JP2005233615A - Apparatus and method for detecting obstacle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reliably detect obstacles by preventing the yet to be detected and misdetection of obstacles, using a simple constitution. <P>SOLUTION: A reflecting object observing part 7 of a measuring device 3 has millimeter waves irradiated to a crossing road 2, receives reflected waves from each reflector 4, and observes the distance to each reflector 4 and reflected intensities. A determination processing part 8 determines the presence or the absence of obstacles, on the basis of variations in the distance to a reflecting location and the reflection intensities of millimeter waves outputted from the reflecting object-observing part 7 under the control of a crossing control device 5 and outputs determination results to the crossing control device 5. A self-diagnosis part 10 receives the input of the distance to the reflecting location and the reflection intensities of millimeter waves from the determination processing part 8 and determines that anomalies have occurred in the measuring device 3, when the reflection intensities deviate from a prescribed range, determined according to natural variations for a prescribed time and that the distance to the reflecting location deviates from the inside of the crossing road 2, which is an object to be detected. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an obstacle detection device and a detection method for detecting an automobile or a pedestrian on, for example, a railroad crossing on which a train travels, and particularly to improvement of detection accuracy.

  Railroad crossing warning devices for railroad safety devices start a railroad crossing warning when a train traveling on the track approaches the railroad crossing, cut off traffic on the railroad crossing, and use cars and pedestrians that pass the train safely and through the railroad crossing. In order to ensure the safety of the road, after the train crosses the railroad crossing, the road block is immediately released to ensure smooth road traffic.

  In order to prevent the safe operation of the train on this railroad crossing, for example, a railroad crossing obstacle detection device using a laser sensor, an infrared sensor, an optical sensor using a visible camera, an ultrasonic sensor, a loop coil sensor, or the like is used. ing. Railroad crossing obstacle detection devices using these sensors are easily affected by weather such as rain, snow, fog, and wind, and illuminance, and depending on the system configuration, installation time and cost may be borne. On the other hand, a sensor that uses a short millimeter wave with a wavelength of around several millimeters among microwaves is not easily affected by weather, illuminance, etc., and does not require large-scale construction such as wiring or piping between lines. The installation period and cost can be reduced, and obstacles in the crossing can be reliably detected.

  For example, a crossing obstacle detection device disclosed in Patent Document 1 includes a radar using laser light or millimeter waves, and radiates laser light or millimeter waves into a crossing from a rotationally driven distance sensor. The direction information of the object and the distance information of the object corresponding to the direction information are detected, and the distance information of the object for each direction information stored in advance is compared with the distance information of the object corresponding to the detected direction information. Then, it is determined whether or not the detected object is an obstacle. In addition, reflecting plates are provided at three different corners outside the railroad crossing, and the rotation direction of the distance sensor and the transmission / reception performance are checked and calibrated based on the reflected signal of the reflecting plate.

Such obstacle detection can also be applied to crime prevention. For example, the approach detection method disclosed in Patent Document 2 irradiates a detection area with a millimeter wave generated by a millimeter wave radar, and is installed in the irradiation area. When a reflected wave from a plurality of reflected objects is detected and a reflected wave from at least one of the plurality of reflected objects cannot be detected, it is determined that an intruding object exists in the detection area. Further, the position of the intruding object is specified according to the position of the reflecting object that cannot detect the reflected wave.
JP 2003-11824 A Japanese Patent No. 3371900

  In order to reliably detect obstacles in a level crossing, it is possible to eliminate undetected blind spots in the level crossing, which is the detection target area, to reliably determine obstacles without erroneous detection, and Means such as performing self-diagnosis that can be judged are essential.

  The crossing obstacle detection device disclosed in Patent Document 1 checks and calibrates the rotation direction and transmission / reception performance of the distance sensor based on the reflection signal of the reflector, but the obstacle detection is reflected directly from the object. Since it is determined by the reflected wave whether or not it is an obstacle, the reflected wave may not return depending on the direction of the object facing the distance sensor, and undetected may occur. In addition, since the mechanism for rotationally driving the distance sensor is provided, the reliability of the apparatus is affected.

