationship diagram with the magnetic sensor section when passing through the installation position of the permanent magnet in FIG. 5 ; An example of magnetic field distribution by the permanent magnet of FIG. An example of magnetic field distribution by the permanent magnet of FIG. An example of magnetic field distribution by the permanent magnet of FIG. An example of a type of permanent magnet. FIG. 11 is a positional relationship diagram with the magnetic sensor section when passing through the installation position of the permanent magnet in FIG. 10 ; An example of magnetic field distribution by the permanent magnet of FIG. An example of magnetic field distribution by the permanent magnet of FIG. An example of magnetic field distribution by the permanent magnet of FIG. An example of a type of permanent magnet. An example of magnetic field distribution by the permanent magnet of FIG. An example of magnetic field distribution by the permanent magnet of FIG. An example of magnetic field distribution by the permanent magnet of FIG. An example of a type of permanent magnet. An example of magnetic field distribution by the permanent magnet of FIG. An example of magnetic field distribution by the permanent magnet of FIG. An example of magnetic field distribution by the permanent magnet of FIG. An example of a type of permanent magnet. An example of magnetic field distribution by the permanent magnet of FIG. An example of magnetic field distribution by the permanent magnet of FIG. An example of magnetic field distribution by the permanent magnet of FIG. An example of the correlation coefficient of the magnetic field distribution by multiple types of permanent magnets. The functional block diagram of an on-vehicle control device. An example of detected data. An example of installed magnet data. 4 is a flowchart of determination processing;

Preferred embodiments of the present invention will be described below with reference to the drawings. In addition, the form which can apply this invention is not limited to the following embodiment. Also, in the description of the drawings, the same reference numerals are given to the same elements.

[overall structure]
FIG. 1 is a diagram schematically showing an application example of the on-vehicle device of this embodiment. As shown in FIG. 1 , an on-board device 1 of the present embodiment is mounted on a railway vehicle 3 running on a track 5 and includes a magnetic sensor section 10 and an on-board control device 30 . A plurality of permanent magnets 7 are installed on the track 5 at predetermined installation positions for each type. In this embodiment, the permanent magnets 7 are installed between the left and right rails. The type of permanent magnet 7 is determined by its size, installation orientation, and magnetization pattern.

The magnetic sensor unit 10 is installed on the bottom of the railcar 3 or on a bogie at a position where the permanent magnet 7 can be detected when passing the installation position of the permanent magnet 7 installed on the track 5 . Preferably, the magnetic sensor section 10 is installed at a position facing the permanent magnet 7 when passing through the installation position of the permanent magnet 7 .

The on-board control device 30 calculates the travel position of the railroad vehicle 3 at any time by integrating speed information acquired using a tachometer, a pulse generator, or the like. Further, in the present embodiment, since the installation position of the permanent magnet 7 is determined in advance, when the permanent magnet 7 is detected by the magnetic sensor section 10, the on-vehicle control device 30 detects the detected permanent magnet. Using the installation position of the magnet 7, the calculated running position is corrected.

[Magnetic sensor part]
FIG. 2 is a diagram showing an example of the configuration of the magnetic sensor section 10. As shown in FIG. FIG. 2 shows a schematic plan view of the magnetic sensor unit 10 viewed from above. As shown in FIG. 2 , the magnetic sensor section 10 has a plurality of magnetic sensor elements 12 arranged in a plane facing the track 5 . In the example of FIG. 2, the magnetic sensor unit 10 has a total of 16 magnetic sensor elements 12 arranged in a plane, four rows in the left-right direction and four rows in the front-rear direction of the railcar 3 . The distance between the adjacent magnetic sensor elements 12 is such that the magnetic sensor elements 12 do not overlap each other, and it is preferable that the distance between the centers of the magnetic sensor elements 12 is within 150 mm in both the left-right direction and the front-rear direction.

The magnetic sensor element 12 is an element that detects a magnetic field and outputs a current or voltage corresponding to the magnitude and direction of the magnetic field as a detected value. The magnetic sensor element 12 is, for example, a Hall element, a magnetoresistive element (MR element), a magneto-impedance element (MI element), a flux gate sensor, or the like.

The magnetic sensor element 12 is a three-axis sensor having three detection axes (X-axis, Y-axis and Z-axis). They are arranged with their axes aligned with each other in the vertical direction of the railcar 3 . A detected value of the magnetic sensor element 12 is output to the on-board control device 30 . The on-board control device 30 detects the magnetic field distribution based on the detected values of the magnetic sensor elements 12 .

