JP2022108013A - On-board device - Google Patents

Abstract

To provide a method capable of suppressing, to a possible extent, the cost of a dedicated device on the ground for accurately calculating, on a railway vehicle, a travel position of the railway vehicle.SOLUTION: An on-board device 1 mounted on a railway vehicle 3 comprises: a travel position calculation part for calculating a travel position as necessary; an image acquisition part for acquiring images along a travel line during travelling; a determination part that, upon the travel position entering a prescribed corrected interval including a prescribed correction position, starts to compare the image acquired by the image acquisition part with a reference image preliminarily set as an image along the travel line at the corrected position, and determines a timing to satisfy a prescribed image compatibility condition; and a first calibration part for calibrating the calculated position of the travel position calculation part so that a travel position at a timing affirmatively determined by the determination part becomes the corrected position.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to an on-board device for calculating a running position of a railway vehicle.

Conventionally, as a method of calculating the running position of a railway vehicle on the train, it is common to use a rotation detection signal from a tacho-generator (TG) or a pulse generator (PG). It was done. In recent years, construction of a technique that utilizes signals received from GNSS (Global Navigation Satellite System) satellites is underway. Since an error may occur in the running position calculated by such a method, it is necessary to correct it by some method from the viewpoint of safety. For example, as disclosed in Japanese Unexamined Patent Application Publication No. 2002-100002, a common method is to detect a ground marker such as a ground coil installed on the ground and correct the traveling position based on the installation position of the detected ground marker.

Japanese Patent Application Laid-Open No. 2003-267220

However, in the conventional method of correcting the running position, it is necessary to install a large number of dedicated facilities such as ground markers for correcting the running position because the track on which the railway vehicle runs is long. There was a problem that the cost required for maintenance (maintenance) was high.

The present invention has been made in view of the above-mentioned circumstances, and its object is to minimize the cost associated with dedicated equipment on the ground for accurately calculating the running position of a railway vehicle on the vehicle. It is to provide the technology that makes it possible.

A first invention for solving the above problems is
An on-board device mounted on a railway vehicle,
a traveling position calculation unit that calculates a traveling position as needed;
an image acquisition unit that acquires an image along the route while driving;
When the traveling position enters a predetermined correction section including a predetermined correction position, start comparing the image acquired by the image acquisition unit with a reference image preset as an image along the railway at the correction position. a determination unit that determines the timing at which a predetermined image matching condition is satisfied;
a first correcting unit that corrects the calculated position of the traveling position calculating unit so that the traveling position at the timing at which the judging unit makes an affirmative determination becomes the corrected position;
An on-vehicle device comprising

According to the first invention, it is possible to accurately calculate the running position of a railway vehicle on the vehicle without using dedicated equipment on the ground. In other words, the on-board device calculates the running position of the railway vehicle at any time, compares the image along the railway during running with the reference image preset as the image along the railway at the corrected position, and satisfies the predetermined image matching condition. The timing is determined, and the running position is corrected so that the running position at the timing when the affirmative determination is made becomes the corrected position. The timing at which the image matching condition is satisfied is the timing at which the position of the railway vehicle becomes the corrected position. It is possible to calculate well. In addition, since the comparison between the railroad image and the reference image is started when the predetermined correction section is entered, it is possible to accurately determine the timing at which the image matching condition is satisfied. As a result, it is possible to accurately calculate the running position of the railroad vehicle on the train without using dedicated equipment on the ground for correcting the running position. Therefore, it is possible to save the cost associated with dedicated facilities on the ground.

A second invention is based on the first invention,
The traveling position calculation unit calculates the traveling position at any time by integrating the traveling distance from a given calculation starting point position using the received signal received from the GNSS (Global Navigation Satellite System) satellite,
The first correction unit updates the calculated starting point position with the corrected position.
It is an on-board device.

According to the second invention, when the travel position is calculated at any time by integrating the travel distance from the given calculation starting point position using the received signal received from the GNSS satellite, the travel position is calculated as the travel distance is integrated. However, by updating the calculated starting point position with the corrected position, the error is eliminated, so that the traveling position can be calculated with high accuracy.

A third invention is the first or second invention,
The determination unit performs image matching processing for determining a degree of similarity between the image acquired by the image acquisition unit and the reference image, and sets the timing that the similarity satisfies a predetermined peak condition as the image matching condition. determine the
It is an on-board device.

According to the third invention, the captured image along the railroad track during travel gradually changes according to the travel position of the railroad vehicle. In other words, the degree of similarity determined by image matching processing between the railroad image and the predetermined reference image changes as the railroad vehicle travels, and peaks (maximum) at the timing when the travel position of the railroad vehicle reaches the corrected position. should be. Therefore, by determining the timing at which the similarity satisfies the peak condition, it is possible to accurately determine the timing at which the traveling position of the railway vehicle becomes the corrected position.

