JP7809478B2 - Obstacle detection device - Google Patents

Description

The present invention relates to an obstacle detection device that detects the presence or absence of an obstacle in a monitoring area.

One example of this type of obstacle detection device is the level crossing obstacle detection device described in Patent Document 1. This level crossing obstacle detection device is configured with a sensor circuit located near the level crossing and a level crossing control unit. The sensor circuit includes a laser sensor capable of emitting laser light of a predetermined beam size at the reflection reference point and receiving reflected light of the emitted laser light; a drive unit that rotates the laser sensor and intermittently emits laser light at predetermined timings; a target monitoring unit that outputs a first signal indicating that the reflection point of the laser light identified based on the output of the laser sensor is located within a predetermined monitoring area; and a second signal indicating that the reflection reference point has not been detected as a result of judging the laser sensor output. An abnormality judgment unit that outputs a third signal indicating that the laser sensor is not operating normally. The level crossing control unit judges the first, second, and third signals output by the sensor circuit and, if necessary, notifies a train that an obstacle is present at the level crossing and notifies an external party of an abnormality in the sensor circuit or the reflection reference point.

Patent No. 6179014

However, in the railroad crossing obstacle detection device described in Patent Document 1, the abnormality determination unit determines whether the laser sensor is abnormal based on the emitted laser light emitted toward areas other than the monitored area. As a result, the abnormality determination unit cannot determine whether the reflection reference point is abnormal.

Furthermore, in the railroad crossing obstacle detection device described in Patent Document 1, if the laser sensor's emission angle is a predetermined target judgment angle included in the range of the monitoring area angle and the reflection point of the laser light is determined to be located at the reflection reference point, the target monitoring unit ends processing without outputting either the first or second signal. On the other hand, if the laser sensor's emission angle is the target judgment angle and the reflection point of the laser light is determined to be located in the monitoring area, the target monitoring unit outputs the first signal, and if not, the target monitoring unit outputs the second signal. Therefore, for example, if an object is present at a position corresponding to the target judgment angle in the monitoring area, the target monitoring unit will not output the second signal.

In other words, with the level crossing obstacle detection device described in Patent Document 1, even if an abnormality occurs at the reflection reference point, this may not be reported to the outside. In other words, with the level crossing obstacle detection device described in Patent Document 1, there is a possibility that the opportunity to report to the outside that an abnormality has occurred in the device may be missed.

So-called obstacle detection devices, including the level crossing obstacle detection device described in Patent Document 1, are generally installed to ensure safety. However, such devices are assumed to be operating normally, and are required to promptly report any abnormalities, and even if there is a possibility that an abnormality has occurred, to the outside world and prompt appropriate action to be taken.

The present invention aims to provide an obstacle detection device that ensures safety while quickly notifying the outside world if there is a possibility of an abnormality occurring in the device.

According to one aspect of the present invention, an obstacle detection device includes a laser ranging sensor that scans a monitoring area with laser light and receives reflected light, and a light reflecting unit that is arranged on the opposite side of the laser ranging sensor across the monitoring area, and is configured to notify the outside that an obstacle is present if the reflection position of the scanned laser light is within the monitoring area , and to notify the outside that an abnormality may have occurred if it is determined that an abnormality may have occurred in the laser ranging sensor or the light reflecting unit based on the reflected light of the laser light in the direction of the light reflecting unit, determine whether the presence of an obstacle has already been notified to the outside, and if it has not already been notified, notify the outside that an obstacle is present.

The present invention provides an obstacle detection device that ensures safety while quickly notifying the outside world if there is a possibility of an abnormality occurring in the device.

1 is a diagram showing a railroad crossing where an obstacle detection device according to an embodiment is installed; FIG. 2 is a schematic plan view of the obstacle detection device. FIG. 2 is a block diagram showing a schematic configuration of a control system for an obstacle detection device and the like. 4 is a flowchart illustrating an example of processing performed by a processing unit of the obstacle detection device. 5 is a flowchart showing an example of a sensor diagnosis process performed in step S2 of FIG. 4. 5 is a part of a flowchart showing an example of the overall diagnosis process performed in step S3 of FIG. 4. 5 is a part of a flowchart showing an example of an overall diagnosis process performed in step S3 of FIG. 4. 5 is a part of a flowchart showing an example of the overall diagnosis process performed in step S3 of FIG. 4. 5 is a flowchart showing an example of an obstacle determination process performed in step S4 of FIG. 4.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

Figure 1 shows a railroad crossing RC on which an obstacle detection device 10 according to an embodiment of the present invention is installed, Figure 2 is a schematic plan view of the obstacle detection device 10, and Figure 3 is a block diagram showing the control system configuration of the obstacle detection device 10 and other components.

