JP4731517B2 - Railroad crossing obstacle detection device - Google Patents

Description

  The present invention relates to an obstacle detection device that detects, for example, an automobile or a pedestrian on a railroad crossing on a track on which a train travels, and particularly relates to improvement in detection accuracy.

  Railroad crossing warning devices for railroad safety devices start a railroad crossing warning when a train traveling on a track approaches the railroad crossing, block traffic on the railroad crossing, and drive 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. On the other hand, as shown in Patent Document 1 and Patent Document 2, a crossing obstacle detection device using a short millimeter sensor having a wavelength of several millimeters among microwaves is not easily affected by weather, illuminance, and the like, and is simple. It is possible to reliably detect an obstacle in a level crossing with the configuration.

  The crossing obstacle detection device disclosed in Patent Document 1 is composed of a radar using laser light and millimeter waves, and radiates laser light and millimeter waves into the crossing from a rotationally driven distance sensor, and based on the reflected signal. 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. In addition, it is determined whether or not the detected object is an obstacle. In addition, reflectors are provided at three different corners outside the railroad crossing, and the rotation direction and transmission / reception performance of the distance sensor are checked and calibrated based on the reflection signal of the reflector.

A crossing obstacle detection device disclosed in Patent Document 2 includes a measuring device having a millimeter wave sensor and a reflector across a railroad crossing, and radiates millimeter waves from the reflector to the railroad crossing from the millimeter wave sensor of the measuring device. When a reflected wave is received, the distance and reflected intensity from the received reflected wave to the reflector are observed, and the fluctuation in the observed distance to the reflector and reflected intensity is outside the predetermined reference range, an abnormality occurs in the measuring device. It has a self-diagnosis function to determine that
JP 2003-11824 A JP 2005-233615 A

  When irradiating a millimeter wave to a railroad crossing with the crossing obstacle detection device shown in Patent Document 1 and Patent Document 2, a beam having a certain angle with respect to the horizontal direction is irradiated, and reflection from an object within the range is performed. A wave is received to determine whether there is an obstacle. When detecting obstacles using this millimeter wave, the detection range is defined by the horizontal receiving sensitivity and measurement distance, but the characteristics of the elements of the millimeter wave sensor that transmits and receives millimeter waves fluctuate due to temperature changes, etc. However, as the transmission power and reception sensitivity change, an error occurs in the measurement distance. For this reason, the detection range in the horizontal direction may fluctuate, and for example, an object outside the detection range such as the outside from the crossing barrier may be determined as an obstacle.

  An object of the present invention is to provide a railroad crossing obstacle detection device that improves such disadvantages and can reliably detect an obstacle by preventing an erroneous detection of the obstacle with a simple configuration. .

The level crossing obstacle detection device of the present invention includes a plurality of standard reflectors, a sensor unit, and a processing device, and the plurality of standard reflectors are disposed at predetermined positions outside the obstacle detection region across the level crossing. The sensor unit has a plurality of surface sensors and is installed in the vicinity of a level crossing barrier provided on a level crossing, and the plurality of surface sensors are arranged at a certain angle with respect to the horizontal direction, The processing device is set in advance by irradiating a millimeter-wave beam having a certain angle in the vertical direction and receiving a reflected beam from an opposing standard reflector and a reflected beam from an obstacle in a railroad crossing. An obstacle is detected from the reception signal of the surface sensor in accordance with a change in reflection intensity obtained from the reflection signal from the standard reflector input from the surface sensor with respect to the reference reflection intensity of the standard reflector. And correcting the threshold of fit.

In the processing device, a known distance between the surface sensor and the standard reflector and a maximum detection distance of the surface sensor are preset, and a known distance between the surface sensor and the standard reflector, It is desirable to correct the maximum detection distance of the surface sensor based on the measurement distance to the standard reflector detected by the reception signal input from the surface sensor.

Further, the processing device is set with a maximum detection distance of each surface sensor when the train does not pass through the railroad crossing and a maximum detection distance of each surface sensor when the train passes, and an obstacle is detected when the train passes. It is preferable to reduce the maximum detection distance of each surface sensor to be detected.

  In this invention, a standard wave reflector is irradiated with a millimeter wave beam from a surface sensor, the reflection intensity from the standard reflector is measured from the received signal of the reflection beam from the standard reflector, and the reference reflection with the measured reflection intensity is set. Improve the accuracy of the obstacle detection area by correcting the threshold for detecting obstacles from the reception signal of the surface sensor according to changes in strength and narrowing the horizontal detection area of the surface sensor within the railroad crossing It is possible to eliminate the blind spot of the obstacle detection, and to prevent the object outside the railroad crossing barrier and the fence from being detected as an obstacle, so that the obstacle in the railroad crossing can be detected stably.