A fourth invention is, in any one of the first to third inventions,
The corrected position is a position where the road center of a railroad crossing crossing the railroad track appears in a predetermined portion of the image along the railroad track acquired by the image acquisition unit.
It is an on-board device.

According to the fourth invention, when the image along the railway is an image in front of the railway vehicle in the direction of travel, the railroad crossing appears in a straight line in the image along the railway so as to traverse left and right. Then, as the railroad vehicle approaches the railroad crossing, the position of the railroad crossing in the railroad image gradually moves downward, and the size of the railroad crossing gradually increases. Therefore, by setting the position where the center of the road of the railroad crossing crossing the railroad is shown in a predetermined part (for example, the center part) of the image along the railway as the correction position, the timing at which the image matching condition between the image along the railway and the reference image is satisfied can be accurately determined. As a result, it is possible to accurately correct the travel position.

A fifth invention is, in any one of the first to fourth inventions,
The image acquisition unit acquires a photographed image or a distance image as the image along the railway,
It is an on-board device.

According to the fifth aspect, it is possible to acquire a photographed image or a distance image as a wayside image.

A sixth invention is, in any one of the first to fifth inventions,
The railway vehicle runs on a railroad track on which metal markers are installed at predetermined installation positions,
an electromagnetic induction sensor capable of detecting the metal marker when passing through the installation position;
a second correction unit that corrects the calculated position of the travel position calculation unit so that the travel position at the detection timing by the electromagnetic induction sensor becomes the installation position;
It is an on-vehicle device further comprising

According to the sixth invention, when the railway vehicle travels on the railroad track on which the metal marker is installed, the travel position is adjusted so that the travel position at the detection timing of the metal marker by the electromagnetic induction sensor is the installation position of the metal marker. position is corrected. As a result, it becomes possible to correct the traveling position with higher accuracy. In addition, metal markers that can be detected by electromagnetic induction sensors do not require electrical circuits like beacons, so installation and maintenance costs are low. can be significantly reduced.

A seventh invention is based on the sixth invention,
There are a plurality of types of the metal marker, each of which has a different material, size, or shape,
A track on which the railroad vehicle travels has a predetermined section in which the metal markers of different types are dispersedly arranged at different predetermined installation positions,
The second correction unit determines the installation position of the detected metal marker by determining the type of the metal marker based on the waveform of the metal marker detected by the electromagnetic induction sensor. correcting the calculated position of the traveling position calculation unit based on the position;
It is an on-board device.

According to the seventh invention, different types of metal markers are distributed in advance at different installation positions on the railroad track on which the railroad vehicle runs, so that the types of metal markers can be detected based on the waveforms of the metal markers detected by the electromagnetic induction sensor. is determined, the installation position can be determined, and the travel position can be corrected based on the determined installation position.

Application example of on-board equipment. Explanatory drawing of correction|amendment of the driving|running|working position by the image along a track. Explanatory drawing of the setting of a correction|amendment area. FIG. 5 is an explanatory diagram of correcting the traveling position based on the waveform detected by the electromagnetic induction sensor; The block diagram of an electromagnetic induction sensor. Explanatory drawing of the detection waveform of the metal marker by an electromagnetic induction sensor. An example of detection waveforms of metal markers of different types. The functional block diagram of a control apparatus. An example of corrected section data. An example of reference image data. An example of GNSS unreceivable section data. An example of metal marker data. 4 is a flowchart of travel position calculation processing;

Preferred embodiments of the present invention will be described below with reference to the drawings. In addition, the present invention is not limited by the embodiments described below, and the forms to which the present invention can be applied are not limited to the following embodiments. 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, the on-board device 1 of the present embodiment is mounted on a railway vehicle 3, and includes a control device 10, a GNSS (Global Navigation Satellite System) receiver 20, a camera 30, and an electromagnetic induction sensor 40 .

GNSS receiver 20 receives satellite signals from GNSS satellites. GNSS includes GPS (Global Positioning System), EGNOS (European Geostationary Navigation Overlay Service), QZSS (Quasi Zenith Satellite System), GLONASS (Global Navigation Satellite System), GALILEO, BeiDou (BeiDou Navigation Satellite System), and the like.

The camera 30 is installed at or near the driver's cab of the railroad vehicle 3 and captures an image along the track in front of the railroad vehicle 3 in the traveling direction. This photographing is moving image photographing, but may be continuous still image photographing. Further, the camera 30 may use different camera system types based on differences in wavelength regions such as visible light and infrared light, or may use different camera system types in combination. The electromagnetic induction sensor 40 is installed at the bottom of the railway vehicle 3 at a position where the metal marker can be detected when passing through the installation position of the metal marker installed on the track 5 .

