JP2004098984A - Railroad crossing obstacle detecting device and railroad crossing obstacle detecting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To high-precisely discriminate an obstacle in the vicinity of a crossing rod when a gate arm is closed. <P>SOLUTION: When a radar processing means discriminates an obstacle 17b in the vicinity of a crossing rod 16 from output information of a radar transmitting and receiving means 18, it outputs a start signal for starting a radar transmitting and receiving means 20 for the vicinity of the crossing rod. The radar transmitting and receiving means 20 for the vicinity of the crossing rod transmits a radar beam to the vicinity of the crossing rod 16 in parallel with the crossing rod 16 in response to the start signal, and it receives a reflected wave of the transmitted radar beam. An incoming object discriminating means discriminates the obstacle 17b within the railroad crossing 15 in the vicinity of the crossing rod 16 from information of the reflected wave and high-precisely discriminates the obstacle 17b in the vicinity of the crossing rod 16. An alarm signal is output from an alarm processing means for receiving an output signal of the incoming object discriminating means. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a railroad crossing obstacle detection device and a railroad crossing obstacle detection method for detecting an obstacle such as an automobile or a pedestrian present in a railroad crossing and near a blocking bar when the railroad crossing is shut off.
[0002]
[Prior art]
FIG. 8 is a layout diagram of a radar device that constitutes a conventional railroad crossing obstacle detection device described in Patent Document 1, for example, and FIG. 9 is a block diagram showing a configuration of a conventional railroad crossing obstacle detection device. In FIG. 8, reference numeral 101 denotes a radar transmitting / receiving means for transmitting a radar beam (radar transmission wave) into a railroad crossing and receiving its reflected wave, 102 denotes a train traveling on an orbit 103 from X direction, and 104 denotes Y A train traveling on the track 105 in the X direction from the side, 106 indicates a railroad crossing provided on the tracks 103 and 105, and 107 indicates an obstacle entering the railroad crossing 106.
[0003]
In FIG. 9, reference numeral 108 denotes a radar processing unit for inputting an output signal from the radar transmitting / receiving unit 101, 109 denotes an alarm processing unit for inputting an output signal of the radar processing unit 108, and 109a denotes an output from the alarm processing unit 109. A warning signal 110 is output means for receiving stop signal 109a and outputting stop information to the train 102 or 104 approaching the railroad crossing 106, and 111 is a warning when the train 102 or 104 enters the railroad crossing control section of the railroad crossing 106. 3 shows a train detection signal output to the processing means 109.
[0004]
The radar transmitting / receiving means 101 is installed outside a railroad crossing 106 provided on a track 103 on which a down train 102 travels and a track 105 on which an up train 104 travels in a plurality of sections. The radar transmission / reception means 101 generates a radar transmission wave by, for example, FM (frequency modulation) modulating a continuous electromagnetic wave of a millimeter wave or a submillimeter wave, and transmits the radar transmission wave to the entire railroad crossing 106 while turning the radar transmission wave on a horizontal plane. Receiving the reflected wave reflected in the railroad crossing 106. The radar processing unit 108 obtains an image of the cross-section plane from the information of the reflected wave received by the radar transmission / reception unit 101, performs image processing, and recognizes the obstacle 107.
[0005]
For example, when the train 102 approaches the railroad crossing 106 and the train detection signal 111 is input, the alarm processing unit 109 determines and recognizes from the size of the obstacle 107 based on the output information from the radar processing unit 108. Whether the obstacle 107 is a car, a pedestrian, a bicycle, or the like is identified. As a result of the identification, when the obstacle 107 is a car, when the train 102 enters a railroad crossing control section and the car as the obstacle 107 is detected even after a predetermined time has elapsed since the start of the railroad crossing warning, The alarm processing unit 109 outputs an alarm signal 109a to the output unit 110. The output unit 110 sends the warning signal 109a to a railroad crossing warning device (not shown), emits a special signal light emitter (not shown), transmits stop information to the train 102, and stops the train 102.
[0006]
[Patent Document 1]
JP 2001-130412 A
[Problems to be solved by the invention]
The conventional level crossing obstacle detection device is configured as described above, and the radar beam transmitted from the radar transmitting / receiving means has a predetermined divergence angle. In the vicinity, it is difficult to accurately determine whether an obstacle is inside or not inside a railroad crossing. That is, for example, even if a radar beam is transmitted near the blocking bar that blocks the level crossing so as to be parallel to the blocking bar, the radar beam is also transmitted from the blocking bar to the outside of the level crossing, and the This is because when a person or a car is waiting just outside the blocking bar, the effect appears on the reflected wave.
