Monitoring system

Abstract

This makes it possible to perform tasks on laser radar easily while avoiding complexity in the system configuration. [Solution] The monitoring system of the present disclosure includes a laser radar that irradiates a monitoring area set up within a level crossing with laser light and receives reflected light from the irradiated laser light to obtain measurement results including the three-dimensional position coordinates of a plurality of measurement points within the monitoring area irradiated with laser light; a processing unit that is communicably connected to the laser radar and monitors the monitoring area by processing the measurement results; a power supply unit that is electrically connected to the processing unit and supplies power to the processing unit; and a box installed on the road surface around the monitoring area and housing at least one of the processing unit and the power supply unit. The laser radar includes a mounting portion that is attached to the box or another support installed on the road surface, and the height of the mounting portion of the laser radar is less than or equal to the height of the top of the box, with reference to the position on the road surface along the height direction perpendicular to the road surface.

Description

Technical Field

[0001] The present invention relates to a monitoring system.

Background Art

[0002] Patent Documents 1 to 8 disclose techniques related to a monitoring system for monitoring a railroad crossing using a laser beam. Patent Documents 1 to 4 disclose a technique of using a two-dimensional lidar to sweep a laser beam parallel to the ground over a railroad crossing and monitoring the presence or absence of obstacles within the railroad crossing based on the received reflected light. Patent Documents 5 to 8 disclose a technique of three-dimensionally monitoring an entire railroad crossing using a three-dimensional lidar.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Patent Document 7

Patent Document 8

Summary of the Invention

Problems to be Solved by the Invention

[0004] When monitoring a level crossing using a two-dimensional laser radar, the detection range that can be detected by the laser beam is a two-dimensional area. In this case, in order to detect objects that have fallen over within the level crossing using the laser beam, the two-dimensional laser radar is usually installed at a low position close to the ground (for example, at a height of 0.3m from the ground). However, when the laser radar is installed at such a low position, the illumination of the laser beam is easily obstructed by objects such as weeds that may be present at the level crossing, or by mud splashes from passing vehicles and trains. Furthermore, if an object is located close to the laser radar, shadowing is likely to occur, where an object in the foreground obscures an object in the background. From the perspective of avoiding the decrease in object detection accuracy caused by these phenomena, two laser radars are usually installed diagonally across the level crossing, which complicates the system configuration.

[0005] On the other hand, when using a 3D laser radar to monitor a level crossing, it is installed at a high location (for example, 5m above the ground) to enable 3D monitoring. In this case, the above-mentioned problems that occur when using a 2D laser radar can be avoided, and the entire level crossing can be monitored with a single laser radar while maintaining high detection accuracy. However, when laser radar is installed at a high location in this way, work at height is required during installation and inspection of the laser radar. During work at height, workers may come close to the overhead wires, so adjustments are made to deactivate the overhead wires in advance to ensure worker safety. When such prior adjustments and work at height are required, there is a risk that work such as installation and inspection of the laser radar will be very time-consuming and laborious.

[0006] This disclosure describes a monitoring system that allows for easy operation of laser radar while avoiding increased system configuration complexity. [Means for solving the problem]

[0007] The monitoring system of this disclosure includes a laser radar that irradiates a monitoring area set within a level crossing with laser light and receives reflected light from the irradiated laser light to obtain measurement results including the three-dimensional position coordinates of multiple measurement points within the monitoring area irradiated with laser light; a processing unit that is communicably connected to the laser radar and monitors the monitoring area by processing the measurement results; a power supply unit that is electrically connected to the processing unit and supplies power to the processing unit; and a box installed on the road surface around the monitoring area and housing at least one of the processing unit and the power supply unit. The laser radar includes a mounting portion that is attached to the box or another support installed on the road surface, and the height of the mounting portion of the laser radar is less than or equal to the height of the top of the box, with respect to the position on the road surface along the height direction perpendicular to the road surface.

[0008] In this monitoring system, the enclosure housing at least one of the processing unit and power supply unit is typically installed at a low location close to the road surface. The mounting section of the laser radar, which emits three-dimensional laser light, is attached to the enclosure or other support structure installed at a low location, and the height of the laser radar mounting section is less than or equal to the height of the top of the enclosure. Therefore, the laser radar is also installed at a low location, similar to the enclosure. When the laser radar is placed at a low location in this way, unlike when the laser radar is placed at a high location close to the overhead lines, high-altitude work is unnecessary during installation and inspection of the laser radar, and adjustments such as pre-emptively shutting off the overhead lines are not required. Furthermore, by using a three-dimensional laser radar capable of acquiring the three-dimensional position coordinates of each measurement point in the monitoring area, it is not necessary to use multiple laser radars to monitor the entire monitoring area, unlike when using a two-dimensional laser radar. Therefore, the above monitoring system makes it possible to perform work on the laser radar easily while avoiding complexity of the system configuration.

[0009] In some embodiments, the laser radar may include a laser radar main body that includes an irradiating unit for emitting laser light and a light-receiving unit for receiving reflected light, and a support unit that supports the laser radar main body, with a bottom portion facing away from the laser radar main body serving as a mounting portion. In this case, the laser radar can be easily attached to a box or other support, thus facilitating the installation of the laser radar.

[0010] In some embodiments, the laser radar mounting section may be attached to the outer surface of the enclosure. In this case, unlike when the laser radar mounting section is located away from the enclosure, the distance between the laser radar and the equipment inside the enclosure can be reduced, eliminating the need for equipment such as optical fibers and media converters to ensure communication between the laser radar and the equipment inside the enclosure. This simplifies the system configuration.

[0011] In some embodiments, the enclosure comprises a main body that houses at least one of the processing unit and the power supply unit, and a roof portion that includes the upper end of the enclosure and is attached to the main body, and the mounting portion for the laser radar may be attached to the roof portion. In this case, the height of the laser radar mounted on the roof portion can be easily adjusted by adjusting the shape of the roof portion.

[0012] In some embodiments, the box may be installed on the road surface inside the level crossing, at least 3 meters away from the monitoring area along the direction of the railway tracks that pass through the level crossing. In this case, even if the laser radar is positioned at a low level, it will be difficult for pedestrians and others passing through the level crossing to access the laser radar attached to the box, thus preventing malfunctions of the laser radar caused by tampering by pedestrians and others.