  In addition, the maximum detection distance of the preset surface sensor is corrected based on the known distance between the preset surface sensor and the standard reflector and the measured distance to the standard reflector detected by the received signal input from the surface sensor. By narrowing down the detection area, the accuracy of the obstacle detection area can be increased.

  In addition, set the maximum detection distance of each surface sensor that detects obstacles when the train passes along with the maximum detection distance of each surface sensor when the train does not pass the railroad crossing in the processing device, and set each maximum detection distance It is possible to prevent a train passing through a railroad crossing from being detected as an obstacle by correcting the obstacle and narrowing the obstacle detection area.

  FIG. 1 is a block diagram showing a configuration of a crossing obstacle detection device of the present invention. As shown in the figure, the level crossing obstacle detection device 1 includes two sets of sensor units 2a and 2b, a processing device 3, and a plurality of reflectors 4a to 4f serving as reflection reference points. Each of the two sets of sensor units 2 has three sets of surface sensors 5a to 5c, and walks in the vicinity of the level crossing barrier 8 provided on the level crossing 7 of the track 6 as shown in the layout diagram of FIG. It is installed at a certain height that can detect people and vehicles. The reflectors 4a and 4d have two reflecting surfaces that are orthogonal to each other, and are disposed at positions outside the track 6 that faces the railroad crossing barrier 8 with the railroad crossing 7 interposed therebetween. The reflectors 4b and 4e are disposed between the tracks 6. The reflectors 4 c and 4 f are disposed at positions outside the railroad track 6 and the railroad crossing 7 near the railroad crossing barrier 8 across the railroad crossing 7. The surface sensors 5a to 5c are arranged at a constant angle α with respect to the horizontal direction, and receive a reflected beam from an obstacle in the railroad crossing 7 by a millimeter wave beam 9 having a constant angle in the horizontal direction and the vertical direction. The surface sensor 5a provided in one sensor unit 2a receives the reflected beam from the reflector 4a or the reflector 4b at an angle α in the horizontal direction that irradiates the millimeter wave beam 9, and the surface sensor 5b receives from the reflector 4b or the reflector 4c. The surface sensor 5c receives the reflected beam, and receives the reflected beam from the reflector 4c or the reflector 4d. The surface sensor 5a provided in the other sensor unit 2b receives the reflected beam from the reflector 4d or the reflector 4e, the surface sensor 5b receives the reflected beam from the reflector 4e or the reflector 4f, and the surface sensor 5c is reflected by the reflector 4f or The reflected beam from the reflector 4a is received.

  The processing device 3 includes a signal processing unit 10, a detection condition storage unit 11, a reflection intensity measurement unit 12, a distance calculation unit 13, a reflection intensity determination unit 14, a threshold correction unit 15, a maximum detection distance correction unit 16, and a data processing unit 17. Have. The signal processing unit 10 removes unnecessary signals from the signals input from the surface sensors 5a to 5c and outputs a target received signal. In the detection condition storage unit 11, for example, set distances Rai to Rci between the reflectors 4 that are previously opposed to the surface sensors 5a to 5c, reference reflection strengths Pai to Pci of reflection strength from the opposing reflectors 4, and the surface sensors 5a to 5c. A reference threshold Th1 for detecting a person for each of the surface sensors 5a to 5c, a reference threshold Th2 for detecting a car, and a surface sensor 5a necessary for detecting an obstacle in the railroad crossing 8 at normal time from the received signal of 5c. The maximum detection distances Ra to Rc of ˜5c and the maximum detection distances Rta to Rtc of the surface sensors 5a to 5c determined so as not to detect the train passing through the railroad crossing 8 as an obstacle when the train passes are stored. The reference threshold value Th1 for detecting a person and the reference threshold value Th2 for detecting a car are strong in the reflection level from the person and the reflection level from the car. Therefore, the reference threshold value for detecting a person. Th1 is higher than a reference threshold Th2 for detecting the automobile.