[0008]
The present invention has been made in order to solve the above-described problems, and provides a railroad crossing obstacle detection device and a railroad crossing obstacle detection method that can accurately determine an obstacle near a blocking bar. It is intended.
[0009]
[Means for Solving the Problems]
A level crossing obstacle detection device according to the present invention transmits a first radar transmission wave to a first reflection transmission in the level crossing blocked by a blocking bar when a train approaches a level crossing and enters an alarm section. Radar transmitting / receiving means for receiving a wave, radar processing means for detecting an obstacle in the level crossing from the information of the first reflected wave, and determining whether or not the obstacle is located near the blocking bar, When it is determined that the object is located near the blocking bar, a radar transmitting / receiving unit for the blocking bar vicinity that transmits a second radar transmission wave near the blocking bar and receives a second reflected wave; Receiving the output signals of the intruding object detecting means, the radar processing means and the intruding object detecting means for judging whether or not the obstacle has entered the crossing from the wave information, and recognizing the obstacle in the crossing Alarm signal Those having a warning processing means for force.
[0010]
In addition, the method for detecting an obstacle at a level crossing according to the present invention transmits the first radar transmission wave to the level crossing blocked by the blocking bar when the train approaches the level crossing and enters the warning section. Receiving the reflected wave, detecting the obstacle in the railroad crossing from the information of the first reflected wave, and determining whether the obstacle is located near the blocking bar, Transmitting a second radar transmission wave near the blocking bar and receiving a second reflected wave when it is determined that the obstacle is located near the blocking bar; It is provided with a step of determining whether an object has entered the railroad crossing, and a step of outputting an alarm signal when the obstacle is recognized in the railroad crossing.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1 FIG.
1 to 7 are diagrams necessary for explaining the first embodiment of the present invention. FIG. 1 is a layout diagram of a level crossing obstacle detecting device, and FIG. 2 is a block diagram showing a configuration of the level crossing obstacle detecting device. 3 is a perspective view showing a transmission state of a radar beam (radar transmission wave) near the blocking bar, FIG. 4 is a flowchart showing a method of detecting an obstacle at a level crossing, and FIG. 5 is a distance relationship between an obstacle in the level crossing and a reference reflector. FIG. 6 is a diagram showing a reception level of a reflected wave of a radar beam transmitted near the blocking bar. FIG. 7 is a layout diagram showing the layout of the radar transmission / reception means for the vicinity of the blocking bar and the components related thereto.
[0012]
1 and 2, reference numeral 11 denotes a track on which a down train 12 travels from the X direction to the Y direction in a double track section, 13 denotes a track on which an up train 14 travels from the Y direction to the X direction in the double track section, and 15 denotes a track. Railroad crossings 16 provided on both tracks 11, 13 are blocking bars, which block the traffic of cars and pedestrians when the trains 12, 14 approach the railroad crossing 15. 17a and 17b are obstacles such as cars and pedestrians in the railroad crossing 15, and 18 is a radar transmitting / receiving means installed near the railroad crossing 15, for example, FM-modulating a continuous wave of a millimeter wave or a submillimeter electromagnetic wave and transmitting the radar. A wave (corresponding to a first radar transmission wave or a radar beam) is generated, and the radar transmission wave is swung on a horizontal plane approximately equal to the height of the blocking bar 16 when the railroad crossing 15 is blocked. The signal is transmitted to the entire railroad crossing 15 on the inside, and the reflected wave (corresponding to the first reflected wave) is received. The turning angle of the radar transmission wave is indicated by reference numeral 18r.
[0013]
Reference numeral 19 denotes a radar processing unit which obtains an image of a cross-section plane from the information of the reflected wave received by the radar transmission / reception unit 18, performs image processing to recognize an obstacle 17 a in the railroad crossing 15, and crosses the alarm processing unit 23 to be described later. When an internal obstacle detection signal 19a is sent and an obstacle 17b is detected near the blocking bar 16, a starting signal 19b for activating a radar transmitting / receiving unit 20 for a blocking bar nearby, which will be described later, is output. The radar processing means 19 grasps the position of the obstacle 17a or 17b from the transmission angle and the distance of the radar beam, and judges whether or not the obstacle 17a or 17b is located near the blocking bar 16.