FIG. 3 is a diagram for explaining how to represent the magnetic field distribution in this embodiment. The magnetic sensor element 12 is a three-axis sensor having three detection axes, and the on-vehicle control device 30 detects the magnetic field distribution based on the detection value of each detection axis of each magnetic sensor element 12 for each of these three detection axes. do. A magnetic field distribution about one detection axis is expressed as a two-dimensional array in which the detection value of each magnetic sensor element 12 along the detection axis is represented as an element I(i, j). Positive and negative values of the detected value of the magnetic sensor element 12 represent the direction of the magnetic field, and the magnitude (absolute value) represents the magnitude (strength) of the magnetic field. The two-dimensional array corresponds to the arrangement positions of the magnetic sensor elements 12 in the magnetic sensor unit 10. The front-rear direction (running direction) of the railroad vehicle 3 is the i direction of the two-dimensional array, and the left-right direction of the railroad vehicle 3 (the sleeper direction). ) corresponds to the j direction.

A plurality of types of permanent magnets 7 are installed on the track 5 at predetermined installation positions for each type. The type of permanent magnet 7 is determined by its size, installation orientation, and magnetization pattern. If the type of permanent magnet 7 is different, the magnetic field (generated magnetic field) generated by the permanent magnet 7 will be different. The magnetic field distribution detected by the sensor unit 10 is different. Using this, the on-vehicle control device 30 determines the type of the detected permanent magnet 7 based on the magnetic field distribution detected by the magnetic sensor section 10 . Then, the traveling position is corrected using the installation position of the determined type of permanent magnet 7 .

FIG. 4 is a diagram for explaining determination of the type of permanent magnet 7. As shown in FIG. The type of permanent magnet 7 is determined by comparing a reference magnetic field distribution predetermined in association with the type of permanent magnet 7 and the magnetic field distribution detected by the magnetic sensor unit 10 (detected magnetic field distribution). The reference magnetic field distribution is the reference of the magnetic field distribution detected when passing through the installation position of the corresponding type of permanent magnet 7 . As the reference magnetic field distribution for each type of permanent magnet 7, a plurality of reference magnetic field distributions for each relative position with respect to the installation position of the permanent magnet 7 of the type are determined.

Since the magnetic field distribution is detected for each detection axis, the reference magnetic field distribution is also determined for each detection axis. Specifically, at the timing when the railway vehicle 3 passes through a position relative to the installation position of the permanent magnet 7, the magnetic field distribution that will be detected by the magnetic sensor unit 10 mounted on the railway vehicle 3 is It is defined as a reference magnetic field distribution corresponding to the relative position of the magnet 7 . In the example of FIG. 4, the reference magnetic field distribution is defined for each of three relative positions: a position corresponding to the installation position, a position 100 mm before the installation position, and a position 200 mm before the installation position. In FIG. 4, the installation position of the permanent magnet 7 and the position in front thereof are defined as the relative positions, but the position behind the installation position that has passed through the installation position may also be included.

The reference magnetic field distribution can be determined, for example, based on the magnetic field distribution detected when the railway vehicle 3 actually runs on the track 5 after the permanent magnets 7 are 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 permanent magnet 7 and the magnetic sensor unit 10, it can be determined based on the results of experiments in laboratories, factories, etc., or computer simulations. can.

When the railway vehicle 3 traveling on the track 5 passes the installation position of the permanent magnet 7, it passes in order from the relative position that is nearer to and farther from the installation position of the permanent magnet 7. As shown in FIG. For this reason, the on-vehicle control device 30 stores the magnetic field distribution (detected magnetic field distribution) detected by the magnetic sensor unit 10, the type of the permanent magnet 7, and the relative position corresponding to the installation position of the permanent magnet 7. Whether or not each of the reference magnetic field distributions matches is determined repeatedly at predetermined time intervals (for example, intervals of several milliseconds). Among the reference magnetic field distributions for each installation position for one type of permanent magnet 7, a predetermined number or more of the reference magnetic field distributions are continuously matched, and the railway vehicle 3 passes in the matching order. If it is in the order of relative positions (that is, the order of installation positions farther from the installation position), it is determined that the type of permanent magnet 7 has been detected. For example, while the railway vehicle 3 is running, the detected magnetic field distribution is detected in time series. Suppose that it is determined that the magnetic field distribution conforms to the reference magnetic field distribution. Immediately after that, it is assumed that the latest detected magnetic field distribution detected at the next point in time is determined to match the reference magnetic field distribution at a position 100 mm before the installation position among the reference magnetic field distributions of the permanent magnet 7 of type α. Then, it is determined that the reference magnetic field distribution of the same type of permanent magnet 7 is matched twice in a row, and the order of matching is the order of the relative positions through which the railway vehicle 3 passes. If the continuous predetermined number is "2", it is determined that the permanent magnet 7 of type α has been detected by these two continuous determinations.

[Conformity determination between detected magnetic field and reference magnetic field distribution]
Whether or not the detected magnetic field distribution and the reference magnetic field distribution match is determined based on the correlation coefficient. The magnetic field distribution is represented by detection values along the detection axis by the plurality of magnetic sensor elements 12 for each detection axis (see FIG. 3). Therefore, the correlation coefficient between the detected magnetic field distribution and the reference magnetic field distribution for each detection axis is calculated. The correlation coefficient between the detected magnetic field distribution and the reference magnetic field distribution of one detection axis is obtained as a normalized cross-correlation coefficient according to the following equation (1) using the values of each element of the detected magnetic field distribution and the reference magnetic field distribution. Calculated.

