JP2845801B2 - Railroad crossing obstacle detection system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a railroad crossing obstacle detection system, and more particularly to a railroad crossing obstacle detection system capable of detecting the presence or absence of an obstacle when a train approaches a railroad crossing.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Unexamined Patent Publication No.
In the technology disclosed in Japanese Patent Laid-Open No. H10-209, an ultrasonic sensor that emits an ultrasonic wave and receives its reflected wave is installed near a railroad crossing, and by rotating this ultrasonic sensor, obstacles are observed in the entire area within the railroad crossing. Can be detected.
When an obstacle is detected, a notification is sent to an operation management system or the like.

[0003] As another example, Japanese Patent Application Laid-Open No. 3-87768 is disclosed.
No. 3 discloses an infrared ray emitted to a level crossing, receives reflected light, measures the distance to the reflecting surface, determines the presence or absence of an obstacle in the level crossing based on a change in the measured distance, and detects an obstacle. Is detected, the train signal is controlled via a relay contact or the like.

[0004]

As described above, conventionally, information on detecting an obstacle in a railroad crossing is indirectly transmitted through a cable, a relay contact, or the like, and indirectly through an operation management system or a train signal. Will be notified. For this reason, when a failure occurs in relays, cables, operation management systems, train signals, etc., it is impossible to ensure safety because the notification to the train is delayed or impossible, reducing the reliability of the system. There is a problem.

An object of the present invention is to provide a railroad crossing obstacle detection system capable of improving the reliability of the system by enabling the train to directly detect the presence or absence of an obstacle in the railroad crossing.

[0006]

According to the railroad crossing obstacle detection system of the present invention, a reflector for reflecting a radio wave arriving via a railroad crossing toward an approaching train is installed on one side of the railroad crossing.
This reflector and a transmitter that radiates pulsed radio waves toward the approaching train are installed on the other side of the railroad crossing, and the direct wave directly radiated from this transmitter and the reflected wave reflected by the reflector are reflected The train side determines whether there is an obstacle in the railroad crossing based on the reception status of the received direct wave and reflected wave. Specifically, a reflecting means installed at one corner of a railroad crossing and reflecting radio waves arriving after passing over the railroad crossing toward an approaching train, and the train and the Transmitting means for radiating pulsed radio waves toward the reflecting means; radio waves (direct waves) mounted on the train and directly radiating from the transmitting means; and radio waves (reflected waves) reflected by the reflecting means And an obstacle detecting means for determining the presence or absence of an obstacle in the railroad crossing based on the reception status of the direct wave and the reflected wave which are mounted on the train and received by the receiving means.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention. Here, the train 3 crosses the railroad crossing 7 from the illustrated direction.
Shall approach. The same applies to a train in the opposite direction, and a description thereof will be omitted.

The transmitter 1 is installed at one corner of the railroad crossing 7. The reflector 2 is installed at the oblique front corner on the other side of the railroad crossing 7. Further, the train 3 is equipped with a receiver 4 and an obstacle detector 5.

The transmitter 1 radiates pulsed radio waves in two directions. That is, a radio wave (hereinafter, referred to as a direct wave) 11 radiating toward the train 3 approaching the railroad crossing 7 and a radio wave 12 radiating toward the reflector 2.

The reflector 2 receives a radio wave 12 arriving obliquely across the railroad crossing 7 from the transmitter 1 and reflects it as a reflected wave 13 toward the train 3 approaching the railroad crossing.

The receiver 4 mounted on the train 3 receives the direct wave 11 from the transmitter 1 installed at the railroad crossing and the reflected wave 13 reflected by the reflector 2, respectively. Thirteen pulse signals Sp are output. The obstacle detector 5 outputs the pulse signal Sp from the receiver 4.
The presence or absence of an obstacle in the railroad crossing is determined based on the above, and when it is determined that there is an obstacle, a warning is issued and the crew is notified.

Next, the operation will be described.

