JP2013032999A - Submergence monitoring device and submergence monitoring system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a submergence monitoring device and a submergence monitoring system with excellent submergence detection accuracy and excellent cost performance.SOLUTION: A submergence monitoring device that comprises: receiving means 1 that emits a radio wave to a prescribed area in which a plurality of radar reflectors 9 are placed and receives reflection waves from the plurality of the radar reflectors 9; storage means 3 that stores a reference value corresponding to the intensity of the reflection waves for each of the plurality of the radar reflectors 9 when the radar reflectors 9 are submerged; identification means 4 that identifies the submerged radar reflectors 9 as submerged reflectors by comparing the intensity of the reflection wave received by the receiving means 1 with the reference value stored in the storage means 3; output means 5 and 6 that output information about the submergence of an installation point of the submerged reflectors identified by the identification means 4.

Description

  The present case relates to a submergence monitoring device and a submergence monitoring system for monitoring a submergence state of a road surface.

  2. Description of the Related Art Conventionally, a technique has been developed that uses a water level gauge to detect a flooded state on a road for vehicle traffic or an area above sea level. In other words, the flooding of road surfaces due to heavy rains and river inundation, and inundation of coastal areas due to tsunamis, overtoppings, etc. are grasped at an early stage, and this is used for traffic regulation and evacuation guidance. In recent years, underpass structures have been applied to intersections of railway lines and vehicle roads in various places, particularly in urban areas, and there are concerns about the occurrence of traffic obstacles due to flooding.

  There are several methods for detecting the flood level, such as detecting the position of the float floating on the water surface, grasping the water depth based on the water pressure acting on the pressure sensitive element, and the reflected wave of the ultrasonic wave irradiated to the water surface. What measures the distance to the water surface using is known. In addition, based on the reflection intensity of electromagnetic waves irradiated on the pavement road surface, the technology to grasp the frozen state and flooding state of the road surface, and the distance to the reflective surface is calculated based on the time required until the reflected wave is detected The technique to do is also proposed (for example, refer patent document 1).

JP 2004-325193 A

  However, in the conventional technology as described above, it is necessary to provide sensors for detecting the water level at each point where it is desired to grasp the flooded state. For example, as described in Patent Document 1, in the case of receiving a reflected wave traveling in a direction perpendicular to the water surface, only a vertically downward distance can be detected. Therefore, when the extended distance of the road surface to be monitored ranges from several tens of meters to several hundreds of meters, such as an underpass structure, it is necessary to install a plurality of sensor devices, which is not cost effective. There is.

In addition, this type of water level detection device is required to have a high degree of robustness and operational reliability because it is used when an unforeseen situation such as heavy rain or river flooding occurs. In other words, when multiple sensor devices are installed, each sensor device must be properly protected from vibration, impact, and intrusion of muddy water while securing a power supply line to each sensor device. There is a risk that running costs related to maintenance will rise.
On the other hand, although it is possible to reduce the cost by reducing the number of installed sensor devices, the detection resolution related to the submergence generation area decreases with a decrease in the number of installation places, that is, the submergence detection accuracy decreases.

One of the purposes of the present case has been invented in view of the problems as described above, and is to improve cost performance while improving the accuracy of submergence detection.
In addition, the present invention is not limited to the above-described object, and is an operational effect derived from each configuration shown in “Mode for Carrying Out the Invention” to be described later. It can be positioned as a purpose.

The disclosed submergence monitoring device is configured to receive a radio wave toward a predetermined area where a plurality of radar reflectors are installed and receive reflected waves from the plurality of radar reflectors, and when the radar reflectors are submerged. Storage means for storing a reference value corresponding to the intensity of the reflected wave at each of the plurality of radar reflectors.
Further, a specifying means for specifying the submerged radar reflector as a submerged reflector by comparing the intensity of the reflected wave received by the receiving means with the reference value stored in the storage means; and Output means for outputting information indicating that the specified installation point of the submerged reflector is submerged.

The disclosed submersion monitoring system is a submersion monitoring system for monitoring a submergence state of a road surface, and irradiates a plurality of radar reflectors installed in a predetermined region on the road surface and radio waves toward the predetermined region. And a radar device that receives a first reflected wave from the plurality of radar reflectors and a second reflected wave from a vehicle traveling on the road surface.
In this case, the radar apparatus includes an identification unit, a storage unit, a specifying unit, and an output unit. The discriminating means discriminates the first reflected wave and the second reflected wave, and the storage means sets a reference value corresponding to the intensity of the reflected wave when the radar reflector is submerged in the plurality of radar reflectors. Remember every time. The specifying unit specifies the submerged radar reflector as a submerged reflector by comparing the intensity of the first reflected wave, the second reflected wave, and the reference value stored in the storage unit. Further, the output means transmits information to the road manager that the installation point of the submerged reflector specified by the specifying means is submerged.

  According to the disclosed technology, by comparing the reflection intensity of reflected waves from a plurality of radar reflectors with a reference value, it is possible to accurately identify the position where the radar reflector is submerged with a simple configuration. The detection accuracy of submergence in a predetermined area can be improved at a low cost.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which illustrates the application object of the flood monitoring system which concerns on embodiment, (a) is a schematic diagram which shows through the underpass structure to which this system is applied, (b) is the underpass structure of (a). It is typical sectional drawing. It is a figure for demonstrating the radar reflector of this flood monitoring system, (a) is a front, a side view of a radar reflector, (b) is a graph which illustrates the reflective characteristic of a radar reflector. It is a system configuration figure of a flood monitoring device concerning this flood monitoring system. The reflected wave detected by this submersion monitoring apparatus is made into a graph, and the detection position of the reflected wave and its variation with time are exemplified. It is a graph which illustrates the time-dependent fluctuation | variation of the intensity of the reflected wave detected with this flooding monitoring apparatus. It is a graph for demonstrating the failure determination by this submersion monitoring apparatus, (a), (b) shows the time-dependent fluctuation | variation of the detection intensity of the reflected wave at the time of failure of a submersion monitoring apparatus, (c) is a radar reflector. The variation with time of the detection intensity of the reflected wave at the time of breakage is shown. It is a flowchart regarding the flooding determination in this flooding monitoring apparatus. It is a flowchart regarding selection of the output content by this flood monitoring apparatus. It is a flowchart regarding the failure detection in this flood monitoring apparatus. It is a perspective view for demonstrating the flood monitoring apparatus which concerns on a modification. It is a perspective view for demonstrating the flooding monitoring apparatus which concerns on a modification. It is a graph for demonstrating the failure determination by the flood monitoring apparatus which concerns on a modification.

  Hereinafter, embodiments of the present submersion monitoring apparatus will be described with reference to the drawings. However, the embodiment described below is merely an example, and there is no intention to exclude various modifications and technical applications that are not clearly shown in the embodiment described below. In other words, the present embodiment can be implemented with various modifications (combining the embodiments and modifications) without departing from the spirit of the present embodiment.

