On-board signal recognition system and control method for railways

Abstract

The purpose of the present invention is to provide an onboard signal recognition system for a railway, with which stable train operation can be realized by not recognizing that there are no signals only when a traffic light temporarily cannot be captured in the field of view of a camera, while reliably recognizing that there are no signals due to all lamps of the traffic light being off.　For this purpose, an onboard signal recognition system for a railway according to the present invention is characterized by comprising a determination information output device that outputs determination information indicating that a traffic light to be recognized is outside of the field of view of an imaging device, and a signal aspect recognition device that recognizes a signal aspect of a traffic light in front of a train using the determination information. For example, in recognition of the signal aspect of the traffic light, with reference to an acceleration sensor output value, the aspect recognition process is suspended while a predetermined threshold value is exceeded, and the aspect recognition process is restarted after the acceleration sensor output value returns to a specified value or lower.

Description

Technical Field

[0001] The present invention relates to a signal recognition system and a control method for recognizing a signal indication of a signal device mounted on a train.

Background Art

[0002] In the railway field, the need for automatic train operation has been increasing. To realize a train automatic operation system for railways, a function for recognizing the signal indication of signal devices installed beside the track or the like is required. More specifically, based on information such as the position of the train itself, the installation position and type of the signal device, it is necessary to compare with an image of the signal device acquired by a camera or the like to recognize the signal indication content.

[0003] As a technique similar to such a technique for recognizing the signal indication content of a signal device, for example, there is a technique described in Japanese Patent Application Laid-Open No. 2011-201426 (Patent Document 1). This publication states that "it is characterized by including an imaging device that captures the outside of the vehicle, a GPS receiver that performs positioning by a satellite navigation system, a train position detection unit that obtains the train position based on the positioning result of the GPS receiver, a trackside installation device data storage unit that holds the device position and device image related to the trackside installation device installed along the track, and a trackside installation device detection unit that detects the approach of the train position to the device position and captures an image taken by the imaging device at different approach positions and detects the device image from the plurality of images and compares the detection results to confirm the operation of the trackside installation device" (paragraph 0008).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] [[ID=着38]] Railway signals always display some kind of signal indication. If all the lights on a signal are off, it is considered an abnormal condition called no signal, and the train must stop immediately because it is not safe to travel. In conventional signaling systems, "no signal" means that all the lights are off and the information that the signal should be displaying cannot be recognized. In systems that use camera images to recognize signal indications, if a signal that should be present cannot be found, it is natural to treat it as "no signal" because, similar to the case where all the lights are off, the information that the signal should be displaying cannot be recognized.

[0006] In automated train driving systems for railways, cameras are mounted near the driver's cab to photograph the area in front of the train's direction of travel. However, if the front of the train temporarily swings sharply to the left or right, for example when passing over a switch, the signal to be recognized may move out of the camera's field of view. If the inability to find the target signal at this time is treated as a no-signal, the train may have to stop once every time it passes a switch, disrupting stable train operation. On the other hand, if a signal with all its lights off cannot be correctly recognized as a no-signal, the same level of safe operation as before cannot be achieved.

[0007] Patent Document 1 concerns monitoring the operating status of railway line equipment. Patent Document 1 does not address the above-mentioned problem, namely how to perform recognition processing when a signal is temporarily unable to be captured in the camera's field of view, even though it can reliably recognize a signal with all lamps turned off as having no signal.