[0013] In some embodiments, the enclosure may be an equipment box housing the processing unit and power supply unit. Since the equipment box is usually located at a low height (e.g., about 2m high) where working at height (e.g., working at a height of 5m) is not required, the risk of working at height can be more reliably reduced by ensuring that the height of the laser radar mounting section is below the height of the top edge of the equipment box. Furthermore, by installing the laser radar at a position close to the height of the top edge of the equipment box, the height of the laser radar can be made higher than the height at which a two-dimensional laser radar is installed (e.g., about 0.3m to 0.75m), thus reducing the risk of problems such as interference with laser beam irradiation by objects such as weeds or mud splashes, and the occurrence of shadowing, compared to when using a two-dimensional laser radar. Therefore, with the above configuration, the risk of working at height can be more reliably reduced while accurately monitoring objects within the monitoring area.

[0014] In some embodiments, the processing device includes an object detection unit that uses measurement results from a laser radar to detect the presence or absence of a monitored object in a monitoring area; an obstacle determination unit that determines whether or not to detect a monitored object detected in the monitoring area after the level crossing has begun to close as an obstacle that may obstruct a train traveling across the level crossing; and an output unit that outputs an obstacle detection signal to notify that an obstacle has been detected when an obstacle is detected in the monitoring area. The obstacle determination unit may detect a monitored object as an obstacle if, after the level crossing has begun to close, at least one of a first monitored object and a second monitored object has been detected as a monitored object in the monitoring area, and the sum of the total time during which the detection of the first monitored object continues and the total time during which the detection of the second monitored object continues exceeds a predetermined waiting time from the time when one of the first or second monitored objects was detected first. In conventional obstacle determination processing, a monitored object is detected as an obstacle if the detection of the monitored object in the monitoring area continues for a predetermined waiting time or longer after the level crossing has begun to close. In this case, as with the surveillance system described above, when the laser radar is installed at a low position, the lower the laser radar is installed, the higher the risk of shadowing occurring. When shadowing occurs, the following problems may arise in conventional obstacle detection processing. For example, consider a situation where, when viewed from the laser radar, the first object to be monitored is in front of the laser radar, and the second object to be monitored is hidden behind the first object, resulting in shadowing. In this situation, in conventional obstacle detection processing, if the first object to be monitored passes through the surveillance area and the second object to be monitored is detected before a predetermined waiting time has elapsed from the start of detection of the first object to be monitored, the waiting time is counted again from the start of detection of the second object to be monitored. In this case, since a considerable amount of time may have passed since the start of the barrier closure at the railroad crossing at the start of detection of the second object to be monitored, the timing of the output of the obstacle detection signal notifying that an obstacle has been detected may be delayed.In contrast, with the above configuration, if at least one of the first and second monitored objects is detected as a monitored object after the level crossing has begun to close, and the sum of the total time the first monitored object is detected and the total time the second monitored object is detected exceeds a predetermined waiting time from the time the first or second monitored object was detected first, then an obstacle is detected. In this case, even if shadowing occurs where the second monitored object is hidden behind the first monitored object, and the first monitored object passes through the monitoring area and the second monitored object is detected, it can be assumed that the second monitored object was present behind the first monitored object while only the first monitored object was detected, and the counting of the waiting time from the time the first monitored object was detected can be continued. This allows the second monitored object, which was hidden behind the first monitored object, to be detected early as an obstacle that could hinder train movement. This improves the accuracy of obstacle detection within the monitoring area.

[0015] In some embodiments, the processing device includes an object detection unit that uses measurement results from a laser radar to detect the presence or absence of a monitored object in a monitoring area; an obstruction determination unit that determines whether or not to detect a monitored object detected in the monitoring area as an obstruction that may interfere with the monitoring of the monitoring area by laser light; and an output unit that outputs an obstruction detection signal to notify that an obstruction has been detected when an obstruction is detected in the monitoring area. The obstruction determination unit may detect a monitored object as an obstruction when the increase per unit time of the number of measurement points indicating a monitored object detected in the monitoring area is equal to or greater than a first reference value, and the ratio of the number of measurement points indicating a monitored object to the total number of measurement points set in the monitoring area is equal to or greater than a second reference value. In the above monitoring system, when the laser radar is installed at a low location, the lower the laser radar is installed, the higher the risk that the irradiation of laser light into the monitoring area will be obstructed by obstructions such as workers approaching the laser radar. Such obstructions can cause shadowing, which covers a large part of the monitoring area, and can therefore be a factor that hinders the monitoring of the monitoring area. When the irradiation of laser light into the monitoring area is obstructed by obstacles such as workers approaching the laser radar, the temporal change in the measurement point indicating the obstacle has different characteristics from the temporal change in the measurement point indicating pedestrians passing through a railroad crossing. Specifically, when the irradiation of laser light into the monitoring area is obstructed by obstacles such as workers approaching the laser radar, the increase per unit time in the number of measurement points indicating obstacles approaching the laser radar becomes extremely large, and the ratio of the number of measurement points indicating the monitored object to the total number of measurement points set in the monitoring area also becomes extremely large. Therefore, in the above configuration, the monitored object is detected as an obstacle when the increase per unit time in the number of measurement points indicating the monitored object detected in the monitoring area is equal to or greater than the first criterion value, and when the ratio of the number of measurement points indicating the monitored object to the total number of measurement points set in the monitoring area is equal to or greater than the second criterion value. This allows the system to notify that the laser beam is being obstructed by obstacles such as workers approaching the laser radar, thus avoiding the risk of continued shadowing due to the obstacles. As a result, the accuracy of obstacle detection within the monitoring area can be improved.

Advantages of the Invention

[0016] According to the present disclosure, it is possible to easily perform operations on the lidar while avoiding complication of the system configuration.

Brief Description of the Drawings

[0017] [Figure 1] FIG. 1 is a diagram schematically showing the configuration of a monitoring system according to an embodiment. [Figure 2] FIG. 2 is a schematic diagram of a monitoring area of a monitoring system set within a level crossing as viewed from above. [Figure 3] FIG. 3 is a perspective view showing the instrument box of FIG. 2. [Figure 4] FIG. 4 is a diagram schematically showing the configuration of the instrument box of FIG. 2. [Figure 5] FIG. 5(a) is a diagram for explaining an example of an obstacle determination process performed by the processing device of FIG. 1. FIG. 5(b) is a diagram for explaining a process following the process of FIG. 5(a). [Figure 6] FIG. 6(a) is a diagram for explaining another example of an obstacle determination process performed by the processing device of FIG. 1. FIG. 6(b) is a diagram for explaining a process following the process of FIG. 6(a). [Figure 7] FIG. 7 is a diagram for explaining a process following the process of FIG. 6(b). [Figure 8] FIG. 8(a) is a schematic diagram showing a monitoring area as viewed from the lidar. FIG. 8(b) is a diagram for explaining an example of an occlusion determination process performed by the processing device of FIG. 1. [Figure 9] FIG. 9 is a view of FIG. 8(b) as viewed from the side. [Figure 10] FIGS. 10(a) and 10(b) are diagrams for explaining an example of a simulation process performed by the processing device of FIG. 1. [Figure 11] FIG. 11(a) is a schematic diagram showing another example of the installation position of the instrument box. FIG. 11(b) is a perspective view showing the instrument box of FIG. 11(a). [Figure 12]Figures 12(a), 12(b), and 12(c) are schematic diagrams showing other examples of laser radar installation locations. [Modes for carrying out the invention]

[0018] Embodiments of this disclosure will be described below with reference to the drawings. In the following description, the same or equivalent elements will be denoted by the same reference numerals, and redundant descriptions will be omitted as appropriate.