In Equation (1), “I (i, j)” is the value of the element of the detected magnetic field distribution (value detected by the magnetic sensor element (i, j)), and “I _a ” is each of the detected magnetic field distributions. is the average value of the element I (i, j), "T (i, j)" is the value of the element of the reference magnetic field distribution, and " _Ta " is the value of each element T (i, j ), “σ _I ” is the standard deviation of each element I(i, j) of the detected magnetic field distribution, and “σ _T ” is the standard deviation of each element T(i, j) of the reference magnetic field distribution. is the standard deviation.

The correlation coefficient has a value in the range of "-1.0 to 1.0", with "1.0" representing a perfect match. Then, when the correlation coefficients for all (three) detection axes are equal to or greater than a predetermined threshold value (for example, "0.9"), it is determined that the detected magnetic field distribution matches the reference magnetic field distribution. Note that the average or sum of the correlation coefficients for each detection axis is calculated as the total correlation coefficient, and this total correlation coefficient is a predetermined threshold value (for example, if the average of the correlation coefficients is the total correlation coefficient, " 0.9", or "2.7" if the sum of the correlation coefficients is the overall correlation coefficient), it may be determined that the detected magnetic field distribution matches the reference magnetic field distribution. If the correlation coefficient is positive, the magnetism is the same, and if it is negative, the magnetism is opposite. However, it shows that the magnetism is reversed.

The on-vehicle control device 30 determines whether or not the permanent magnet 7 has been detected based on the suitability determination described above. Specifically, as described above, it is assumed that the detected magnetic field distribution detected in chronological order has continuously matched a predetermined number or more of the plurality of reference magnetic field distributions for each installation position for one type. and if the matched order is the order of the relative positions that the railway vehicle 3 passes by, it is determined that the type of permanent magnet 7 has been detected. After determining that the permanent magnet 7 has been detected, the on-vehicle control device 30 next determines the timing at which the installation position of the permanent magnet 7 is passed in order to correct the traveling position calculated on the vehicle. For example, the detection timing of the detected magnetic field distribution matching the reference magnetic field distribution determined at the installation position of the detected permanent magnet 7 is regarded as the passage timing of the installation position of the permanent magnet 7 and determined. The travel position calculated at this passing timing is corrected to the installation position of the permanent magnet 7 .

[Examples of types of magnets]
5, 10, 15, 19, and 23 are diagrams showing examples of types of permanent magnets 7. FIG. Each of the permanent magnets 7a to 7e shown in FIGS. 5, 10, 15, 19, and 23 is formed in a thin rectangular shape which is substantially square in top view. The shape of the permanent magnet 7 is not limited to the square shape, and may be other shapes such as a round shape.

7 to 9, 12 to 14, 16 to 18, and 20 to 22 are the permanent magnets 7a to 7e shown in FIGS. 5, 10, 15, 19, and 23, respectively. is a magnetic field distribution (detected magnetic field distribution) detected when passing through the installation position of , showing the detected magnetic field distribution for each of the three detection axes (X-axis, Y-axis, and Z-axis). This detection magnetic field distribution is obtained by using the configuration of the magnetic sensor unit 10, as shown in FIG. The element 12 is arranged with a center interval of 120 mm, and the vertical interval between the permanent magnet 7 and the magnetic sensor unit 10 when passing through the installation position of the permanent magnet 7 is 150 mm. , are values calculated by simulation calculation.

The timing at which the railway vehicle 3 passes the installation position of the permanent magnet 7 means that the center of the square shape of the permanent magnet 7 when viewed from the top and the center of the installation surface of the magnetic sensor element 12 having a substantially square shape are in a plane. The timing is set to coincide with each other in terms of vision.

5 and 10 are examples of two types of permanent magnets 7a and 7b having different sizes. Both of the permanent magnets 7a and 7b have a magnetization pattern magnetized in the vertical direction (thickness direction), and are oriented such that the upper part is the N pole and the lower part is the S pole.

The size of the permanent magnet 7a shown in FIG. Specifically, the permanent magnet 7a has a length of 100 mm in the front-rear direction and the left-right direction. Since the magnetic sensor elements 12 are arranged at a center interval of 150 mm, the size of the magnetic sensor unit 10 is about 500 mm in the longitudinal and lateral directions. Therefore, as shown in FIG. 6, when the railway vehicle 3 passes the installation position of the permanent magnet 7a, the permanent magnet 7a is entirely covered with the magnetic sensor section 10 provided in the railway vehicle 3 in a top view. become. In FIG. 6, the vertical distance between the magnetic sensor section 10 and the permanent magnet 7a is shown wider than it actually is. 7 to 9 show the magnetic sensor unit 10 when the railway vehicle passes the installation position of the permanent magnet 7a, that is, when the positional relationship between the permanent magnet 7a and the magnetic sensor unit 10 is the relationship shown in FIG. is the magnetic field distribution detected by