[0008] Therefore, the present invention aims to provide an on-board signal recognition system for railways that can ensure stable train operation by reliably recognizing no signal due to all signal lamps being turned off, while not recognizing it as no signal only when the signal cannot be temporarily captured in the camera's field of view. [Means for solving the problem]

[0009] To solve the above problems, one representative example of the present invention is a railway on-board signal recognition system characterized by comprising: a determination information output device that outputs determination information indicating that the signal to be recognized is out of the field of view of the camera device; and a signal indication recognition device that uses the determination information to recognize the signal indication of the signal in front of the train. For example, when recognizing the signal indication of a signal, the system refers to the output value of an acceleration sensor, suspends the indication recognition process while it exceeds a predetermined threshold, and resumes the indication recognition process after the acceleration sensor output value returns to below a specified value. [Effects of the Invention]

[0010] According to the present invention, when performing signal indication recognition using camera images, even if the front of the train swings sharply to the left or right when passing through a switch, causing the signal to be recognized to temporarily move out of the camera's field of view, it is possible to detect that the signal has temporarily moved out of the camera's field of view by referring to the acceleration sensor output value. As long as the acceleration sensor output value exceeds a predetermined threshold, the signal indication recognition process can be suspended, and when it falls below the threshold, the signal indication recognition process can be resumed. This makes it possible to achieve both signalless recognition by turning off all lamps, as in conventional signal systems, and stable train operation by not recognizing cases where the signal temporarily moves out of the camera's field of view as signalless. Other issues, configurations, and effects not mentioned above will be clarified by the following description of the embodiments. [Brief explanation of the drawing]

[0011] [Figure 1] This figure shows a first embodiment of the present invention. [Figure 2] This is an example of the time progression of acceleration sensor output when passing through a switch. [Figure 3] This figure shows a second embodiment of the present invention. [Figure 4] This figure shows a third embodiment of the present invention. [Figure 5] This figure shows a fourth embodiment of the present invention. [Figure 6]This is an example of the angle at which the signal light is visible relative to the central axis of the shooting area of ​​the shooting device 1100 when passing a turnout. [Modes for carrying out the invention]

[0012] The following examples will be described with reference to the drawings. [Example 1] Figure 1 shows a first embodiment of the present invention. In this embodiment, the on-board signal recognition system 1000 according to the present invention comprises a camera 1100, an on-board database device 1200, a train position detection device 1300, a judgment information output device 1400, an acceleration sensor 1600, and a signal indication recognition device 1500, and is mounted on a train.

[0013] The camera 1100 captures images of the area ahead using an optical camera mounted on the train and outputs the captured images. The onboard database device 1200 stores and outputs information about the location and type of signal lights (signal information). The train position detection device 1300 detects and outputs the current position of the train (train position). The acceleration sensor 1600 outputs the acceleration of the camera 1100. Specifically, it outputs acceleration in the lateral direction relative to the direction of train travel (horizontal direction relative to the ground). The judgment information output device 1400 uses the output value of the acceleration sensor 1600 to determine if the front of the train is temporarily swinging to the left or right when passing a switch, and outputs judgment information if it determines that the signal light to be recognized is outside the field of view of the camera 1100.

[0014] The signal indication recognition device 1500 uses the captured image output by the camera 1100, the installation location and signal information of the signal to be recognized output by the onboard database device 1200, the train position output by the train position detection device 1300, and the judgment information output by the judgment information output device 1400 to perform signal indication recognition processing on the signal in front of the train and output the result.

[0015] When all the lamps of the traffic signal to be recognized are turned off and when the traffic signal corresponding to the traffic signal to be recognized cannot be recognized from the captured image, the signal display recognition device 1500 determines that there is no signal. However, while the determination information is being output, even if the traffic signal to be recognized cannot be recognized from the captured image, it does not determine that there is no signal.

[0016] In this case, the signal display recognition device 1500 may hold the signal recognition result before the determination information is output and output the same signal recognition result while the determination information is being output, or may output that the signal recognition process is interrupted as the signal recognition result. If it is held, the display recognition process can be easily resumed, and if it is interrupted, the handling during that period can be separately determined. Which is more desirable depends on the specifications of other devices (not mentioned in this specification) that receive the signal recognition result of the signal display recognition device 1500. As described above, in this embodiment, a control method including a step of outputting determination information from the determination information output device and a step of performing signal display recognition of the traffic signal in front of the train using the determination information is executed on the vehicle, thereby ensuring stable and safe operation of the train.