[1. Device configuration]
Fig.1 (a) shows the example which applied the submersion monitoring apparatus 10 which concerns on this submergence monitoring system with respect to the vehicle road of an underpass structure. The underpass structure means a structure in which one route or road is hidden under the other at the intersection of the railway or main road. Hereinafter, a road that passes below at such an intersection is referred to as an underpass 11, and a passing vehicle in the underpass 11 is referred to as a vehicle 14.

  The general underpass 11 route shape has the lowest elevation at the intersection, and has a downwardly convex shape in a vertical section in the direction in which the route extends. Therefore, the underpass 11 is provided with drainage facilities such as a drainage groove and a pump to prevent puddles when water flows in due to snow or rain. On the other hand, if a large amount of water flows into the intersection due to heavy rain or river flooding, the road surface will be flooded if the water inflow speed exceeds the drainage speed, which may hinder the passage of the vehicle 14.

  In view of this, in the submergence monitoring system, the intersection of the underpass 11 is constantly monitored by a radar, so that information to that effect is notified to the driver, road manager, etc. when the submergence occurs. The electric bulletin board 12 in FIG. 1A is a display device for notifying the driver of the vehicle 14 of such information. For example, the electronic bulletin board 12 is installed on the front side of the intersection with respect to the traveling direction of the vehicle 14. Is done. Hereinafter, the intersecting portion of the underpass 11 is also referred to as a low portion 11a.

In this submergence monitoring system, a submergence monitoring device 10 having a function as a radar device and a plurality of radar reflectors 9 are used.
The submergence monitoring device 10 irradiates a predetermined monitoring target region with millimeter wave radio waves (electromagnetic waves having a wavelength of about 1 to 10 [mm] and a frequency of about 30 to 300 [GHz]), Based on the reflected wave, the flooded state of the monitoring target area, the traffic information inside the underpass 11, the average traffic speed, the traffic jam information, and the like are detected. The millimeter wave band radio waves have excellent environmental resistance and high straightness (difficult to scatter), so that they have stable detection performance as compared with radio waves in other frequency bands. The maximum detection distance by the submergence monitoring device 10 reaches several hundreds [m] at the level of a marketed product, although it depends on the output of radio waves.

  The submersion monitoring device 10 is fixed at a position where radio waves can be directly (or indirectly) irradiated to at least the lower portion 11 a of the underpass 11. In FIG. 1A, the submersion monitoring device 10 is arranged on the back side of the low place 11a with reference to the traveling direction of the vehicle 14 passing through the underpass 11.

  In this embodiment, it is assumed that at least one or more traveling lanes and the roadside adjacent thereto are set as the monitoring target area. Note that the submersion monitoring device 10 may be disposed in front of the low place 11a with reference to the traveling direction of the vehicle 14. Further, a radar device (which measures traffic volume) used in an existing road traffic information communication system may be diverted to function as the inundation monitoring device 10 of the present embodiment.

  The radar reflector 9 is a reflector for efficiently reflecting radio waves emitted from the submergence monitoring device 10. The radar reflector 9 is fixed to each of the low places 11 a of the underpass 11 on the road side that does not hinder the traveling of the vehicle 14 along the extending direction of the underpass 11. The height at which the radar reflector 9 is fixed is a height close to the road surface.

In the present embodiment, as shown in FIG. 1B, three radar reflectors 9a, 9b, 9c are provided at distances L ₁ , L ₂ , L ₃ from the submergence monitoring device 10, and the respective altitudes are set. Set to H ₁ , H ₂ , H ₃ . The magnitude relationship between the distances L ₁ , L ₂ , and L ₃ is L ₁ <L ₂ <L ₃ , and the magnitude relationship between the altitudes H ₁ , H ₂ , and H ₃ is H ₂ <H ₁ <H ₃ . Hereinafter, when individually distinguishing these radar reflectors 9, they are also referred to as a first reflector 9a, a second reflector 9b, and a third reflector 9c in order of increasing distance from the submergence monitoring device 10. In addition, the installation point of the 2nd reflector 9b is a position with the lowest altitude (position where it is easy to flood most) in the low place 11a of the underpass 11.

  The reflection direction of the radio wave by the radar reflector 9 includes at least the direction in which the flood monitoring device 10 exists when viewed from the radar reflector 9. In addition, if a corner reflector (retro reflector) or a spherical metal reflector is used, a reflected wave having a relatively stable reflection intensity is reflected to the submersion monitoring device 10 regardless of the mounting accuracy of the radar reflector 9. Can be expected.

  In the present embodiment, a case where a radar reflector 9 having a shape as shown in FIG. The radar reflector 9 is provided with a reflector portion 91 that reflects radio waves, and a pedestal portion 92 for fixing the reflector portion 91 to the road surface. The reflector portion 91 is a triangular pyramid portion formed by joining the short sides of three metal plates cut into a right-angled isosceles triangle shape, and radio waves incident on the inner side of the cone surface are parallel to the incident direction. Reflects in the opposite direction. The above-described altitude H of the radar reflector 9 is set with reference to the position of the apex of the reflector unit 91.

A reflection characteristic graph of the radar reflector 9 during submergence is illustrated in FIG. This graph shows a state where the radar reflector 9 is fixed on the road surface and irradiated with millimeter wave radio waves from the horizontal direction, and the radar reflector 9 is gradually submerged while maintaining the intensity of the radio waves constant. This shows a change in the intensity E _R (reflection intensity) of the reflected wave. The horizontal axis of the graph corresponds to the height of the water surface from the road surface (water level from the lower end of the pedestal portion 92). The value X ₁ is the height of the lower end of the reflector unit 91, and the value X ₂ is the height of the vertex of the reflector unit 91. Here, the elevation difference X ₂ −X ₁ from the lower end to the apex of the reflector portion 91 is set to several [cm] (for example, about 5 [cm]).

When the water level is located below the lower end of the reflector portion 91, a predetermined reflection intensity _ERA is obtained. On the other hand, when the water level reaches the lower end of the reflector portion 91, the reflection intensity E _R rapidly decreases as the reflection area decreases, and when the top of the reflector portion 91 is completely submerged, the reflection intensity E _R becomes almost zero. As described above, since the millimeter wave band radio wave is easily absorbed in water, it is possible to determine that the radar reflector 9 has been submerged because the reflection intensity E _R from the reflector portion 91 is significantly reduced.