In FIG. 1, when there is no obstacle in the railroad crossing, the receiver 4 mounted on the train 3 can receive the direct wave 11 and the reflected wave 13 when approaching the railroad crossing 7, respectively. However, if there is an obstacle inside the railroad crossing,
Radio wave 12 radiated from transmitter 1 toward reflector 10
However, the receiver 4 of the train 3 cannot normally receive the reflected wave 13 because the obstacle 4 is blocked by the obstacle or the reflection direction is shifted. Therefore, the direct wave 11 and the reflected wave 1
The presence or absence of an obstacle in the railroad crossing can be detected on the train side based on the reception status of No. 3.

By the way, the reflected wave 13 is usually
Since radio waves to reach the receiver 4 is reflected by the reflector 2 after being periodically radiated from heat of the reflected wave 13
Who播経path is longer than the propagation path of the direct wave 11 is received by the delay a predetermined time than the direct wave 11. This reflection
The delay time of the wave from the direct wave, that is, the direct wave and the reflected wave
Pulse interval between the propagation path of the direct wave and the reflected wave, i.e., determined by the installation position of the transmitter 1 and the reflector 2.

FIG. 2 is a block diagram showing an example of the obstacle detector 5.

Here, it is assumed that the pulse interval between the direct wave and the reflected wave, which is normally received, is set to be constant at each level crossing.

The pulse detector 51 receives the pulse signal Sp output from the receiver 4 and detects a pulse interval between a direct wave and a reflected wave. The timer 52 outputs a constant pulse interval between the direct wave and the reflected wave. The determination unit 53 includes the pulse detection unit 5
1 is compared with a fixed pulse interval output by the timer 52, and when they do not match, it is determined that there is an obstacle. The alarm unit 54 issues an alarm when the determination unit 53 determines that there is an obstacle.

FIG. 3 is a block diagram showing another embodiment of the present invention, and shows an example which can be applied to a case where the pulse interval between the direct wave and the reflected wave differs at each railroad crossing.

Here, a modulator 14 is added to the transmitter 1 at the railroad crossing, and a demodulator 41 is added to the receiver 4 on the train side. The modulation unit 14 is provided to transmit the level crossing information to the train side by modulating the direct wave with the level crossing information. The demodulation unit 41 is provided to demodulate level crossing information from a direct wave. Note that the railroad crossing information is information such as a pulse interval between a direct wave and a reflected wave that differs for each railroad crossing, a railroad crossing identification number assigned to each railroad crossing in advance, and the like.

The obstacle detector 6 receives the pulse signal Sp output from the receiver 4 and the railroad crossing information output from the demodulator 41, and determines whether there is an obstacle in the railroad crossing.

FIG. 4 is a block diagram showing an example of the obstacle detector 6.

The pulse detector 61 receives the pulse signal Sp output from the receiver 4 and detects a pulse interval between a direct wave and a reflected wave. The memory 62 outputs data indicating a pulse interval between a direct wave and a reflected wave of the corresponding railroad crossing according to the railroad crossing information demodulated by the demodulator 41. The determination unit 63 compares the pulse interval detected by the pulse detection unit 61 with the pulse interval output by the memory 62, and determines that there is an obstacle when they do not match. The alarm unit 64 issues an alarm when the determining unit 63 determines that there is an obstacle.

When data D indicating a pulse interval between a direct wave and a reflected wave is added to the direct wave 11 and transmitted as railroad crossing information, the demodulation unit 41 of the train transmits the direct wave and the reflected wave of the approaching railroad crossing. Is demodulated from the direct wave and output to the memory 62. The memory 62 holds the data D indicating the pulse interval and outputs the data D to the determination unit 63.

The judging section 63 compares the pulse interval detected by the pulse detecting section 61 with the pulse interval output from the memory 62, and judges that there is an obstacle when they do not match.
The warning unit 64 issues a warning and notifies the crew when the determination unit 63 determines that there is an obstacle.