[0014]
Reference numeral 20 denotes a radar transmission / reception unit for the vicinity of the blocking bar activated by the activation signal 19b, which generates a radar transmission wave (corresponding to a second radar transmission wave or a radar beam) and fixes the radar transmission wave. The beam is narrowed down so as to have a divergence angle and transmitted near the blocking bar 16 in a direction substantially parallel to the blocking bar 16 (the height at which the radar beam is transmitted is about the height of the blocking bar 16), and the reflected wave (second ). Reference numeral 20a is a reference reflector that reflects the radar beam transmitted from the radar transmitting / receiving unit 20 near the blocking rod at the other end of the blocking rod.
As shown in FIG. 3, the state of the radar beam being transmitted in the vicinity of the blocking bar is shown in FIG. 30 is transmitted, and the radar beam 30 (reflected wave) reflected by the reference reflector 20a at the other end of the blocking bar 16 is also received.
[0015]
Numeral 21 denotes an intruding object detecting means. When a radar beam transmitted / received by the radar transmitting / receiving means 20 for an intercepting rod is blocked by an obstacle 17b, a measured value of a distance to the obstacle 17b and a reference reflector 20a are used. From the change amount (reduction amount) of the reception level, it is determined how much the obstacle 17b has entered the railroad crossing 15 (degree of approach), and whether the obstacle 17b is located as an obstacle to the railroad crossing 15. When the object 17b is approaching, it determines that the obstacle 17b is present in the level crossing 15 and outputs an approaching object detection signal 21a near the blocking bar.
[0016]
Reference numeral 22 denotes a train detection signal. For example, when the train 12 enters a predetermined section (railway crossing warning section) of the track 11, it is detected that a train has entered and is output. This train detection signal 22 can be set to be output, for example, when a railroad crossing is blocked by a blocking bar. Reference numeral 23 denotes an alarm processing means which receives an obstacle detection signal 19a in a level crossing and an intrusion object detection signal 21a near a blocking rod when the train detection signal 22 is input, and when the obstacle 17b is recognized, An alarm signal 23a is output to the output means 24. An output unit 24 receives the alarm signal 23a and sends the signal (alarm signal 23a) to a level crossing alarm device (not shown). The railroad crossing warning device (not shown) causes the signal light emitter to emit light, transmits stop information to the train 12, and stops the train 12.
[0017]
Next, the operation of the railroad crossing obstacle detection device will be described with reference to the flowchart showing the railroad crossing obstacle detection method of FIG. As described above, when the train 12 travels from the X direction to the Y direction and enters the level crossing warning section, the train detection signal 22 is input to the warning processing means 23, and at the same time, the blocking bar 16 is lowered and the level crossing 15 is changed. Will be shut off. In this state, the radar transmission / reception means 18 is activated, turns the radar transmission wave, transmits it to the entire railroad crossing 15, and receives the reflected wave (S1). Then, the radar processing means 19 determines whether an obstacle 17a has been detected in the level crossing 15 from the received reflected wave (S2), and outputs an obstacle detection signal 19a within the level crossing when the obstacle 17a is detected. (S3).
[0018]
Next, the radar processing unit 19 determines whether or not the obstacle 17a is near the blocking bar 16 (S4). Is determined (S9). When the train detection signal 22 is input and the obstacle detection signal 19a within the railroad crossing is input, the alarm processing means 23 17a is determined to be recognized, and an alarm signal 23a is output (S10). The output means 24 receiving the warning signal 23a sends the signal to, for example, a level crossing warning device (not shown). A railroad crossing warning device (not shown) causes the signal light emitter to emit light, transmits stop information to the train 12, and stops the train 12.
[0019]
On the other hand, when the obstacle 17b exists near the blocking bar 16, the following processing is performed. First, similarly to the above case, the radar processing unit 19 detects the obstacle 17b by the radar beam transmitted from the radar transmitting / receiving unit 18 to the vicinity of the blocking bar 16 substantially in parallel with the blocking bar 16 (S2). The object detection signal 19a is output (S3). Next, it is determined that the obstacle 17b is located near the blocking bar 16 (S4), and an activation signal 19b is output from the radar processing unit 19 (S5) to activate the radar transmitting / receiving unit 20 near the blocking bar (S6). . The radar transmission / reception means 20 for the vicinity of the blocking bar receives the reflected wave of the radar beam transmitted substantially in parallel with the blocking bar 16 and sends the information to the entering object detecting means 21.