For example, as shown in FIG. 2B, a predetermined threshold value E _RTH smaller than the reflection intensity E _RA at the time of non-submergence is set in advance, and the reflection intensity E _R from an arbitrary radar reflector 9 is set as the threshold value. when below the E _RTH, can be regarded as the radar reflector 9 is submerged at a position which is provided has occurred (submerged depth of at least the road surface becomes X ₁₎ ones. Further, a lower limit threshold E _RMIN of a detection limit level smaller than the threshold E _RTH is set, and when the reflection intensity E _R from any radar reflector 9 falls below the lower limit threshold E _RMIN , the radar reflector 9 It may be considered that the flood depth of the road surface is X ₂ at the position where is provided.

Note that the reflection intensity E _RA when the radar reflector 9 is not submerged is smaller as the distance between the radar reflector 9 and the submergence monitoring device 10 is longer. Therefore, in the present embodiment, threshold _values E _RTH1 to E _RTH3 having sizes corresponding to the distances L _{1 to} L ₃ are set for each of the three radar reflectors 9a to 9c.

[2. Control configuration]
[2-1. Overview]
The submergence monitoring device 10 is a radar device that detects an object such as a vehicle 14 or an object passing through the radar reflector 9 or the underpass 11 and includes, for example, an antenna, a transmission / reception circuit module, an arithmetic circuit module, and the like. Is. The electronic circuit module incorporated therein may be manufactured as an LSI (Large Scale Integration) device in which a microprocessor, a ROM (Read Only Memory), a RAM (Random Access Memory), and the like are integrated, for example.

  FIG. 3 is a system configuration diagram schematically representing the function of the submersion monitoring device 10. The submersion monitoring device 10 is connected via a network 7 so as to be able to communicate with a traffic control center 8a that is an administrator of the underpass 11, a police authority 8b, and a third party such as a rescue center 8c. The network 7 is a wired or wireless communication network formed using, for example, a wireless communication network for mobile phones or the Internet.

  The flood monitoring apparatus 10 includes a radar unit 1, a signal processing unit 2, a storage unit 3, a determination unit 4, a display unit 5, and a communication unit 6. Each function of the radar unit 1, the signal processing unit 2, the storage unit 3, the determination unit 4, the display unit 5, and the communication unit 6 may be realized by an electronic circuit (hardware) or programmed as software. Alternatively, a part of these functions may be provided as hardware and the other part may be software.

[2-2. Elements related to input]
The radar unit 1 (receiving means) is a part for transmitting and receiving millimeter-wave radio waves, and radiates transmission waves from an antenna (not shown) and receives the reflected waves. The region to be irradiated with radio waves (monitoring target region) is a region including at least each point where the radar reflector 9 is provided. Therefore, unless the radar reflector 9 is damaged or submerged, the reflected wave from the radar reflector 9 is received by the radar unit 1. In addition, when there is a vehicle 14 that passes through the radio wave irradiation area, a reflected wave from the vehicle 14 reaches the radar unit 1. Information on the transmitted wave and the reflected wave transmitted / received here is transmitted to the signal processing unit 2.

  The object measurement method is, for example, the FM-CW method (Frequency Modulated Continuous Wave). The radar unit 1 transmits radio waves while gradually changing the frequency, and detects the distance and relative speed to the object that reflects the transmission wave based on the frequency difference (bead frequency) between the transmission wave and the reflected wave. In this embodiment, since the position of the submersion monitoring device 10 is fixed with respect to the road surface, the distance to the radar reflector 9 is constant, and the relative speed is always zero.

The signal processing unit 2 performs signal processing on the transmission information from the radar unit 1. Here, a bead signal obtained by mixing the reflected wave and the transmitted wave transmitted from the radar unit 1 is generated, the frequency of the bead signal is calculated, and the object that reflects the reflected wave based on the frequency of the bead signal is calculated. Distance L and the velocity V of the object are calculated. Here, the intensity E _R of the reflected wave from the object is detected. Distance L, information of velocity V and the intensity E _R for these objects is transmitted to the determination unit 4. Note that the object here includes not only the radar reflector 9 but also a vehicle 14 that passes on the underpass 11.

The storage unit 3 (storage means) has thresholds E _{RTH1 to} E _RTH3 for each of the three radar reflectors 9a to _9c , that is, thresholds E _{RTH1 to} E _{RTH3 having} a size corresponding to the distances L _{1 to} L _3. Is memorized. These threshold _values E _{RTH1 to} E _RTH3 are indexes for determining whether or not each of the three radar reflectors 9a to 9c is submerged. The magnitude relationship between the three thresholds E _{RTH1 to} E _RTH3 is E _RTH3 <E _RTH2 <E _RTH1 , contrary to the magnitude relationship of the distances L _{1 to} L ₃ .

[2-3. Judgment elements]
The determination unit 4 (identification unit, identification unit) mainly performs three types of determination based on the information of the object transmitted from the signal processing unit 2. The first determination is a determination as to whether the object is the radar reflector 9 or the vehicle 14. The second determination is a determination of whether or not the radar reflector 9 has been submerged (that is, a flooding determination). The third determination is a failure determination of the radar reflector 9 and the submersion monitoring device 10 itself. The determination result in the determination unit 4 is transmitted to the display unit 5 and the communication unit 6.

[2-3-1. Target identification]
Regarding the first determination, the determination unit 4 identifies the information of the object as the information of the radar reflector 9 and the information of the vehicle 14 and specifies information corresponding to the submerged radar reflector 9. Here, when the speed V of the object detected at a distance L _n from flooding the monitoring device 10 is less than the predetermined speed V _0, radar reflector 9 in which the target object is provided at a distance L _n It is judged that there is. The predetermined speed V ₀ here is, for example, a minute value close to zero. That is, objects that do not move at distances L _{1 to} L ₃ are identified as radar reflectors 9a to 9c, respectively.

On the other hand, all other objects are determined to be the vehicle 14. That is, when the distance L to the object is other than the distances L _{1 to} L ₃ or the speed V of the object is equal to or higher than the predetermined speed V ₀ , the reflected wave is reflected from the vehicle 14 ( 2), the object is identified as the vehicle 14.

When the temporal change of the position information of the object transmitted from the signal processing unit 2 is plotted, a graph as shown in FIG. 4 is obtained. Since the three radar reflectors 9 are fixed at positions of distances L _{1 to} L ₃ , the corresponding graphs are linear (thick solid lines) parallel to the time axis at the positions of distances L _{1 to} L _3. .

  If the object is the vehicle 14, the corresponding graph has a gradient corresponding to the traveling speed. When the submersion monitoring device 10 is disposed in front of the vehicle 14 relative to the monitoring target region, the vehicle 14 approaches the submersion monitoring device 10 as time passes in the monitoring target region, so the slope of the graph corresponding to the vehicle 14 is right Shoulder falls (thin solid line). Further, as shown in FIG. 4, the slower the traveling speed, the smaller the decreasing gradient. When the vehicle 14 stops, the gradient of the graph becomes zero.