  In addition, the approaching object detection method disclosed in Patent Document 2 determines that an intruding object exists when a reflected wave from a reflecting object cannot be detected, and therefore has entered when a phenomenon in which the reflected wave cannot be detected occurs. It may not be possible to determine whether the object is due to an object, an abnormality in the apparatus, or the reflector is lost, and erroneous detection may occur.

  An object of the present invention is to provide an obstacle detection device and a detection method capable of solving such a problem and reliably detecting an obstacle by preventing undetected and erroneous detection of the obstacle with a simple configuration. It is.

  The obstacle detection device of the present invention includes a measurement device and one or a plurality of reference reflectors arranged as reflection reference points at predetermined positions in the detection target region, and the measurement device is determined as a reflection object observation unit. The reflection object observing means receives a reflected wave from the reference reflector and the reflection object by irradiating a detection target region with an electromagnetic wave, and receives the reflected wave from the received reflected wave. And the distance to the reflecting object and the reflection intensity are observed, and the determination processing unit determines that there is an obstacle when the variation in the distance and the reflection intensity observed by the reflecting object observation unit is within a reference range, and The self-diagnosis means determines that the apparatus is abnormal when fluctuations in distance and reflection intensity between the reference reflector and the reflection object observed by the reflection object observation means are outside a predetermined reference range.

  The reflecting object observing means irradiates electromagnetic waves to the entire horizontal and vertical directions of the detection target region to prevent obstacle detection leaks.

  Further, the reflection object observing means irradiates millimeter wave band or microwave band electromagnetic waves, and the reference reflector is also less susceptible to disturbance by observation of the distance and reflection intensity, thereby preventing erroneous detection.

  Further, when the distance and the reflection intensity observed by the reflecting object observing means have fluctuated for a certain time, the determination processing means determines that the reflecting object is an obstacle and prevents erroneous detection.

  The self-diagnostic means determines that the apparatus is abnormal when the reflection intensity deviates from a predetermined threshold for a predetermined time or more and the distance between the reference reflector and the reflection object deviates from the detection target area. And less susceptible to natural fluctuations and disturbances.

  Furthermore, the detection target area is used as a railroad crossing, and the presence or absence of obstacles in the railroad crossing and the presence or absence of a device abnormality are reliably detected to ensure safe driving of the train and the safety of cars and pedestrians passing through the railroad crossing. .

  In the obstacle detection method of the present invention, an electromagnetic wave is irradiated to a detection target region, a reflected wave from a reflected object is received, a distance and a reflected intensity from the received reflected wave to the reflected object are observed, and the observed distance and reflected It is characterized by determining the presence or absence of an obstacle by determining the fluctuation in intensity, and determining that the apparatus is abnormal when the observed distance to the reflecting object and the fluctuation in reflection intensity are outside a predetermined reference range.

  This invention receives the reflected wave from the reflected object of the electromagnetic wave irradiated to the detection target area, determines the distance from the received reflected wave to the reflected object and the fluctuation of the reflected intensity, and determines the presence or absence of an obstacle. At the same time, it is possible to determine whether there is an abnormality in the device based on whether the observed distance to the reflecting object and the fluctuation in reflection intensity are outside the predetermined reference range, thereby preventing erroneous detection of the obstacle and accurately detecting the obstacle. The presence or absence can be detected.

  In addition, it is possible to reliably detect the presence or absence of an obstacle in the detection target region by irradiating the entire surface in the horizontal direction and the vertical direction of the detection target region with electromagnetic waves and preventing an obstacle from being detected.

  Furthermore, by irradiating the detection target region with electromagnetic waves in the millimeter wave band or the microwave band, it is difficult to be affected by disturbances, and erroneous detection can be prevented.