Also, the size of the permanent magnet 7b in FIG. Specifically, the permanent magnet 7b has a length of 800 mm in the front-rear direction and the left-right direction. Since the size of the magnetic sensor unit 10 is "about 500 mm" in the front-rear direction and the left-right direction, as shown in FIG. As seen, only a portion of the permanent magnet 7b is covered with the magnetic sensor section 10 provided on the railway vehicle 3. As shown in FIG. In FIG. 11, the vertical distance between the magnetic sensor section 10 and the permanent magnet 7b is shown wider than it actually is. 12 to 14 show the magnetic sensor unit 10 when the railway vehicle passes the installation position of the permanent magnet 7b, that is, when the positional relationship between the permanent magnet 7b and the magnetic sensor unit 10 is the relationship shown in FIG. is the magnetic field distribution detected by

A comparison of the magnetic field distribution by the permanent magnets 7a shown in FIGS. 7 to 9 and the magnetic field distribution by the permanent magnets 7b shown in FIGS. The magnetic field distribution based on the Y-axis detection values is similar in how the direction of the magnetic field (positive or negative of the detected value) and the magnitude of the magnetic field (absolute value of the detected value) change. On the other hand, regarding the magnetic field distribution based on the detected value of the Z axis perpendicular to the XY plane on which the magnetic sensor element 12 is arranged, the direction of the magnetic field (positive and negative of the detected value) is the same, but Because of the difference in the size of the permanent magnets 7a and 7b facing each other, the manner of change in the magnitude of the magnetic field (absolute value of the detected value) differs.

Calculation of the correlation coefficient between the magnetic field distribution by the permanent magnets 7a shown in FIGS. 7 to 9 and the magnetic field distribution by the permanent magnets 7b shown in FIGS. .9”, the magnetic field distribution based on the Y-axis detection value is “0.9”, and the magnetic field distribution based on the Z-axis detection value is “-0.9”. Therefore, the permanent magnets 7a and 7b having different sizes can be discriminated and detected from the magnetic field distribution.

15, 19 and 23 are examples of three types of permanent magnets 7c to 7e with different magnetization patterns. The permanent magnets 7c-7e have the same size. Specifically, the length in the front-back direction and the length in the left-right direction are both "100 mm". Therefore, the size relationship between the permanent magnets 7c to 7e and the magnetic sensor section 10 is the same as the size relationship between the permanent magnet 7a and the magnetic sensor section 10 shown in FIG.

The permanent magnet 7c shown in FIG. 15 has a magnetization pattern magnetized so that magnetism in a top view has the same polarity diagonally. 15, the permanent magnet 7c is installed such that the upper left and lower right are N poles, and the upper right and lower left are S poles. 16 to 18 show magnetic field distributions detected by the magnetic sensor unit 10 when the railway vehicle 3 passes the installation position of the permanent magnet 7c.

Since the permanent magnet 7 generates a magnetic flux directed from the N pole to the S pole, the magnetic field distribution (detected magnetic field distribution) detected by the magnetic sensor section 10 differs if the installation orientation is different even if the magnetization pattern is the same. Therefore, permanent magnets 7 having the same magnetization pattern but different orientations can be treated as different types of permanent magnets 7 . For example, the permanent magnet 7, which has the same magnetization pattern as the permanent magnet 7c but is arranged in an installation orientation in which the upper left and lower right are S poles and the upper right and lower left are N poles, is of a different type from the permanent magnet 7c. treated as

The permanent magnet 7d shown in FIG. 19 has a magnetization pattern in which magnet pieces with different magnetization patterns in the vertical direction are arranged side by side. It is suitable for installation where 20 to 22 show magnetic field distributions detected by the magnetic sensor section 10 when the railway vehicle 3 passes the installation position of the permanent magnet 7d.

Likewise, with respect to the permanent magnet 7d, a permanent magnet having the same magnetization pattern as the permanent magnet 7d but having a different installation orientation is treated as a different type from the permanent magnet 7d. For example, an installation orientation in which the magnetic poles on the upper surface are N pole on the right and S pole on the left is handled as a different type. Similarly, the permanent magnet 7, which is oriented such that the top magnetic pole is the north pole and the bottom is the south pole, or that the top magnetic pole is the bottom north pole and the top south pole is also a permanent magnet. Treated as a different type from 7d.

The permanent magnet 7e shown in FIG. 23 has a magnetization pattern that is magnetized in the front-rear direction, and is oriented such that the front is the N pole and the rear is the S pole when viewed from above. 24 to 26 show magnetic field distributions detected by the magnetic sensor section 10 when the railway vehicle 3 passes the installation position of the permanent magnet 7e.

Likewise, with regard to the permanent magnet 7e, a permanent magnet having the same magnetization pattern as the permanent magnet 7e but having a different installation direction is treated as a different type from the permanent magnet 7e. For example, when viewed from the top, the N pole is at the back and the S pole is at the front, the N pole is at the right and the S pole is at the left, and the N pole is at the left and the S pole is at the right. Permanent magnets 7 in any orientation are treated as different types from the permanent magnets 7e.