[0020]
When the radar beam transmitted / received by the radar transmission / reception means 20 near the blocking bar is blocked by the obstacle 17b, the intruding object detection means 21 measures the measured distance to the obstacle 17b and the reception level from the reference reflector 20a. Judging how much an intruding object (an obstacle that has entered a railroad crossing) has entered from the amount of change (decreasing amount), the intruding object has entered beyond the limit distance, and the time during which the intruding object has been detected has exceeded a certain level Then, it is determined that the obstacle 17b exists in the railroad crossing 15 (S7), and the obstacle detection signal 21a near the blocking bar is output (S8). The limit distance for approaching a railroad crossing can be set according to various conditions such as the size of the railroad crossing. When the train detection signal 22 is input, the alarm processing means 23 receives the obstacle detection signal 19a in the level crossing and the intrusion object detection signal 21a near the blocking bar 21a, and when the obstacle 17b is recognized in the level crossing 15, the alarm signal 23a Is output (S10). Then, the danger is notified to the train 12 by the warning signal 23a, for example, via a railroad crossing warning device (not shown).
[0021]
Next, a method of detecting an obstacle will be described with reference to FIGS. When an obstacle 17b located in the vicinity of the blocking bar 16 enters the railroad crossing 15 from the position of the blocking bar 16, the radar transmitting / receiving means 20 for the vicinity of the blocking bar reflects the transmitted radar beam 30 on the reference reflector 20a. While receiving the wave, the reflected wave from the entering obstacle 17b is also received. Here, as shown in FIG. 5, the distance X at which the obstacle 17b enters the railroad crossing 15, the length Y at which the radar beam 30 is blocked by the obstacle 17b and the reference reflector 20a of length Z is hidden. Assuming that the distances between the radar transmitting / receiving means 20 and the obstacle 17b and the reference reflector 20a are Rx and Ry, respectively, the following relationship is established between them.
X = (Rx / Ry) Y (1)
[0022]
As shown in FIG. 6, regarding the reception level of the radar transmission / reception means 20 for the vicinity of the blocking bar, the radar beam 30 is blocked by an intruding object (corresponding to the obstacle 17b here), and the reference reflector 20a is hidden. As a result, the reception level from the reference reflector 20a decreases. Assuming that the reception level Vz from the reference reflector 20a having the length Z when the reference reflector 20a is not hidden, and the decrease amount Vy of the reception level from the reference reflector 20a when the reference reflector 20a is hidden, , The following relationship is established between the length Z of the reference reflector 20a and the length Y hidden by the intruding object.
Y = (Vy / Vz) Z (2)
[0023]
From the equations (1) and (2), the approach distance X of the approaching object is as follows.
X = (Rx / Ry) (Vy / Vz) Z (3)
Here, since the reference reflector 20a can be set at a predetermined distance at a predetermined distance, Ry and Z can be set in advance. Further, the reception level Vz from the reference reflector 20a when there is no intruding object and there is no hidden portion can be measured in advance. Further, the distance Rx from the radar exit to the intruding object, and the reduction amount Vy of the reception level of the reference reflector 20a when the reference reflector 20a is hidden, are measured from the measurement of the reflected wave by the radar transmission / reception means 20 for the vicinity of the blocking rod. That value is obtained. Therefore, the approach distance X of the approaching object is obtained.
[0024]
FIG. 7 exemplifies the arrangement and dimensions of the radar transmission / reception means 20 for the vicinity of the blocking bar and the components related thereto. Assuming that the distance (11) from the radar transmission / reception port of the radar transmission / reception means 20 for the blocking bar to one end of the blocking bar 16 is 7 m, and the length (12) of the blocking bar 16 corresponding to the length of the railroad crossing 15 is 14 m. If the spread angle 20r of the radar beam 30 is 3.3 degrees and the length of the reference reflector 20a is 60 cm, the approach state of the obstacle 17b up to 20 cm from the blocking bar 16 into the railroad crossing 5 will be described. Can be accurately detected by the radar transmitting / receiving means 20 for the vicinity of the blocking rod.
[0025]
As described above, when the obstacle 17b is detected in the vicinity of the blocking bar 16, the radar transmitting / receiving means 20 for the vicinity of the blocking bar 16 is activated to detect an obstacle in a range limited to the vicinity of the blocking bar 16. Since the position of the obstacle 17b and the degree of entry into the railroad crossing 15 can be detected in more detail, the obstacle 17b near the blocking bar 16 can be accurately determined.