[0017] FIG. 2 shows an example of the passage of time of the acceleration sensor output when passing through a splitter. In this figure, the horizontal axis represents the elapsed time, and the vertical axis represents the lateral acceleration of the imaging device 1100. The upper side of the vertical axis indicates that, for example, acceleration is applied to the left side with respect to the train traveling direction, and the lower side of the vertical axis indicates that acceleration is applied to the right side.

[0018] Assume that at time T0, it enters the splitter and then enters the left - hand track. The imaging device 1100 is temporarily subject to a large acceleration to the left, and then, after swaying back, is temporarily subject to an acceleration to the opposite right - hand side after time T1, and when it passes through the splitter at time T2, the lateral acceleration becomes almost 0. At this time, in the T0 - T1 period, it can be judged from the acceleration that the imaging device 1100 is temporarily swung largely to the left. A threshold value Th21 for the signal being out of the imaging field of view is determined in advance, and when the acceleration exceeds Th21, determination information is output. Similarly, in the T1 - T2 period, a threshold value Th22 is determined, and when the acceleration exceeds Th22, determination information is output.

[0019] As shown in FIGS. 1 and 2, when performing signal indication recognition, by performing recognition processing including determination information, a on - vehicle signal recognition system for railways can be provided that can realize stable train operation without treating it as a non - signal even when it cannot be recognized temporarily from the captured image.

[0020] [Embodiment 2] FIG. 3 is a diagram showing a second embodiment of the present invention. In this embodiment, an illuminance sensor 3600 measures the brightness outside the train and outputs it to a determination information output device 3400. The determination information output device 3400 detects that the train has entered or exited the tunnel from the change in illuminance (bright → dark, dark → bright) and outputs determination information for a predetermined time. Since the other configurations are the same as those in Embodiment 1, the description is omitted.

[0021] As the illuminance changes, when an optical camera is used as the imaging device 1100 and automatic exposure control is performed, it takes time for the camera to follow the change in brightness, so there is a period when the exposure is temporarily excessive or insufficient and the signal cannot be recognized from the captured image. Therefore, the use of determination information suppresses the signal indication recognition device 1500 from recognizing it as a non - signal. For example, when the change amount of illuminance exceeds a predetermined threshold value, the determination information output device outputs determination information. Thereby, a on - vehicle signal recognition system for railways can be provided that can realize stable train operation without treating it as a non - signal even when the signal cannot be recognized temporarily after passing through the entrance and exit of the tunnel.

[0022] [Example 3] Figure 4 shows a third embodiment of the present invention. In this embodiment, in addition to the location of signal lights and signal light information, the onboard database 4200 stores and outputs exclusion section information indicating that in certain sections, the camera 1100 has difficulty photographing the signal lights due to, for example, structures or trees beside the tracks. The judgment information output device 4400 uses the exclusion section information output by the onboard database device 4200 and the train position output by the train position detection device 1300 to detect that the train is currently located within the section indicated by the exclusion section information and outputs judgment information. The other configurations are the same as in embodiments 1 and 2, so their explanation is omitted.

[0023] The signal indication recognition device 1500 can provide a railway on-board signal recognition system that enables stable train operation without signal loss even when part or all of the signal is obscured by structures or trees beside the tracks and the camera device 1100 cannot photograph the signal, by performing signal recognition processing using the judgment information. The excluded section information can also be used when the camera device 1100 cannot photograph the signal due to curved sections or the gradient of the tracks.

[0024] [Example 4] Figure 5 shows a fourth embodiment of the present invention. In this embodiment, the onboard database device 1200 outputs the signal installation location, and the train position detection device 1300 outputs the train position to the judgment information output device 5400. The judgment information output device 5400 estimates the direction of the train from the latest value of the train position and the value from one cycle ago, and outputs judgment information if the signal cannot be photographed by the photography device 1100 based on the signal installation location, the current train position, and the estimated train direction. The rest of the configuration is the same as in embodiments 1 to 3, so the explanation is omitted.