  In addition, when the observed distance and reflection intensity fluctuate for a certain period of time, it is determined that the reflection object is an obstacle, or the reflection intensity deviates from a predetermined threshold for a certain period of time and the reference reflector or reflection object When the distance to the point deviates from the detection target area, it is determined that the device is abnormal, making it less susceptible to natural fluctuations and disturbances, and reliably determining whether there is an obstacle or whether there is a device abnormality. Can do.

  In addition, by using the detection target area as a railroad crossing and detecting the presence or absence of obstacles on the railroad crossing and the presence or absence of equipment abnormalities, we will ensure safe driving of the train and the safety of cars and pedestrians passing through the railroad crossing. be able to.

  FIG. 1 is a perspective view showing the structure of a crossing obstacle detection device according to the present invention. As shown in the figure, the level crossing obstacle detection device provided on the level crossing road 2 of the track 1 on which the train travels is composed of two sets of measuring devices 3a and 3b and a plurality of sets, for example, when the track 1 is a double track, When reflectors 4a to 4f serving as reflection reference points are provided and track 1 is a double line as shown in FIG. 2, it has ten sets of reflectors 4a to 4j. The measuring devices 3a and 3b are installed at an optimum fixed height that can detect pedestrians such as infants and wheelchairs and light vehicles to large vehicles at the entrance and exit of the level crossing road 2 and in the vicinity of the level crossing barrier 6 respectively. It is connected to the crossing control device 5 via an interface. Each reflector 4 is located near the railroad crossing barrier 6 across the railroad crossing 2, outside the railroad track 1 and the railroad crossing 2, and outside the track 1 between the railroad 1 and the railroad crossing barrier 6 across the railroad crossing 2. It is arranged at the position.

  As shown in the block diagram of FIG. 3, the measuring device 3 includes a reflective object observation unit 7, a determination processing unit 8, a storage unit 9, and a self-diagnosis unit 10.

  The reflection object observation unit 7 irradiates the railroad crossing 2 with an electromagnetic wave, for example, a millimeter wave, receives the reflection wave from each reflector 4 and observes the distance to each reflector 4 and the reflection intensity. IF (Intermediate Frequency) / BB (Base Band) unit 11, RF (Radio Frequency) unit 12, antenna 13, and signal processing unit 14. The IF / BB unit 11 frequency-modulates the transmission wave in accordance with the radar system, obtains an intermediate frequency signal, and sends it to the RF unit 12. This radar system may be any of FM (Frequency Modulated) -CW (Continuous Wave) system, pulse system, 2-frequency CW system, or spread spectrum system as long as the distance of an object can be detected. The RF unit 12 sends the intermediate frequency signal frequency-modulated by the IF / BB unit 11 to the antenna 13 after performing power amplification and frequency multiplication in the millimeter wave band. The antenna 13 irradiates the railroad crossing 2 with a millimeter wave transmission signal that is frequency-modulated into a triangular wave, a sine wave, or a rectangular wave from the RF unit 12, and receives a reflected wave from the reflector 4. Further, the RF unit 12 amplifies the reflected wave from the reflector 4 received by the antenna 13 with low noise and sends the amplified wave to the IF / BB unit 11. The IF / BB unit 11 mixes the reflected wave and the transmission wave received by the RF unit 12 to obtain a beat signal including a distance component. The signal processing unit 14 samples the beat signal obtained by the IF / BB unit 11 and performs digital conversion, and uses spectrum analysis from fast Fourier calculation to calculate millimeter waves from spectrum data of frequency and received power intensity (reflection intensity). The distance to the reflection position and the reflection intensity are calculated. The storage unit 9 stores in advance the distance to the reflector 4 corresponding to the measuring device 3 as the range of the detection target region.