FIG. 27 shows correlation coefficients calculated for the magnetic field distributions of the permanent magnets 7c to 7e. The correlation coefficients shown in FIG. 27 are average values of correlation coefficients for each detection axis (X-axis, Y-axis and Z-axis). 16 to 18, FIGS. 20 to 22, and FIGS. 24 to 26 are calculated using the magnetic field distributions. As shown in FIG. 27, the correlation coefficients of magnetic field distributions due to different types of permanent magnets 7 are small. Therefore, it can be seen that the permanent magnets 7c to 7e of different types can be discriminated and detected.

[Function configuration]
FIG. 28 is a block diagram showing the functional configuration of the on-board control device 30. As shown in FIG. 28, the on-board control device 30 includes an operation unit 102, a display unit 104, a sound output unit 106, a communication unit 108, a processing unit 200, and a storage unit 300, and functions as a kind of computer. Can be configured.

The operation unit 102 is realized by an input device such as a button switch, a touch panel, or a keyboard, and outputs an operation signal to the processing unit 200 according to the operation performed. The display unit 104 is implemented by, for example, a display device such as an LCD (Liquid Crystal Display) or a touch panel, and performs various displays according to display signals from the processing unit 200 . The sound output unit 106 is implemented by, for example, a sound output device such as a speaker, and performs various sound outputs according to sound signals from the processing unit 200 . The communication unit 108 is implemented by, for example, a wired or wireless communication device, and communicates with an external device via a given communication network.

The processing unit 200 is realized by an arithmetic device such as a CPU (Central Processing Unit), for example, and based on the programs and data stored in the storage unit 300, instructs and transfers data to each unit constituting the on-vehicle control device 30. , and the overall control of the on-board control device 30 is performed. In addition, the processing unit 200 functions as functional blocks of a travel position calculation unit 202 , a travel position correction unit 204 , a detection unit 206 and a determination unit 208 by executing the determination program 302 stored in the storage unit 300 . However, these functional blocks can also be configured as independent arithmetic circuits by ASIC (Application Specific Integrated Circuit), FPGA (Field Programmable Gate Array), or the like.

The traveling position calculation unit 202 calculates the traveling position of the railroad vehicle 3 at any time. Specifically, for example, by integrating the traveled distance from a given starting position using the speed information obtained from the rotation detection signal by the tachometer or pulse generator attached to the axle, the travel position can be determined at any time. calculate.

The travel position correction unit 204 corrects the travel position calculated by the travel position calculation unit 202 using the installation position of the permanent magnet 7 of the type determined by the determination unit 208 . Specifically, the timing at which the magnetic field distribution (detected magnetic field distribution) detected by the detection unit 206 is determined to match the reference magnetic field distribution corresponding to the installation position of the permanent magnet 7 of the type determined by the determination unit 208 is It is the timing of passing the installation position. Then, the travel position calculated at the passage timing is updated with the installation position, thereby correcting the travel position.

The detection unit 206 detects the magnetic field distribution based on the detection values of each of the magnetic sensor elements 12 for each of the plurality of detection axes of the magnetic sensor elements 12 of the magnetic sensor unit 10 . Specifically, the magnetic field distribution about one detection axis is expressed as a two-dimensional array in which the detection value of each magnetic sensor element 12 along the detection axis is set as an element I(i, j). The two-dimensional array corresponds to the arrangement positions of the magnetic sensor elements 12 in the magnetic sensor unit 10. The front-rear direction (running direction) of the railroad vehicle 3 is the i direction of the two-dimensional array, and the left-right direction of the railroad vehicle 3 (the sleeper direction). ) corresponds to the j direction (see FIG. 3).

The magnetic field distribution detected by the detector 206 is accumulated and stored as detection data 320 . FIG. 29 is a diagram showing an example of detection data 320. As shown in FIG. The detection data 320 is data relating to the magnetic field distribution detected by the magnetic sensor section 10 and is generated for each detection by the magnetic sensor section 10 . One detection data 320 is associated with a detection ID 321, and includes detection time 322, X-axis detection magnetic field distribution data 323, Y-axis detection magnetic field distribution data 324, Z-axis detection magnetic field distribution data 325, and detection time 322. A calculated travel position 329 calculated by the travel position calculator 202 is stored. Further, the detection data 320 stores correlation coefficient data 326 and determination results 327 . The correlation coefficient data 326 stores the correlation coefficient between the magnetic field distribution calculated by the determination unit 208 and the reference magnetic field distribution for each type and relative position of the permanent magnet 7 . The reference magnetic field distribution ID, which is identification information for identifying the reference magnetic field distribution for each type and relative position of the permanent magnet 7, is stored in association with the calculated correlation coefficient for each detection axis. The reference magnetic field distribution is the reference magnetic field distribution for each type and relative position of the permanent magnets 7 stored in the installed magnet data 310 (see FIG. 30). The installation magnet data 310 also stores installation position data 312 that serves as a reference for the relative position. The determination result 327 stores data (reference magnetic field distribution ID, etc.) indicating the reference magnetic field distribution determined by the determination unit 208 to match the detected magnetic field distribution.