The control device 10 uses the received signal received by the GNSS receiver 20 to calculate the running position of the railroad vehicle 3 at any time. In addition, the travel position is corrected at an arbitrary timing using the image along the track captured by the camera 30 or using the waveform detected by the electromagnetic induction sensor 40 . Specifically, the travel position is calculated by accumulating the travel distance from a predetermined calculation starting point position based on the speed information of the railroad vehicle 3 calculated based on the received signal from the GNSS satellite. Then, the travel position is corrected by updating the calculated starting point position.

[Correction of driving position by wayside image]
FIG. 2 is a diagram for explaining the correction of the travel position using the image along the railroad track. For the sake of clarity, the railroad crossing 7 is represented as a rectangle. As shown in the upper part of FIG. 2, a correction position and a correction section including this correction position are determined in advance on the track 5 on which the railroad vehicle 3 travels.

In the example of FIG. 2, the correction position and the correction section are determined before the railroad crossing 7 on the railroad 5 . Therefore, the railroad image captured by the camera 30 in the correction section is an image of the railroad crossing 7 . Since the railroad image is an image in front of the railroad vehicle 3 in the traveling direction, the railroad crossing 7 appears in the railroad image in a straight line so as to traverse left and right. In addition, the position of the railroad crossing 7 in the image along the railway line is located above the railroad crossing 7 immediately after entering the corrected section because the railroad crossing 7 is far away, but as the vehicle approaches the railroad crossing 7, the position changes from above to below. As it gradually moves toward the center, its size gradually increases.

When the control device 10 determines that the vehicle has reached (entered) the correction section based on the travel position, it starts comparing the image along the railroad track captured by the camera 30 with a reference image prepared in advance, and obtains a predetermined image. Determine the timing that satisfies the conformance condition. Specifically, image matching processing is performed to determine the degree of similarity between the railroad image and the reference image, and the timing of satisfying the image matching condition is determined with the image matching condition that the similarity satisfies a predetermined peak condition. The reference image is an image set in advance as an image along the track at the corrected position, and an image captured by the camera 30 when the running position of the railway vehicle 3 coincides with the corrected position can be prepared as the reference image. . For example, a position where the center of the road of the railroad crossing 7 crossing the railroad line can be set as the correction position in a predetermined portion (for example, the center portion) of the image along the railroad track. When the railroad crossing 7 is photographed from above the vehicle, the photographed image is characteristic in that the road edges are captured in a straight line from left to right in an easy-to-understand manner. Therefore, in this embodiment, the railroad crossing 7 is used for determining the image matching condition. In addition, where in the captured image the characteristic image appears and what size it appears in is also greatly related to the degree of similarity. This is because the entire captured image is subject to image matching processing.

Note that the correction position is not limited to the position where the railroad crossing is included in the railroad image. Any other position may be used as long as it is a position where a characteristic object, building, or scenery that can be determined to have a high degree of similarity at a certain travel timing in the image matching processing of the entire captured image appears in the image along the railroad track. For example, positions at which branch points and curves of a railway line, characteristic buildings such as buildings along the railway line, and geographical features along the railway line such as mountains appear in the image along the railway line may be set as correction positions.

In addition, assuming use in dark places such as tunnels where there are no feature images or conditions with poor visibility such as fog, a retroreflective material with good reflectance is installed at the correction position, and the retroreflective image captured by the camera 30 is used. You may make it acquire the image containing a reflector as a wayside image. In this case, the retroreflective material is the main characteristic portion, and similarity is determined in the image matching process.

The control device 10 performs matching processing with the reference image for each frame of the railroad image captured by the camera 30 to calculate the degree of similarity. The relationship between the travel position in the correction section and the similarity of the image along the railroad taken at that travel position is shown in the lower graph of FIG. 2 . Since the reference image is an image taken at the correction position, the similarity between the image along the track and the reference image is small immediately after entering the correction section, increases as the correction position is approached, and reaches a maximum at the correction position. After passing the correction position, it decreases with distance from the correction position. The control device 10 sets the maximum similarity between the captured image and the reference image as a peak condition, and corrects the traveling position so that the traveling position at the timing when the image along the railroad that satisfies the peak condition is captured becomes the corrected position. . A travel position that satisfies this peak condition can be determined after passing through the correction position. Therefore, for example, after passing through the correction section, the control device 10 determines the photographing time of the railroad image whose similarity to the reference image in the correction section satisfies the peak condition (the similarity is maximized), The calculated starting point position is updated so that the traveling position at that photographing time becomes the corrected position. If the calculated starting position is set as the corrected position, then the traveling position at the shooting time is set as the corrected position, and the calculated starting position is updated with the corrected position. Accurate position data of the correction position is stored and set in advance. Then, the traveling position is updated by updating the traveling distance from the updated calculated starting point position.