First, we will briefly explain the railroad crossing RC on which the obstacle detection device 10 according to the embodiment is installed.

Referring to Figure 1, railroad crossing warning devices 21, 21 and railroad crossing barriers 22, 22 are installed at the railroad crossing RC. However, Figure 1 only shows the railroad crossing warning devices 21, 21, railroad crossing barriers 22, 22, and road R on the far side of tracks T1, T2, and omits the railroad crossing warning devices 21, 21, railroad crossing barriers 22, 22, and road R on the near side of tracks T1, T2. Also, although not shown in Figure 1, a first train detection unit 51 (see Figure 3) is installed upstream of the railroad crossing RC on tracks T1, T2 in the direction of train travel for detecting a train approaching the railroad crossing RC, and a second train detection unit 52 (see Figure 3) is installed downstream of the railroad crossing RC on tracks T1, T2 in the direction of train travel for detecting that a train has passed the railroad crossing RC. The first train detection unit 51 and the second train detection unit 52 are not particularly limited, but may be composed of track circuits, ground coils, etc.

The operation of the crossing warning devices 21, 21 and crossing gates 22, 22 is controlled by the crossing control device 23. The crossing control device 23 receives a train detection signal from the first train detection unit 51 (hereinafter referred to as the "first train detection signal") and a train detection signal from the second train detection unit 52 (hereinafter referred to as the "second train detection signal") (see Figure 3). When the crossing control device 23 determines that a train is approaching the crossing RC based on the first train detection signal from the first train detection unit 51, it activates the crossing warning devices 21, 21 to warn those in the vicinity that a train is approaching the crossing RC, and lowers the barrier bars 22a, 22a of the crossing gates 22, 22 to prevent people, vehicles, etc. from entering the crossing RC from the road R. Furthermore, when the crossing control device 23 determines that a train has passed the crossing RC based on the second train detection signal from the second train detection unit 52, it stops the operation of the crossing warning devices 21, 21 and raises the barrier bars 22a, 22a of the crossing gates 22, 22, allowing people, vehicles, etc. to enter the crossing RC from the road R.

Next, we will explain the obstacle detection device 10 according to the embodiment.

The obstacle detection device 10 is configured to detect the presence or absence of obstacles in a monitoring area MA (see Figure 2) that is set primarily for the level crossing RC. In this embodiment, the monitoring area MA is set as a substantially rectangular area in a plan view that includes all or most of the level crossing RC, and the four corners C1 to C4 of the monitoring area MA are located outside the level crossing RC.

Referring to Figures 1 to 3, the obstacle detection device 10 includes a first laser ranging sensor 11, a second laser ranging sensor 12, a first light reflecting unit 13, a second light reflecting unit 14, special signal emitters 15, 15, a processing unit 16, and a wireless communication unit 17.

The first laser ranging sensor 11 is a so-called ToF (Time of Flight) sensor and is positioned outside the monitoring area MA and near a first corner C1 of the monitoring area MA. The first laser ranging sensor 11 is held at a first predetermined height by a support. The first laser ranging sensor 11 is configured to scan a laser beam within the monitoring area MA in a plane parallel to the road surface of the railroad crossing RC (i.e., a horizontal plane), and to receive reflected light of the scanned laser beam. The first laser ranging sensor 11 is also configured to generate and receive diagnostic reflected light for self-diagnosis.

More specifically, in this embodiment, the first laser ranging sensor 11 is configured to (1) emit laser light by changing the emission direction along a plane (horizontal plane) parallel to the road surface of the railroad crossing RC, (2) receive reflected light of the emitted laser light, (3) calculate the distance to the reflection position of the laser light based on the time difference between the emission timing of the laser light and the reception timing of the reflected light of the laser light, (4) generate diagnostic reflected light by reflecting the emitted laser light on an internal reflective surface or the like, and receive the generated diagnostic reflected light, and (5) measure the intensity (light intensity) of the received reflected light.

Like the first laser ranging sensor 11, the second laser ranging sensor 12 is a so-called Time of Flight (ToF) sensor and is located outside the monitoring area MA and near the third corner C3, which is diagonally opposite the first corner C1. In other words, the second laser ranging sensor 12 is located diagonally across the monitoring area MA from the first laser ranging sensor 11. The second laser ranging sensor 12 is held at a second predetermined height by a support pillar and is configured to scan a laser beam within the monitoring area MA in a plane parallel to the road surface of the railroad crossing RC (i.e., a horizontal plane) and to receive reflected light of the scanned laser beam. The second laser ranging sensor 12 is also configured to generate and receive diagnostic reflected light for self-diagnosis. Note that the second predetermined height is preferably different from the first predetermined height, but may be the same as the first predetermined height.