The determination unit 208 compares the magnetic field distribution detected by the detection unit 206 with the reference magnetic field distribution detected by the detection unit 206 when passing through the installation position of the permanent magnet 7, thereby determining whether the permanent magnet It is determined whether or not the installation position of 7 has been passed. The reference magnetic field distribution includes a reference magnetic field distribution for each detection axis. Compare with magnetic field distribution. Further, the magnetic field distribution detected by the detection unit 206 is compared with each reference magnetic field distribution for each type of the permanent magnet 7 to determine the type of the permanent magnet 7 installed at the installation position to be passed. Also, the magnetic field distribution detected by the detection unit 206 in time series is compared with each of the reference magnetic field distributions, and the type of the permanent magnet 7 installed at the passing installation position is determined based on the number of times it is determined to match.

Specifically, the magnetic field distribution (detected magnetic field distribution) detected by the detection unit 206, the type of the permanent magnet 7, and the placement of the permanent magnet 7 are detected at predetermined time intervals (for example, intervals of several milliseconds). It is repeatedly determined whether or not the reference magnetic field distribution for each relative position corresponding to the position matches. Among the reference magnetic field distributions for each installation position for one type of permanent magnet 7, a predetermined number or more of the reference magnetic field distributions are continuously matched, and the railway vehicle 3 passes in the matching order. If it is in the order of relative positions (that is, the order of installation positions farther from the installation position), it is determined that the type of permanent magnet 7 has been detected. Whether or not the detected magnetic field distribution matches the reference magnetic field distribution is determined based on the correlation coefficient for each detection axis calculated by Equation (1).

The reference magnetic field distribution for each type and relative position of the permanent magnet 7 is defined as installed magnet data 310 . FIG. 30 is a diagram showing an example of installation magnet data 310. As shown in FIG. The installed magnet data 310 is data relating to the permanent magnets 7 installed on the track 5 and is prepared for each type of permanent magnet 7 . One installation magnet data 310 stores installation position data 312 and reference magnetic field distribution data 313 of the permanent magnet 7 of the type in association with a type ID 311 .

The installation position data 312 is data of the position (installation position) where the permanent magnet 7 of the type is installed. The number of installation positions stored in the installation position data 312 is not limited to one, and a plurality of installation positions can be stored. When the permanent magnets 7 of the same type ID 311 are installed at a plurality of installation positions, they are installed according to predetermined installation conditions so that errors do not occur in calculating and correcting the travel position. For example, as an installation condition for circulating and arranging permanent magnets 7 of different types, an erroneous installation position is determined by determining whether or not the types of detected front and rear permanent magnets 7 match this installation condition. try not to As another example, the installation condition may be that the permanent magnet 7 should be installed at a position for a specific application according to the type of permanent magnet 7 . In this case, for example, when the train stops at each station, the type of permanent magnets 7 to be installed at fixed positions is fixed, or the type of permanent magnets 7 to be installed at kilometer posts in units of 10 km is fixed. do. Even if there is an error in the travel position calculated on the vehicle, the error will not be 1 km. When determining the installation position by detecting the type of the permanent magnet 7, even if there are a plurality of corresponding installation positions, it is possible to select and determine the correct installation position by judging these installation conditions together. can. Also, the installation position can be expressed in kilometers.

The reference magnetic field distribution data 313 is data relating to the reference magnetic field distribution corresponding to the type of permanent magnet 7, and is prepared for each relative position with respect to the installation position. Even if a plurality of installation positions are associated with the type of permanent magnet 7, the permanent magnets 7 are of the same type, so if the relative positions are the same, the reference magnetic field distribution data 313 will also be the same. One reference magnetic field distribution data 313 stores the corresponding relative position, X-axis reference magnetic field distribution data, Y-axis reference magnetic field distribution data, and Z-axis reference magnetic field distribution data in association with the reference magnetic field distribution ID. ing.

Returning to FIG. 28, the storage unit 300 is realized by a storage device such as a hard disk, a ROM (Read Only Memory), a RAM (Random Access Memory), etc. In addition to storing programs and data, it is used as a work area for the processing unit 200, and temporarily stores calculation results executed by the processing unit 200 according to various programs, input data via the operation unit 102 and the communication unit 108, and the like. stored in In this embodiment, the storage unit 300 stores a determination program 302 , installation magnet data 310 , and detection data 320 .

[Process flow]
FIG. 31 is a flowchart for explaining the flow of determination processing performed by the on-board control device 30. FIG. This processing is realized by the processing unit 200 executing the determination program 302, and is started prior to departure from the starting station, for example.

First, the traveling position calculation unit 202 starts calculating the traveling position (step S1). Then, the detection unit 206 determines whether the magnetic field is detected by the magnetic sensor unit 10 . Specifically, it is determined that a magnetic field is detected when a predetermined number or more of the detection values of the respective detection axes of the magnetic sensor elements of the magnetic sensor unit 10 are greater than or equal to a predetermined threshold value. .