[0019] The monitoring system 1 shown in Figures 1 to 3 monitors objects within the monitoring area X. As shown in Figure 2, the monitoring area X is a pre-defined three-dimensional space for monitoring the area within the level crossing 4 where the automobile road 2 and the railway road 3 intersect. The objects to be monitored are objects that the monitoring system 1 can detect within the monitoring area X, such as pedestrians, vehicles, and animals passing through the monitoring area X.

[0020] As shown in Figure 1, the monitoring system 1 comprises a laser radar 10, a processing unit 20, a power supply unit 30, and an equipment box 40 (enclosure).

[0021] The laser radar 10 irradiates a laser beam L into the monitoring area X and receives the reflected light of the irradiated laser beam L. The laser radar 10 is a three-dimensional laser radar capable of acquiring the three-dimensional position coordinates of each measurement point in the monitoring area X. The laser radar 10 is also referred to as, for example, LiDAR (Light Detection and Ranging). The laser radar 10 comprises, for example, an irradiating unit 11, a reflecting unit 12, and a light receiving unit 13.

[0022] The irradiation unit 11 includes a light-emitting element that generates laser light L. The irradiation unit 11 irradiates the laser light L at a predetermined irradiation cycle. The reflection unit 12 is equipped with a mirror that reflects the laser light L. The reflection unit 12 reflects the laser light L irradiated from the irradiation unit 11 toward the monitoring area X using the mirror. By changing the angle of the mirror and thus changing the reflection angle of the laser light L, the laser light L is sequentially reflected to multiple positions within the monitoring area X. The reflection unit 12 reflects the reflected light that has been reflected by an object and returned to the laser radar 10 toward the light-receiving unit 13. The light-receiving unit 13 receives the reflected light.

[0023] The laser radar 10 receives reflected light from the laser beam L and generates measurement results including the three-dimensional position coordinates of each measurement point in the monitoring area X. The measurement results include, for example, information on the irradiation direction (angle) of the laser beam L in the irradiation unit 11, and information on the distance from the laser radar 10 to the point of reflection of the laser beam L.

[0024] Both the processing unit 20 and the power supply unit 30 are housed in the equipment box 40. The processing unit 20 is connected to the laser radar 10 and the higher-level equipment of the monitoring system 1 via wired or wireless communication. The processing unit 20 monitors the monitoring area X by processing the measurement results from the laser radar 10. The processing unit 20 outputs the monitoring results within the monitoring area X to the higher-level equipment of the monitoring system 1. The higher-level equipment uses the monitoring results from the monitoring system 1 for various controls, such as controlling railway signals and controlling the operation of trains passing through the level crossing 4.

[0025] The processing unit 20 is an electronic control unit having, for example, a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory). The processing unit 20 performs various functions, for example, by loading a program stored in ROM into RAM and executing the program loaded into RAM with the CPU. The processing unit 20 may be composed of multiple electronic control units.

[0026] The power supply unit 30 is electrically connected to the processing unit 20 and supplies the processing unit 20 with the power necessary to drive it. The power supply unit 30 includes, for example, a rectifier 31 (power receiving unit), a voltage-resistant transformer 32, and a battery 33 (power supply unit). The rectifier 31 receives AC power from an external power source such as a commercial power supply, converts the AC power to DC power, and supplies it to the processing unit 20. The voltage-resistant transformer 32 is a lightning-resistant transformer and is used for stable operation of the processing unit 20. The battery 33 is a backup power source in case of a momentary power outage caused by a grid switch or the like. The battery 33 is located, for example, in the equipment box 40 at a lower position than the rectifier 31 and the voltage-resistant transformer 32 (see Figure 4). The power supply unit 30 only needs to include at least one of a rectifier 31, a power-insulating transformer 32, and a battery 33. It may include only a rectifier 31, only a battery 33, or only a rectifier 31 and a battery 33.

[0027] As shown in Figure 3, the equipment box 40 is, for example, a rectangular box and is installed on the road surface R around the monitoring area X set up within the level crossing 4. For example, the equipment box 40 is installed on the road surface R of the railway road 3 that passes through the level crossing 4. The railway road 3 is the entire railway site including two railway tracks 3a, 3a. Specifically, the railway road 3 is the entire site sandwiched between a virtual line L5 that passes through one barrier arm 5 and extends along the track direction D2, and a virtual line L5 that passes through the other barrier arm 5 and extends along the track direction D2, when viewed along the height direction D1 perpendicular to the road surface R. The road surface R inside the level crossing 4 means the road surface R between the pair of virtual lines L5. The road surface R outside the level crossing 4 means the road surface R outside the pair of virtual lines L5. Note that the track direction D2 is the direction in which the two railway tracks 3a, 3a extend, and it intersects with the height direction D1.

[0028] The equipment box 40 is positioned, for example, outside of two railway tracks 3a, 3a on the road surface R of the railway road 3, and is located at a predetermined distance from the monitoring area X set within the level crossing 4. The equipment box 40 is located, for example, at a distance d of 3m to 30m from the monitoring area X along the track direction D2. The lower limit of the distance d between the equipment box 40 and the monitoring area X in the track direction D2 may be, for example, 5m, 6m, or 7m.

[0029] As shown in Figure 3, the equipment box 40 includes a box body 41, a lid 43, a support 44, and a roof 45.

[0030] The box body 41 is the main body of the equipment box 40, which has an internal space for housing the processing unit 20 and the power supply unit 30, and is shaped like a rectangular parallelepiped extending along the height direction D1. Within the internal space of the box body 41, for example, the processing unit 20 is located in an upper area higher than the power supply unit 30, and the power supply unit 30 is located in a lower area lower than the processing unit 20 (see Figure 4).

[0031] The support portion 44 is the base portion of the equipment box 40 that supports the box body portion 41, and is installed on the road surface R. The support portion 44 is provided at the lower end of the box body portion 41 in the height direction D1. The support portion 44 includes a bottom surface 40a that faces the opposite side from the box body portion 41 in the height direction D1. The bottom surface 40a is the lower surface including the lower end of the box body portion 41 in the height direction D1, and is in contact with the road surface R.