  The reflection intensity measurement unit 12 receives the reception signals of the surface sensors 5a to 5c from the signal processing unit 10, and measures the reflection intensities Pas to Pcs from the reflector 4 with which the millimeter wave beam 9 faces from the input reception signal. The distance calculation unit 13 inputs the reception signals of the surface sensors 5a to 5c and calculates distances Ras to Rcs to the opposing reflector 4. The reflection intensity determination unit 14 compares the reflection intensities Pas to Pcs measured by the reflection intensity measurement unit 11 with the reference reflection intensities Pai to Pci stored in the detection condition storage unit 12 from the opposite reflector 4 of the millimeter wave beam 9. The presence / absence of the change in the reflection intensity and the degree of the change are detected. The threshold correction unit 15 corrects the reference thresholds Th1 and Th2 stored in the detection condition storage unit 11 based on the degree of change in the reflection intensity from the reflector 4 detected by the reflection intensity determination unit 14. The maximum detection distance correction unit 16 receives a signal indicating whether or not a train has passed from the railroad crossing control device 18 and calculates a distance from any of the maximum detection distances Ra to Rc and the maximum detection distances Rta to Rtc stored in the detection condition storage unit 11. Correction is performed by the measured distances Ras to Rcs between the surface sensors 5a to 5c and the reflector 4 calculated by the unit 13 and the known set distances Rai to Rci. The data processing unit 17 detects the presence or absence of an obstacle based on the threshold value corrected by the threshold value correction unit 15 and the maximum detection distance corrected by the maximum detection distance correction unit 16 from the reception signals of the surface sensors 5a to 5c.

  Processing when the crossing obstacle detection device 1 detects an obstacle existing in the crossing road 7 will be described with reference to the flowchart of FIG.

  The surface sensors 5a to 5c of one sensor unit 2a irradiate the millimeter wave beam 9 at all times or at a predetermined period, and the surface sensor 5a receives a reflected beam from, for example, the reflector 4a and processes the received signal. The surface sensor 5b receives, for example, the reflected beam from the reflector 4b and outputs a received signal to the processing device 3, and the surface sensor 5c receives, for example, the reflected beam from the reflector 4d and processes the received signal. Output to. The signal processing unit 10 of the processing device 3 processes the input signal and outputs the reception signals of the surface sensors 5a to 5c to the reflection intensity measuring unit 12 and the distance measuring unit 13, respectively (step S1). The reflection intensity measurement unit 12 measures the reflection intensities Pas to Pcs from the reflectors 4a, 4b, and 4d from the input reception signal and outputs the measurement to the reflection intensity determination unit 14 (step S2). The distance measuring unit 13 measures the distances Ras to Rcs between the surface sensors 5a to 5c and the reflectors 4a, 4b, and 4d based on the received reception signal, and outputs the distances to the maximum detection distance correcting unit 16 (step S3). The reflection intensity determination unit 14 compares the measured reflection intensity Pas to Pcs with the reference reflection intensity Pai to Pci stored in advance in the detection condition storage unit 11, and reflects the reflection intensity of the millimeter wave beam 9 from the reflectors 4a, 4b, and 4d. Change amounts ΔPa to ΔPc are detected, and the detected reflection intensity change amounts ΔPa to ΔPc are output to the threshold correction unit 15 (step S4). The threshold value correction unit 15 corrects the reference threshold values Th1 and Th2 stored in the detection condition storage unit 11 as the threshold values Th11 and Th21 based on the reflection intensity changes ΔPa to ΔPc input from the reflection intensity determination unit 14, and the corrected threshold values Th11 and Th21. Is output to the data processing unit 18 (step S5).

  On the other hand, the maximum detection distance correction unit 16 inputs the measurement distances Ras to Rcs from the distance measurement unit 13 to the reflectors 4a, 4b, and 4d at the normal time when the train passing signal is not input from the level crossing control device 18, and the input measurement The maximum detection distances Ra to Rc of the detection areas by the surface sensors 5a to 5c stored in the detection condition storage unit 11 are corrected by the distances Ras to Rcs and the known set distances Rai to Rci stored in the detection condition storage unit 11. It correct | amends to -Rcc (step S6, S7). That is, the characteristics of the transmission / reception units constituting the surface sensors 5a to 5c vary with temperature, and an error occurs in the measurement distance. Therefore, reflectors 4a, 4b and 4d, which are standard reflectors, are provided at known set distances Rai to Rci, and the measurement distances Ras to Rcs calculated by receiving the reflected beams from the reflectors 4a, 4b and 4d by the surface sensors 5a to 5c. For example, the maximum detection distance Ra of the surface sensor 5a is corrected as a corrected maximum detection distance Rac = (Rai / Ras) · Ra.