[0026]
Further, the radar transmission / reception means for the vicinity of the blocking bar transmits the second radar transmission wave from one end of the blocking bar toward the other end so as to be parallel to the blocking bar near the blocking bar. On the other end side of the second reflected wave to receive a second reflected wave including a reflected wave from the reference reflector disposed in the railroad crossing so that its reflection surface is at a right angle to the blocking rod, , The degree of entry of the obstacle into the railroad crossing can be accurately determined.
[0027]
Further, the approaching object detecting means 21 detects the degree of entry of the obstacle 17b into the level crossing 15, and when the obstacle 17b has entered the level crossing 15 beyond the limit distance, the obstacle 17b Since it is determined that the vehicle is present in the railroad crossing 15, the limit distance of approach to the railroad crossing can be set according to various conditions such as the size of the railroad crossing 15, and taking into account the limit distance, the railroad crossing of the obstacle 17b is performed. Can be accurately determined.
[0028]
Further, when the radar processing means 19 detects the obstacle 17b near the blocking bar 16, the radar transmitting / receiving means 20 for the vicinity of the blocking bar is activated, so that the radar beam generating unit (not shown) does not always operate. Therefore, the life of the radar beam generator can be extended.
[0029]
Further, the radar beam 30 transmitted from the radar transmission / reception means 20 near the blocking bar has a fixed divergence angle, and the divergence angle is narrowed down so that the radar beam 30 is limited to a range limited to the vicinity of the blocking bar. Can be accurately detected.
Further, as shown in FIG. 1, the radar beam 30 transmitted from the radar transmission / reception means 20 for the vicinity of the blocking bar is substantially at the same height as the blocking bar 16 when the railroad crossing is blocked, and is parallel to the blocking bar 16. Although the transmission is described based on the line along the blocking bar 16 as an example, it is also possible to determine an obstacle based on a line that is shifted from the blocking bar 16 by, for example, about 10 cm in parallel.
[0030]
As the reference reflector 20a, besides using an ordinary metal plate, a reflector having a recursive property with respect to a radar beam can be used.
Further, FIG. 1 shows an arrangement in which the blocking bar 16 is arranged only on the track 11 side, but the blocking bar 16, the radar transmitting / receiving means 20 for the blocking bar vicinity and the entering object are provided on the track 13 side and both tracks 11, 13 side. It goes without saying that the same effect can be expected even if the detection means 21 is arranged.
[0031]
Also, a case has been described where a continuous wave of electromagnetic waves is FM-modulated to generate a radar transmission wave. However, similar effects can be expected even if a modulation method such as pulse modulation or spread spectrum (SS) modulation is employed. .
[0032]
In addition, the description has been given of the case where the radar transmission wave is transmitted while turning the radar transmission wave in the horizontal plane by the radar transmission / reception means 18. However, a plurality of radar beams are prepared in advance so that they can be transmitted in the horizontal plane, and sequentially transmitted while switching. Can expect the same effect. In this case, one of the plurality of radar beams may be used as the radar transmitting / receiving unit 20 for the vicinity of the blocking bar.
[0033]
Furthermore, the description has been given of the case where the obstacle is recognized by performing image processing on the cross-section image obtained from the reflected wave of the radar transmission wave, but the threshold of the reception level of the reflected wave is set, and the threshold is exceeded. The same effect can be expected even if an obstacle is recognized based on whether or not the obstacle is recognized.
[0034]
【The invention's effect】
According to the railroad crossing obstacle detection device of the present invention, when the train approaches the railroad crossing and enters the warning section, the first radar transmission wave is transmitted to the railroad crossing blocked by the blocking bar and the first radar transmission wave is transmitted. Radar transmitting / receiving means for receiving a reflected wave, detecting an obstacle in the railroad crossing from information on the first reflected wave, and radar processing means for determining whether or not the obstacle is located near the blocking bar; When it is determined that the obstacle is located near the blocking bar, a radar transmitting / receiving unit for the blocking bar vicinity that transmits a second radar transmission wave near the blocking bar and receives a second reflected wave, the second Based on the information of the reflected wave, an approaching object detecting means for determining whether the obstacle has entered the level crossing, an output signal of the radar processing means and the approaching object detecting means are received, and the obstacle in the level crossing is received. Alarm signal when recognized For including an alarm processing means for force, whether an obstacle in the vicinity of the blocking bar is present in the railroad crossing, whether present outside crossing can be accurately determined.