[0032] The lid 43 is attached to the box body 41 so as to open and close an opening formed on the side of the box body 41. By opening and closing the lid 43, the processing unit 20 and the power supply unit 30 can be placed inside the box body 41, and the processing unit 20 and the power supply unit 30 can be removed from inside the box body 41.

[0033] The roof section 45 is attached to the upper end of the box body section 41 in the height direction D1. The roof section 45 may be detachably attached to the upper end of the box body section 41, for example. The roof section 45 includes a pair of top surfaces 40b facing away from the road surface R in the height direction D1. As shown in Figure 4, each top surface 40b is an upper surface including the upper end P40 of the box body section 41 in the height direction D1. The upper end P40 is the highest part of the equipment box 40 in the height direction D1. Each top surface 40b extends so as to intersect each other at the upper end P40, and the height of each top surface 40b decreases as it moves away from the upper end P40. Each top surface 40b and the bottom surface 40a constitute the outer surface of the equipment box 40.

[0034] The laser radar 10 includes a laser radar body 15 and a support 16. The laser radar body 15 is the main body portion of the laser radar 10, housing the irradiation unit 11, the reflecting unit 12, and the light receiving unit 13. The support 16 is the base portion of the laser radar 10 that supports the laser radar body 15. The support 16 includes a bottom surface P10 (bottom) facing away from the laser radar body 15. The bottom surface P10 functions as a mounting portion to be attached to an equipment box 40 or other support installed on the road surface R. The bottom surface P10 is, for example, positioned parallel to the road surface R.

[0035] The laser radar 10 is positioned such that, with respect to the position of the road surface R along the height direction D1, the height H10 of the bottom surface P10 of the laser radar 10 is less than or equal to the height H40 of the upper end P40 of the equipment box 40. The height H40 is the distance between the road surface R along the height direction D1 and the upper end P40 of the equipment box 40, and is, for example, 0.75m or more and 2m or less. The height H40 may also be 0.8m or more and 1.7m or less. As an example, the height H40 is 0.8m, 1m, or 1.7m. Therefore, the height H10 is the distance between the road surface R along the height direction D1 and the bottom surface P10 of the laser radar 10, and is less than or equal to the height H40. The height H10 may be, for example, 0.75m or more and 2m or less, or 0.8m or more and 1.7m or less. Furthermore, if the shape of the base surface P10 changes in the height direction D1, such as when the base surface P10 is inclined with respect to the road surface R, or when the base surface P10 is not a flat surface, then the height H10 can be defined as the height of the lowest part of the base surface P10 in the height direction D1.

[0036] This embodiment describes the case where the laser radar 10 is installed on the roof portion 45 of the equipment box 40. In this case, the bottom surface P10 of the laser radar 10 is attached to the top surface 40b of the roof portion 45, which includes the upper end P40 of the equipment box 40, so the height H10 of the bottom surface P10 is lower than the height H40 of the upper end P40 of the equipment box 40. As long as the height H10 is less than or equal to the height H40, the laser radar 10 may be installed on the side of the equipment box 40, not just on the roof portion 45.

[0037] Next, referring again to Figure 1, the specific processing content of the processing unit 20 will be explained in detail. As shown in Figure 1, the processing unit 20 has a functional configuration that includes an object detection unit 21, a level crossing control unit 22, an obstacle determination unit 23, an obstruction determination unit 24, a simulation unit 25, and an output unit 26.

[0038] The object detection unit 21 uses the measurement results from the laser radar 10 to detect the presence or absence of a target object on the road surface R within the monitoring area X. Specifically, the object detection unit 21 uses the measurement results to calculate the distance to the reflection point of the laser beam L, and detects the presence or absence of a target object using a well-known method based on the calculated distance and the irradiation direction of the laser beam L.

[0039] The level crossing control unit 22 controls the switching between the closed and open states of the level crossing 4 by controlling the equipment of the level crossing 4, such as the barrier arm 5 and the warning device. When the level crossing control unit 22 receives a train detection signal that a train is approaching the level crossing 4, it starts closing the level crossing 4. Specifically, the level crossing control unit 22 outputs a level crossing closing signal to the equipment of the level crossing 4, which sounds the alarm and lowers the barrier arm 5. As a result, the level crossing 4 is closed, and passage through the level crossing 4 by pedestrians and vehicles is blocked.

[0040] Subsequently, when the level crossing control unit 22 receives a train passing signal indicating that a train has passed through the level crossing 4, it begins to open the level crossing 4. Specifically, the level crossing control unit 22 outputs a level crossing opening signal to the equipment of the level crossing 4, thereby stopping the alarm and raising the barrier arm 5. As a result, the level crossing 4 becomes open, allowing pedestrians and vehicles to pass through the level crossing 4. In this embodiment, the level crossing control unit 22 is included inside the monitoring system 1, but the level crossing control unit 22 may be located outside the monitoring system 1. In this case, the monitoring system 1 may receive signals from the external level crossing control unit 22.

[0041] The obstacle determination unit 23 determines whether to detect the object detected by the object detection unit 21 as an obstacle that could obstruct the progress of a train, after the level crossing control unit 22 has started to close the level crossing 4. The timing at which the level crossing control unit 22 starts to close the level crossing 4 is, for example, the timing at which the level crossing control unit 22 outputs a level crossing closure signal to the equipment of the level crossing 4 instructing it to close. Normally, if an object is detected after the level crossing 4 has started to close, the unit detects the object as an obstacle and outputs an obstacle detection signal notifying that an obstacle exists at the level crossing 4 if the detection of the object continues for a predetermined waiting time (for example, 5 seconds) or longer. The predetermined waiting time is a reference time for determining whether to detect the object as an obstacle, and is set in advance to, for example, 4 to 6 seconds.

[0042] However, conventional obstacle detection processes have the following problems. For example, consider the case shown in Figures 5(a) and 5(b) where, after the level crossing 4 begins to close, the object detection unit 21 detects a pedestrian M as a monitored object, and then, after a certain amount of time has elapsed since detecting the pedestrian M, it detects a vehicle V as another monitored object. In this case, shadowing may occur where the pedestrian M is hidden behind the vehicle V for the laser radar 10. When such shadowing occurs, the laser beam L from the laser radar 10 hits only the vehicle V and not the pedestrian M, so an undetectable region N is formed behind the vehicle V that cannot be detected by the laser beam L.

