JP2003220952A - Detecting device of obstruction for crossing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent generation of dead angle that hinders detecting obstruction in a railroad crossing. <P>SOLUTION: The detecting device consists of a pseudo-noise code generating means 22, a modulating means 23, a transmitting antenna 24, a receiving antenna 25, a demodulating means 26, a signal processing means 27 and a logical processing means 30. The pseudo-noise code generating means 22 generates the pseudo-noise code, the modulating means 23 makes a transmission wave by undergoing spread spectrum modulation a carrier wave using with the pseudo-noise code. The transmitting antenna 24 emits the transmission wave in the crossing and the receiving antenna 25 receives a reflection wave of the transmission wave. The modulating means 26 takes correlation between the pseudo-noise code extracted by inverse spreading the reflection wave and the pseudo-noise code by undergoing spread spectrum modulation the carrier wave with using the modulating means 23. The signal processing means 27 outputs an object detection signal with calculating a position of the obstacle regarding that the obstacle exists in the crossing when the correlation level of the pseudo-noise code extracted with the modulating means 26 is within a predetermined value. The logical processing means 30 outputs an alarm signal with detecting that the obstacle exists in the crossing when the train approaching signal and the object detection signal are inputted. <P>COPYRIGHT: (C)2003,JPO

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 device for detecting an obstacle inside a level crossing.

[0002]

2. Description of the Related Art FIG. 5 shows, for example, Japanese Patent Laid-Open No. 10-76954.
FIG. 6 is a plan view of a railroad crossing to which the conventional railroad crossing obstacle detection device described in Japanese Patent Laid-Open Publication No. 2004-242242 is applied, and FIG. In FIG. 5, four sets of light emitters / receivers 2 to 2 are arranged so as to traverse four locations inside the railroad crossing 1.
5, and reflectors 6-9 are installed. Hereinafter, the combination of the light emitting / receiving device 2 and the reflector 6 will be described as an example. 5 and 6, a train approach signal output when a train (not shown) approaches a predetermined distance from the railroad crossing 1 drives a railroad crossing device such as the barrier 10. Further, when the train approach signal is input to the control circuit 11, the control circuit 11 outputs the beam transmission circuit 12 until the train leaves the railroad crossing 1.
A drive signal is sent to. The light emitting element 2a receives a drive current from the beam transmission circuit 12, and irradiates the reflector 6 with a light beam whose output value changes with the passage of time. If the light beam is blocked while the light emitting element 2a irradiates the light beam,
The output of the light receiving element 2b lowers, the obstacle detection signal of the beam receiving circuit 13 becomes 0, and the special light emitter (not shown) is indicated via the control circuit 11 that there is an obstacle in the railroad crossing 1. . On the other hand, if there is no obstacle in the detection area on the light beam emitted from the light emitting element 2a and there is no abnormality in the light emitting / receiving device 2 and the reflector 6, the light receiving element 2b passes through the reflector 6 to move the light emitting element 2a. An output that changes similarly to the output change is obtained. Further, when there is no obstacle in the detection area and the light emitting / receiving device 2 and the reflector 6 are abnormal, the output of the light receiving element 2b does not follow the output change of the light emitting element 2a. In this way, when the output of the light receiving element 2b that does not follow is obtained,
Since some abnormality has occurred in the level crossing obstacle detection device, a failure detection signal is transmitted from the control circuit 11 to a management center such as a station via a communication line.

[0003]

Since the conventional level crossing obstacle detecting device is constructed as described above, the light beam emitted from the light emitting and receiving device 2 is blocked by the obstacle and the output of the light receiving element 2b is lowered. To detect the presence of obstacles,
When the obstacle inside the railroad crossing 1 exists at a position deviating from the light beam emitted from the light emitting and receiving device 2, there is a problem that the obstacle cannot be detected and a blind spot occurs in which the obstacle cannot be detected. Further, the light emitted from the light emitting element 2a is reflected by the reflector 6
The light is received by the light receiving element 2b via the, and it is determined that an abnormality has occurred when the output of the light receiving element 2b does not follow the output change of the light emitting element 2a. Since the output does not follow the output change of the light emitting element 2a, it is difficult to accurately determine the normal operation of the device. The present invention has been made to solve the above problems, and an object of the present invention is to provide a level crossing obstacle detection device capable of preventing a blind spot in which an obstacle cannot be detected from occurring within the level crossing. It was done. Further, it is another object of the present invention to provide a level crossing obstacle detection device capable of determining a normal operation of the device without being affected by the weather.

