JPH09207783A - Railroad crossing monitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently record a monitored image at a railroad crossing in a recording medium and to eliminate a false alarm due to headlamp of a car. SOLUTION: This device is constituted to set frame picture images on a railroad crossing road 3 and its neighbourhood photographed by a TV camera after announcement of a railroad crossing closing signal of a railroad crossing safety device 1 as standard frame picture images, and when it compares the frame picture images photographed by the TV camera and the standard frame picture images with each other and detects a differential value exceeding a previously set threshold value between both of the frame picture images, to record the frame picture images of the TV camera 2 in a recording part and to output an alarm signal. The frame picture image from which the maximum differential value is detected out of the frame picture images of the TV camera 2 to be compared with the standard frame picture images is selectively recorded in the recording part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a TV camera to photograph a vehicle or a person trying to forcibly invade and cross a railroad crossing where a warning of train passage has begun at a railroad crossing.
The present invention relates to a level crossing monitoring device capable of recording.

[0002]

2. Description of the Related Art As an example of the railroad crossing monitoring device, Japanese Patent Laid-Open No.
There is one described in JP-A-2-48263. This railroad crossing monitoring device is composed of a TV camera that captures images on and near the railroad crossing, and an image processing device that processes the image captured by the TV camera. The image processing device immediately after passing the train captured by the TV camera. If you record and set the frame image of the above (it is judged that there are no obstacles immediately after passing the train) as the reference frame image, the TV that is taken from the time the train crossing barrier starts to go down until the train passes The frame image of the camera is compared with the reference frame image, and the difference value of the frame image is detected. Then, if there is a difference value exceeding a preset threshold value, the frame image is determined to be "obstacle present", and in this case, an operation confirmation signal (alarm signal) is output and a frame value exceeding the threshold value is output. The image is output to the central monitoring device or ground transmission device of the station that is monitoring the railroad crossing. The frame image output to the central monitoring device is displayed on the monitor such as the station monitoring room, and the frame image output to the ground transmission device is wirelessly transmitted to the train passing the railroad crossing to monitor the driver's seat of the train. Is displayed in.

[0003]

The level crossing monitoring device is supposed to view the frame image determined to be abnormal on the monitor of the central monitoring device or the monitor of the train.
Attempting to record and save this frame image in the level crossing monitoring device or the central monitoring device causes the following problems.

Since all frame images exceeding the threshold value are regarded as abnormal, in the frame image of the TV camera photographed 30 frames per second, hundreds or thousands of frame images are recorded with one crossing. there is a possibility. Further, since the railroad crossing operates several tens of times a day, a large-capacity recording device for recording the frame image is required, which increases the cost of the railroad crossing monitoring device and the central monitoring device. Will end up. In addition, the confirmation work of searching for a video that accurately captures an obstacle from a large number of recorded frame images becomes very troublesome, and the search efficiency is poor.

Further, the railroad crossing monitoring device is useless when the headlight of the vehicle hits the TV camera at night, the headlight may be displayed in the frame image, and an erroneous detection may occur in the comparison of the frame images in the image processing device. There are problems such as that various warnings are output, a large amount of useless frame images are recorded, and even necessary images are not recorded properly.

An object of the present invention is to solve the above-mentioned problems and to provide an inexpensive crossing road monitoring device which can always operate accurately.

[0007]

As shown in FIGS. 1 and 2, the crossing monitoring device according to claim 1 of the present invention is photographed by a TV camera 2 after the crossing closing signal of the crossing security device 1 is issued. A frame image on or near the railroad crossing 3 is set as a reference frame image, and then the frame image captured by the TV camera 2 and the reference frame image are compared with each other and preset between both frame images. In a railroad crossing monitoring device that records a frame image of the TV camera 2 in the recording unit 4 or outputs an alarm signal when a difference value exceeding a threshold is detected, the monitoring device is a TV that is compared with a reference frame image. It is provided with a still image recording function of selectively recording, in the recording unit 4, the frame image in which the maximum difference value is detected among the frame images of the camera 2.

According to the second aspect of the present invention, the railroad crossing monitoring apparatus has a date / time recording function of adding date / time / day of the week to the frame image recorded in the recording unit 4.