[0043] In this case, the object detection unit 21 starts detecting vehicle V while stopping the detection of pedestrian M. As a result, the count of the waiting time from the start of detection of pedestrian M is initialized, and the count of the waiting time from the start of detection of vehicle V begins. Subsequently, if vehicle V passes through the monitoring area X before the count of the waiting time from the start of detection of vehicle V is completed, pedestrian M, which was hidden behind vehicle V, is detected again, and the count of the waiting time from the start of detection of pedestrian M begins again. In this case, by the time pedestrian M is detected again, a considerable amount of time may have passed since the start of the barrier closure of the level crossing 4, which may cause a delay in detecting obstacles within the level crossing 4.

[0044] In contrast, in this embodiment, if a pedestrian M (first monitored object) and a vehicle V (second monitored object) are detected as monitored objects after the level crossing control unit 22 has started to close the level crossing 4, the obstacle determination unit 23 will detect the pedestrian M as an obstacle if the total time obtained by adding the total time the pedestrian M is detected and the total time the vehicle V is detected exceeds the waiting time from the start of the detection of the pedestrian M.

[0045] The total time that pedestrian M is detected is the sum of only the time that pedestrian M is detected continuously, and does not include the time that pedestrian M is not detected. Therefore, if the detection of pedestrian M is interrupted, the total time that pedestrian M is detected is the sum of the time that pedestrian M was detected continuously up to the point of interruption and the time that pedestrian M was detected again after the point of interruption. Similarly, the total time that vehicle V is detected is the sum of only the time that vehicle V is detected continuously, and does not include the time that vehicle V is not detected.

[0046] According to the obstacle detection process of this obstacle detection unit 23, even if a pedestrian M hides behind the vehicle V before a predetermined waiting time has elapsed from the start of detection of the first pedestrian M, the system can still consider the pedestrian M to be behind the vehicle V and continue counting the waiting time from the start of detection of the previously detected pedestrian M. Therefore, in Figures 5(a) and 5(b), for example, if a pedestrian M hides behind the vehicle V 2 seconds after the start of detection of the pedestrian M, the waiting time count continues from the start of detection of the pedestrian M, meaning that 2 seconds have already been counted at the start of detection of the vehicle V.

[0047] Subsequently, if vehicle V passes through the monitoring area X before the waiting time (e.g., 5 seconds) is counted from the start of detection of pedestrian M, and pedestrian M, who was hidden behind vehicle V, is detected again, the start of the waiting time count remains the same as the start of the initial detection of pedestrian M. Therefore, when pedestrian M is detected again, and the waiting time count of 5 seconds from the start of the initial detection of pedestrian M is completed, the newly detected pedestrian M is detected as an obstacle that has remained in the monitoring area X for longer than the waiting time.

[0048] As shown in Figures 6(a), 6(b), and 7, the same applies when a pedestrian M enters the monitoring area X behind vehicle V after vehicle V has been detected first. For example, suppose that vehicle V leaves the level crossing 4 before the waiting time has elapsed after vehicle V has been detected, and pedestrian M, who was hiding behind vehicle V, is detected. In this case, the obstacle determination unit 23 assumes that pedestrian M was behind vehicle V during the time that vehicle V was being detected, and after counting a waiting time of, for example, 5 seconds from the start of detection of the first detected vehicle V, it detects the later detected pedestrian M as an obstacle that has been lingering in the monitoring area X for longer than the waiting time.

[0049] Thus, even if shadowing occurs in one of the first or second monitored objects, the obstacle detection unit 23 of this embodiment assumes that shadowing has occurred in that object, and the waiting time count is carried over between the first and second monitored objects. As a result, an obstacle can be detected immediately after a predetermined waiting time has elapsed since the first monitored object was detected.

[0050] The output unit 26 outputs the object detection result of the object detection unit 21 to a higher-level device of the monitoring system 1. Furthermore, when the obstacle determination unit 23 detects an obstacle within the monitoring area X, the output unit 26 outputs an obstacle detection signal to a notification device provided in the higher-level device of the monitoring system 1, notifying that an obstacle has been detected within the monitoring area X. This allows the operator to recognize the presence of an obstacle within the monitoring area X that could obstruct train operation. The operator can then perform various tasks, such as checking for obstacles, based on the notification from the notification device.

[0051] The obstruction determination unit 24 shown in Figure 1 determines whether the object detected by the object detection unit 21 is an obstruction that interferes with monitoring within the monitoring area X using the laser beam L. Examples of obstruction objects include workers performing tasks on the laser radar 10 and the equipment box 40, as well as passersby or animals. As shown in Figure 8(a), if monitoring within the monitoring area X is not obstructed by an obstruction, the laser radar 10 can shine the laser beam on the passerby M lying in the monitoring area X, and the object detection unit 21 can successfully detect the passerby M as an object to be monitored.

[0052] On the other hand, as shown in Figures 8(b) and 9, for example, when installing the laser radar 10 on the equipment box 40, or when inspecting the equipment box 40, the laser beam L may be obstructed by the head of a worker W. In this case, the area behind the worker W's head becomes an undetectable area N that cannot be detected by the laser beam L, resulting in shadowing in the area behind the worker W's head. In this case, even if a passerby M is lying in the area behind the worker W's head, it is expected that the passerby M will not be detected as an obstacle.

[0053] In contrast, in this embodiment, the obstruction determination unit 24 uses the measurement results of the laser radar 10 to determine whether or not the obstruction of worker W is interfering with monitoring within the monitoring area X. When worker W attempts to work on the laser radar 10 and the equipment box 40, worker W approaches the laser radar 10, so it is expected that the number of measurement points corresponding to worker W will increase dramatically over time. The number of measurement points corresponding to worker W refers to the number of measurement points indicating the position of worker W among the multiple measurement points set in the monitoring area X. Furthermore, as worker W approaches the laser radar 10, the undetectable area N behind worker W widens, and it is expected that the proportion of the number of measurement points corresponding to worker W to the total number of measurement points set in the monitoring area X will increase dramatically.

[0054] Therefore, when worker W is detected as a monitored object, the obstacle determination unit 24 detects worker W as an obstacle that may interfere with monitoring in the monitoring area X if the increase in the number of measurement points corresponding to worker W per unit time is equal to or greater than a first reference value (condition 1), and the ratio of the number of measurement points corresponding to worker W to the total number of measurement points set in the monitoring area X is equal to or greater than a second reference value (condition 2). The first reference value in condition 1 is a value used as a criterion for determining whether or not worker W is moving towards the laser radar 10, for example, 15 points / second. The second reference value in condition 2 is a value used as a criterion for determining whether or not worker W is getting too close to the laser radar 10, for example, 70%, 80%, or 90% or more.