More specifically, in this embodiment, the second laser ranging sensor 12, like the first laser ranging sensor 11, is configured to (1) emit laser light by changing the emission direction along a plane (horizontal plane) parallel to the road surface of the railroad crossing RC, (2) receive reflected light of the emitted laser light, (3) calculate the distance to the reflection position of the laser light based on the time difference between the emission timing of the laser light and the reception timing of the reflected light of the laser light, (4) generate diagnostic reflected light by reflecting the emitted laser light on an internal reflective surface, etc., and receive the generated diagnostic reflected light, and (5) measure the intensity (light intensity) of the received reflected light.

The first light reflecting unit 13 is arranged on the opposite side of the monitoring area MA from the first laser ranging sensor 11. In other words, the first light reflecting unit 13 is arranged on the same side of the monitoring area MA as the second laser ranging sensor 12. The first light reflecting unit 13 is configured to be able to reflect laser light emitted from the first laser ranging sensor 11 and directed toward it.

The first light reflecting unit 13 is composed of multiple reflectors spaced apart in the direction of movement of people, automobiles, etc. at the railroad crossing RC, as indicated by the white arrows in Figure 2. Although not particularly limited, in this embodiment, the first light reflecting unit 13 is composed of three reflectors (first to third reflectors 31 to 33). The first reflector 31 is positioned near the second corner C2 of the monitoring area MA, the third reflector 33 is positioned near the third corner C3 of the monitoring area MA and the second laser ranging sensor 12, and the second reflector 32 is positioned midway between the first reflector 31 and the third reflector 33. The first to third reflectors 31 to 33 are each held by a support at the same first predetermined height as the first laser ranging sensor 11.

The second light reflecting unit 14 is positioned on the opposite side of the monitoring area MA from the second laser ranging sensor 12. In other words, the second light reflecting unit 14 is positioned on the same side of the monitoring area MA as the first laser ranging sensor 11. The second light reflecting unit 14 is configured to reflect laser light emitted from the second laser ranging sensor 12 and directed toward it.

Like the first light reflecting unit 13, the second light reflecting unit 14 is composed of multiple reflectors (here, three reflectors: fourth to sixth reflectors 34 to 36) spaced apart in the direction of movement of people, vehicles, etc. on the railroad crossing RC. The fourth reflector 34 is positioned near the fourth corner C4 of the monitoring area MA, the sixth reflector 36 is positioned near the first corner C1 of the monitoring area MA and the first laser ranging sensor 11, and the fifth reflector 35 is positioned midway between the fourth reflector 34 and the sixth reflector 36. The fourth to sixth reflectors 34 to 36 are each held by a support at the same second predetermined height as the second laser ranging sensor 12.

The special signal lights 15, 15 are positioned on either side of the monitoring area MA. By emitting light, the special signal lights 15, 15 display a stop signal to trains traveling on tracks T1, T2 toward the level crossing RC.

The processing unit 16 stores information regarding the range (boundary) of the monitoring area MA, as well as position information for the first laser ranging sensor 11, the second laser ranging sensor 12, the first light reflecting unit 13, and the second light reflecting unit 14. Specifically, the processing unit 16 stores the direction of and distance to each point on the boundary of the monitoring area MA as seen from the first laser ranging sensor 11, the direction of the first light reflecting unit 13 (first to third reflectors 31 to 33) as seen from the first laser ranging sensor 11, and the distance from the first laser ranging sensor 11 to the first light reflecting unit 13 (first to third reflectors 31 to 33). The processing unit 16 also stores the direction of and distance to each point on the boundary of the monitoring area MA as seen from the second laser ranging sensor 12, as well as the direction of the second light reflecting unit 14 (fourth to sixth reflectors 34 to 36) as seen from the second laser ranging sensor 12 and the distance from the second laser ranging sensor 12 to the second light reflecting unit 14 (fourth to sixth reflectors 34 to 36).

In addition, the processing unit 16 receives the first train detection signal from the first train detection unit 51 and the second train detection signal from the second train detection unit 52 from the railroad crossing control device 23, as well as the emission direction of the laser light, the distance to the reflection position of the laser light, and the intensity of the reflected laser light from the first laser ranging sensor 11 and the second laser ranging sensor 12.

The processing unit 16 is configured to determine whether or not there is an obstacle within the monitoring area MA, primarily when a train approaches the level crossing RC, and if it determines that an obstacle is present within the monitoring area MA, to notify the outside world of this (obstacle determination processing). This obstacle determination processing by the processing unit 16 continues until the train (including cases where there are multiple trains) approaching the level crossing RC passes over the level crossing RC.