According to a third aspect of the present invention, the railroad crossing monitoring apparatus has a still image output function for externally outputting the frame image recorded in the recording unit 4.

In the crossing monitoring device according to claim 4 of the present invention, the TV camera 2 has an infrared illumination 5 for irradiating the photographing area with infrared rays, a filter 6 for transmitting light in the infrared region, and the same filter 6. The filter attachment / detachment device 7 that can be attached to and detached from the TV camera 2 is provided.

According to the fifth aspect of the present invention, the infrared light 5 is turned on by a crossing closing signal of the crossing security device 1.

According to a sixth aspect of the present invention, there is provided a railroad crossing monitoring device in which the infrared illumination 5 and the filter attaching / detaching device 7 are timer-controlled to operate.

According to a seventh aspect of the present invention, there is provided a railroad crossing monitoring device in which the infrared illumination 5 and the filter attaching / detaching device 7 operate under the control of an illuminance meter for measuring the brightness of the external environment.

In the crossing road monitoring device according to the eighth aspect of the present invention, two or more TV cameras 2 are arranged on both sides of the crossing road 3.

[0015]

1 and 2 show an embodiment of a railroad crossing monitoring device of the present invention. As shown in FIG. 1, a TV camera 2 (2a) and a TV camera 2 (2a) are provided on both sides of a railroad crossing 3 as shown in FIG. 2 (2
b) is installed. Each of the TV cameras 2a and 2b is designed to be able to photograph a vehicle or a person intruding into the railroad crossing 3 from approximately the front side. For example, images such as those shown in FIGS. 3 (a) to 3 (d) should be photographed. You can Each of the TV cameras 2a and 2b is equipped with an infrared light source 5 that emits infrared rays, a filter 6 that blocks the headlights of automobiles and allows infrared rays to pass through, and a filter attachment / detachment device 7 that attaches / detaches the filter 6 to / from the TV camera 2. Therefore, when each photographing area is irradiated with infrared rays, the infrared rays can be photographed through the filter 6.

Infrared illumination 5 of the TV cameras 2a and 2b
The turning on / off of and the switching operation of the filter attaching / detaching device 7 of the filter 6 are appropriately controlled by the timer 9 shown in FIG.
For example, from 7:00 am to 17:00 in the evening, the infrared illumination 5 is turned off, and the filter 6 is removed. From 17:00 in the evening to 7:00 the next morning, the infrared illumination 5 is turned on and the filter 6 is set on the lens. I am doing it. TV cameras 2a, 2b
Is capable of accurately capturing an image of a vehicle or a person passing through the level crossing 3 while avoiding the influence of the headlight of the vehicle or the like on the captured image at night when the infrared illumination 5 is turned on and the filter 6 is set. It enables you to do it.

The infrared illuminator 5 and the filter attaching / detaching device 7 may detect ambient brightness with a separately installed illuminance meter and operate based on the brightness or darkness, or the TV cameras 2a and 2b may operate. The image processing may be performed based on the check result of the change state of the brightness value of the image when the image of the captured image is processed. The change in the brightness value can be detected by the digitization processing unit 21 of the image processing circuit described later.

The TV cameras 2a and 2b start photographing upon reception of a railroad crossing closing signal issued by a railroad crossing security device (breaker) 1 provided at the railroad crossing, and stop photographing upon receiving a train passage signal thereafter. And the TV camera 2a,
The video imaged by 2b is processed by the image processing circuit shown in FIG. An example of image processing by this image processing circuit will be described in detail below.

In this image processing circuit, the TV camera 2
The video captured in (2a or 2b) is displayed in the A / D converter 2
0, converted into digital data through the digitization processing unit 21, and written in the first frame image memory 22 or the second frame image memory 23. Writing into these frame image memories 22 and 23 is controlled by a control circuit (not shown), and the frame image immediately after receiving the level crossing closing signal of the level crossing protection device 1 is recorded in the first frame image memory 22. In the frame image memory 23, a frame image input thereafter is overwritten and recorded at any time. The frame image written in the first frame image memory 22 and the second frame image
The frame images written in the frame image memory 23 are compared by the comparison unit 24, and the number of pixels having a change between the frame images is counted. In this case, a pixel having a change means a pixel having a brightness difference between the pixels and having a brightness difference exceeding a set threshold value (threshold value related to brightness). The determination unit 25 determines whether or not the counted number of pixels exceeds a threshold value (threshold value regarding the number of pixels), that is, whether or not a difference value exceeding the threshold value occurs between both frame images. If it is determined that there is a difference value that exceeds the threshold value, the frame image in the second frame image memory 23 is written in the first detected frame image memory 26a (recording unit 4). At this time, an alarm signal is output to the outside through the I / O unit 27.