[0055] In the above-mentioned conditions 1 and 2, worker W is an example of a “monitoring object” in this disclosure, and can be explained by replacing worker W with “monitoring object.” The obstruction determination unit 24 detects “monitoring objects” that satisfy both conditions 1 and 2 as “obstructions” that can obstruct monitoring within the monitoring area X, and does not detect “monitoring objects” that do not satisfy at least one of conditions 1 or 2 as “obstructions.” If a monitoring object that satisfies only condition 1 is sufficiently far from the laser radar 10, shadowing by that monitoring object is unlikely to occur, and therefore it cannot be said that the monitoring object is obstructing monitoring within the monitoring area X. Also, as a monitoring object that satisfies only condition 2, for example, a large vehicle such as a truck that can obstruct most of the monitoring area X can be considered, but in this case, it is expected that shadowing will be eliminated as the vehicle passes, and therefore it cannot be said that the monitoring within the monitoring area X is being obstructed.

[0056] The output unit 26 outputs an obstacle detection signal to notify that an obstacle has been detected when the obstacle detection unit 24 detects an obstacle. The output unit 26 outputs the obstacle detection signal to, for example, an alarm 50 installed in the equipment box 40. When the alarm 50 receives the obstacle detection signal, it notifies that monitoring in the monitoring area X is being obstructed by an obstacle by generating an alarm sound and illuminating a warning light, etc. The alarm 50 is installed, for example, on the top surface 40b of the roof portion 45 of the equipment box 40 and positioned close to the laser radar 10. The alarm 50 only needs to be in a position where it is visible when viewing the laser radar 10 from the monitoring area X, and may be installed on elements other than the roof portion 45 of the equipment box 40.

[0057] The simulation unit 25 shown in Figure 1 simulates the measurement results when the laser radar 10 is installed at a low location. As shown in Figures 10(a) and 10(b), when a three-dimensional laser radar 10 is moved from a high location where it was previously installed to a low location, the risk of problems such as shadowing increases, as described above. Therefore, the simulation unit 25 simulates whether there are any problems caused by installing the laser radar 10 at a low location before actually installing the laser radar 10 at a low location.

[0058] The simulation unit 25 converts, for example, measurement results from a conventional 3D laser radar 10 installed at a high altitude (e.g., about 5m) to measurement results from a 3D laser radar 10 installed at a low altitude (e.g., about 2m). In this case, the simulation unit 25 acquires positional information for each measurement point P when the laser beam L from the laser radar 10 installed at a high altitude (e.g., about 5m) is irradiated onto monitored objects such as vehicles V and pedestrians M. The positional information for each measurement point P includes the distance from the laser radar 10 installed at a high altitude to each measurement point P, and the direction of irradiation of the laser beam L. Then, based on the height information of the low altitude where the laser radar 10 is actually installed, the simulation unit 25 performs a coordinate transformation on the positional information of each measurement point P to generate a simulation result that includes information on the measurement points P when the laser radar 10 is installed at a low altitude.

[0059] The output unit 26 can inform the operator of the simulation results from the simulation unit 25 by outputting the simulation results to a screen or the like. The operator can use the simulation results to check in advance whether the level crossing 4 can be monitored without fail when the laser radar 10 is actually installed at a low location, and whether there are any obstructions that could obstruct the monitoring area X by causing shadowing. The operator can then determine whether the height H10 of the laser radar 10 is appropriate, etc.

[0060] The effects of the monitoring system 1 of this embodiment, as described above, will now be explained.

[0061] In this embodiment, the bottom surface P10 of the three-dimensional laser radar 10 is attached to an equipment box 40 installed at a low location, and the height H10 of the bottom surface P10 of the laser radar 10 is less than or equal to the height H40 of the upper end P40 of the equipment box 40. Therefore, the laser radar 10 is installed at a low location, similar to the equipment box 40. When the laser radar 10 is placed at a low location in this way, unlike when the laser radar 10 is placed at a high location close to the overhead lines, high-altitude work is not required when installing or inspecting the laser radar 10, and adjustments such as pre-emptively de-energizing the overhead lines are not necessary. Furthermore, when using a three-dimensional laser radar 10, unlike when using a two-dimensional laser radar, it is not necessary to use multiple laser radars to monitor the entire monitoring area X. Therefore, according to this embodiment, work on the laser radar 10 can be easily performed while avoiding complexity of the system configuration.

[0062] As in this embodiment, the laser radar 10 may have a laser radar main body 15 including an irradiation unit 11 and a light receiving unit 13, and a support unit 16 that supports the laser radar main body 15. In this case, the laser radar 10 can be easily attached to the equipment box 40, making the installation work of the laser radar 10 easier.

[0063] As in this embodiment, the bottom surface P10 of the laser radar 10 may be attached to the top surface 40b of the equipment box 40. In this case, unlike when the laser radar 10 is installed at a distance from the equipment box 40, the distance between the laser radar 10 and the equipment inside the equipment box 40 can be reduced, eliminating the need for equipment such as optical fibers and media converters to ensure communication between the laser radar 10 and the equipment inside the equipment box 40. This simplifies the system configuration.

[0064] As in this embodiment, the bottom surface P10 of the laser radar 10 may be attached to the roof portion 45 of the equipment box 40. In this case, the height of the laser radar 10 attached to the roof portion 45 can be easily adjusted by adjusting the shape of the roof portion 45.

[0065] As in this embodiment, the equipment box 40 may be installed on the road surface R inside the level crossing 4, at least 3 m away from the monitoring area X along the track direction D2. In this case, even if the laser radar 10 is positioned at a low location, it will be difficult for pedestrians passing through the level crossing 4 to access the laser radar 10 attached to the equipment box 40, thus preventing malfunctions of the laser radar 10 caused by tampering by pedestrians.

[0066] As in this embodiment, the equipment box 40 may house the processing unit 20 and the power supply unit 30. Since the equipment box 40 is usually located at a low height (e.g., about 2m high) where working at height (e.g., working at a height of 5m) is not required, the risk of working at height can be more reliably reduced by ensuring that the height of the bottom surface P10 of the laser radar 10 is less than or equal to the height of the upper edge P40 of the equipment box 40. Furthermore, by installing the laser radar 10 at a position close to the height of the upper edge P40 of the equipment box 40, the height of the laser radar 10 can be made higher than the height at which a two-dimensional laser radar is installed (e.g., about 0.3m to 0.75m), thus reducing the risk of problems such as interference with the irradiation of the laser beam L by objects such as weeds or mud splashes, and the occurrence of shadowing, compared to when using a two-dimensional laser radar. Accordingly, with the above configuration, the risk of working at height can be more reliably reduced while accurately monitoring objects within the monitoring area X.