[0025] The signal indication recognition device 1500 can provide a railway on-board signal recognition system that enables stable train operation without signal loss by performing signal recognition processing using judgment information, even when the camera device 1100 is temporarily unable to photograph the signal, such as when passing through a turnout or traveling on a curved section.

[0026] Figure 6 shows an example of the angle at which the signal is visible relative to the central axis of the camera's field of view when passing a switch. In this figure, the horizontal axis represents elapsed time, and the vertical axis represents the angle at which the signal is visible relative to an axis extended vertically forward from the center of the camera's field of view. The upper part of the vertical axis represents, for example, the signal being visible to the left of the train's direction of travel and its estimated angle, while the lower part of the vertical axis represents the signal being visible to the right and its estimated angle.

[0027] For example, if a train enters a switch at time T0 and then enters the left-hand track, the camera 1100 will temporarily face left from T0 onwards, then, due to a reversal, face right from time T1 onwards, and when it passes the switch at time T2, it will be facing almost the direction of the signal. In this way, the orientation of the camera 1100 changes over time. At this time, it can be determined from the estimated angle that the camera 1100 is temporarily swung significantly to the left in the T0-T1 section, and a threshold Th61 is predetermined at which the signal goes out of the field of view. If the estimated angle exceeds Th61, judgment information is output. Similarly, in the T1-T2 section, a threshold Th62 is predetermined, and if the estimated angular acceleration exceeds Th62, judgment information is output.

[0028] As shown in Figures 5 and 6, by including judgment information in the recognition process when recognizing signal indications, it is possible to provide an on-board signal recognition device for railways that can ensure stable train operation without signal loss even when recognition is temporarily impossible from the captured image.

[0029] It should be noted that the present invention is not limited to the embodiments described above, and various modifications are included. The embodiments described above are explained in detail to make the present invention easier to understand, and are not necessarily limited to those having all the configurations described. Furthermore, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. In addition, it is possible to add, delete, or replace parts of the configuration of each embodiment with other configurations. In the embodiments described above, the imaging device 1100 can be an optical camera in the visible light range, a non-visible light range (e.g., an infrared camera), or a combination thereof.

