JPH09277928A - Obstacle detection system for railroad crossing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To directly detect if an obstacle exists or not in a railroad crossing on the train side. SOLUTION: A transmitter 1 emits pulses of radio waves 11, 12. A reflector 2 receives the radio wave 12 from the transmitter 1 diagonally crossing a railroad crossing 7 to reach it to be reflected toward a train 3 as a reflection wave 13. In the case where an obstacle is not existing in the railroad crossing 7, a receiver 4 mounted on the train 3 respectively receives the direct wave 11 emitted from the transmitter 1, and the reflection wave 13 reflected by the reflector 2. In the case where an obstacle exists in the railroad crossing 7, the radio wave 12 emitted from the transmitter 1 toward the reflector 2 is shielded, so the reflection wave 13 is not correctly received by the receiver 4 on the train 3. An obstacle detector 5 mounted on the train 3 determines if an obstacle exists or not in the railroad crossing 7 based on the direct wave 11 and the reflection wave 13 received, and generates an alarm when it is determined that the obstacle exists to inform the crew of it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a level crossing obstacle detection system, and more particularly to a level crossing obstacle detection system capable of detecting the presence or absence of an obstacle when a train approaches a level crossing.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Patent Laid-Open No. 4-314670.
In the one disclosed in the publication, an ultrasonic sensor that emits an ultrasonic wave and receives the reflected wave is installed in the vicinity of the railroad crossing, and by rotating the ultrasonic sensor, an obstacle is generated in the entire area inside the railroad crossing. Is detected.
Then, when an obstacle is detected, the operation management system or the like is notified.

As another example, JP-A-3-8768.
In the method disclosed in Japanese Patent No. 3, the infrared rays are radiated to the railroad crossing surface, the reflected light is received, the distance to the reflective surface is measured, and the presence or absence of an obstacle in the railroad crossing is determined based on the change in the measured distance. When it detects, the train signal device is controlled via a relay contact or the like.

[0004]

As described above, conventionally, information obtained by detecting an obstacle in a railroad crossing is indirectly transmitted via a cable, a relay contact, or the like, through an operation management system or a train signal device. Be reported to. For this reason, when failures occur in relays, cables, operation management systems, train traffic lights, etc., it is not possible to ensure safety by delaying or not being able to notify trains, and system reliability is reduced. 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 allowing the train side to directly detect the presence or absence of an obstacle in the railroad crossing.

[0006]

The crossing obstacle detection system of the present invention has a reflector installed on one side of a crossing for reflecting an electric wave arriving via the crossing toward an approaching train.
This reflector and a transmitter that emits pulsed radio waves toward the approaching train are installed on the other side of the railroad crossing, and the direct wave emitted from this transmitter and the reflected wave reflected by the reflector are The train side receives the signal, and the train side determines whether there is an obstacle inside 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 the railroad crossing to reflect an electric wave that has passed over the railroad crossing toward an approaching train, and the train and the train installed at the other corner of the railroad crossing. Transmission means for respectively emitting pulsed radio waves toward the reflection means, radio waves (direct waves) directly mounted on the train and radiated from the transmission means, and radio waves reflected by the reflection means (reflected waves) And a obstacle detection unit that is mounted on the train and determines the presence or absence of an obstacle in the railroad crossing based on the reception status of the direct wave and the reflected wave received by the reception unit.

[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 from the direction shown in the figure.
Shall approach. Since the same applies to the train in the opposite direction, the description will be omitted.

The transmitter 1 is installed at one corner of the railroad crossing 7. Further, the reflector 2 is installed at the diagonally forward 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 radiated toward the train 3 approaching the railroad crossing 7 and a radio wave 12 radiated toward the reflector 2.

The reflector 2 receives the radio wave 12 coming from the transmitter 1 diagonally across the railroad crossing 7 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, and the direct wave 11 and the reflected wave are received. The pulse signal Sp of 13 is output. In addition, the obstacle detector 5 uses the pulse signal Sp from the receiver 4.
Based on the above, the presence or absence of an obstacle inside the railroad crossing is determined, and when it is determined that there is an obstacle, an alarm is issued and the crew member is notified.

Next, the operation will be described.

In FIG. 1, when there is no obstacle inside 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 waves 12 emitted from the transmitter 1 toward the reflector 10
However, the receiver 4 of the train 3 cannot normally receive the reflected wave 13 because it is blocked by an obstacle or the reflection direction is displaced. Therefore, the direct wave 11 and the reflected wave 1
Based on the reception status of No. 3, the presence or absence of an obstacle inside the railroad crossing can be detected on the train side.