[2-3-2. Determination of flooding]
Regarding the second determination, the determination unit 4 compares the reflection intensity E _R for each of the radar reflectors 9 located at the distances L _{1 to} L ₃ with the threshold value E _RTH and the reflection intensity E _R is _{equal to} or greater than the threshold value E _RTH. Sometimes, it is determined that the radar reflector 9 is not submerged. In the present embodiment, since the thresholds E _{RTH1 to} E _RTH3 at the respective distances L _{1 to} L ₃ are set, the magnitude of the reflection intensity E _R when it is determined that the first reflector 9a is submerged is This is different from the magnitude of the reflection intensity E _R when it is determined that the second reflector 9b is submerged. For example, the condition for determining that the first reflector 9 a is not submerged is “the reflection intensity E _R from the first reflector 9 a is _{equal to} or greater than the threshold E _RTH1 ”, and the second reflector 9 b is The condition for determining that the object is not submerged is “the reflection intensity E _R from the second reflector 9 b is _{equal to} or greater than the threshold E _RTH2 ”.

When the reflection intensity E _R from the first reflector 9a is smaller than the threshold value E _RTH1, the first reflector 9a is submerged, submerged at the installation point of the first reflector 9a is determined to have occurred. Moreover, it is judged that the flood level at this time is the altitude H ₁ to which the first reflector 9a is attached. Similarly, in the case of the second reflector 9b and the third reflector 9c, the reflection intensity E _R is compared with the thresholds E _RTH2 and E _RTH3 , respectively, and the presence / absence of _submergence and the _submergence water level at each installation point are determined. The

When the flooding times when the reflection intensities E _R of the radar reflectors 9a to _{9c are} less than the thresholds E _{RTH1 to} E _RTH3 are t ₁ , t ₂ , and t ₃ , respectively, these times t _{1 to} t ₃ are shown in FIG. Corresponds to the time when the straight line graph corresponding to the radar reflectors 9a to 9c disappears. For example, if the water depth has increased gradually during the flooding of the underpass 11, the context of the time t ₁ ~t ₃ becomes t _2, t _1, t ₃ to the old order.

FIG. 5 is a graph in which the change over time in the reflection intensity E _R is plotted on the graph among the information on the object transmitted from the signal processing unit 2. Since the reflection intensity E _R from the radar reflector 9 generally decreases according to the traveling distance of the reflected wave, the reflection intensity E _R from the first reflector 9 a is normal when the radar reflector 9 is not submerged. Becomes the largest, and the reflection intensity E _R from the third reflector 9c becomes the smallest.
On the other hand, when flooding occurs, the reflection intensity E _R starts to decrease in descending order of elevation. Therefore, the reflection intensity E _R of the second reflector 9b first decreases, and then the reflection intensity E _R decreases in the order of the first reflector 9a and the third reflector 9c.

In general, the reflection intensity E _R from the vehicle 14 increases as the vehicle 14 approaches the submersion monitoring device 10. Therefore, the gradient of the graph corresponding to the vehicle 14 in FIG. 5 rises to the right, and the shape corresponding to the graph corresponding to the vehicle 14 in FIG. 4 is inverted vertically. Thus, reflection intensity E _R of the moving object does not become constant, the amount of change is in accordance with the moving speed. Therefore, the radar reflector 9 and the vehicle 14 may be identified using such characteristics.

[2-3-2. Failure determination]
Regarding the third determination, the determination unit 4 determines the damage of the radar reflector 9 or the failure of the submersion monitoring device 10 itself using the reflection intensity E _R from the vehicle 14 identified in the first determination. Determination unit 4, the reflection intensity E _R of all radar reflector 9 is less than the respective reflection intensities E _R is the threshold E _RTH (threshold _{E RTH1, E RTH2, E RTH3} ), and reflection from the vehicle 14 When the intensity E _R is less than the predetermined intensity E _RB, it is determined that the flood monitoring apparatus 10 has failed. In this case, it is determined that the radar function (radar unit 1, antenna, etc.) of the submersion monitoring device 10 has failed.
For example, as shown in FIG. 6A, when the reflection intensity E _R of the radio wave from the monitoring target area decreases as a whole after a predetermined time t ₄ , this phenomenon is caused by the flooding monitoring device 10. It is considered to result from functional decline.

On the other hand, when the reflection intensity E _{R of} all the radar reflectors 9 is less than the threshold E _RTH and the reflection intensity E _R from the vehicle 14 is equal to or greater than the predetermined intensity E _RB , the radar function is maintained. Therefore, the determination unit 4 determines that the orientation of the main body of the submersion monitoring device 10 has changed. In this case, although the radar function of the submersion monitoring device 10 does not fail, the determination unit 4 does not sufficiently fulfill the function of monitoring the submergence in the underpass 11. Is determined to have occurred.
For example, as shown in FIG. 6B, although the reflection intensity E _R of all the radar reflectors 9 has decreased after a predetermined time t ₅ , a change is seen in the reflection intensity E _R from the vehicle 14. If not, the cause of this phenomenon is considered to be derived from the movement of the monitored area.

For each radar reflector 9, the elapsed time when the reflection intensity E _R is less than the threshold E _RTH is equal to or longer than a predetermined time, and the speed V of the vehicle 14 passing through the underpass 11 is the predetermined speed V. _When it is ₁ or more, it is determined that the radar reflector 9 has failed (for example, a part or all of the radar reflector 9 has been damaged or the direction of the reflector unit 91 has changed). For the failure of the radar reflector 9 here, the radio wave incident on the reflector portion 91 has a sufficient strength due to a part or all of the radar reflector 9 being damaged or the orientation of the reflector portion 91 being changed. The state where it is no longer possible to reflect by is included.

That is, when the reflection intensity E _R from the radar reflector 9 as temporarily reduced (if radar reflector 9 may become invisible or visible from flooding the monitoring device 10 for a predetermined time), flooded monitoring It is determined that no obstacle has passed between the apparatus 10 and the radar reflector 9, and it is determined that the radar reflector 9 has not failed. Even if the reflection intensity E _R decreases for a long time, if the speed V of the passing vehicle 14 is less than the predetermined speed V _1, it is assumed that the vehicle 14 is slowing down due to flooding, and the radar reflector 9 is broken. Judge that is not.
For example, as shown in FIG. 6 (c), when the reflection intensity E _R of the second reflector 9b is lowered in a short time from a predetermined time t ₆ to time t _7, the the second reflector 9b failure It is considered not. In addition, the first reflector 9a and the third reflector 9c, in which the reflection intensity E _R is not reduced, are also considered not to have failed.