When the crossing identification number D is added to the direct wave 11 as the level crossing information and transmitted from the transmitter 1, the memory 62 stores the direct wave and the reflected wave of each level crossing in correspondence with the level crossing identification number. Is stored in advance in advance.

In this case, the train demodulation section 41 demodulates the railroad crossing identification number D and outputs it to the memory 62. Memory 62
Outputs the pulse interval data of the railroad crossing corresponding to the railroad crossing identification number D to the determination unit 63. The determination unit 63 includes the detection unit 6
1 is compared with the pulse interval output from the memory 62, and when they do not match, it is determined that there is an obstacle.

In this way, even if the pulse interval between the direct wave and the reflected wave differs at each railroad crossing, the presence or absence of an obstacle can be directly recognized on the train side.

[0029]

As described above, according to the present invention, the presence or absence of an obstacle in a railroad crossing can be directly and reliably detected on the side of the train approaching the railroad crossing. Reliability can be improved and safety can be ensured as compared to a system in which a train is notified via the like. In addition, since it is only necessary to install the transmitter and the reflector at the railroad crossing, it is possible to reduce the cost of arranging and maintaining relays and cables for notifying the result of obstacle detection, which is conventionally required.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram showing an example of an obstacle detector 5 shown in FIG.

FIG. 3 is a block diagram showing another embodiment of the present invention.

FIG. 4 is a block diagram illustrating an example of an obstacle detector 6 illustrated in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transmitter 2 Reflector 3 Train 4 Receiver 5, 6 Obstacle detector 7 Railroad crossing 11 Direct wave 13 Reflected wave 14 Modulation unit 51, 61 Detection unit 52, 62 Memory 53, 63 Judgment unit 54, 64 Alarm unit 41 Demodulation Part D railroad crossing information

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B61L 29/00

Claims (4)

(57) [Claims] 1. A reflecting means installed at one corner of a railroad crossing to reflect a radio wave arriving after passing on the railroad crossing toward an approaching train, and the reflecting means installed at the other side corner of the railroad crossing, and Transmitting means for periodically radiating pulsed radio waves toward the reflecting means; radio waves (direct waves) mounted on the train and directly radiating from the transmitting means; and radio waves reflected by the reflecting means (direct waves) Receiving means for receiving the reflected wave), and obstacle detecting means for determining the presence or absence of an obstacle in the railroad crossing based on the reception state of the direct wave and the reflected wave received by the receiving means mounted on the train. A level crossing obstacle detection system comprising: 2. The reflection normally received by said receiving means.
Wave delay for direct waves is constant at all railroad crossings
And the obstacle detection means delays the reflected wave received by the reception means with respect to the direct wave.
When certain delay preset in the all crossing the extending time
The railroad crossing obstacle detection system according to claim 1, wherein the presence / absence of an obstacle is determined by comparing the distance between the two . 3. The transmission means according to claim 1, wherein said transmitting means is configured to delay the reflected direct wave with respect to the direct wave to be radiated with respect to the direct wave.
A modulating unit that adds information indicating time, the receiving unit includes a demodulating unit that demodulates the information from the received direct wave, and the obstacle detecting unit receives the information by the receiving unit.
And said information and the delay time for the direct wave of the signal has been reflected wave
The obstacle detection system according to claim 1, wherein the presence or absence of an obstacle is determined by comparing the two . 4. The transmitting means according to claim 1 , further comprising:
Modulation that adds a preset railroad crossing identification number for each railroad crossing
And the obstacle detection means is preset for each level crossing.
The delay time data of the reflected wave
Has a memory that is stored in advance in association with the
And the railroad crossing identification number demodulated by the demodulation unit
Read the corresponding delay time data from the memory
For the direct wave of the reflected wave received by the receiving means
The level crossing obstacle detection system according to claim 1 , wherein the presence / absence of an obstacle is determined by comparing with a delay time .