[0030] The following describes, but is not limited to, embodiments that may constitute the present invention. (Aspect 1) A determination information output device outputs determination information indicating that the traffic light to be recognized is outside the field of view of the imaging device (1100), A signal indication recognition device (1500) that uses the aforementioned determination information to recognize the signal indication of the signal light in front of the train, A railway-use onboard signal recognition system characterized by comprising the following features. (Aspect 2) The on-board signal recognition system for railways described in Embodiment 1 is The system includes an acceleration sensor (1600) for measuring the acceleration of the aforementioned imaging device (1100), A railway onboard signal recognition system characterized in that when the output value of the acceleration sensor exceeds a predetermined threshold, the judgment information output device (1400) outputs judgment information. (Aspect 3) The on-board signal recognition system for railways described in embodiment 1 or 2 is: The train is equipped with an illuminance sensor (3600) that measures the brightness outside the train, A railway onboard signal recognition system characterized in that when the amount of change in the output value of the illuminance sensor exceeds a predetermined threshold, the judgment information output device (3400) outputs judgment information. (Aspect 4) The on-board signal recognition system for railways described in any one of embodiments 1 to 3 is: The system includes an on-board database device (4200) that stores exclusion section information indicating that the section in which the signal to be recognized is not within the field of view of the camera, and a train position detection device (1300), The above-mentioned judgment information output device (4400) is characterized in that it outputs judgment information using the excluded section information and the train position output by the train position detection device, and is an on-board signal recognition system for railways. (Aspect 5) The on-board signal recognition system for railways described in any one of the embodiments 1 to 4 is: Equipped with an onboard database device (1200) and a train position detection device (1300), The above-mentioned judgment information output device (5400) is characterized in that it outputs judgment information using the signal installation location output by the on-board database device and the train position output by the train position detection device, and is an on-board signal recognition system for railways. (Aspect 6) In a railway on-board signal recognition system described in any one of embodiments 1 to 5, The above-mentioned signal indication recognition device (1500) is characterized in that it interrupts the signal recognition process while the determination information is being output, making it an on-board signal recognition system for railways. (Aspect 7) In a railway on-board signal recognition system described in any one of embodiments 1 to 5, The signal indication recognition device (1500) is characterized in that, while the judgment information is being output, it retains and continues to output the signal recognition result from before the judgment information was output. This is an on-board signal recognition system for railways. (Pattern 8) In a railway on-board signal recognition system described in any one of embodiments 1 to 5, The above-mentioned signal indication recognition device (1500) is characterized in that it interrupts the signal recognition process while the determination information is being output and resumes the signal recognition process after the determination information is no longer being output. (Aspect 9) In a railway on-board signal recognition system described in any one of embodiments 1 to 5, The above-mentioned signal indication recognition device (1500) is characterized in that it interrupts the signal recognition process when the judgment information is output and resumes the signal recognition process after a predetermined interruption time has elapsed. (Aspect 10) The process involves outputting determination information from a determination information output device indicating that the traffic light to be recognized is outside the field of view of the imaging device (1100), and The process involves using the aforementioned determination information to recognize the signal indication of the signal light in front of the train using a signal indication recognition device (1500), A railway-use onboard signal recognition and control method characterized by including the following: (Aspect 11) In the on-board signal recognition control method for railways described in Embodiment 10, A railway-based onboard signal recognition control method characterized in that the determination information is output when the acceleration of the aforementioned imaging device exceeds a predetermined threshold. (Aspect 12) In the on-board signal recognition control method for railways described in embodiment 10 or 11, A railway onboard signal recognition control method characterized in that the determination information is output when the amount of change in the illuminance outside the train exceeds a predetermined threshold. (Aspect 13) In the on-board signal recognition and control method for railways described in any one of embodiments 10 to 12, A railway onboard signal recognition control method characterized by outputting exclusion section information indicating that the section in which the signal to be recognized is not within the field of view of the camera, and the determination information based on the train position. (Aspect 14) In the on-board signal recognition control method for railways described in any one of embodiments 10 to 13, A railway onboard signal recognition control method characterized in that the aforementioned determination information is output based on the location of the signal and the position of the train. (Aspect 15) In the on-board signal recognition control method for railways described in any one of embodiments 10 to 14, A railway-based onboard signal recognition control method characterized by interrupting the signal recognition process while the aforementioned determination information is being output. (Aspect 16) In the on-board signal recognition control method for railways described in any one of embodiments 10 to 14, A railway onboard signal recognition control method characterized in that, while the aforementioned determination information is being output, the signal recognition result from before the output of the determination information is retained and continues to be output. (Aspect 17) In the on-board signal recognition control method for railways described in any one of embodiments 10 to 14, A railway onboard signal recognition control method characterized by interrupting the signal recognition process while the aforementioned determination information is being output, and resuming the signal recognition process after the determination information is no longer being output. (Aspect 18) In the on-board signal recognition control method for railways described in any one of embodiments 10 to 14, A railway onboard signal recognition control method characterized by interrupting the signal recognition process when the aforementioned determination information is output, and resuming the signal recognition process after a predetermined interruption period has elapsed. [Explanation of Symbols]

[0031] 1000...On-board signal recognition system, 1100...Photography device, 1200, 4200...On-board database device, 1300...Train position detection device, 1400, 3400, 4400, 5400...Decision information output device, 1500...Signal indication recognition device, 1600...Accelerometer, 3600...Illuminance sensor

Claims

1. A determination information output device outputs determination information indicating that the traffic light to be recognized is temporarily out of the field of view of the imaging device (1100), A signal indication recognition device (1500) that uses the aforementioned determination information to recognize the signal indication of a signal light in front of the train, A railway-use onboard signal recognition system characterized by comprising the following features.