Specifically, in this embodiment, the processing unit 16 determines whether or not an obstacle is present within the monitoring area MA based on information input from the first laser ranging sensor 11 and the second laser ranging sensor 12. If the processing unit 16 determines that an obstacle is present within the monitoring area MA, it outputs an obstacle detection signal indicating the presence of an obstacle and an operation control signal to operate the special signal emitters 15, 15. More specifically, if the processing unit 16 determines that an obstacle is present within the monitoring area MA, it transmits the obstacle detection signal from the wireless communication unit 17 to notify trains approaching the railroad crossing RC of the presence of an obstacle, and also transmits the obstacle detection signal from the wireless communication unit 17 to the nearest station, management center, etc., to notify the nearest station, management center, etc. of the presence of an obstacle. Furthermore, if the processing unit 16 determines that there is an obstacle within the monitoring area MA, it sends the operation control signal to the special signal lights 15, 15, causing the special signal lights 15, 15 to emit light (to display a stop signal), thereby alerting trains (and their crew) traveling toward the railroad crossing RC that there is an obstacle.

The processing unit 16 is also configured to diagnose the first laser ranging sensor 11, the second laser ranging sensor 12, the first light reflecting unit 13 (the first to third reflectors 31 to 33), and the second light reflecting unit 14 (the fourth to sixth reflectors 34 to 36), and if it determines that there is a possibility of an abnormality in any of these, to notify the outside.

Specifically, in this embodiment, the processing unit 16 determines whether or not there is a possibility that an abnormality has occurred in the first laser ranging sensor 11, the second laser ranging sensor 12, the first light reflecting unit 13, and the second light reflecting unit 14, based on information input from the first laser ranging sensor 11 and the second laser ranging sensor 12. If the processing unit 16 determines that there is a possibility that an abnormality has occurred in at least one of the first laser ranging sensor 11, the second laser ranging sensor 12, the first light reflecting unit 13, and the second light reflecting unit 14, it outputs an abnormality determination signal indicating that there is a possibility that an abnormality has occurred in at least one of the first laser ranging sensor 11, the second laser ranging sensor 12, the first light reflecting unit 13, and the second light reflecting unit 14. More specifically, the processing unit 16 transmits the abnormality determination signal from the wireless communication unit 17 to the nearest station, management center, etc., thereby notifying the nearest station, management center, etc. that an abnormality may have occurred in at least one of the first laser ranging sensor 11, the second laser ranging sensor 12, the first light reflecting unit 13, and the second light reflecting unit 14; in other words, that an abnormality may have occurred in the obstacle detection device 10.

Furthermore, when the processing unit 16 determines that there is a possibility that an abnormality has occurred in at least one of the first laser ranging sensor 11, the second laser ranging sensor 12, the first light reflecting unit 13, and the second light reflecting unit 14 when a train is approaching a railroad crossing RC, it not only notifies the outside world of this, but also notifies the outside world of the presence of an obstacle. The reason for this is as follows: If there is a possibility that there is an abnormality in at least one of the first laser ranging sensor 11, the second laser ranging sensor 12, the first light reflecting unit 13, and the second light reflecting unit 14, there is a risk that the obstacle determination process will not be performed properly. Therefore, even if the obstacle determination process determines that there is no obstacle, the possibility that there is an obstacle within the monitoring area MA cannot be completely ruled out. Therefore, if there is a possibility that an abnormality has occurred in at least one of the first laser distance measuring sensor 11, second laser distance measuring sensor 12, first light reflecting unit 13, and second light reflecting unit 14, it is better to treat this as an obstacle being present in the monitoring area MA in order to ensure safety.

Specifically, in this embodiment, when the processing unit 16 determines that there is a possibility of an abnormality occurring in at least one of the first laser ranging sensor 11, the second laser ranging sensor 12, the first light reflecting unit 13, and the second light reflecting unit 14 while a train is approaching a railroad crossing RC, it outputs the abnormality determination signal, the obstacle detection signal, and the operation control signal. In other words, the processing unit 16 transmits the abnormality determination signal from the wireless communication unit 17 to the nearest station, management center, etc., emits the obstacle detection signal from the wireless communication unit 17, transmits the obstacle detection signal from the wireless communication unit 17 to the nearest station, management center, etc., and transmits the operation control signal to the special signal emitters 15, 15.

The processing performed by the processing unit 16 will be further described with reference to Figures 4 to 9. Figures 4 to 9 are flowcharts showing an example of the processing performed by the processing unit 16. This flowchart is started, for example, when the startup processing of the obstacle detection device 10 is completed and the first laser ranging sensor 11 and second laser ranging sensor 12 begin normal operation.