[0067] As in this embodiment, the obstacle determination unit 23 may detect an object as an obstacle if, after the level crossing 4 has started to close, at least one of the first and second objects to be monitored has been detected as an object within the monitoring area X, and the sum of the total time during which the first object to be monitored has been detected and the total time during which the second object to be monitored has been detected exceeds a predetermined waiting time from the time when the first object to be monitored or the second object to be detected first was detected. In this case, even if shadowing occurs where the second object to be monitored is hidden behind the first object to be monitored, and the first object to be monitored passes through the monitoring area X and the second object to be monitored is detected, the unit can assume that the second object to be monitored was present behind the first object to be monitored while only the first object to be monitored was detected, and can continue counting the waiting time from the time when the first object to be monitored was detected. This allows the second object to be monitored, which was hidden behind the first object to be monitored, to be detected early as an obstacle that could obstruct the movement of a train. This improves the accuracy of obstacle detection within the monitoring area X.

[0068] As in this embodiment, the obstruction determination unit 24 may detect a monitored object as an obstruction if the increase per unit time of the number of measurement points indicating a monitored object detected within the monitoring area X is equal to or greater than a first reference value, and the ratio of the number of measurement points indicating a monitored object to the total number of measurement points set within the monitoring area X is equal to or greater than a second reference value. In this case, even if the irradiation of the laser beam L is obstructed by an obstruction such as a worker W approaching the laser radar 10, it is possible to notify that the obstruction is interfering with monitoring within the monitoring area X, thereby avoiding the risk of continued shadowing due to the obstruction. As a result, the accuracy of detecting obstacles within the monitoring area X can be improved.

[0069] While embodiments of this disclosure have been described above, this disclosure is not limited to the embodiments described above.

[0070] For example, the installation location of the equipment box 40 is not limited to the example shown in the embodiment described above, and can be changed as appropriate. For example, as in the monitoring system 1A shown in Figures 11(a) and 11(b), the equipment box 40 may be installed on the road surface R between the two railway tracks 3a, 3a, rather than on the road surface R outside the two railway tracks 3a, 3a. When the equipment box 40 is placed between the two railway tracks 3a, 3a in this way, it becomes more difficult for pedestrians and others passing through the level crossing 4 to access the laser radar 10, thereby reducing the risk of malfunctions occurring in the laser radar 10 due to tampering by such pedestrians and others. Furthermore, if there are close and far tracks among the two railway tracks 3a, 3a as seen from the perspective of the laser radar 10, if the equipment box 40 is placed between the two railway tracks 3a, 3a, the laser radar 10 can continue to monitor the far track even when a train passes on the close track, thus further enhancing safety.

[0071] The equipment box 40 does not necessarily have to be installed on the road surface R inside the level crossing 4, but may also be installed on the road surface R outside the level crossing 4. That is, the equipment box 40 may be installed on the road surface R located outside the railway road 3. Furthermore, the road surface R on which the equipment box 40 is installed may be the road surface of a railway road that includes a single railway track, or it may be the road surface located outside the said railway road. The equipment box 40 may house only one of the processing unit 20 and the power supply unit 30. That is, the equipment box 40 may house only the processing unit 20, or only the power supply unit 30. The equipment box 40 may house other devices in addition to the processing unit 20 and the power supply unit 30. The monitoring system 1 may have another box capable of housing at least one of the processing unit 20 and the power supply unit 30 instead of the equipment box 40.

[0072] The laser radar 10 does not necessarily have to be installed in the equipment box 40. For example, as in the monitoring system 1B shown in Figure 12(a), the laser radar 10 may be installed on a support 60 other than the equipment box 40. The support 60 is, for example, a support column located close to the equipment box 40 and installed on the road surface R around the monitoring area X. The height of the support 60 from the road surface R is lower than the height H40 of the equipment box 40. The bottom surface P10 of the laser radar 10 is attached to the upper end of the support 60. Therefore, the height H10 of the laser radar 10 is lower than the height H40 of the equipment box 40. A cable C connected to the processing unit 20 inside the equipment box 40 extends outside the equipment box 40 along the road surface R and the support 60 and is connected to the laser radar 10 attached to the upper end of the support 60.

[0073] As shown in the monitoring system 1C in Figure 12(b), the laser radar 10 may be mounted on a support 70 located far from the equipment box 40. The support 70 is a support column taller than the height H40 of the equipment box 40 and is installed on the road surface R around the monitoring area X. The support 70 extends to a height where high-altitude work is required and a conventional three-dimensional laser radar is mounted thereon. The bottom surface P10 of the laser radar 10 is attached to a support installed midway along the support 70, and the height H10 of the laser radar 10 is lower than the height H40 of the equipment box 40. A cable C connected to the processing unit 20 inside the equipment box 40 extends outside the equipment box 40 along the lower part of the road surface R and the support 70, and is connected to the laser radar 10 mounted midway along the support 70.

[0074] As shown in the monitoring system 1D in Figure 12(c), the laser radar 10 may be mounted on a support 80 located far from the equipment box 40. The support 80 is a support column that is taller than the height H40 of the equipment box 40 and is installed on the road surface R around the monitoring area X. The height of the support 80 from the road surface R is lower than the height H40 of the equipment box 40. The bottom surface P10 of the laser radar 10 is attached to the upper end of the support 80. Therefore, the height H10 of the laser radar 10 is lower than the height H40 of the equipment box 40. A cable C connected to the processing unit 20 inside the equipment box 40 extends outside the equipment box 40 along the lower part of the road surface R and the support 80, and is connected to the laser radar 10 mounted on the upper end of the support 80.

[0075] <Note> This disclosure includes [1] a laser radar that irradiates a monitoring area set within a railroad crossing with laser light and receives reflected light from the irradiated laser light to obtain measurement results including the three-dimensional position coordinates of a plurality of measurement points within the monitoring area irradiated with laser light, A processing device that is communicatively connected to the laser radar and monitors the monitoring area by processing the measurement results, A power supply unit that is electrically connected to the aforementioned processing unit and supplies power to the aforementioned processing unit, A box installed on the road surface surrounding the monitoring area, housing at least one of the processing unit and the power supply unit, Equipped with, The laser radar includes a mounting portion that is attached to the enclosure or another support installed on the road surface. With respect to the position of the road surface along the height direction perpendicular to the road surface, the height of the mounting portion of the laser radar is less than or equal to the height of the upper end of the box. "A monitoring system."

[0076] This disclosure includes [2] "The laser radar is, A laser radar main body includes an irradiation unit that irradiates the laser light and a light receiving unit that receives the reflected light, The laser radar has a bottom portion facing the opposite side from the main body portion, which is included as the mounting portion, and a support portion that supports the main body portion of the laser radar. The monitoring system described in [1].