FIG. 3 is a diagram for explaining setting of correction intervals. The correction interval is determined based on the received signal accuracy by the GNSS receiver. For example, as shown in the upper side of FIG. 3, a GNSS receiver is installed at a correction position, and positioning positions repeatedly measured by this GNSS receiver are collected for a certain period of time. Then, when the distribution of the collected positioning positions is regarded as a normal distribution (Gaussian distribution) with the corrected position as the average value μ, the range of μ ± 6σ or μ ± 3σ is the correction interval for the correction position set as

Alternatively, a railway vehicle equipped with a GNSS receiver travels to the corrected position a plurality of times, and collects travel positions at the calculated corrected positions in each travel. The traveling position is calculated on the vehicle by calculating the traveling distance from a predetermined starting position to the corrected position using the signal received by the GNSS receiver. Then, for the collected travel positions, similarly, when the corrected position is regarded as a normal distribution (Gaussian distribution) with the average value μ, the range of μ ± 6σ or μ ± 3σ is corrected for the corrected position. Set as an interval.

Alternatively, the correction interval may be set based on a failure rate defined by a predetermined safety standard (SIL standard, ASIL standard, etc.) instead of the range of μ±6σ or μ±3σ. For example, a range that satisfies the failure rate (error rate) corresponding to the safety level defined by the SIL standard may be set as the correction interval.

Also, the GNSS receiver used when setting the correction section may be the device itself that is scheduled to be mounted on the railroad vehicle 3, or may be another device with the same model number.

[Correction of travel position by detection waveform of electromagnetic induction sensor]
4A and 4B are diagrams for explaining the correction of the traveling position based on the waveform detected by the electromagnetic induction sensor 40. FIG. Of the track 5 on which the railroad vehicle 3 runs, at least in the section where the GNSS signal cannot be received by the GNSS receiver 20 and where it is difficult for the camera 30 to capture a clear image along the track, different types of metal markers 9 are placed. , are distributed at different predetermined installation positions. The metal marker 9 is a plate-like body made of metal, and there are a plurality of types with different materials, sizes, and shapes.

Such sections are typically tunnel sections. In sections where GNSS signals cannot be received, the sky is not open, and it is often difficult to capture images along the route. Therefore, the section in which the GNSS signal cannot be received (the GNSS unreceivable section) is set as the section in which the traveling position is corrected based on the waveform detected by the electromagnetic induction sensor 40 . As shown in FIG. 4, the metal markers 9 are dispersedly arranged within the GNSS unreceivable section, and are also arranged near both ends of the GNSS unreceivable section (within the GNSS receivable section) (see FIG. 4). 4 installation positions (a) and (d) correspond). The control device 10 determines the installation position of the detected metal marker 9 by determining the type of the metal marker 9 based on the detected waveform of the metal marker 9 by the electromagnetic induction sensor 40, and the determined installation position. Based on this, the running position is corrected.

FIG. 5 is a diagram showing the configuration of the electromagnetic induction sensor 40. As shown in FIG. As shown in FIG. 5 , the electromagnetic induction sensor 40 has a sensor section 42 and a transmission/reception amplifier section 44 . The sensor unit 42 includes a transmission coil TX1 and reception coils RX1 and RX2. The inter-coil distances between the transmitting coil TX1 and the receiving coils RX1 and RX2 are set at slightly different distances.

The transmission/reception amplifier section 44 includes a power amplifier 44a and an oscillator 44b. Oscillator 44b supplies an alternating current of frequency f0. The power amplifier 44a amplifies the alternating current of frequency f0 supplied from the oscillator 44b and applies it to the transmission coil TX1. The alternating current of frequency f0 supplied by the oscillator 44b is output to the signal processing unit 212 of the control device 10 as a transmission signal, and the differential output signals of the receiving coils RX1 and RX2 are output to the signal processing unit 212 as reception signals. output. By setting the transmitting coil TX1 and the receiving coils RX1 and RX2 at slightly different distances, the differential output signal level of the receiving coils RX1 and RX2 is output even when the metal marker 9 is not detected. be done. By constantly monitoring the differential output signal level, abnormalities such as coil disconnection can be determined, and the reliability of the electromagnetic induction sensor 40 can be improved.

The signal processing unit 212 is a lock-in amplifier, and measures the amplitude R and phase θ of the received signal by comparing the transmitted signal with the reference signal. Then, the amplitude R and the phase θ in the polar coordinate system are output as coordinate values (X, Y) in the XY coordinate system.