  As shown in the layout diagram of FIG. 1 or FIG. 2, the antenna 13 of the reflecting object observing unit 7 is provided with a pencil beam antenna corresponding to the number of reflectors 4 that reflect the irradiated millimeter wave, or a horizontal millimeter wave. The wide beam method for detecting the plurality of reflectors 4 by widening the beam width or the electronic scanning method for electronically switching a plurality of antennas is selected. The width of the millimeter wave irradiated from the antenna 13 in the horizontal direction is such that there is no gap so that the entire surface of the railroad crossing 2 can be irradiated. For example, as shown in FIG. 2, when a pencil beam type antenna 13 is used at a crossing of multiple lines, millimeter wave beams 15 irradiated from the pencil beam antennas of one antenna 13a overlap each other, and the other antenna 13b The millimeter-wave beams 15 irradiated from the pencil beam antennas are overlapped with each other so that the entire surface of the railroad crossing 2 is irradiated from the antennas 13a and 13b. Further, the vertical beam width of the millimeter wave irradiated from the antenna 13 prevents the irradiated beam 15 from passing between the wheels of the large vehicle, as shown in FIG.

  The determination processing unit 8 receives the control of the railroad crossing control device 5 and stores the distance to the reflection position of the millimeter wave output from the signal processing unit 14 of the reflection object observation unit 7 and the reflection intensity in the storage unit 9 until the reflection position. The presence or absence of an obstacle is determined from the distance and the reflection intensity fluctuation, and the determination result is output to the crossing control device 5.

  The self-diagnosis unit 10 inputs the distance from the determination processing unit 8 to the reflection position of the millimeter wave and the reflection intensity, diagnoses whether there is an abnormality in the measuring device 3, and outputs the diagnosis result to the level crossing control device 5. There is an abnormality in the measuring device 3 when the reflection intensity deviates from a predetermined range determined according to natural fluctuation for a certain time and the distance to the reflection position deviates from the level crossing 2 that is the detection target area. Is determined.

  The level crossing control device 5 inputs the obstacle determination processing result and the self-diagnosis determination result from the measuring device 3 and detects the presence of an obstacle on the level crossing 2 or when an abnormality occurs in the measuring device 3 Then, a signal notifying the abnormality is sent to the alarm device 16, the alarm device 16 is caused to emit light, and the status is sent to the maintenance device 18 via the notification device 17 to notify the administrator.

  Processing when the presence of an obstacle in the railroad crossing 2 is detected by the measuring device 3 configured as described above will be described with reference to the flowchart of FIG.

  First, as shown in FIG. 5, the determination processing unit 8 of the measuring device 3 confirms whether the initial setting mode or the detection execution mode is set as the operation mode (step S1), and the crossing control device 5 When the initial setting mode is set as the operation mode (step S2), all the processes are reset and the reflection object observation unit 7 starts measurement (step S3). The reflecting object observing unit 7 irradiates the level crossing 2 which is the detection target area with no obstacle, receives the reflected wave, and reaches each reflector 4 which is the reference reflecting object in the detection target area. The distance and the reflection intensity are observed for a certain time (step S4). That is, the signal processing unit 14 of the reflecting object observation unit 7 sends a transmission wave to the IF / BB unit 11. The IF / BB unit 11 modulates the frequency of the transmitted transmission wave and sends an intermediate frequency signal to the RF unit 12. The RF unit 12 generates a millimeter wave by the transmitted intermediate frequency signal and irradiates the railroad crossing 2 from the antenna 13. The reflected wave received by the antenna 14 is amplified with low noise and sent to the IF / BB unit 11. The IF / BB unit 11 generates a beat signal including a distance component from the received reflected wave and transmission wave, and sends the beat signal to the signal processing unit 14. The signal processing unit 14 samples the sent beat signal, performs digital conversion, calculates the distance to each reflector and the reflection intensity, and sends it to the determination processing unit 8.