2. The on-board signal recognition system for railways described in claim 1 is: The system includes an acceleration sensor (1600) for measuring the acceleration of the aforementioned imaging device (1100), A railway onboard signal recognition system characterized in that when the output value of the acceleration sensor exceeds a predetermined threshold, the judgment information output device (1400) outputs judgment information.

3. (delete)

4. The on-board signal recognition system for railways described in claim 1 is: The system includes an on-board database device (4200) that stores exclusion section information indicating that the signal to be recognized is in a section not within the field of view of the camera, and a train position detection device (1300), The above-mentioned judgment information output device (4400) is characterized in that it outputs judgment information using the excluded section information and the train position output by the train position detection device, and is an on-board signal recognition system for railways.

5. The on-board signal recognition system for railways described in claim 1 is: The vehicle is equipped with an onboard database device (1200) and a train position detection device (1300), The above-mentioned determination information output device (5400) is characterized in that it outputs determination information using the signal installation location output by the on-board database device and the train position output by the train position detection device, and is an on-board signal recognition system for railways.

6. In the on-board signal recognition system for railways according to any one of claims 1, 2, 4, or 5, The above-mentioned signal indication recognition device (1500) is characterized in that it interrupts the signal recognition process while the determination information is being output. This is an on-board signal recognition system for railways.

7. In the on-board signal recognition system for railways according to any one of claims 1, 2, 4, or 5, The signal indication recognition device (1500) is characterized in that, while the determination information is being output, it retains and continues to output the signal recognition result from before the determination information was output. This is an on-board signal recognition system for railways.

8. In the on-board signal recognition system for railways according to any one of claims 1, 2, 4, or 5, The above-mentioned signal indication recognition device (1500) is characterized in that it interrupts the signal recognition process while the determination information is being output and resumes the signal recognition process after the determination information is no longer being output.

9. In the on-board signal recognition system for railways according to any one of claims 1, 2, 4, or 5, The above-mentioned signal indication recognition device (1500) is characterized in that it interrupts the signal recognition process when the determination information is output and resumes the signal recognition process after a predetermined interruption time has elapsed.

10. The process involves outputting determination information from a determination information output device indicating that the traffic light to be recognized is temporarily out of the field of view of the imaging device (1100), and The process involves using the aforementioned determination information to recognize the signal indication of the signal light in front of the train using a signal indication recognition device (1500), A railway-use onboard signal recognition and control method characterized by including the following:

11. In the on-board signal recognition control method for railways described in claim 10, A railway-based onboard signal recognition control method characterized in that the determination information is output when the acceleration of the aforementioned imaging device exceeds a predetermined threshold.

12. (delete)

13. In the on-board signal recognition control method for railways described in claim 10, A railway onboard signal recognition control method characterized by outputting exclusion section information indicating that the section in which the signal to be recognized is not within the field of view of the camera, and the determination information based on the train position.

14. In the on-board signal recognition control method for railways described in claim 10, A railway onboard signal recognition control method characterized in that the aforementioned determination information is output based on the location of the signal and the position of the train.

15. A determination information output device outputs determination information indicating that the traffic light to be recognized is temporarily out of the field of view of the imaging device (1100), The system includes a signal indication recognition device (1500) that uses the aforementioned determination information to recognize the signal indication of a signal light in front of the train, The above-mentioned signal indication recognition device is characterized in that it does not recognize the signal as having no signal while the determination information is being output. This is an on-board signal recognition system for railways.

16. The process involves outputting determination information from a determination information output device indicating that the traffic light to be recognized is temporarily out of the field of view of the imaging device (1100), and The process includes using the aforementioned determination information to recognize the signal indication of the signal in front of the train using a signal indication recognition device (1500), The above-mentioned signal indication recognition device is characterized in that it does not recognize the signal as having no signal while the determination information is being output. This is a railway onboard signal recognition control method.

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