The comparison between the first frame image memory 22 and the second frame image memory 23 is performed every time a frame image is overwritten and recorded in the second frame image memory 23 and exceeds the previously detected difference value at the time of comparison. When the difference value is detected, the frame image of the second frame image memory 23 at that time is overwritten and recorded in the first detected frame image memory 26a, and the image is updated. This processing is performed until the train passage signal is output (while the train is passing the railroad crossing), and the frame image having the maximum difference value is recorded in the first detection frame image memory 26a.

When the passage of the train is detected by the railroad crossing security device 1, the train passage signal is output from the device 1, the railroad crossing closing signal is issued again and the second crossing monitoring starts, and the image of FIG. In the processing circuit, the recording destination of the frame image is moved from the first detection frame image memory 26a to the second detection frame image memory 26b, and the maximum difference value detected by the second crossing crossing is detected in the second detection frame image memory 26b. The frame image of is recorded. The image processing circuit of FIG. 2 has many similar detection frame image memories 26,
Every time the railroad crossing is closed and opened, only one abnormal frame image is recorded in the detected frame image memory 26 (the frame image is not recorded unless the difference exceeding the threshold is detected even when the railroad crossing is closed). In this image processing circuit, a maximum of one frame image is recorded by opening and closing the railroad crossing once, so even if the railroad crossing opens and closes tens of times a day, for example, one month's quantile is recorded collectively. It is possible to

Further, in the image processing circuit of FIG. 2, when the frame images of the second frame image memory 2 are recorded in the detected frame image memories 26a and 25b which are the first and second, they are counted by the timer 9. The date, time, and day of the week are recorded so as to be superimposed on the frame image (date and time recording function). Further, address information and ID information for identifying the level crossing protection device 1 are also recorded in an overlapping manner.

Further, in the image processing circuit of FIG.
The frame image recorded in the detected frame image memory 26a or 25b can be output to the outside through the I / O unit 27 (still image output function), and the output image is analyzed by an image processing computer device or the like to recklessly intrude. It is possible to analyze the model number of the vehicle.

An operation example of the railway crossing monitoring device of the present invention described above will be described. 3 (a) to 3 (d) are examples of images taken by the railroad crossing monitoring device.
(E) to (g) are examples of the differences detected at that time. 1. When the railroad crossing safety device 1 outputs a railroad crossing closing signal, T
A frame image as shown in FIG. 3A is captured by the V camera 2, and the frame image is recorded in the first frame image memory 22 as a reference image.

2. The images of the TV camera 2 that are subsequently captured are sequentially overwritten in the second frame image memory 23. At this time, for example, when the image shown in FIG. 3B is recorded in the second frame image memory 23, both frame image memories 2
A difference image as shown in FIG. 3E is obtained from the frame images 2 and 23. In this case, since the difference value exceeds the set threshold value, the frame image in FIG. 3B is the first detection frame. It is recorded in the image memory 26a.

3. Subsequently, when an image as shown in FIG. 3C is photographed and the image is overwritten and recorded in the second frame image memory 23, a difference image as shown in FIG. 3F is obtained. In this case, Since the difference value exceeds the previous difference value, the image in FIG.
6a is overwritten.

4. However, subsequently, an image as shown in FIG. 3D is captured, and the image is recorded in the second frame image memory 23.
When the difference image as shown in FIG. 3 (g) is obtained by overwriting recording, the difference value does not exceed the previous difference value. Therefore, the image in FIG. 3 (d) is the first detection frame image. The memory 26a is not overwritten. As a result of the above, the first
The detection frame image memory 26a records the image of FIG. 3 (c) that best captures the reckless intruding vehicle. The alarm signal output when the difference value exceeding the threshold value is detected is stopped when the difference value falls below the threshold value.