If a magnetic field is detected (step S3: YES), the detection unit 206 detects the magnetic field distribution for each detection axis based on the detection value of each magnetic sensor element 12 (step S5). Next, the determination unit 208 calculates correlation coefficients between the magnetic field distribution (detected magnetic field distribution) detected by the detection unit 206 and the reference magnetic field distribution for each type of permanent magnet 7 and for each relative position from the installation position. (Step S7). Then, it is determined whether the detected magnetic field distribution and each reference magnetic field distribution match depending on whether the calculated correlation coefficient is equal to or greater than a predetermined threshold.

If there is a reference magnetic field distribution that matches the detected magnetic field distribution (step S9: YES), then the continuity of the matching reference magnetic field distribution is determined (step S11). That is, the detected magnetic field distribution is continuously matched with a predetermined number or more of the reference magnetic field distributions of the same type for each relative position, and the matching order depends on the running direction of the railway vehicle 3. If the passing order is determined, it is determined that there is continuity. If it is determined that there is continuity (step S13: YES), it is determined that the corresponding type of permanent magnet 7 has been detected (step S15). Then, the traveling position correction unit 204 corrects the traveling position using the installation position of the determined type of permanent magnet 7 (step S17). At this time, among the detected magnetic field distributions detected in time series, the detected magnetic field distribution that matches the reference magnetic field distribution at the relative position (that is, relative position zero) corresponding to the installation position of the determined type of permanent magnet 7 is specified. do. Then, the travel position calculated by the travel position calculation unit 202 is adjusted so that the calculated travel position 329 calculated at the detection time 322 of the specified detected magnetic field distribution becomes the installation position of the determined type of permanent magnet 7 . is corrected.

After that, it is determined whether or not this process is to be terminated by satisfying the termination condition such as arrival at the terminal station. If not (step S19: NO), the process returns to step S3 to repeat the same process. If it ends (step S19: YES), this process ends.

[Effect]
According to this embodiment, the on-board device 1 can detect the permanent magnet 7 installed on the track 5 . That is, the magnetic field distribution based on the detection values of the plurality of magnetic sensor elements 12 of the magnetic sensor unit 10 is detected, and the detected magnetic field distribution is used as the reference of the magnetic field distribution detected when passing through the installation position of the permanent magnet 7. By comparing with the reference magnetic field distribution, it is determined that the installation position of the permanent magnet 7 has been passed. As a result, the permanent magnet 7 can be detected separately from other magnetic sources, and it can be determined that the installation position of the permanent magnet 7 has been passed. A train position detection device using the permanent magnets 7 installed on the track 5 as ground equipment can be constructed at a lower cost than a conventional train position detection device using ground coils or the like as ground equipment.

It goes without saying that the embodiments to which the present invention can be applied are not limited to the above-described embodiments, and can be changed as appropriate without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1... On-board apparatus 10... Magnetic sensor part 12... Magnetic sensor element 30... On-board control apparatus 200... Processing part 202... Traveling position calculation part 204... Traveling position correction part 206... Detection part 208... Judgment part 300... Storage part 302 ... determination program 310 ... installed magnet data 320 ... detection data 3 ... railway vehicle 5 ... track 7 (7a to 7e) ... permanent magnet

Claims (10)