[0004]

A crossing obstacle detecting apparatus according to the present invention includes a pseudo noise code generating means for generating a pseudo noise code by a start signal, and a spread wave by spread spectrum modulating a carrier wave by a pseudo noise code. Modulation means to be created, a transmission antenna that emits the transmission wave into the railroad crossing, a reception antenna that receives the reflected wave of the transmission wave, a pseudo-noise code that is extracted by despreading the reflected wave and the spectrum spread of the carrier wave by the modulation means. Demodulation means for obtaining a correlation with the modulated pseudo noise code, generating an activation signal, and the correlation level of the pseudo noise code extracted by the demodulation means when there is an obstacle in the railroad crossing when the correlation level is within a predetermined range, A signal processing means for calculating the position of an obstacle and outputting an object detection signal, and a train approach signal output when a train approaches a predetermined distance from a railroad crossing and enters an alarm section In which the body detection signal is constituted by the logic processing means detects that the obstacle is present in the crossing outputs an alarm signal when input. Further, a first train detection means that detects a train on the side where the train enters the railroad crossing and outputs a first train detection signal, and a second train that detects the train on the side where the train exits the railroad crossing and outputs the second train detection signal. A second train detection means for outputting a train detection signal is provided, and the logic processing means receives a train approach signal and while the train is inside the railroad crossing and both train detection signals are input. The signal processing means determines that the reflected wave received by the receiving antenna is the transmitted wave emitted from the transmitting antenna, and the received level of the received reflected wave is the threshold value stored as the receiving level corresponding to the train. In the above case, it is determined that the obstacle detection function is normal.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. 1 is a plan view of a railroad crossing to which Embodiment 1 is applied, FIG. 2 is a block diagram showing a configuration of Embodiment 1, FIG. 3 is an explanatory view showing a reception level of a reflected wave in FIG. 2, and FIG. 4 is a train. It is explanatory drawing which shows the state which exists in a railroad crossing. 1 to 4, 14
Is a railroad track, 15 is a railroad crossing crossing the railroad track 14, and 16 is a train approach signal, which is output when the train 17 approaches a predetermined distance from the railroad crossing 15 and enters an alarm section. 18 is a railroad crossing 15
The crossing gates installed on both sides of the railroad crossing block the crossing of the level crossing 15 by the train approach signal 16. Reference numeral 19 denotes an alarm, which gives an alarm by the train approach signal 16. Reference numeral 20 is an obstacle such as a person or an automobile existing inside the railroad crossing 15, 21 is a railroad crossing obstacle detection device installed in the vicinity of the railroad crossing 15, and is constituted by the following 22 to 29. Reference numeral 22 denotes a pseudo noise code generating means activated by an activation signal from a signal processing means 27 which will be described later and generates a pseudo noise (PN) code. Reference numeral 23 is a modulation means, which spread spectrum (SS) modulates a carrier wave with a pseudo noise code to create a transmission wave. 24 is, for example, 20 m to 40 m forward
The transmission wave generated by the modulation means 23 is emitted toward the inside of the railroad crossing 15 by the transmission antenna whose detection range is. Reference numeral 25 denotes a receiving antenna, which receives a reflected wave of the transmitted wave emitted from the transmitting antenna 24. 26 is a demodulation means, which is the receiving antenna 2
The correlation between the pseudo-noise code obtained by despreading the reflected wave received by 5 and the pseudo-noise code obtained by the spread spectrum modulation of the carrier wave by the modulator 23 is obtained.