By the way, the reflected wave 13 is usually transmitted by the transmitter 1.
After being radiated from the direct wave 11, it is reflected by the reflector 2 and reaches the receiver 4, so that the direct wave 11 is delayed by a certain time and received at a certain pulse interval. This pulse interval is determined by the propagation paths of the direct wave and the reflected wave, that is, the installation positions 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 that is normally received is set to be constant at each railroad crossing.

The pulse detector 51 receives the pulse signal Sp output from the receiver 4 and detects the pulse interval between the direct wave and the 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
The pulse interval detected by 1 is compared with the constant 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, showing an example applicable to the case where the pulse intervals of the direct wave and the reflected wave are different at each railroad crossing.

Here, the modulator 14 is added to the level crossing transmitter 1, and the demodulation unit 41 is added to the train side receiver 4. The modulator 14 is provided to transmit the railroad crossing information to the train side by modulating the direct wave with the railroad crossing information. The demodulation unit 41 is provided to demodulate the railroad crossing information from the direct wave. The railroad crossing information is information such as a pulse interval between a direct wave and a reflected wave, which is different for each railroad crossing, and a railroad crossing identification number given in advance to each railroad crossing.

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 or not there is an obstacle inside 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 the pulse interval between the direct wave and the reflected wave. The memory 62 outputs data indicating the pulse interval between the direct wave and the reflected wave of the relevant railroad crossing according to the railroad crossing information demodulated by the demodulation unit 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 determination unit 63 determines that there is an obstacle.

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

The judging unit 63 compares the pulse interval detected by the pulse detecting unit 61 with the pulse interval output by the memory 62, and when they do not match, judges that there is an obstacle.
The alarm unit 64 issues an alarm 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 and transmitted from the transmitter 1 as crossing information, the memory 62 stores the direct wave and the reflected wave of each crossing in correspondence with the crossing identification number. The pulse interval data of is stored in advance.

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

By doing so, 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 surely detected on the side of the train approaching the railroad crossing. Reliability can be improved and safety can be ensured compared to a system that notifies trains via such as. Further, since it is only necessary to install the transmitter and the reflector at the railroad crossing, it is possible to reduce the installation cost / maintenance cost of the relay, the cable, etc. for reporting the obstacle detection result, which has been conventionally required.

[Brief description of 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 showing an example of the obstacle detector 6 shown in FIG.

[Explanation of symbols]

 1 transmitter 2 reflector 3 train 4 receiver 5,6 obstacle detector 7 railroad crossing 11 direct wave 13 reflected wave 14 modulator 51, 61 detector 52, 62 memory 53, 63 judgment unit 54, 64 alarm unit 41 demodulation Part D crossing information

Claims (5)

[Claims] 1. A reflecting means installed at one corner of a railroad crossing for reflecting an electric wave arriving passing through the railroad crossing toward an approaching train, and the train and the train installed at the other corner of the railroad crossing. Transmission means for respectively emitting pulsed radio waves toward the reflection means, radio waves (direct waves) directly mounted on the train and radiated from the transmission means, and radio waves reflected by the reflection means (reflected waves) Receiving means for receiving the respective, and an obstacle detecting means mounted on the train to determine the presence or absence of an obstacle in the railroad crossing based on the reception status of the direct wave and the reflected wave received by the receiving means. Level crossing obstacle detection system. 2. The pulse intervals of the direct wave and the reflected wave that are normally received by the receiving means are constant at all railroad crossings, and the obstacle detecting means sets the pulse intervals of the received direct wave and the reflected wave. The level crossing obstacle detection system according to claim 1, wherein the presence or absence of an obstacle is determined by comparing the predetermined pulse interval. 3. The transmitting means has a modulator for adding information regarding each railroad crossing to the radiated direct wave, and the receiver has a demodulator for demodulating the information from the received direct wave. The crossing obstacle detection system according to claim 1, wherein the obstacle detection means determines the presence or absence of an obstacle based on the pulse intervals of the direct wave and the reflected wave and the information. 4. The railroad crossing obstacle detection system according to claim 3, wherein the information is information indicating a predetermined pulse interval preset for each railroad crossing. 5. The information is a level crossing identification number that can identify a level crossing, and the obstacle detection unit stores in advance data indicating a pulse interval set for each level crossing in association with the level crossing identification number. 4. The presence or absence of an obstacle is determined by reading the data indicating the corresponding pulse interval from the memory according to the level crossing identification number demodulated by the demodulation unit. The crossing obstacle detection system described.