In step S1 of FIG. 4, the processing unit 16 determines whether a train is approaching the railroad crossing RC. This determination is made based on whether the first train detection signal has been input from the first train detection unit 51. If a train is not approaching the railroad crossing RC, i.e., if the first train detection signal has not been input from the first train detection unit 51, the processing unit 16 performs sensor diagnosis processing (see FIG. 5) in step S2. On the other hand, if a train is approaching the railroad crossing RC, i.e., if the first train detection signal has been input from the first train detection unit 51, the processing unit 16 performs overall diagnosis processing (see FIG. 6) in step S3 and obstacle determination processing (see FIG. 7) in step S4 as parallel processing.

Note that, although steps S3 and S4 are performed in parallel here, steps S3 and S4 may also be performed sequentially.

Figure 5 is a flowchart showing an example of the sensor diagnostic process performed in step S2 of Figure 4. In this sensor diagnostic process, the first laser ranging sensor 11 and the second laser ranging sensor 12 are diagnosed.

In step S21 of FIG. 5, the processing unit 16 inputs the intensity of the diagnostic reflected light from the first laser ranging sensor 11 and the second laser ranging sensor 12.

In step S22, the processing unit 16 determines whether the intensity of the diagnostic reflected light is equal to or greater than a first predetermined level. If the intensity of the diagnostic reflected light from the first laser ranging sensor 11 and the intensity of the diagnostic reflected light from the second laser ranging sensor 12 are equal to or greater than the first predetermined level, the processing unit 16 ends this flow.

On the other hand, if the intensity of the diagnostic reflected light from the first laser ranging sensor 11 and/or the intensity of the diagnostic reflected light from the second laser ranging sensor 12 is less than the first predetermined level, the process proceeds to step S23, where the processing unit 16 determines that there is a possibility that an abnormality has occurred in the first laser ranging sensor 11 and/or the second laser ranging sensor 12 (sensor abnormality determination). Then, in step S24, the processing unit 16 outputs a first abnormality determination signal indicating that there is a possibility that an abnormality has occurred in the first laser ranging sensor 11 and/or the second laser ranging sensor 12. Specifically, the processing unit 16 transmits the first abnormality determination signal from the wireless communication unit 17 to the nearest station, management center, etc.

Here, it is preferable that the processing unit 16 identifies a laser ranging sensor that may be malfunctioning based on the comparison result between the intensity of the diagnostic reflected light and the first predetermined level, and include information indicating the identified laser ranging sensor in the first abnormality determination signal. Furthermore, the processing unit 16 may determine that a malfunction may be occurring in the corresponding laser ranging sensor if the intensity of the diagnostic reflected light is below the first predetermined level multiple times in succession.

Figures 6 to 8 are flowcharts showing an example of the overall diagnostic process performed in step S3 of Figure 4. This overall diagnostic process performs an overall diagnosis of the first laser ranging sensor 11, the second laser ranging sensor 12, the first light reflecting unit 13 (first to third reflectors 31 to 33), and the second light reflecting unit 14 (fourth to sixth reflectors 34 to 36).

In step S31 of FIG. 6, the processing unit 16 inputs the direction of laser light emission, the distance to the position where the laser light is reflected, and the intensity of the reflected laser light from the first laser ranging sensor 11 and the second laser ranging sensor 12.

In step S32, the processing unit 16 determines whether the emission direction of the laser light is toward the light reflector. Specifically, the processing unit 16 determines whether the emission direction of the laser light from the first laser ranging sensor 11 is toward the first light reflector 13, i.e., whether it is toward any of the first to third reflectors 31 to 33 as viewed from the first laser ranging sensor 11. The processing unit 16 also determines whether the emission direction of the laser light from the second laser ranging sensor 12 is toward the second light reflector 14, i.e., whether it is toward any of the fourth to sixth reflectors 34 to 36 as viewed from the second laser ranging sensor 12.

If the emission direction of the laser light is toward the light reflecting section, i.e., if the emission direction of the laser light from the first laser ranging sensor 11 is toward the first light reflecting section 13 or if the emission direction of the laser light from the second laser ranging sensor 12 is toward the second light reflecting section 14, proceed to step S33. On the other hand, if the emission direction of the laser light is not toward the light reflecting section, i.e., if the emission direction of the laser light from the first laser ranging sensor 11 is not toward the first light reflecting section 13 and the emission direction of the laser light from the second laser ranging sensor 12 is not toward the second light reflecting section 14, proceed to step S36.