On the other hand, if the speed V of the vehicle 14 is equal to or higher than the predetermined speed V ₁ even though the reflection intensity E _R has been reduced for a long time, the reflector function of the radar reflector 9 is reduced (for example, the reflector portion 91 It is determined that the radar reflector 9 is out of order.
The time t ₈ after in FIG. 6 (c), the reflection intensity E _R of the second reflector 9b is reduced over time. Alone from the reference reflection intensity E _R, it is possible to distinguish whether this or decrease in reflection intensity E _R is a thing due to the submergence of the reflector portion 91, or a thing due to the decrease of the reflector functions other than submerged difficult. However, if the reflector portion 91 of the second reflector 9b is actually submerged, the speed V of the vehicle 14 passing through the underpass 11 is lowered by the flooding of the road surface, as shown in FIG. The slope of the graph corresponding to the vehicle 14 should be small. Therefore, in this embodiment, reflection intensity E _R is lowered for a long time, and the velocity V is equal to the predetermined speed V ₁ or more, it is determined that the radar reflector 9 has failed.

[2-4. Elements related to output]
The display unit 5 (output unit, notification unit, alarm unit) outputs information corresponding to the determination result of the determination unit 4 to the electronic bulletin board 12. Here, when the determination unit 4 determines that submergence has occurred in the underpass 11, a control signal for displaying the submergence water level is output to the electric bulletin board 12, and the driver of the vehicle 14 is notified of the submergence water level. . For example, when the installation point of the first reflector 9a is submerged, the electronic bulletin board 12 displays “submerged water level X ₂ cm”.

  Further, when the submergence occurs only at the installation point of the second reflector 9b, that is, when only the radar reflector 9 having the lowest altitude is submerged (for example, the depth of the submergence is several [cm] from the road surface. ], It is determined that there is no hindrance to the passage of the vehicle 14, and a control signal for causing the electronic bulletin board 12 to display “notice of passage” or the like is output.

On the other hand, when submergence occurs at least in both the first reflector 9a and the second reflector 9b, that is, when the submergence water level is higher than the altitude H ₂ (for example, the depth of the submergence is several tens of [ cm], it is determined that the vehicle 14 will be obstructed, and a control signal for displaying “no traffic” or the like on the electronic bulletin board 12 is output.
Furthermore, when there is a vehicle 14 that is about to enter the underpass 11 during flooding (when the presence of the vehicle 14 is detected by a radar function that measures traffic), in addition to the control signal described above, Then, a control signal for causing the electronic bulletin board 12 to display “submerged”, “speed down”, etc. is output.

The communication unit 6 (output unit, rescue unit) outputs a signal for transmitting information according to the determination result of the determination unit 4 to the traffic control center 8a, the police authority 8b, and the rescue center 8c. Here, when the determination unit 4 determines that submersion has occurred in the underpass 11, a transmission signal for transmitting the submersion level to the traffic control center 8a is output.
Also, if the flood occurs in both the at least a first reflector 9a and a second reflector 9b, i.e., when the flood water level is altitude H ₂ or more, the vehicle 14 is impassable the underpass 11 It is determined that the state has been reached, and a transmission signal for requesting traffic control by the underpass 11 is output to the police authorities 8b.

Further, in a state flooding occurs in both the at least a first reflector 9a and a second reflector 9b, and, when the speed V of the vehicle 14 in the underpass 11 is less than a predetermined passage speed V ₂ is It is determined that the vehicle 14 is stuck in the underpass 11 due to the flooding, and a transmission signal for requesting rescue is output to the rescue center 8c. When the stack of the vehicles 14 occurs, the gradient of the graph corresponding to the vehicle 14 in FIG. 4 becomes almost zero. Therefore, the stack of the vehicle 14 may be detected using the information on the distance L instead of the speed V.

[3. flowchart]
FIG. 7 to FIG. 9 are flowcharts illustrating a control procedure performed by the submersion monitoring apparatus 10. The series of controls shown in these flowcharts are repeatedly performed inside the flood monitoring apparatus 10 independently of each other.
FIG. 7 is a flow related to determination of flooding, FIG. 8 is a flow related to output, and FIG. 9 is a flow related to failure determination. Note that a variable k described in FIG. 7 is a variable for distinguishing the three radar reflectors 9. The initial value of the variable k is k = 0, and takes an integer value corresponding to the number of radar reflectors 9 installed.

[3-1. Determination of flooding]
Each step of the flowchart of FIG. 7 is mainly performed by the radar unit 1, the signal processing unit 2, and the determination unit 4. In step A10, an object existing in the monitoring target area is detected. That is, the information of the reflected wave that has reached the radar unit 1 is transmitted to the signal processing unit 2, the distance L to the object that reflected the reflected wave and the velocity V of the object are calculated, and the reflected wave intensity E _R Is detected.

In Step A20, it is identified whether the detected object is the radar reflector 9 or the vehicle 14. In the determination unit 4, the objects that do not move at the distances L _{1 to} L ₃ are extracted from all the detected objects, and these are respectively the first reflector 9a, the second reflector 9b, and the third reflector 9c. Identified as All other objects are identified as the vehicle 14. Information regarding the radar reflector 9 and the vehicle 14 identified here is recorded in a storage device (not shown).

In Step A30, it is determined whether or not the variable k is k = 3. The initial value of the variable k is k = 0, and the process proceeds to step A40 at first. In the subsequent step A40, the value k + 1 is substituted for the variable k, and the process proceeds to step A50.
In Step A50, it is determined whether or not the reflection intensity E _R of the kth reflector is _{equal to} or greater than a threshold value E _RTHk . When the variable k is k = 1, the reflection intensity E _R of the first reflector 9a is compared with the threshold value E _RTH1, and when E _R ≧ E _RTH1 , the process proceeds to Step A60. On the other hand, when E _R <E _RTH1 , the process proceeds to Step A70.

In Step A60, the monitoring counter value C _k for the kth reflector is set to C _k = 0, and the process proceeds to Step A80. On the other hand, in step A70, the value C _k +1 is assigned to the monitoring counter value C _k for the kth reflector, and the process proceeds to step A80. The monitoring counter value C _k here is the number of times that the k-th reflector is determined to have been continuously submerged (the probability that the k-th reflector has been submerged, and the detection error or fluctuation of the water surface The variable is set for each radar reflector 9.

In Step A80, it is determined whether or not the monitoring counter value C _k for the kth reflector is _{equal to} or greater than a predetermined threshold number C _kTH . Here, if C _k ≧ C _kTH , the process proceeds to step A90, where it is determined that the kth reflector is surely submerged, and the process proceeds to step A30. On the other hand, if C _k <C _kTH in step A80, the process proceeds to step A100, where it is determined that the kth reflector is not submerged, and the process proceeds to step A30.

  The flow of steps A30 to A100 is repeatedly performed according to the number of radar reflectors 9 installed. When the submergence determination for all the radar reflectors 9 is completed, the control proceeds from step A20 to step A110.