FIG. 6 is a diagram showing an example of changes in waveforms detected by the electromagnetic induction sensor 40 when the railroad vehicle 3 passes the metal marker 9. As shown in FIG. In the example of FIG. 6, as shown in the lower left, in the railway vehicle 3, the electromagnetic induction sensor 40 has the receiving coil RX1 on the front side, the transmitting coil TX1 in the center, and the receiving coil RX2 on the rear side with respect to the traveling direction. is installed as FIG. 6 shows four states (1) to (4) in which the relative positional relationship between the metal marker 9 and each coil of the electromagnetic induction sensor 40 differs when the railroad vehicle 3 passes the metal marker 9. , the waveforms of the transmission signal and the reception signal, and the amplitude R and the phase θ in the polar coordinate system output from the signal processing unit 212 are plotted on the XY coordinates. ) and .

First, in the state (1) where the electromagnetic induction sensor 40 is away from the metal marker 9 and the metal marker 9 is not detected (non-detection), the transmission current of frequency f0 is supplied to the transmission coil TX1. , an alternating magnetic field is emitted from the transmitting coil TX1. By setting the receiving coils RX1 and RX2 at slightly different distances, a waveform having the amplitude of the received signal of R0 and the phase of the transmitted signal of θ0 is output. plotted. In this example, the phase θ0 is set to 45 [deg].

Next, in the state (2) in which the front-side receiving coil RX1 detects the metal marker 9, the magnetic field of the metal marker 9 pulls the emitted magnetic field of the transmission coil TX1 toward the front side and changes the front-side receiving coil. The magnetic field penetrating the coil RX1 interlinks with the receiving coil RX1 and the transmitting coil TX1, and is accompanied by the demagnetizing effect of the eddy current, thereby reducing the magnetic field penetrating the receiving coil RX1. The demagnetizing effect is also accompanied by a phase change of the received signal. Therefore, the amplitude R of the received signal once decreases and then increases to R1, and the phase θ with respect to the transmitted signal increases to θ1=90°. Therefore, the points plotted during the transition from state (1) to state (2) change in an arc from coordinate values (X0, Y0) in state (1) to coordinate values (X1, Y1). do.

Subsequently, in the state (3) in which the rear-side receiving coil RX2 detects the metal marker 9, the direction in which the magnetic field of the metal marker 9 attracts the emitted magnetic field of the transmission coil TX1 changes from the front side to the rear side. The magnetic flux penetrating the receiving coil RX1 increases and returns to state (1), while the magnetic flux penetrating the rear receiving coil RX2 decreases. Therefore, the amplitude R of the received signal becomes R2, and the phase θ with respect to the transmitted signal decreases to θ2=0°. Therefore, the points plotted during the transition from state (2) to state (3) change in an arc from coordinate values (X1, Y1) to coordinate values (X2, Y2) in state (2). do.

In the state (4) in which the electromagnetic induction sensor 40 is separated from the metal marker 9 and no longer detects the metal marker 9 (non-detection), the state returns to the same state as the state (1). Therefore, the points plotted during the transition from state (3) to state (4) follow a circular arc from coordinate values (X2, Y2) in state (3) to coordinate values (X0, Y0) in state (1). change to draw

In this way, the detected waveform of the metal marker 9 by the electromagnetic induction sensor 40 when passing the installation position of the metal marker 9 changes. Also, when the traveling direction of the railcar 3 is the opposite direction, the reception coil RX1 detects the metal marker 9 after the reception coil RX2 detects the metal marker 9, so the shape of the detected waveform is the same. However, the change direction of the trajectory is opposite.

In addition, when the metal marker 9 is of a different type, the magnetic field emitted from the transmission coil TX1 is attracted differently when the metal marker 9 approaches, resulting in a different detection waveform. FIG. 7 shows, as an example of waveforms detected by the electromagnetic induction sensor 40, experimental results of detection waveforms for metal markers 9 of different types. In FIG. 7, the material is "SPCC (Steel Plate Cold Commercial) material", the size is the same as "vertical and/or horizontal length of 100 mm", but four types of metal markers 9 with different shapes are: A photograph showing the appearance, waveforms detected by the electromagnetic induction sensor 40, and chronological changes in the X and Y coordinate values are shown. That is, from left to right, the square-shaped metal marker "quadrilateral", the square-shaped metal marker "punching metal" having a large number of holes (punching), the round-shaped metal marker "round", and the triangular shape. There are four types of metal markers, "triangle".