In step S33, the processing unit 16 determines whether the distance to the reflection position of the laser light matches the distance to the light reflector (this does not need to be an exact match, as long as it is roughly the same; the same applies below). Specifically, if the laser light emitted from the first laser ranging sensor 11 is emitted in the direction of the first reflector 31, the processing unit 16 determines whether the distance to the reflection position of the laser light from the first laser ranging sensor 11 matches the distance from the first laser ranging sensor 11 to the first reflector 31. Although not described here, the same applies when the laser light emitted from the first laser ranging sensor 11 is emitted in the direction of the second and third reflectors 32 and 33. Furthermore, if the laser light emitted from the second laser ranging sensor 12 is emitted in the direction of the fifth reflector 35, the processing unit 16 determines whether the distance to the reflection position of the laser light from the second laser ranging sensor 12 matches the distance from the second laser ranging sensor 12 to the fifth reflector 35. Although not explained further, the same applies when the laser light emitted from the second laser distance measuring sensor 12 is directed toward the fourth and sixth reflectors 34 and 36.

If the distance to the reflection position of the laser light matches the distance to the light reflecting section, proceed to step S34. On the other hand, if the distance to the reflection position of the laser light does not match the distance to the light reflecting section, proceed to step S37 (Figure 7).

For example, if the installation state (orientation, etc.) of at least one of the first laser ranging sensor 11, second laser ranging sensor 12, and first to sixth reflectors 31 to 36 changes from its original state, the first laser ranging sensor 11 and/or second laser ranging sensor 12 will no longer be able to receive the reflected light from at least one reflector, and the distance to the reflected position of the laser light will no longer match the distance to the light reflecting portion.

In step S34, the processing unit 16 determines whether the intensity of the reflected light is equal to or greater than a second predetermined level. If the intensity of the reflected light is equal to or greater than the second predetermined level, the process proceeds to step S35. On the other hand, if the intensity of the reflected light is less than the second predetermined level, the process proceeds to step S37 (Figure 7). Here, the second predetermined level may be the same as the first predetermined level, or may be a different level. The second predetermined level may also be set for each reflector.

In step S35, the processing unit 16 determines whether the intensity of the reflected light is equal to or greater than a third predetermined level (>second predetermined level). If the intensity of the reflected light is equal to or greater than the third predetermined level, the process proceeds to step S36. On the other hand, if the intensity of the reflected light is less than the third predetermined level, the process proceeds to step S41 (Figure 8).

For example, if the laser output performance of the first laser ranging sensor 11 and/or the second laser ranging sensor 12 deteriorates, if the first light reflecting portion 13 (first to third reflectors 31 to 33) becomes dirty, and/or if the second light reflecting portion 14 (fourth to sixth reflectors 34 to 36) becomes dirty, the intensity of the reflected light may fall below the second predetermined level or the third predetermined level. Furthermore, the intensity of the reflected light may also fall below the second predetermined level or the third predetermined level if dense fog or heavy rain occurs.

In step S36, the processing unit 16 determines whether a train (including cases where there are multiple trains) has passed the railroad crossing RC. This determination is made based on whether a train detection signal has been input from the second train detection unit 52. If the train has passed the railroad crossing RC, this flow ends. On the other hand, if the train has not passed the railroad crossing RC, the process returns to step S31, and the processing unit 16 continues processing this flow.

In step S37 (Figure 7), the processing unit 16 determines that there is a possibility that an abnormality has occurred in at least one of the first laser ranging sensor 11, the second laser ranging sensor 12, the first light reflecting unit 13 (first to third reflectors 31 to 33), and the second light reflecting unit 14 (fourth to sixth reflectors 34 to 36) (abnormality determination).

Then, in step S38, the processing unit 16 outputs a second abnormality determination signal indicating that an abnormality may have occurred in at least one of the first laser ranging sensor 11, the second laser ranging sensor 12, the first light reflecting unit 13, and the second light reflecting unit 14. Specifically, the processing unit 16 transmits the second abnormality determination signal from the wireless communication unit 17 to the nearest station, management center, etc.

Furthermore, in step S39, the processing unit 16 determines whether the obstacle detection signal and the operation control signal have been output. If the obstacle detection signal and the operation control signal have been output, the flow ends. On the other hand, if the obstacle detection signal and the operation control signal have not been output, the flow proceeds to step S40, where the processing unit 16 outputs the obstacle detection signal and the operation control signal. Specifically, the processing unit 16 transmits the obstacle detection signal from the wireless communication unit 17, transmits the obstacle detection signal from the wireless communication unit 17 to the nearest station, management center, etc., and transmits the operation control signal to the special signal emitters 15, 15.

Here, step S39 is provided to avoid duplicate output of the obstacle detection signal and the operation control signal when these signals have already been output in the obstacle determination process, which is mainly processed in parallel. Therefore, if duplicate output of these signals is not a problem, step S39 can be omitted.

In step S41 (Figure 8), the processing unit 16 determines that at least one of the first laser ranging sensor 11, the second laser ranging sensor 12, the first light reflecting unit 13 (first to third reflectors 31 to 33), and the second light reflecting unit 14 (fourth to sixth reflectors 34 to 36) is in a minor fault state (minor fault determination). In other words, the processing unit 16 determines that the performance of the obstacle detection device 10 has deteriorated.