[0035]
Further, the level crossing obstacle detecting method according to the present invention transmits the first radar transmission wave to the level crossing interrupted by the blocking bar when the train approaches the level crossing and enters the warning section, and transmits the first radar transmission wave. Receiving the reflected wave, detecting an obstacle in the railroad crossing from the information of the first reflected wave, and determining whether the obstacle is located near the blocking bar; When it is determined that the obstacle is located near the blocking bar, a step of transmitting a second radar transmission wave near the blocking bar and receiving a second reflected wave, from the information of the second reflected wave, A step of determining whether or not the vehicle has entered the railroad crossing, and a step of outputting an alarm signal when the obstacle is recognized in the railroad crossing. Exists outside the railroad crossing It is possible to accurately determine.
[Brief description of the drawings]
FIG. 1 is a layout diagram of a railroad crossing obstacle detection device according to a first embodiment of the present invention.
FIG. 2 is a block diagram illustrating a configuration of a railroad crossing obstacle detection device according to the first embodiment of the present invention.
FIG. 3 is a perspective view showing a transmission state of a radar beam near a blocking bar according to the present invention.
FIG. 4 is a flowchart showing a railroad crossing obstacle detection method of the present invention.
FIG. 5 is a layout diagram showing a distance relationship between an obstacle in a railroad crossing and a reference reflector using the railroad crossing obstacle detection device of the present invention.
FIG. 6 is a diagram showing a reception level of a reflected wave of a radar beam according to the present invention.
FIG. 7 is a layout diagram of the radar transmission / reception means for the vicinity of the blocking bar of the present invention and components related thereto.
FIG. 8 is a layout diagram showing a configuration of a conventional level crossing obstacle detecting device.
FIG. 9 is a block diagram showing a configuration of a conventional railroad crossing obstacle detection device.
[Explanation of symbols]
11, 13 track 12, 14 train 15 railroad crossing 16 blocking bar 17a, 17b obstacle 18 radar transmitting / receiving means 18r turning angle 19 radar processing means 19a obstacle detection signal at railroad crossing 20 radar transmitting / receiving means near blocking rod 20a reference reflector 20r spread Angle 21 Entry detection means 21a Entry detection signal near blocking bar 22 Train detection signal 23 Alarm processing means 23a Alarm signal 24 Output means 30 Radar beam.

Claims (5)

A radar transmitting / receiving means for transmitting a first radar transmission wave and receiving a first reflected wave within the railroad crossing blocked by the blocking bar when the train approaches a railroad crossing and enters an alarm section; Radar processing means for detecting an obstacle in the railroad crossing from the reflected wave information and determining whether the obstacle is located near the blocking bar, and determining that the obstacle is located near the blocking bar. In the case where the second radar transmission wave is transmitted near the blocking bar and the second reflected wave is received, the radar transmission / reception means for the blocking bar is used. Alarm processing means for receiving an intruding object detecting means for judging whether the vehicle has entered the vehicle, receiving the output signals of the radar processing means and the intruding object detecting means, and outputting an alarm signal when the obstacle in the railroad crossing is recognized. Characterized by having Level crossing obstacle detection device that. The radar transmitting / receiving means near the blocking bar transmits the second radar transmission wave from one end of the blocking bar to the other end thereof in the vicinity of the blocking bar so as to be parallel to the blocking bar. Receiving the second reflected wave including the reflected wave from the reference reflector disposed in the railroad crossing so that the reflection surface is at a right angle to the blocking bar at the other end of the blocking bar. The railroad crossing obstacle detection device according to claim 1, wherein: The approaching object detecting means detects a degree of the obstacle entering the level crossing, and when the obstacle has entered the level crossing beyond a limit distance, the obstacle is located at the level crossing. The level crossing obstacle detecting device according to claim 1, wherein it is determined that the level crossing exists. The said 2nd radar transmission wave is a radar beam with a fixed divergence angle transmitted so that it may become parallel with the said interruption | blocking bar | burr which interrupt | blocks the said level crossing, The said 1st or 2nd characterized by the above-mentioned. The level crossing obstacle detection device according to claim 2. A step of transmitting a first radar transmission wave and receiving a first reflected wave in the railroad crossing blocked by a blocking bar when the train approaches a railroad crossing and enters an alarm zone; Detecting an obstacle in the level crossing from the information of the wave, and determining whether the obstacle is located near the blocking bar, when it is determined that the obstacle is located near the blocking bar, Transmitting a second radar transmission wave near the blocking bar and receiving a second reflected wave; determining whether the obstacle has entered the railroad crossing from information on the second reflected wave; A step of outputting an alarm signal when the obstacle is recognized in the railroad crossing.

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