An on-board device mounted on a vehicle running on a track in which a magnet is installed at a predetermined installation position,
The magnet includes a plurality of types of magnets that differ in any one of size, installation orientation, and magnetization pattern,
A predetermined type of the magnet is installed at the installation position,
a magnetic sensor unit having a plurality of magnetic sensor elements arranged in a predetermined positional relationship for detecting the magnetic field generated by the magnet when passing through the installation position;
a detection unit that detects a magnetic field distribution based on the detection value of each of the magnetic sensor elements;
The magnetic field distribution detected by the detection unit in time series when passing through the installation position is a reference magnetic field distribution that is a reference for the magnetic field distribution , is for each type of the magnet, and is relative to the installation position. a determination unit that compares with each reference magnetic field distribution for each relative position , determines the type of the magnet based on the number of times it is determined that it matches, and determines whether or not the magnet has passed through the installation position;
On-board equipment. The magnetic sensor unit has at least a plurality of magnetic sensor elements arranged in the lateral direction of the vehicle,
The on-vehicle device according to claim 1. The magnetic sensor unit has at least a plurality of magnetic sensors arranged in a plane along the front, rear, left, and right directions of the vehicle,
The on-vehicle device according to claim 1 or 2. In the track, the type of the magnet to be installed is predetermined for each installation position where the magnet is installed,
The determination unit determines the type of the magnet installed at the installation position to pass through.
The on-vehicle device according to any one of claims 1 to 3. An on-board device mounted on a vehicle running on a track in which a magnet is installed at a predetermined installation position,
The magnet includes a plurality of types of magnets,
A predetermined type of the magnet is installed at the installation position,
A plurality of magnetic sensor elements arranged in a plane along the front, rear, left, and right directions of the vehicle for detecting the magnetic field generated by the magnet when passing through the installation position, and any one of the plurality of types. Even if the magnet is installed at the installation position, any one of the plurality of magnetic sensor elements is arranged to face the magnet when passing through the installation position a magnetic sensor unit having a plurality of magnetic sensor elements ;
a detection unit that detects the planar magnetic field distribution by the entirety of the plurality of magnetic sensor elements based on the detection value of each of the magnetic sensor elements;
By comparing a reference magnetic field distribution, which is a reference of the planar magnetic field distribution detected by the detection unit when passing through the installation position, with the planar magnetic field distribution detected by the detection unit, the installation position is detected. A determination unit that determines whether or not the position has been passed;
On-board equipment. An on-board device mounted on a vehicle running on a track in which a magnet is installed at a predetermined installation position,
The magnet is installed at the installation position with a magnetization pattern magnetized in the front-rear direction along the track when viewed from the vehicle,
a magnetic sensor unit having a plurality of magnetic sensor elements arranged in a plane along the front, rear, left, and right directions of the vehicle for detecting the magnetic field generated by the magnet when passing through the installation position;
a detection unit that detects the planar magnetic field distribution by the entirety of the plurality of magnetic sensor elements based on the detection value of each of the magnetic sensor elements;
By comparing a reference magnetic field distribution, which is a reference of the planar magnetic field distribution detected by the detection unit when passing through the installation position, with the planar magnetic field distribution detected by the detection unit, the installation position is detected. A determination unit that determines whether or not the position has been passed;
On-board equipment. The magnetic sensor element has a plurality of detection axes,
The detection unit detects the magnetic field distribution for each detection axis,
The reference magnetic field distribution includes a reference magnetic field distribution for each detection axis,
The determination unit compares, for each detection axis, a reference magnetic field distribution of the detection axis with the magnetic field distribution of the detection axis detected by the detection unit.
The on-vehicle device according to any one of claims 1 to 6 . An on-vehicle device mounted on a vehicle running on a track in which a magnet is installed at a predetermined installation position, the device being located at a predetermined position for detecting the magnetic field generated by the magnet when passing through the installation position. A determination method for determining whether an on-vehicle device having a magnetic sensor unit having a plurality of magnetic sensor elements arranged in a relationship has passed through the installation position,
The magnet includes a plurality of types of magnets that differ in any one of size, installation orientation, and magnetization pattern,
A predetermined type of the magnet is installed at the installation position,
Detecting a magnetic field distribution based on the detection value of each of the magnetic sensor elements;
The magnetic field distribution detected in time series when passing through the installation position is a reference magnetic field distribution that serves as a reference for the magnetic field distribution, by type of the magnet, and by position relative to the installation position. comparing with each of the reference magnetic field distributions , determining the type of the magnet based on the number of times it is determined to be suitable, and determining whether or not the installation position has been passed;
Judgment method including. An on-vehicle device mounted on a vehicle running on a track in which a magnet is installed at a predetermined installation position, the device being located at a predetermined position for detecting the magnetic field generated by the magnet when passing through the installation position. A determination method for determining whether an on-vehicle device having a magnetic sensor unit having a plurality of magnetic sensor elements arranged in a relationship has passed through the installation position,
The magnet includes a plurality of types of magnets,
A predetermined type of the magnet is installed at the installation position,
The plurality of magnetic sensor elements are arranged in a plane along the front, rear, left, and right directions of the vehicle. is arranged so that one of the plurality of magnetic sensor elements faces the magnet when passing through the installation position,
Detecting the planar magnetic field distribution by the entirety of the plurality of magnetic sensor elements based on the detected value of each of the magnetic sensor elements;
By comparing a reference magnetic field distribution that is a reference of the planar magnetic field distribution detected when passing the installation position and the detected planar magnetic field distribution, it is possible to determine whether the installation position has been passed. determining whether or not
Judgment method including. An on-vehicle device mounted on a vehicle running on a track in which a magnet is installed at a predetermined installation position, the device being located at a predetermined position for detecting the magnetic field generated by the magnet when passing through the installation position. A determination method for determining whether an on-vehicle device having a magnetic sensor unit having a plurality of magnetic sensor elements arranged in a relationship has passed through the installation position,
The magnet is installed at the installation position with a magnetization pattern that is magnetized in a longitudinal direction along the track as viewed from the vehicle,
The plurality of magnetic sensor elements are arranged in a plane along the front, rear, left, and right directions of the vehicle,
Detecting the planar magnetic field distribution by the entirety of the plurality of magnetic sensor elements based on the detected value of each of the magnetic sensor elements;
By comparing a reference magnetic field distribution that is a reference of the planar magnetic field distribution detected when passing the installation position and the detected planar magnetic field distribution, it is possible to determine whether the installation position has been passed. determining whether or not
Judgment method including.

Images