  When the data processing unit 17 receives the reception signals from the surface sensors 5a to 5c, the data processing unit 17 performs an obstacle detection process using the received signals that exceed the correction threshold values Th11 and Th21 input from the threshold value correction unit 15 among the input reception signals. (Step S8). That is, the detection range in which the obstacle is detected by the millimeter wave beams 9a to 9c irradiated by the surface sensors 5a to 5c is determined by the threshold value of the received signal due to reflection from the obstacle, and as shown in FIG. When there is a received signal that exceeds the reference threshold values Th1 and Th2 determined according to the reflection intensity Pai, an obstacle is present, and the detection angle α in the horizontal direction is determined by the reference threshold values Th1 and Th2. When the reflection intensity changes, for example, as shown in FIG. 4B, when the reflection intensity Pas is larger than the standard reflection intensity Pai, if the presence or absence of an obstacle is detected by the reference threshold values Th1 and Th2, the horizontal direction Detection angle spreads to an angle β, and an object outside the level crossing barrier 9 is detected as an obstacle. Therefore, when the reflection intensity Pas changes with respect to the standard reflection intensity Pai, as shown in FIG. 4C, horizontal detection is performed as thresholds Th11 and Th21 obtained by largely correcting the reference thresholds Th1 and Th2 according to the change amount ΔP. The horizontal detection area is narrowed down in the railroad crossing 7 so that the angle becomes the angle α. Further, when detecting an obstacle, it is assumed that there is no obstacle to be detected in a range exceeding the corrected maximum detection distances Rac to Rcc of the detection area by the surface sensors 5a to 5c input from the maximum detection distance correction unit 16. In this way, the accuracy of the obstacle detection area can be improved, the blind spot for obstacle detection can be eliminated, and an object outside the level crossing barrier 8 and a barrier can be detected as obstacles.

  When the processing device 3 repeats the various processes (steps S9, S1 to S8) and inputs a train passing signal from the crossing control device 18, the maximum detection distance correction unit 16 receives the measurement distances Ras to Rcs input from the distance measurement unit 13. FIG. 5 shows the maximum detection distances Rta to Rtc of the detection area by the surface sensors 5a to 5c at the time of passing the train stored in the detection condition storage unit 11 by the known set distances Rai to Rci stored in the detection condition storage unit 11. As described above, the corrected maximum detection distances Rtac to Rtcc are corrected and output to the data processing unit 17 (step S10). The data processing unit 17 performs an obstacle detection process assuming that there is no obstacle to be detected in the range exceeding the input corrected maximum detection distances Rtac to Rtcc (step S8). In this way, it is not necessary to detect the train 19 passing through the railroad crossing 7 as an obstacle.

  In the above description, the case where the sensor units 2a and 2b are provided with three sets of surface sensors 5a to 5c has been described. However, the sensor units 2a and 2b are provided with one set of surface sensors 5, and the surface sensor 5 is fixed at a certain angle. You may scan every time.

It is a block diagram which shows the structure of the level crossing obstacle detection apparatus of this invention. It is a top view which shows arrangement | positioning of a sensor unit with respect to a railroad crossing, and an irradiation beam. It is a flowchart which shows the process of a level crossing obstruction detection apparatus. It is a schematic diagram which shows the detection angle of the horizontal direction of the surface sensor which changes with the threshold values with respect to reflection intensity. It is a top view which shows the correction | amendment maximum detection distance at the time of a train passage.

Explanation of symbols

1; Railroad crossing obstacle detection device, 2; Sensor unit, 3; Processing device, 4;
5; surface sensor, 6; track, 7; railroad crossing, 8; railroad crossing barrier, 9; millimeter wave beam,
10; Signal processing unit, 11; Detection condition storage unit, 12; Reflection intensity measurement unit,
13; distance calculation unit; 14; reflection intensity determination unit; 15; threshold correction unit;
16; Maximum detection distance correction unit, 17; Data processing unit, 18; Crossing control device, 19; Train.

Claims (3)

A plurality of standard reflectors, a sensor unit and a processing device;
The plurality of standard reflectors are arranged at predetermined positions outside the obstacle detection area across the railroad crossing,
The sensor unit has a plurality of surface sensors and is installed in the vicinity of a level crossing barrier provided on a railroad crossing, and the plurality of surface sensors are arranged at a fixed angle with respect to the horizontal direction, Irradiate a millimeter-wave beam having a certain angle in the vertical direction, receive a reflected beam from a standard reflector facing it, and receive a reflected beam from an obstacle in the railroad crossing,
The processing device detects an obstacle from a reception signal of the surface sensor in accordance with a change in reflection intensity obtained from a reflection signal from a standard reflector input from the surface sensor with respect to a reference reflection intensity of a standard reflector set in advance A crossing obstacle detection device characterized by correcting a threshold for detecting a road. In the processing device, a known distance between the surface sensor and the standard reflector and a maximum detection distance of the surface sensor are preset, and a known distance between the surface sensor and the standard reflector, The level crossing obstacle detection device according to claim 1, wherein a maximum detection distance of the surface sensor is corrected based on a measurement distance to a standard reflector detected by a reception signal input from the surface sensor. Wherein the processing unit, the maximum detection distance and, crossing obstacle detection according to claim 2, wherein the maximum detection range of each surface sensor during the train passage is set in each surface sensor when the crossing road train does not pass apparatus.

Images