As shown in FIG. 7, the detected waveform differs depending on the type of metal marker 9. FIG. The control device 10 compares the waveform detected by the electromagnetic induction sensor 40 with a predetermined waveform detected for each type of the metal marker 9 by, for example, pattern matching processing, thereby determining the type of the detected metal marker 9. be able to. Further, the traveling direction of the railcar 3 can also be determined from the change order of the trajectory in the same detected waveform.

[Function configuration]
FIG. 8 is a block diagram showing the functional configuration of the control device 10. As shown in FIG. 8, the control device 10 comprises 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 constitutes a kind of computer. be able to.

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 communication network.

The processing unit 200 is realized by an arithmetic device such as a CPU (Central Processing Unit), for example. , performs the overall control of the control device 10 . In addition, the processing unit 200 executes the traveling position calculation program 302 stored in the storage unit 300 to perform the traveling position calculation unit 202, the image acquisition unit 204, the determination unit 206, the first correction unit 208, the second It functions as each functional block of the correction unit 210 . 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, the GNSS receiver 20 calculates the traveling speed at any time using the received signal received from the GNSS (Global Navigation Satellite System) satellite, and from this traveling speed, the traveling distance from the given calculated starting position is integrated. By doing so, the traveling position is calculated at any time. Alternatively, the travel position can be calculated at any time by accumulating the travel distance from a given calculation starting position using a rotation detection signal from a tachometer (TG) or pulse generator (PG) attached to the axle. can be Alternatively, when an acceleration sensor is mounted on the railway vehicle 3, the traveling distance from a given calculation starting position is integrated using the acceleration in the traveling direction of the railway vehicle obtained from the detection signal of the acceleration sensor. The travel position may be calculated at any time.

The calculated position calculated by the traveling position calculation unit 202 is accumulated and stored as traveling position data 310 in association with the calculation time. Also, the current calculated starting point position is stored as calculated starting point position data 312 in association with the update time by the first correction unit 208 or the second correction unit 210 .

The image acquisition unit 204 acquires a photographed image or a distance image as an image along the railroad vehicle while the railroad vehicle 3 is running. Specifically, the image captured by the camera 30 in front of the railroad vehicle 3 in the direction of travel is acquired as a wayside image. Alternatively, when an optical sensor such as LiDAR or a distance sensor such as an ultrasonic sensor is mounted on the railcar 3, a distance image obtained by the distance sensor may be acquired. The railway image acquired by the image acquisition unit 204 is accumulated and stored as the railway image data 322 in association with the acquisition time and the like.

The determination unit 206 obtains an image acquired by the image acquisition unit 204 when the traveling position enters a predetermined correction section including a predetermined correction position, a reference image preset as a roadside image at the correction position, and to determine the timing at which predetermined image matching conditions are satisfied. Specifically, image matching processing is performed to determine the degree of similarity between the image acquired by the image acquisition unit 204 and the reference image, and the image matching condition is set such that the similarity satisfies a predetermined peak condition as the image matching condition. Determine the timing of satisfaction (see FIG. 2).

The correction section is predetermined as correction section data 314 . FIG. 9 is a diagram showing an example of the corrected section data 314. As shown in FIG. As shown in FIG. 9, the correction section data 314 is associated with a section number, which is an identification number, for each correction section, and corresponds to the range of the correction section, the correction position in the correction section, and the correction position. and the image number of the reference image to be processed are stored in association with each other. The range of the correction interval is the range expressed in kilometers. The corrected position is the position expressed in kilometers. The reference image is predetermined as reference image data 318 .

FIG. 10 is a diagram showing an example of the reference image data 318. As shown in FIG. As shown in FIG. 10, the reference image data 318 associates each reference image with an image number, and associates the reference image, the correction position corresponding to the reference image, and the upward/downward traveling direction. Stored.

The first correction unit 208 corrects the calculated position of the traveling position calculating unit 202 by updating the calculated starting point position with the corrected position so that the traveling position at the timing when the determination unit 206 makes an affirmative determination becomes the corrected position. do. The corrected position is, for example, the position where the road center of the railroad crossing that crosses the railroad line appears in a predetermined portion (for example, the central portion) of the railroad image acquired by the image acquisition unit 204 .

The second correction unit 210 corrects the calculated position of the traveling position calculating unit 202 so that the traveling position at the detection timing of the electromagnetic induction sensor 40 of the metal marker 9 installed on the railroad 5 becomes the installation position. Specifically, by determining the type of the metal marker 9 based on the detected waveform of the metal marker 9 by the electromagnetic induction sensor 40, the installation position of the detected metal marker 9 is determined. Based on this, the calculated position of the traveling position calculator 202 is corrected. There are a plurality of types of metal markers that are different in material, size, and shape. 9 are distributed at different predetermined installation positions.