  In step A110, the variable k is set to k = 0, and information on all the objects identified as the vehicle 14 in step A20 is tracked as vehicle traffic information. For example, a predicted value of the distance L that can be detected in the next calculation cycle is calculated based on the information on the speed V of each object. Further, when there is a predicted value of the distance L of the vehicle 14 calculated in the previous calculation cycle, this is compared with the distance L obtained in the current calculation cycle, and whether or not they are the same vehicle 14. Is tested.

In this flowchart, a state in which the reflection intensity E _R from the radar reflector 9 is repeatedly detected is less than the threshold value E _RTHk , and it is determined that the radar reflector 9 has been submerged only after the number of times reaches the threshold number C _kTH or more. The If the reflection intensity E _R is recovered, the determination is immediately reversed, and it is determined that the radar reflector 9 is not submerged. Thereby, the influence of the detection error and the fluctuation (ripple wave) of the submergence surface is removed, and the submergence state at the installation point of the radar reflector 9 is accurately grasped.

[3-2. output]
Each step of the flowchart of FIG. 8 is mainly performed by the display unit 5 and the communication unit 6. In Step B10, it is determined whether or not the installation point of the third reflector 9c is flooded. When the third reflector 9c is submerged, the process proceeds to Step B40, and when it is not submerged, the process proceeds to Step B20. In Step B20, it is determined whether or not the installation point of the first reflector 9a is submerged. When the first reflector 9a is submerged, the process proceeds to Step B50, and when it is not submerged, the process proceeds to Step B30.

  Similarly, in step B30, it is determined whether or not the installation point of the second reflector 9b is submerged. If the second reflector 9b is submerged, the process proceeds to step B60. If the second reflector 9b is not submerged, the flow ends.

Control proceeds to step B40 when the third reflector 9c having the highest elevation among the three radar reflectors 9 is submerged, that is, when all the radar reflectors 9 are submerged. Therefore, the control signal from the display unit 5 in step B40 in the electric bulletin board 12 are output, together with the display "No traffic" to the electric bulletin board 12, flood water level corresponding to the altitude H ₃ installation point of the third reflector 9c Is displayed and the process proceeds to step B70.

Further, when the process proceeds from step B20 to step B50, the first reflector 9a and the second reflector 9b among the three radar reflectors 9 are submerged. Therefore, a warning that traffic is prohibited and the flood level corresponding to the altitude H ₁ of the installation point of the first reflector 9a are displayed on the electronic bulletin board 12, and the process proceeds to Step B70.

In step B70, a communication signal is output from the communication unit 6 to the police authority 8b, and traffic control in the underpass 11 is requested. In subsequent step B80, it is determined whether or not there is a vehicle 14 (stack vehicle) stopped in the underpass 11. Here when a predetermined passage speed V ₂ less than the vehicle 14 is present the flow proceeds to step B90, the process proceeds to step B100 in the absence.

Incidentally, most elevations low position in the underpass 11 is located a distance L is L ₂ from flooding the monitoring device 10. That is, the vehicle 14 detected at a position where the distance L from the submergence monitoring device 10 is less than L ₂ is the vehicle 14 that has passed through the deepest portion of the flooded road surface without being stacked. Therefore, as an object distance L from flooding the monitoring device 10 only vehicle 14 detected by the L ₂ or more positions, it may be configured to detect a stack of the vehicle 14.
Alternatively, a flooded area (that is, two distances L corresponding to the boundary position between the flooded area and the non-flooded area) is calculated, and only the vehicle 14 detected in the area is set as a stack detection target. Also good.

In step B90, a transmission signal is output from the communication unit 6 to the rescue center 8c, the rescue of the stacked vehicle 14 is requested, and the process proceeds to step B100.
In addition, when it progresses to step B60 from step B30, since only the 2nd reflector 9b is submerged, it is displayed on the electric bulletin board 12 as "passing attention", and the installation point of the 2nd reflector 9b is displayed. The flood level corresponding to the altitude H ₁ is displayed, and the process proceeds to Step B100. In Step B100, it is determined whether or not there is a vehicle 14 that is about to enter the underpass 11. If this condition is satisfied, the process proceeds to step B110, and if the condition is not satisfied, the process proceeds to step B120.

  In step B110, a control signal is output from the display unit 5 to the electric bulletin board 12, "Submersion" is displayed on the electric bulletin board 12, and the process proceeds to step B120. In the following step B120, a transmission signal is output from the communication unit 6 to the traffic control center 8a, and the flood level output to the electronic bulletin board 12 and the contents of the traffic guidance display are notified. Further, when a transmission signal is output to the police authorities 8b or the rescue center 8c, the information is also notified to the traffic control center 8a.

[3-3. Failure determination]
Each step of the flowchart of FIG. 9 is mainly performed by the determination unit 4. In Step C10, it is determined whether or not each of the radar reflectors 9 has a reflection intensity E _R less than a threshold value E _RTH . Here, the reflection intensity E _R of the first reflector 9a is less than the threshold E _RTH1 , the reflection intensity E _R of the second reflector 9b is less than the threshold E _RTH2 , and the reflection of the third reflector 9c. If the intensity E _R is less than the threshold E _RTH3 , the process proceeds to Step C20, and if this condition is not satisfied, the process proceeds to Step C50. A configuration may be adopted in which it is determined whether or not the reflection intensities E _R from all the radar reflectors 9 have decreased substantially simultaneously (during a predetermined time).

In step C20, it is determined whether or not the reflection intensity E _R from the vehicle 14 is _{equal to} or greater than the predetermined intensity E _RB . When this condition is satisfied, the process proceeds to step C30, where the orientation of the main body of the submersion monitoring device 10 has changed. Determined. This determination is made when, for example, the direction of the antenna of the submergence monitoring device 10 changes and the radar reflector 9 becomes invisible from the submergence monitoring device 10 or when the monitoring target area moves to the adjacent traveling lane side. It corresponds to.
On the other hand, when the condition of step C20 is not satisfied, the process proceeds to step C40, and it is determined that the flood monitoring apparatus 10 has failed. This determination corresponds to, for example, a case where the radar function of the submergence monitoring device 10 is deteriorated.

In Step C50 following Steps C30 and C40, it is determined whether or not the reflection intensity E _{R of} at least one of the radar reflectors 9 is less than the threshold E _RTH , and the process proceeds to Step C60 when this condition is satisfied. On the other hand, when this condition is not established, the routine proceeds to step C90, where it is determined that none of the radar reflectors 9 is damaged, and this flow is terminated.

In step C60, the speed V of the vehicle 14 for passing the underpass 11 it is determined whether the predetermined speed V ₁ or more, the process proceeds to step C70 during establishment of this condition. When this condition is not satisfied, the process proceeds to step C90, where it is determined that none of the radar reflectors 9 is damaged, and this flow is terminated.

