JP2826500B2 - Train station radio system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a train radio system in a station yard, and more particularly, to a train approaching a station, transmitting information indicating the status of the station yard, for example, an image signal of a platform, and receiving it on the train side. And a train radio system in a station premises where safety can be confirmed.

[0002]

2. Description of the Related Art As shown in FIG. 2, for example, a conventional station radio system in a station yard always transmits a platform image signal S1 transmitted from a surveillance camera (not shown) to the inside of the station with a small amount of electric power. A transmitting device 3 is installed, while a receiving device 4 for receiving and displaying an image signal from the transmitting device 3 is installed on the train side.

The receiving device 4 receives and demodulates a radio wave from the transmitting device 3 and outputs an image signal S1. The receiving portion 41 outputs a signal S3 indicating a receiving level. It has a reception squelch unit 42 for turning on / off the switch and a monitor 43 for receiving the image signal S1 and displaying the image.

Here, the reception squelch unit 42 turns on a switch when the reception level is equal to or higher than a predetermined value, and monitors the image signal S1 output from the reception unit 42 on the monitor 43.
Send to The train crew monitors the screen of the monitor 43 to confirm the safety of the platform. Since the reception level decreases as the train moves away from the station, the reception squelch unit 42 turns off the switch when the reception level falls below a predetermined value, and automatically turns off the monitor screen display. To

[0005]

In the above-mentioned conventional station radio system, the monitor display is turned on / off by squelch operating according to the reception level. However, due to the effects of fading due to multipath caused by the antenna's directional characteristics and installation environment, the squelch operation time, that is, the distance from the station premises where communication is possible to the train fluctuates, and appropriate timing Cannot confirm the safety of the platform. Further, since the transmitting device in the station premises always emits radio waves, there is a problem that interference with other radio waves occurs.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a train station radio system in which communication with the station premises can be performed stably at a constant and appropriate timing and the occurrence of radio interference can be reduced. .

[0007]

In the station radio system according to the present invention, the transmission device in the station premises starts transmitting when the train approaches within a predetermined distance, and when the train leaves outside the predetermined distance. It is configured to stop transmission. Specifically, in a station premises train radio system that receives a signal from a transmission device installed in a station yard by a reception device installed in a train, the transmission device is configured such that the train is located within a certain distance. A train position detecting means for outputting a detection signal when the vehicle is present, a transmitting means for transmitting information indicating the situation in the station yard, and turning on / off the transmission of the transmitting means according to the detection signal.
Transmission control means for performing the operation.

[0008]

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 transmitting device 1 installed inside the station yard
Transmits information indicating the situation in the station yard, for example, a platform image signal S1 output by a surveillance camera (not shown) with a small amount of power via an antenna when the train approaches the station yard. On the other hand, the receiving device 2 installed on the train side
Receives the image signal transmitted by the transmission device 1 and displays the image.

The transmitting device 1 measures a distance to a train and outputs distance data D1.
And a train detection unit 12 that detects that the train is located within a certain distance and outputs a detection signal S2 by comparing the distance data D1 with preset setting data D2, and an image signal A transmitting unit 13 that modulates a carrier by S1 and outputs a transmission output signal S0 of a very small power, and turns on / off a transmission output signal S0 of the transmission unit 13 according to a detection signal S2.
And a transmission control unit 14 that performs FF.

The transmission control unit 14 is turned on when the train is located within a predetermined distance, sends out a transmission output signal S0 to the antenna, and when the train is located outside the predetermined distance. The transmission is turned off to stop the transmission. The distance measuring unit 11 is configured to measure a distance by a radio wave or a reflected wave of a sound wave which is hardly affected by rainfall. The value of the setting data D2 to be input to the train detection unit 12 is such that the train crew can confirm the safety of the station premises and operate safely, and the train receiving device 2 can stably and reliably receive radio waves from the transmitting device 1. Set so that the train position can be received.

On the other hand, the receiving device 2 receives and demodulates a radio wave from the transmitting device 1 and outputs an image signal S1.
And a monitor 22 that receives the image signal S1 output by the receiving unit 21 and displays an image.

With this configuration, the transmission device installed in the station premises starts transmission when the train approaches within a predetermined distance, and transmits when the train leaves outside the predetermined distance. Stop, the receiver installed on the train,
When a train approaches the station yard, radio waves can be stably received at a constant level from the transmitting device at an appropriate timing. When the train leaves the predetermined distance after departure, the image display can be automatically stopped.

[0014]

As described above, according to the present invention, the distance from the station yard to the train is measured, and when the train approaches within a predetermined distance, the transmitting device in the station starts transmitting, and the train By configuring so that transmission stops when the vehicle is out of the predetermined distance, the train-side receiving device can receive radio waves from the transmitting device stably at the appropriate timing without being affected by fading etc. Therefore, the train crew can check the status of the station premises on the monitor screen and operate safely. Further, since the emission time of radio waves can be shortened, radio interference can be reduced.

[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 a conventional station premises train radio system.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 transmission device 2 reception device 11 distance measurement unit 12 train detection unit 13 transmission unit 14 transmission control unit 21 reception unit 22 monitor D1 distance data D2 setting data S0 transmission output signal S1 image signal S2 detection signal

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B61L 1/00-25/08 B60L 3/00 B60L 15/40

Claims (2)

(57) [Claims] 1. In a train radio system in a station yard for receiving a signal from a transmitting device installed in a station by a receiving device installed in a train, the transmitting device is arranged such that the train is located within a certain distance. A train position detecting means for outputting a detection signal when there is a vehicle, a transmitting means for transmitting information indicating a situation in the station yard, and a transmission control means for turning on / off the transmission of the transmitting means in response to the detection signal. A train radio system in a station premises, characterized in that: 2. The train position detecting means includes: a distance measuring unit that measures a distance to the train by a reflected radio wave or a sound wave emitted; and a distance measured by the distance measuring unit and a predetermined distance. 2. The station radio according to claim 1, further comprising: a train detection unit that detects that the train is located within a certain distance by comparing, and outputs the detection signal. system.