  The determination processing unit 8 selects the reflection object in the detection target region, that is, the reflection intensity of each reflector 4 from the distance to each reflection object and the reflection intensity sent, and sets a predetermined range for the observed reflection intensity to each reflector. It is recorded in the storage unit 9 as background information for obstacle determination together with a distance variation allowable range up to 4 (step S5). As shown in FIG. 6, the range of the reflection intensity is obtained by paying attention to the beam 15 that irradiates the region of one reflector 4 provided at the distance R0 from the antenna 14 of the measuring device 3, and the observed reflection intensity is P0. Then, (P0 + n) is stored in the storage unit 9 as the reflection intensity range as the maximum value of the reflection intensity considering natural variation and (P0-n) as the minimum value of the reflection intensity. Then, the detection information and the like recorded in the storage unit 9 are erased (step S6).

  In this state, when the detection execution mode is set as the operation mode by the level crossing control device 5 (step S7), the measuring device 3 radiates millimeter waves into the level crossing road 2, and all reflected waves from within the level crossing road 2 are emitted. The distance to the reflection position of the received reflected wave and the reflection intensity are detected and sent to the determination processing unit 8 (step S8). The determination processing unit 8 compares the distances and reflection intensities to the reflection positions in the detection target area from the distances and reflection intensities sent to the respective reflection positions and the background information recorded in the initial setting mode. The difference is determined (step S9). As a result of this determination, when the distance to each reflection position in the detection target area and the reflection intensity are not different from the background information, the reflection object observation unit 7 observes the distance to each reflection position and the reflection intensity. Is repeated at a processing cycle of, for example, 100 milliseconds (steps S10 and S8).

  When this observation is continued and a difference from the background information occurs in the distance to each reflection position in the detection target region and the reflection intensity (step S10), there is a suspicion that an obstacle exists or an abnormality has occurred in the apparatus. The determination processing unit 8 continues the determination process as suspicious. Then, it is determined whether or not the distance to the reflection position where the difference from the background information is outside the allowable range of the distance to each reflector 4 included in the background information (step S11). As a result of this determination, when the distance to the reflection position is outside the allowable range of fluctuation of the distance to each reflector 4, the reflection intensity that is different from the background information is greater than the range of the reflection intensity of each reflector 4 included in the background information. Is determined (step S12). As a result of this determination, when the distance to the reflection position is outside the allowable fluctuation range of the distance to each reflector 4, and the reflection intensity that differs from the background information is greater than or equal to the reflection intensity range of each reflector 4 included in the background information. The detection information is recorded in the storage unit 9 (step S13).

  For example, as shown in FIG. 7, when attention is paid to a beam 15 that irradiates a region of one reflector 4 provided at a distance R0 from the antenna 14 of the measuring device 3, the vehicle 19 traveling on the railroad crossing 2 is in the horizontal direction. When present at positions C0 and C4 outside the beam 15, only the reflection intensity P0 corresponding to the distance R0 to the reflector 4 is observed as shown in the change characteristic diagram of the received intensity distribution with respect to the distance in FIG. On the other hand, when the vehicle 19 exists at the positions C1 and C3 in the beam 15, the reflection intensity P0 corresponding to the distance R0 to the reflector 4 and the reflection intensity corresponding to the distance to the positions C1 and C3 are observed. . When the vehicle 19 exists at a distance R1 close to the measuring device 3, the observed reflection intensity is the highest reflection intensity P2, and the reflection intensity observed as the vehicle 19 moves away from the measuring device 3 by the distances R1, R2, R0. Is as low as reflection intensities P2, P1, and P0. Therefore, when the vehicle 19 is present in the railroad crossing 2, the reflection intensities P2 and P1 are not less than the reflection intensity range (P0 + n) of each reflector 4, and an obstacle exists in the railroad crossing 2.