Reference numeral 27 is a signal processing means for generating an activation signal for the pseudo noise code generation means 22 and for obstacles in the railroad crossing 15 when the correlation level of the pseudo noise code extracted by the demodulation means 26 is within a predetermined range. Assuming that 20 exists, an object detection signal 27 is calculated by calculating a distance and an angle to the obstacle 20.
Output a. 28 is a first train detection means, which is a railroad crossing 15
When the train 17 is detected on the side where the train 17 enters the inside, the first train detection signal 28a is output. The second train detection signal 29a is a second train detection signal 29a when the train 17 detects the train 17 on the side where the train 17 exits the railroad crossing 15.
Is output. Here, FIG. 3 is an explanatory diagram showing the reception level of the reflected wave in FIG. In addition, in FIG.
c is a train determination signal, which is the reception level received by the reception antenna 25 when the train 17 is inside the railroad crossing 15;
Is a threshold value for discriminating the train determination signal 30c and both are stored in the logic processing means 30 described later. Reference numeral 30 is a logic processing means, and when the train approach signal 16 is input and the object detection signal 27a is input from the signal processing means 27, the railroad crossing 1
It is determined that the obstacle 20 exists within the area 5, and the warning signal 30a
Is output. Further, the logic processing means 30 receives the train approach signal 16 and receives both train detection signals 28a,
When the object detection signal 27a is input while 29a is input and the train 17 is present inside the railroad crossing 15, the train determination signal 30 in which the reception level of the reflected wave is the threshold value 30d or more
If it is c, it is determined that the reflected wave from the train 17 has been received, the detection function is determined to be normal, and the normal operation signal 30b is output.

Next, the operation will be described. 1 to 3
At, when a train (not shown) advances from the X direction to the Y direction and enters a railroad crossing warning section (not shown) at a predetermined distance from the railroad crossing 15, the train is detected and the train approach signal 16
Is output, and the breaker 18 and the alarm 19 are activated. Then, the transmission wave that has been spread-spectrum-modulated by the PN code by the modulation means 23 is emitted from the transmission antenna 24 into the railroad crossing 15. When the obstacle 20 exists inside the railroad crossing 15, the reception antenna 25 receives the reflected wave of the transmission wave reflected by the obstacle 20. The reflected wave is demodulated by the demodulation means 26 by despreading, and the extracted PN code is correlated with the PN code which is the spread spectrum modulation of the carrier wave by the modulation means 23. The signal processing means 27 calculates the distance and angle from the reflected wave received by the receiving antenna 25 to the reflection point where the reflected wave is reflected. If the object detection signal 27a is input while the train approach signal 16 is input, the logic processing means 30 detects the presence of the obstacle 20 inside the railroad crossing 15 and outputs an alarm signal 30a. Warning signal 30a
Sends an alarm to a train (not shown) via a railroad crossing control device (not shown).

FIG. 4 is an explanatory view showing a state in which the train 17 exists inside the railroad crossing 15. 2 to 4, the train 1
When the train 7 approaches the railroad crossing 15, the first train detection means 28
Detects the entry of the train 17 into the railroad crossing 15 and outputs a first train detection signal 28a. Further, when the train 17 advances, the second train detection means 29 installed on the exit side of the railroad crossing 15.
Detects the train 17 and outputs a second train detection signal 29a. When the correlation level of the pseudo noise code extracted by the demodulation means 26 is within a predetermined range, the signal processing means 27 determines that the obstacle 20 exists inside the railroad crossing 15 and calculates the distance and angle to the obstacle 20. And outputs the object detection signal 27a. When the train approach signal 16 is input to the logic processing means 30 and both train detection signals 28a and 29a are input and the object detection signal 27a is input while the train 17 is inside the railroad crossing 15, Train 1 if the reception level of the reflected wave is a train determination signal 30c with a threshold value of 30d or more
Assuming that the reflected wave from 7 is received, it is determined that the detection function is normal, and the normal operation signal 30b is output. And
The normal operation signal 30b is transmitted to a railroad crossing management center such as a station.