In this case, it is considered that inspection or repair of the device is necessary, so in step S42, the processing unit 16 outputs a minor malfunction determination signal indicating that at least one of the first laser ranging sensor 11, the second laser ranging sensor 12, the first light reflecting unit 13, and the second light reflecting unit 14 is in a minor malfunction state. Specifically, the processing unit 16 transmits the minor malfunction determination signal from the wireless communication unit 17 to the nearest station, management center, etc.

Figure 9 is a flowchart showing an example of the obstacle determination process performed in step S4 of Figure 4. As described above, this obstacle determination process determines whether or not an obstacle is present within the monitoring area MA.

In step S51 of FIG. 9, the processing unit 16 inputs the direction of laser light emission and the distance to the position where the laser light is reflected from the first laser ranging sensor 11 and the second laser ranging sensor 12.

In step S52, the processing unit 16 determines whether the reflected position of the laser light is within the monitoring area MA. If the reflected position of the laser light is within the monitoring area MA, the process proceeds to step S53. On the other hand, if the reflected position of the laser light is outside the monitoring area MA, the process proceeds to step S60.

In step S53, the processing unit 16 determines whether the reflected position of the laser light is the same as the previous position. If the reflected position of the laser light is the same as the previous position, the processing proceeds to step S54. On the other hand, if the reflected position of the laser light is different from the previous position, the processing stores the reflected position of the laser light and returns to step S51.

In step S54, the processing unit 16 determines whether the laser light is reflected from the same position multiple times (e.g., three times) in succession. If the laser light is reflected from the same position multiple times in succession, the processing unit 16 proceeds to step S55. On the other hand, if the laser light is not reflected from the same position multiple times in succession, the processing unit 16 counts up the number of times the laser light is reflected from the same position and returns to step S51.

In step S55, the processing unit 16 assigns the object that reflected the laser light (the reflecting object) to a mesh, which is the smallest unit of the object tracking range set in the monitoring area MA, based on the reflected position of the laser light. Specifically, in this embodiment, the monitoring area MA is divided into N x M meshes, and the processing unit 16 identifies the mesh that corresponds to the reflected position of the laser light (to which the reflecting object belongs).

In step S56, the processing unit 16 determines whether the reflecting object has been in the same mesh or an adjacent mesh for a certain period of time or more. If the reflecting object has been in the same mesh or an adjacent mesh for a certain period of time or more, the process proceeds to step S57. On the other hand, if the reflecting object has not been in the same mesh or an adjacent mesh for a certain period of time or more, the process returns to step S51.

In step S57, the processing unit 16 determines that an obstacle is present within the monitoring area MA (obstacle detection).

Furthermore, in step S58, the processing unit 16 determines whether the obstacle detection signal and the operation control signal have been output. If the obstacle detection signal and the operation control signal have been output, the flow ends. On the other hand, if the obstacle detection signal and the operation control signal have not been output, the flow proceeds to step S59, where the processing unit 16 outputs the obstacle detection signal and the operation control signal. The processing of steps S58 and S59 is the same as the processing of steps S39 and S40 in Figure 7.

Here, step S58 is provided to avoid duplicate output of the obstacle detection signal and the operation control signal when these signals have already been output during the overall diagnostic process, which is mainly processed in parallel. Therefore, if duplicate output of these signals is not a problem, step S58 can be omitted.

In step S60, the processing unit 16 determines whether a train (including cases where there are multiple trains) has passed through the railroad crossing RC. If the train has passed through the railroad crossing RC, the flow ends; if the train has not passed through the railroad crossing RC, the flow returns to step S51, and the processing unit 16 continues processing this flow. The processing in step S60 is the same as the processing in step S36 in Figure 6.

As described above, the obstacle detection device 10 according to the embodiment is configured to notify the outside world of the presence of an obstacle when the reflection position of the laser light scanned by the first laser ranging sensor 11 in the monitoring area MA is within the monitoring area MA, and/or when the reflection position of the laser light scanned by the second laser ranging sensor 12 in the monitoring area MA is within the monitoring area MA. More specifically, the obstacle detection device 10 according to the embodiment is configured to notify the outside world of the presence of an obstacle when the reflection position of the laser light is within the monitoring area MA and does not substantially change for a certain period of time or more. Furthermore, the obstacle detection device 10 according to the embodiment is configured to, if it determines that there may be an abnormality in at least one of the first laser ranging sensor 11, the second laser ranging sensor 12, the first light reflector, and the second light reflector 14 based on the reflected light of the laser light emitted from the first laser ranging sensor 11 in the direction of the first light reflector 13 (first to third reflectors 31 to 33) and the reflected light of the laser light emitted from the second laser ranging sensor 12 in the direction of the second light reflector 14 (fourth to sixth reflectors 34 to 36), report this to the outside and also report the presence of an obstacle to the outside.