In step C70, it is determined whether or not the radar reflector 9 for which the reflection intensity E _R has been decreased in step C50 is equal to or longer than a predetermined time since the reflection intensity E _R has decreased. If this condition is satisfied, the process proceeds to step C80, where it is determined that the radar reflector 9 is damaged. On the other hand, when this condition is not established, the routine proceeds to step C90, where it is determined that none of the radar reflectors 9 is damaged, and this flow is terminated.
Note that the flow relating to the failure determination shown in FIG. 9 described above can be incorporated into the flow relating to the output shown in FIG. For example, before executing steps B40, B50, and B60 in FIG.

[4. Action, effect]
(1) The intensity E _R of the reflected wave from the submerged radar reflector 9 changes depending on the flooded state, and the reflection intensity E _R after submergence is significantly lower than the reflection intensity E _R before submergence. Based on such a change characteristic of the reflection intensity E _R , in the above-described embodiment, the threshold value E _RTH of the reflection intensity E _R is set for each of the radar reflectors 9 fixed in each place in the monitoring target region, It is stored in the storage unit 3. This threshold value E _RTH is set in advance according to the distance L to the submersion monitoring device 10, and each of the three radar reflectors _9a to _9c has threshold _values E _RTH1 to E _RTH3 having different sizes.

In the above submergence monitoring system, the threshold _values E _RTH1 to E _RTH3 and the reflection intensity E _R inherent in each radar reflector 9a to _9c are compared, and the reflection intensity E _R is less than the respective threshold _values E _{RTH1 to} E _RTH3. In this case, it is determined that flooding has occurred at the installation point of the radar reflector 9, which is the source of the reflected wave. Further, when the reflection intensity E _R recovers to the respective thresholds E _{RTH1 to} E _RTH3 or more, it is determined that the flooding has been eliminated at the installation point of the radar reflector 9 that is the source of the reflected wave.

Thus, even if the radar reflector 9 is as small as several [cm], its submergence can be detected more accurately than the vehicle 14 or the road structure. Further, by comparing the threshold _values E _RTH1 to E _RTH3 and the reflection intensity E _{R specific} to each of the radar reflectors 9a to 9c, the degree of submergence of each of the radar reflectors 9a to 9c can be accurately grasped. . Based on this, it is possible to accurately specify the degree of submergence on the road surface and the position where the puddle is generated. Therefore, the detection accuracy of the flood in the underpass 11 can be improved.

In particular, the above submergence monitoring system detects the reflection intensity E _R of each of the radar reflectors 9a to 9c, and does not detect the submerged water surface itself. Even if there is, measurement accuracy does not deteriorate. That is, the above flood monitoring system can measure the water level regardless of the state of the water surface, has the advantage of being resistant to environmental changes and being hardly affected by disturbances.

The radar reflector 9 used in the submergence monitoring system is a reflector having a simple structure and does not require power and power for detecting submergence and submergence, but has a stable and constant amount of reflection intensity. E _R can be expected and cost performance can be improved.

  In addition, in the monitoring target area where the puddle may be generated, a metal reflector that is highly resistant to moisture, dust, sludge, and the like and is not likely to break down is provided. It is installed at a high place away from the monitored area. Therefore, the service life and maintenance interval of the submersion monitoring system can be set longer, and cost performance can be improved in this respect as well.

(2) Further, in the above-mentioned flood monitoring system, the three radar reflectors 9a, 9b, 9c are provided at positions L ₁ , L ₂ , L ₃ from the flood monitoring apparatus 10. This makes it possible to uniquely identify the position of the source of the reflected wave from only the information on the distance L included in the reflected wave, and the received reflected wave is one of the three radar reflectors 9a, 9b, 9c. It is possible to easily identify the reflected wave from which.

That is, it is not necessary to identify the position and direction of the reflected wave generation source, the calculation configuration in the radar unit 1 can be simplified, the cost of the submersion monitoring device 10 can be reduced, and the calculation speed is improved. Can be made.
Moreover, since it is not necessary to control the irradiation direction of the radio wave irradiated from the radar unit 1, the configuration of the radar device itself can be further simplified, and the cost can be greatly reduced. In addition, it is easy to divert and use the radar device used in the existing road traffic information communication system, which is advantageous in terms of cost.

(3) In the above flood monitoring system is provided at an altitude H _1, H _2, H ₃ of the three radar reflectors 9a, 9b, 9c are different from each other. Thereby, the flood level can be grasped with high accuracy, and the generation region and the width of the flood in the underpass 11 can be accurately estimated.

  In addition, since the route shape of the general underpass 11 has the lowest altitude at the low portion 11a and is a convex shape downward, even if the shape of the radar reflector 9 is the same, it is arranged at a different position. It is easy to make the altitudes H different from each other. In other words, when the above-mentioned flood monitoring apparatus 10 is applied to the underpass 11, it is not necessary to change the shape of the pedestal portion 92 in order to make the altitude H of the radar reflector 9 different, thereby further reducing the cost. be able to.

  (4) Moreover, in the above-mentioned flood monitoring system, not only the reflected wave from the radar reflector 9 but also the reflected wave from the vehicle 14 traveling through the underpass 11 is detected, and the position information and speed information of the vehicle 14 are obtained. Used control is implemented. As a result, it is possible to constantly monitor flooding that may occur suddenly while observing the traffic volume and traffic conditions in the underpass 11 at normal times.

  (5) In the above flood monitoring system, when a new vehicle 14 enters the underpass 11 in a state where the flood has occurred, “submersion” is displayed on the electronic bulletin board 12. In this way, by performing control to actively notify the driver of the vehicle 14 of flooding, slow driving can be promoted, and the amount of traffic in the underpass 11 can be appropriately controlled. . In addition, information can be provided in advance before the driver of the vehicle 14 encounters flooding, and convenience can be improved.

  (6) Further, in the above flood monitoring system, the entry of the vehicle 14 is prohibited according to the flood level in the underpass 11. For example, when the submerged water level is relatively low and only the second reflector 9b is submerged, the electronic bulletin board 12 displays “passing attention”, whereas the first reflector 9a and the second reflector 9b. If both of them are submerged, “electronic warning” is displayed on the electronic bulletin board 12. In this way, by restricting the entry of the vehicle 14 according to the flood level, the vehicle stack in the underpass 11 due to the flood can be prevented.

(7) On the other hand, if the flood water level stack of the vehicle 14 when it altitude H ₂ or more is detected, the stack vehicle rescue is requested rescue center 8c. Therefore, the traffic obstacle in the underpass 11 can be solved at an early stage.
In addition, regarding the detection of the stack of the vehicle 14, when the stack is detected only for the vehicle 14 detected in the flooded area, the vehicle 14 that has stopped in the underpass 11 is automatically flooded. It is possible to accurately grasp the vehicle 14 that can no longer run. For example, it is possible to distinguish between a vehicle 14 that has been submerged and stuck and a self-propelled vehicle 14 that suddenly stopped in front of the vehicle 14 and accurately count the number of vehicles 14 that need to be rescued. Can do.