As described above, since the existence of the obstacle 20 is detected from the reflected wave emitted from the transmission wave into the railroad crossing 15 and reflected by the obstacle 20, there is a blind spot in the railroad crossing 15 where the obstacle 20 cannot be detected. Can be prevented. Further, the first train detection means 28 detects the train on the side where the train 17 enters the railroad crossing 15 and outputs a first train detection signal 28a, and the second side on the side where the train 17 leaves the railroad crossing 15 is detected. The train detection means 29 detects the train 17 and outputs the second train detection signal 29a, and the train approach signal 16 is input to the logic processing means 30 and the train 17 crosses the railroad crossing 15
The signal processing means 27 determines that the reflected wave received by the receiving antenna 25 is the transmitted wave emitted from the transmitting antenna 24 while both train detection signals 28a and 29a are present inside the vehicle. When the received signal level of the received reflected wave is judged to be the train judgment signal 30c having a threshold value of 30d or more, the logic processing means 30 judges that the function of detecting the obstacle 20 is normal. It is possible to determine the normal operation of the device without receiving it. Although the case where the train (not shown) travels from the X direction to the Y direction has been described in the first embodiment, the same effect can be expected when the train travels from the Y direction to the X direction. it can.

[0010]

According to the present invention, since the presence of an obstacle is detected from the reflected wave reflected by an obstacle by transmitting a transmitted wave into the railroad crossing, a blind spot in which the obstacle cannot be detected occurs. Can be prevented. Further, on the side where the train enters the railroad crossing, the first train detection means detects the train and outputs a first train detection signal, and on the side where the train exits the railroad crossing, the second train detection means Is detected, a second train detection signal is output, the train approach signal 6 is input to the logic processing means, and while the train is inside the level crossing and both train detection signals are input, The signal processing means determines that the reflected wave received by the receiving antenna is that of the transmitted wave emitted from the transmitting antenna, and the received level of the received reflected wave is the threshold stored as the receiving level corresponding to the train. In the above case, by determining that the obstacle detection function is normal, it is possible to determine the normal operation of the device without being affected by the weather.

[Brief description of drawings]

FIG. 1 is a plan view of a railroad crossing to which a first embodiment of the present invention is applied.

FIG. 2 is a block diagram showing the configuration of the first embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a reception level of a reflected wave in FIG.

FIG. 4 is an explanatory diagram showing a state in which a train exists inside a railroad crossing in the first embodiment of the present invention.

FIG. 5 is a plan view of a railroad crossing to which a conventional railroad crossing obstacle detection device is applied.

6 is a configuration diagram showing a main part of the crossing obstacle detection device of FIG. 5. FIG.

[Explanation of symbols]

15 crossings, 17 trains, 20 obstacles, 22 pseudo noise code generating means, 23 modulating means, 24 transmitting antennas, 25 receiving antennas, 26 demodulating means, 27 signal processing means, 28 first train detecting means, 29 second Train detection means, 30 Logic processing means.

Claims (2)

[Claims] 1. A pseudo noise code generation means for generating a pseudo noise code by a start signal, a modulation means for spread spectrum modulating a carrier wave by the pseudo noise code to create a transmission wave, and emitting the transmission wave in a railroad crossing. A transmitting antenna, a receiving antenna for receiving a reflected wave of the transmitted wave, a pseudo noise code extracted by despreading the reflected wave, and a pseudo noise code obtained by spread spectrum modulating the carrier by the modulating means. Taking the position of the obstacle, assuming that there is an obstacle in the railroad crossing when the correlation level of the demodulation means for generating the start signal and the pseudo noise code extracted by the demodulation means is within a predetermined range. A signal processing means for calculating and outputting an object detection signal, a train approach signal output when a train approaches a predetermined distance from the railroad crossing and enters an alarm section, and the object detection signal. A crossing obstacle detection device comprising logic processing means for detecting the presence of an obstacle in the crossing and outputting an alarm signal when a known signal is input. 2. The railroad crossing obstacle detection device according to claim 1, further comprising: first train detection means that detects the train on the side where the train enters the railroad crossing and outputs a first train detection signal. And a second train detection unit that detects the train on the side where the train exits the railroad crossing and outputs a second train detection signal, wherein the logic processing unit receives the train approach signal. While the train is inside the railroad crossing and the both train detection signals are input, the reflected wave received by the receiving antenna is the transmitted wave emitted from the transmitting antenna. When the signal processing means determines that the reception level of the received reflected wave is equal to or higher than the threshold stored as the reception level corresponding to the train, the obstacle detection function is normal. Characteristic to judge Crossing obstacle detection device.