For this reason, the obstacle detection device 10 according to this embodiment can quickly notify the outside if there is a possibility that an abnormality has occurred in the device, and prompt appropriate action to be taken. Furthermore, since the presence of an obstacle is notified to the outside not only when the reflected position of the laser light is within the monitoring area MA, but also when there is a possibility that an abnormality has occurred in the device, a higher level of safety can be ensured compared to conventional technology.

In the above-described embodiment, the processing unit 16 diagnoses the first laser ranging sensor 11 and the second laser ranging sensor 12 based on the intensity of the diagnostic reflected light from the first laser ranging sensor 11 and the intensity of the diagnostic reflected light from the second laser ranging sensor 12. However, this is not limited to this, and the processing unit 16 may diagnose the first laser ranging sensor 11 and the second laser ranging sensor 12 using other methods.

Furthermore, in the above-described embodiment, the obstacle detection device 10 (processing unit 16) transmits the obstacle detection signal, the first abnormality determination signal, the second abnormality determination signal, and the failure determination signal via wireless communication. However, this is not limited to this, and the processing unit 16 may transmit all or part of the obstacle detection signal, the first abnormality determination signal, the second abnormality determination signal, and the failure determination signal via wired communication.

The above describes embodiments of the present invention and their variations. However, the present invention is not limited to the above-described embodiments and variations, and further modifications and variations are possible based on the technical concept of the present invention.

10... Obstacle detection device, 11... First laser ranging sensor, 12... Second laser ranging sensor, 13... First light reflector, 14... Second light reflector, 15... Special signal light emitter, 16... Processing unit, 17... Wireless communication unit, 21... Railroad crossing alarm, 22... Railroad crossing barrier, 23... Railroad crossing control device, 31-36... First to sixth reflectors, RC... Railroad crossing, MA... Monitoring area

Claims (7)

a laser distance measuring sensor that scans a monitoring area with a laser beam and receives reflected light, and a light reflecting unit that is disposed on the opposite side of the monitoring area from the laser distance measuring sensor,
If the reflected position of the scanning laser light is within the monitoring area , an external notification is sent to the effect that an obstacle is present;
When it is determined that there is a possibility that an abnormality has occurred in the laser distance measuring sensor or the light reflecting section based on the reflected light of the laser light in the direction of the light reflecting section, the device notifies the outside that there is a possibility that an abnormality has occurred , determines whether there is a notification to the outside that there is an obstacle, and if there is no notification, notifies the outside that there is an obstacle.
Obstacle detection device. The monitoring area is set to a railroad crossing,
2. The obstacle detection device according to claim 1, wherein the presence of the obstacle is notified to a train approaching the railroad crossing, the nearest station, and a management center, and the possibility of an abnormality is notified to the nearest station and the management center. The monitoring area is set to a railroad crossing,
If the reflected position of the scanning laser light is within the monitoring area, an obstacle detection signal indicating the presence of an obstacle is wirelessly transmitted to the train approaching the crossing, the nearest station, and a management center, and an operation control signal for displaying a stop signal is transmitted to the special signal emitting device,
2. An obstacle detection device as described in claim 1, which, when it determines based on the reflected light of laser light in the direction of the light reflecting portion that there is a possibility of an abnormality occurring in the laser distance measuring sensor or the light reflecting portion, wirelessly transmits an abnormality determination signal to the nearest station and the management center, determines whether the obstacle detection signal and the operation control signal have been output, and if they have not been output, wirelessly transmits the obstacle detection signal to the train, the nearest station, and the management center, and transmits the operation control signal to the special signal light emitter. 4. The obstacle detection device according to claim 1, wherein when a reflection position of the laser light in the direction of the light reflecting portion is not a position corresponding to the light reflecting portion, it is determined that there is a possibility that an abnormality has occurred in the laser distance measuring sensor or the light reflecting portion. An obstacle detection device as described in any one of claims 1 to 4, wherein if the reflection position of the laser light in the direction of the light reflecting portion is a position corresponding to the light reflecting portion, but the intensity of the reflected light is less than a predetermined level, it is determined that there may be an abnormality in the laser ranging sensor or the light reflecting portion. 6. The obstacle detection device according to claim 1 , wherein when the reflected position of the scanning laser light is within the monitoring area and does not change substantially for a certain period of time or more, the presence of an obstacle is notified to an outside. the laser distance measuring sensor scans the laser light in a horizontal plane within the monitoring area;
7. The obstacle detection device according to claim 1 , wherein the light reflecting portion includes a plurality of reflectors that are spaced apart from one another and held at the same height.