  The determination processing unit 8 continues this process, and the distance to the reflection position where the difference from the background information is out of the allowable range of the distance to each reflector 4, and the reflection intensity where the difference from the background information is different. The number of detections that are equal to or greater than the reflection intensity range of each reflector 4 included in the background information is counted (step S14), and it is determined whether or not the number of detections exceeds the predetermined number when a predetermined time has elapsed (step S15, S16). If the number of detections exceeds the predetermined number as a result of this determination, the determination processing unit 8 determines that there is a stationary obstacle or a moving obstacle on the railroad crossing 2 (step S17), and the obstacle detection time. The obstacle detection information indicating the position is recorded in the storage unit 9 and sent to the crossing control device 5 (step S18).

  When the level crossing control device 5 inputs the obstacle detection information, the alarm device 16 informs that there is an obstacle on the level crossing 2 and sends the situation to the maintenance device 18 via the notification device 17 to inform the manager.

  In addition, as a result of determining whether or not the distance to the reflection position where the difference from the background information occurs is outside the allowable fluctuation range of the distance to each reflector 4 included in the background information (step S11), the difference from the background information occurs. When the distance to the reflection position is within the allowable fluctuation range of the distance to each reflector 4 included in the background information, that is, when only the distance R0 to the reflector 4 and the reflection intensity are observed, the difference from the background information is different. When this occurs, the self-diagnosis unit 10 enters a self-diagnosis process for determining whether an abnormality has occurred in the measuring device 3. If the self-diagnosis unit 10 determines that the distance to the reflection position where the difference from the background information has occurred in the determination processing unit 8 is within the allowable variation range of the distance to each reflector 4 included in the background information, the self-diagnosis unit 10 differs from the background information. It is determined whether or not the reflection intensity at which the above occurs is within the range of the reflection intensity of each reflector 4 included in the background information (step S19). As a result of this determination, when the reflection intensity that is different from the background information is outside the range of the reflection intensity of each reflector 4 included in the background information, the number of detections that are outside the range of the reflection intensity is counted (step S20). When the predetermined time has elapsed, it is determined whether or not the number of detections exceeds the predetermined number (steps S21 and S22). If the number of detections exceeds the predetermined number as a result of this determination, the self-diagnosis unit 10 sends information indicating that an abnormality has occurred in the measuring device 3 to the crossing control device 5 (step S23). Further, if the number of detections does not exceed the predetermined number after the predetermined time has elapsed, the measurement apparatus 3 is automatically temporarily set to the initial setting mode for self-confirmation to generate a reference background and perform detection processing. This is executed (steps S24 and S3).

  Further, it is determined whether or not the distance to the reflection position where the difference from the background information is outside the allowable fluctuation range of the distance to each reflector 4 included in the background information (step S11). As a result of this determination, the reflection position When the distance to the reflector 4 is outside the allowable fluctuation range of the distance to each reflector 4, the result of determining whether or not the reflection intensity that is different from the background information is greater than or equal to the reflection intensity range of each reflector 4 included in the background information ( Step S12) Even when the distance to the reflection position is outside the permissible range of the distance to each reflector 4 and the reflection intensity is within the reflection intensity range of each reflector 4 included in the background information, the self-diagnosis unit 10 is self-diagnosis. The diagnosis processing is entered, and the number of times of detection that the distance to the reflection position is outside the permissible range of the distance to each reflector 4 and the reflection intensity is within the reflection intensity range of each reflector 4 included in the background information is measured. (Step S20), when a predetermined time has elapsed, it is determined whether the number of detection times exceeds a predetermined number of times (step S21, S22). If the number of detections exceeds the predetermined number as a result of this determination, the self-diagnosis unit 10 sends information indicating that an abnormality has occurred in the measuring device 3 to the crossing control device 5 (step S23).

  When the level crossing control device 5 inputs information indicating that an abnormality has occurred in the measuring device 3, the level crossing control device 5 stops the processing of the measuring device 3, causes the alarm device 16 to notify the abnormality, and notifies the situation via the notification device 17. Send to 18 and tell the administrator.