In the railroad crossing monitoring device of the present invention, a vehicle or the like may be detected from the image of one TV camera 2, but when the TV camera 2 is attached with a small animal such as an insect or a bird, it is also traversed. In such a case, a large difference value may be detected in the frame image and false alarm may occur. Therefore, if image processing is performed by each of the two TV cameras 2a and 2b, and the abnormality is output only when both of them detect an abnormality at the same time, the two TV cameras 2a and 2b simultaneously.
Since the possibility of detecting abnormalities by small animals in b is extremely low, the number of false alarms issued is greatly reduced.

The railroad crossing monitoring device of the present invention can also be configured as follows. 1. The reference image recorded in the first frame image memory 22 of FIG. 2 is an image when a predetermined time has elapsed after the warning signal of the level crossing protection device 1 was issued. 2. It is possible to record two or three or more frame images in each of the detected frame image memories 26a and 26b, and to record several frame images having a smaller difference value than the maximum difference value. May be. 3. Instead of recording the frame image in the detected frame image memories 26a and 25b, the frame image can be recorded in various recording media such as a magnetic recording medium (hard disk or floppy disk), a flash memory card, a memory card with a backup function, or the like. When the recording medium is removable, an image can be directly taken out by a method of removing and replacing the recording medium without external output via the I / O unit 27.

[0030]

According to the railway crossing monitoring device of the present invention, the following effects can be obtained. 1. Since the frame image in which the largest difference is detected is selectively recorded, the image for identifying an obstacle can be efficiently recorded in a small-capacity memory or magnetic recording medium, which reduces the cost of the device. It becomes possible. 2. Since a large number of useless images are not recorded, it becomes easy to search for obstacles later. 3. Since the malfunction due to the influence of the light of the reckless intruding vehicle is prevented, the crossing can be reliably monitored.

[Brief description of drawings]

1A and 1B are schematic views showing an embodiment of a railroad crossing monitoring device of the present invention.

FIG. 2 is a schematic diagram showing a circuit configuration in the railroad crossing monitoring device in FIG.

3 (a) to (d) are TVs of the level crossing monitoring device of FIG.
These are different examples of frame images captured by a camera, and (e) to (g) are different examples of difference images at each stage.

[Explanation of symbols]

 1 Crossing security device 2 TV camera 3 Crossing road 4 Recording unit 5 Infrared illumination 6 Filter 7 Filter attachment / detachment device

Claims (8)

[Claims] 1. A frame image on or near a railroad crossing (3) photographed by a TV camera (2) after issuing a railroad crossing closing signal of a railroad crossing security device (1) is set as a reference frame image, and thereafter, When the frame image captured by the TV camera (2) is compared with the reference frame image and a difference value exceeding a preset threshold value is detected between the frame images, the frame image of the TV camera (2) is detected. Recording part (4)
In the railroad crossing monitoring device for recording on the screen or outputting an alarm signal, the monitoring device is the frame image in which the maximum difference value is detected among the frame images of the TV camera (2) to be compared with the reference frame image. A railway crossing monitoring device having a still image recording function of selectively recording the image in the recording unit (4). 2. The railroad crossing monitoring device according to claim 1, further comprising a date / time recording function of adding date / time / day of the week to the frame image recorded in the recording unit (4). 3. The railroad crossing monitoring device according to claim 1, further comprising a still image output function for externally outputting the frame image recorded in the recording section (4). 4. The TV camera (2) is provided with an infrared illumination (5) for irradiating the photographing area with infrared rays, a filter (6) for transmitting light in the infrared region, and the filter (6) for TV.
The crossing road monitoring device according to any one of claims 1 to 3, further comprising a filter attaching / detaching device (7) that is attachable to and detachable from the camera (2). 5. The railroad crossing monitoring device according to claim 1, wherein the infrared illumination (5) is turned on by a railroad crossing closing signal of the railroad crossing security device (1). 6. The railroad crossing monitoring device according to claim 4, wherein the infrared illumination (5) and the filter attaching / detaching device (7) are operated under timer control. 7. The railroad crossing monitoring device according to claim 4, wherein the infrared illumination (5) and the filter attaching / detaching device (7) operate under the control of an illuminance meter that measures the brightness of the external environment. 8. The railroad crossing monitoring device according to claim 1, wherein two or more TV cameras (2) are arranged on both sides of the railroad crossing (3). .