[0077] This disclosure includes [3] "the mounting portion of the laser radar is attached to the outer surface of the box body, The monitoring system described in [1] or [2].

[0078] [4] "The box body is A box body that houses at least one of the processing device and the power supply device, The box body includes the upper end and has a roof portion attached to the box body, The mounting portion of the laser radar is attached to the roof portion. The monitoring system described in [3].

[0079] This disclosure includes [5] "The box is installed on the road surface inside the level crossing and is located at least 3 m away from the monitoring area along the direction of the railway line through the level crossing," The monitoring system described in [3] or [4].

[0080] This disclosure includes [6] "The box is an instrument box that houses the processing apparatus and the power supply unit, The monitoring system is one of the following: [1] to [5].

[0081] This disclosure [7] "The processing apparatus is, An object detection unit that uses the measurement results from the laser radar to detect the presence or absence of an object to be monitored within the monitoring area, An obstacle determination unit that determines whether or not to detect the object to be monitored, which is detected within the monitoring area after the barrier of the level crossing has been closed, as an obstacle that could obstruct a train traveling across the level crossing, It includes an output unit that outputs an obstacle detection signal to notify that an obstacle has been detected when the obstacle is detected within the monitoring area, The aforementioned obstacle detection unit, If, after the barrier at the level crossing is closed, at least one of the first and second objects to be monitored is detected as such within the monitoring area, and the sum of the total time during which the first object to be monitored is detected and the total time during which the second object to be monitored is detected exceeds a predetermined waiting time from the time when the first object to be monitored or the second object to be monitored was detected first, then the object to be monitored is detected as such. The monitoring system is one of the following: [1] to [6].

[0082] This disclosure includes [8] "The processing apparatus is, An object detection unit that uses the measurement results from the laser radar to detect the presence or absence of an object to be monitored within the monitoring area, An obstruction determination unit that determines whether or not the object to be monitored detected within the monitoring area is detected as an obstruction that may interfere with the monitoring of the monitoring area by the laser light, It includes an output unit that outputs an obstacle detection signal to notify that an obstacle has been detected when the obstacle is detected within the monitoring area, The aforementioned obstruction detection unit is: The object to be monitored is detected as the shielding object when the increase per unit time of the number of measurement points indicating the object to be monitored detected within the monitoring area is equal to or greater than a first reference value, and the ratio of the number of measurement points indicating the object to be monitored to the total number of measurement points set within the monitoring area is equal to or greater than a second reference value. The monitoring system is one of the following: [1] to [7]. [Explanation of Symbols]

[0083] 1,1A,1B,1C,1D Monitoring System 3a Railway tracks 4 railroad crossings 10 Laser radar 11 Irradiation area 13 Light receiving part 15 Laser radar main unit 16 Support part 20 Processing Units 21 Object detection unit 22 Level crossing control unit 23 Obstacle detection unit 24 Obstruction determination section 26 Output section 30 Power supply 40 Equipment box (box body) 41 Box body 44 Support part 45 Roof section 60,70,80 Support D1 Height direction D2 Track direction L Laser light M Passerby P measurement point P10 Bottom surface (bottom, mounting part) P40 top end R Road surface V Vehicle W Worker X monitoring area

Claims

1. A laser radar that irradiates a monitoring area set up within a level crossing with laser light and receives the reflected light of the irradiated laser light to obtain measurement results including the three-dimensional position coordinates of multiple measurement points within the monitoring area irradiated with laser light, A processing device that is communicatively connected to the laser radar and monitors the monitoring area by processing the measurement results, A power supply unit that is electrically connected to the aforementioned processing unit and supplies power to the aforementioned processing unit, A box installed on the road surface surrounding the monitoring area, housing at least one of the processing unit and the power supply unit, Equipped with, The laser radar includes a mounting portion that is attached to the enclosure or another support installed on the road surface. With respect to the position of the road surface along the height direction perpendicular to the road surface, the height of the mounting portion of the laser radar is less than or equal to the height of the upper end of the box. Monitoring system.

2. The aforementioned laser radar is, A laser radar main body includes an irradiation unit that irradiates the laser light and a light receiving unit that receives the reflected light, The laser radar has a bottom portion facing the opposite side from the main body portion, which is included as the mounting portion, and a support portion that supports the main body portion of the laser radar. The monitoring system according to claim 1.

3. The mounting portion of the laser radar is attached to the outer surface of the box. The monitoring system according to claim 1 or 2.

4. The aforementioned box body is A box body that houses at least one of the processing device and the power supply device, The box body includes the upper end and has a roof portion attached to the box body, The mounting portion of the laser radar is attached to the roof portion. The monitoring system according to claim 3.

5. The box is installed on the road surface inside the level crossing and is located at least 3 meters away from the monitoring area along the direction of the railway tracks that pass through the level crossing. The monitoring system according to claim 3.

6. The aforementioned box is an equipment box that houses the processing device and the power supply device. The monitoring system according to claim 1 or 2.

7. The aforementioned processing apparatus is An object detection unit that uses the measurement results from the laser radar to detect the presence or absence of an object to be monitored within the monitoring area, An obstacle determination unit that determines whether or not to detect the object to be monitored, which is detected within the monitoring area after the barrier of the level crossing has been closed, as an obstacle that could obstruct a train traveling across the level crossing, It includes an output unit that outputs an obstacle detection signal to notify that an obstacle has been detected when the obstacle is detected within the monitoring area, The aforementioned obstacle detection unit, If, after the barrier at the level crossing is closed, at least one of the first and second objects to be monitored is detected as such within the monitoring area, and the sum of the total time during which the first object to be monitored is detected and the total time during which the second object to be monitored is detected exceeds a predetermined waiting time from the time when the first object to be monitored or the second object to be monitored was detected first, then the object to be monitored is detected as such. The monitoring system according to claim 1 or 2.

8. The aforementioned processing apparatus is An object detection unit that uses the measurement results from the laser radar to detect the presence or absence of an object to be monitored within the monitoring area, An obstruction determination unit that determines whether or not the object to be monitored detected within the monitoring area is detected as an obstruction that may interfere with the monitoring of the monitoring area by the laser light, It includes an output unit that outputs an obstacle detection signal to notify that an obstacle has been detected when the obstacle is detected within the monitoring area, The aforementioned obstruction detection unit is: The object to be monitored is detected as the shielding object when the increase per unit time of the number of measurement points indicating the object to be monitored detected within the monitoring area is equal to or greater than a first reference value, and the ratio of the number of measurement points indicating the object to be monitored to the total number of measurement points set within the monitoring area is equal to or greater than a second reference value. The monitoring system according to claim 1 or 2.

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