Also, the second correction unit 210 has a signal processing unit 212 (see FIG. 5). The signal processing unit 212 is a lock-in amplifier, receives the transmission signal and the reception signal from the electromagnetic induction sensor 40, and measures the amplitude R and the phase θ of the reception signal by comparing the transmission signal with the transmission signal as a reference signal. Then, the amplitude R and the phase θ in the polar coordinate system are output as coordinate values (X, Y) in the XY coordinate system. The second correction unit 210 determines the type of the metal marker by using the locus of the coordinate values (X, Y) output by the signal processing unit 212 as the detected waveform of the metal marker 9 (see FIG. 6).

In this embodiment, the metal markers 9 are distributed in GNSS unreceivable sections where signals from GNSS satellites cannot be received. The GNSS unreceivable section is predetermined as GNSS unreceivable section data 316 . FIG. 11 is a diagram showing an example of GNSS unreceivable section data 316. As shown in FIG. According to FIG. 11, the GNSS unreceivable section data 316 stores a list of ranges for each GNSS unreceivable section.

The metal marker 9 is predetermined as metal marker data 320 . FIG. 12 is a diagram showing an example of the metal marker data 320. As shown in FIG. According to FIG. 12, the metal marker data 320 stores, for each of a plurality of types of metal markers, the type of metal marker, the detected waveform of the metal marker of the type, and the installation position of the metal marker of the type in association with each other. is doing.

The type of metal marker is determined by a combination of material, size, and shape. The material is, for example, an SPCC (Steel Plate Cold Commercial) material. The size is the size of the plate-like body, but may include the thickness. The shapes include shapes such as round, elliptical, and polygonal shapes, and surface patterns such as flat surfaces, wavy surfaces, and punched (perforated) surfaces.

A plurality of installation positions are associated with one type of metal marker. This is because the track 5 is long, and many metal markers 9 need to be installed. For example, metal markers of the same type are placed at a predetermined distance or more, or metal markers 9 are placed in the direction along the railroad in order of type. Among the plurality of installation positions associated with the markers, the installation position closest to the current travel position calculated by the travel position calculation unit 202 is determined as the installation position of the metal marker 9 detected this time.

The storage unit 300 is realized by a storage device such as a hard disk, ROM (Read Only Memory), RAM (Random Access Memory), etc., and stores programs, data, etc. for the processing unit 200 to integrally control the control device 10. In addition, it is used as a work area of 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. In this embodiment, the storage unit 300 stores a running position calculation program 302, running position data 310, calculated starting point position data 312, corrected section data 314, GNSS unreceivable section data 316, and reference image data 318. , metal marker data 320 and roadside image data 322 are stored.

[Process flow]
FIG. 13 is a flowchart for explaining the flow of travel position calculation processing performed by the control device 10 . This processing is realized by the processing unit 200 executing the traveling position calculation program 302, and is started prior to departure from the starting station, for example.

First, the processing unit 200 sets the travel position to an initial value (calculated starting point position) (step S1). Next, it is determined whether the reception (capture) of the GNSS signal by the GNSS receiver 20 is successful, and if successful (step S3: YES), the running position calculation unit 202, based on the received GNSS signal, The travel position is calculated as needed by integrating the travel distance from the calculated starting position (step S5).

Subsequently, the determination unit 206 refers to the correction section data 314 to determine whether the traveling position has entered the correction section. Then, image matching processing is performed between the image along the railway line acquired by the image acquisition unit 204 and the reference image corresponding to the correction section determined to have entered, and the timing at which the similarity satisfies the peak condition is determined (step S9). . Then, the first correction unit 208 updates the calculated starting point position with the correction position corresponding to the reference image so that the traveling position at the timing determined by the determination unit 206 becomes the corrected position (step S11).

On the other hand, if the reception (capture) of the GNSS signal has failed (step S3: NO), the processing unit 200 refers to the GNSS unreceivable section data 316 to determine whether it is within the GNSS unreceivable section. . If it is within the GNSS unreceivable section (step S13: YES), the second correction unit 210 determines whether the metal marker 9 has been detected based on whether the detection signal from the electromagnetic induction sensor 40 has changed. If the metal marker 9 is detected (step S15: YES), the type of the detected metal marker 9 is determined by referring to the metal marker data 320 based on the detected waveform, and the installation position is determined (step S17). . Then, the calculated starting position is updated with the installation position so that the traveling position at the detection timing becomes the determined installation position (step S19).

After that, it is judged whether or not this processing is to be ended by satisfying the end condition such as arrival at the terminal station. If it ends (step S21: YES), this process ends.