  In the above description, the millimeter wave band electromagnetic wave is irradiated from the measuring device 3 to the control target region. However, the millimeter wave band electromagnetic wave is not limited and may be a microwave band.

  In the above description, the case of detecting an obstacle on the railroad crossing 2 has been described. However, the present invention can be similarly applied to detection of an intruding object for crime prevention, for example.

It is a perspective view which shows the structure of the level crossing obstruction detection apparatus of this invention. It is a top view which shows arrangement | positioning of a crossing obstruction detection apparatus in the case of a double track. It is a block diagram which shows the structure of a measuring device. It is a side view which shows the beam irradiated from a measuring device. It is a flowchart which shows an obstruction detection process. It is a schematic diagram which shows the reflected beam of a reflector. It is a schematic diagram which shows the reflected beam according to a position to the vehicle which drive | works a railroad crossing. It is a change characteristic view of the received intensity distribution with respect to distance.

Explanation of symbols

1; track, 2; railroad crossing, 3; measuring device, 4; reflector, 5; railroad crossing control device,
6; Railroad crossing barrier, 7; Reflected object observation unit, 8; Determination processing unit, 9; Storage unit,
10; Self-diagnosis unit, 11; IF / BB unit, 12; RF unit, 13; Antenna,
14; Signal processing unit, 16; Alarm device, 17; Notification device, 18; Maintenance device.

Claims (10)

A measuring device and one or a plurality of reference reflectors arranged as reflection reference points at predetermined positions in the detection target region;
The measuring apparatus includes a reflected object observation unit, a determination processing unit, and a self-diagnosis unit, and the reflected object observation unit receives an electromagnetic wave on a detection target region and receives a reflected wave from the reference reflector and the reflected object. Then, the distance and the reflection intensity from the received reflected wave to the reference reflector and the reflection object are observed, and the determination processing means has a variation in the distance and the reflection intensity observed by the reflection object observation means within the reference range. When it is determined that there is an obstacle, the self-diagnostic means is a device when the distance between the reference reflector and the reflection object observed by the reflection object observation means and the fluctuation of reflection intensity are outside a predetermined reference range. An obstacle detection device characterized by determining an abnormality.   The obstacle detection device according to claim 1, wherein the reflection object observation unit irradiates electromagnetic waves to the entire horizontal and vertical directions of the detection target region.   The obstacle detection device according to claim 1, wherein the reflection object observation unit irradiates electromagnetic waves in a millimeter wave band or a microwave band.   4. The obstacle detection according to claim 1, wherein the determination processing unit determines that the reflection object is an obstacle when the distance observed by the reflection object observation unit and the reflection intensity fluctuate for a certain time. apparatus.   The self-diagnosis means determines that the apparatus is abnormal when the reflection intensity deviates from a predetermined threshold for a certain time or more and the distance to the reference reflector or reflection object deviates from the detection target area. Item 5. The obstacle detection device according to any one of Items 1 to 4.   The obstacle detection device according to claim 1, wherein the detection target region is a railroad crossing.   Irradiate an electromagnetic wave to the detection target area, receive the reflected wave from the reflected object, observe the distance and reflected intensity from the received reflected wave to the reflected object, determine the observed distance and reflected intensity fluctuation, and check the obstacle An obstacle detection method characterized by determining whether or not a device is abnormal, and determining that the apparatus is abnormal when fluctuations in the observed distance to the reflecting object and the reflection intensity are outside a predetermined reference range.   The obstacle detection method according to claim 7, wherein the electromagnetic wave applied to the detection region is an electromagnetic wave in a millimeter wave band or a microwave band.   The obstacle detection method according to claim 7 or 8, wherein when the observed distance and reflection intensity fluctuate for a certain time, the reflection object is determined as an obstacle. The failure according to any one of claims 7 to 9, wherein when the reflection intensity deviates from a predetermined threshold for a predetermined time or more and the distance to the reflection object deviates from the detection target area, it is determined that the apparatus is abnormal. Object detection method.

Images