[Effect]
According to the on-board device 1 of the present embodiment, it is possible to accurately calculate the traveling position of the railroad vehicle 3 on-board without using dedicated equipment on the ground. In other words, the on-board device 1 calculates the traveling position of the railroad vehicle 3 as needed, compares the image along the railway during traveling with a reference image set in advance as the image along the railway at the corrected position, and obtains a predetermined image matching condition. is determined, and the travel position is corrected so that the travel position at the timing when the affirmative determination is made becomes the corrected position. The timing that satisfies the image matching condition is the timing at which the position of the railway vehicle becomes the corrected position. It is possible to calculate with high accuracy. In addition, since the comparison between the railroad image and the reference image is started when the predetermined correction section is entered, it is possible to accurately determine the timing at which the image matching condition is satisfied. As a result, it is possible to accurately calculate the running position of the railroad vehicle on the train without using dedicated equipment on the ground for correcting the running position. Therefore, it is possible to save the cost associated with dedicated facilities on the ground.

Further, when the railroad vehicle 3 travels on the track 5 on which the metal marker 9 is installed, the travel position is adjusted so that the travel position at the detection timing of the metal marker 9 by the electromagnetic induction sensor 40 is the installation position of the metal marker 9. position is corrected. This makes it possible to accurately correct the travel position. In addition, since the metal marker 9 detectable by the electromagnetic induction sensor 40 is not equipment having an electric circuit like a beacon, the cost required for installation and maintenance is low. can be significantly reduced compared to

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.

(A) Installation position of the metal marker 9 For example, the metal marker 9 may be dispersedly arranged at any installation position on the railroad 5, not limited to a section such as a tunnel section where the GNSS signal cannot be received by the GNSS receiver 20. .

DESCRIPTION OF SYMBOLS 1... On-board apparatus 10... Control apparatus 200... Processing part 202... Traveling position calculation part 204... Image acquisition part 206... Judgment part 208... 1st correction|amendment part 210... 2nd correction|amendment part 212... Signal processing part 300... Storage Part 302... Traveling position calculation program 310... Traveling position data 312... Calculation starting position data 314... Correction section data 316... GNSS unreceivable section data 318... Reference image data 320... Metal marker data 322... Alongside image data 20... GNSS reception Machine 30 Camera 40 Electromagnetic induction sensor 42 Sensor section 44 Transmission/reception amplifier section 3 Railway vehicle 5 Railroad crossing 9 Metal marker

Claims (7)

An on-board device mounted on a railway vehicle,
a traveling position calculation unit that calculates a traveling position as needed;
an image acquisition unit that acquires an image along the route while driving;
When the traveling position enters a predetermined correction section including a predetermined correction position, start comparing the image acquired by the image acquisition unit with a reference image preset as an image along the railway at the correction position. a determination unit that determines the timing at which a predetermined image matching condition is satisfied;
a first correcting unit that corrects the calculated position of the traveling position calculating unit so that the traveling position at the timing at which the judging unit makes an affirmative determination becomes the corrected position;
On-board equipment. The traveling position calculation unit calculates the traveling position at any time by integrating the traveling distance from a given calculation starting point position using the received signal received from the GNSS (Global Navigation Satellite System) satellite,
The first correction unit updates the calculated starting point position with the corrected position.
The on-vehicle device according to claim 1. The determination unit performs image matching processing for determining a degree of similarity between the image acquired by the image acquisition unit and the reference image, and sets the timing that the similarity satisfies a predetermined peak condition as the image matching condition. determine the
The on-vehicle device according to claim 1 or 2. The corrected position is a position where the road center of a railroad crossing crossing the railroad track appears in a predetermined portion of the image along the railroad track acquired by the image acquisition unit.
The on-vehicle device according to any one of claims 1 to 3. The image acquisition unit acquires a photographed image or a distance image as the image along the railway,
The on-vehicle device according to any one of claims 1 to 4. The railway vehicle runs on a railroad track on which metal markers are installed at predetermined installation positions,
an electromagnetic induction sensor capable of detecting the metal marker when passing through the installation position;
a second correction unit that corrects the calculated position of the travel position calculation unit so that the travel position at the detection timing by the electromagnetic induction sensor becomes the installation position;
The on-vehicle device according to any one of claims 1 to 5, further comprising: There are a plurality of types of the metal marker, each of which has a different material, size, or shape,
A track on which the railroad vehicle travels has a predetermined section in which the metal markers of different types are dispersedly arranged at different predetermined installation positions,
The second correction unit determines the installation position of the detected metal marker by determining the type of the metal marker based on the waveform of the metal marker detected by the electromagnetic induction sensor. correcting the calculated position of the traveling position calculation unit based on the position;
The on-vehicle device according to claim 6.

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