(8) In the above flood monitoring system to identify and reflection intensity E _R from reflection intensity E _R and the vehicle 14 of the radar reflector 9, flooding monitoring device using the reflection intensity E _R from the vehicle 14 10 The failure judgment is carried out. Thereby, even if a failure occurs in the submergence monitoring device 10, the failure can be quickly found in a normal operation state, and maintenance can be performed early. Moreover, since the malfunction of the submergence monitoring apparatus 10 is solved at an early stage, it is possible to suppress erroneous detection and misreporting regarding submergence, further improve the detection accuracy of submergence, and improve control reliability. Can do.

(9) Furthermore, in the above-mentioned flood monitoring system, damage to the radar reflector 9 is determined by referring to the velocity V of the vehicle 14 in addition to the reflection intensity E _R from each radar reflector 9. That is, not only the submergence monitoring apparatus 10 but also the radar reflector 9 can quickly find out its failure and breakage in a normal operation state, and early maintenance can be performed. Therefore, it is possible to suppress false detection and false alarms regarding flooding, further improve the accuracy of flood detection, and improve control reliability.

(10) In the above flood monitoring system, as shown in FIG. 7, the monitoring counter value C _k for each radar reflector 9 is set, taking into consideration the influence of detection errors and fluctuations in the water surface. However, the submergence judgment is carried out reliably. For example, when a small puddle is generated around the radar reflector 9 and the reflection intensity E _R is accidentally reduced only once by the ripples on the water surface, the radar reflector 9 is submerged. Not judged. As described above, not only the comparison between the reflection intensity E _R and the threshold value E _RTH but also the judgment as to whether or not the radar reflector 9 has been submerged by using the number of times the reflection intensity E _R has fallen below the threshold value E _RTH. By carrying out, the detection accuracy of the flood can be further improved.

[5. Modified example]
[5-1. Judgment conditions]
Various determination conditions in the above-described embodiment can be changed as appropriate.
For example, regarding the first determination in the determination unit 4, in the above-described embodiment, the radar reflector 9 and the vehicle 14 are identified based on the distance L and the speed V of the object. Instead of or in addition, the radar reflector 9 and the vehicle 14 may be identified based on the estimated movement trajectory of the object, or based on the shape of the graph as shown in FIG. 4 or FIG. The radar reflector 9 and the vehicle 14 may be identified. By using these plural methods, the accuracy (accuracy) of determination can be changed, or the accuracy can be further increased.

The same applies to the second determination, and instead of comparing the reflection intensity E _R and the single threshold E _RTH , a configuration may be used in which a plurality of thresholds are compared. For example, as shown in FIG. 2B, when the reflection intensity E _R continuously decreases over a predetermined time, it is determined that the radar reflector 9 has been submerged, and when it suddenly decreases abruptly Alternatively, the radar reflector 9 may be damaged or the submersion monitoring device 10 may be suspected. By observing the change gradient of the reflection intensity E _R , the submerged state of the radar reflector 9 can be determined more accurately.

  Further, regarding the third determination, the malfunction of the flood monitoring apparatus 10 or the damage of the radar reflector 9 may be determined in consideration of the altitude H of the installation point. For example, if it is determined that the third reflector 9c has been submerged before it is determined that the second reflector 9b having the lowest elevation has been submerged, and the determination is maintained for a long time, It can be considered that the monitoring device 10 has failed or the radar reflector 9 has been damaged.

Further, in the above-described embodiment, an example of determining a failure of the submergence monitoring device 10 based on the reflection intensity E _R is illustrated, but in addition to or instead of the submergence based on the measured distance L of the object. It is good also as a structure which determines the failure of the monitoring apparatus 10. FIG. That is, when the output of the radio wave irradiated from the submergence monitoring device 10 decreases or the reception sensitivity of the reflected wave decreases, the maximum distance that can be detected by the submergence monitoring device 10 decreases.

  When such a decrease in output and a decrease in reception sensitivity proceed gradually, the distance to the object detected by the submersion monitoring device 10 gradually decreases. As shown in FIG. The target cannot be detected. In this figure, as in FIG. 4, the distance L to the object detected by the submersion monitoring device 10 is drawn on the vertical axis, and the horizontal axis shows time. Therefore, it may be configured to determine that the submersion monitoring device 10 has failed when the distance (detectable distance) to the farthest object among the observed objects becomes extremely small.

[5-2. Output contents]
Various specific contents of the output controlled by the display unit 5 and the communication unit 6 of the above-described embodiment can be considered.
For example, as the type of information displayed on the electronic bulletin board 12 by the display unit 5, not only the submergence notification and warning, but also the presentation of the detour and the estimated vehicle height and vehicle type, the underpass 11 Notification of the inflow speed and drainage speed of inflowing water can be considered. By publishing accurate information without delay, it is possible to prompt the driver of the vehicle 14 to perform a calm and appropriate operation and improve the reliability of the flood monitoring system.

  In the above-described embodiment, the information output destination from the communication unit 6 is exemplified as the traffic control center 8a, the police authority 8b, and the rescue center 8c. However, the specific information output destination is not limited to this. . For example, information may be output to an existing road traffic information communication system or a road-to-vehicle communication network of a nearby road connected to the underpass 11 to widely inform that the underpass 11 has been flooded. As a result, it is possible to more easily avoid the occurrence of traffic obstacles due to flooding, and the convenience can be enhanced.

Moreover, in the above-mentioned embodiment, although the warning display for restricting the approach of the vehicle 14 is output from the display unit 5 when the flood level is higher than the altitude H ₂ , the warning is given according to the flood level. The content of the display may be changed. For example, it may be possible to display that only light vehicles are prohibited when the flood level is relatively low, and that all vehicles are prohibited when the flood level is further increased. Convenience can be further improved by changing the alarm content after considering the risk of each vehicle type that may cause a traffic obstacle.

  Further, in the above-described embodiment, even when there is no vehicle 14 that passes through the underpass 11, the flood level is displayed on the electronic bulletin board 12 when flooding occurs. Such a display may be made when entering the flooded area.

  Further, in the above-described embodiment, the example in which the submergence monitoring system functions as a main body that determines whether or not to request a rescue is illustrated, but instead of such a configuration, a report of submergence or a stack of the vehicle 14 is received. The administrator may separately obtain weather information and determine whether or not to request a rescue.

[5-3. Applicable to]
In the above-described embodiment, an example in which the submersion monitoring system is applied to a vehicle road having an underpass structure is illustrated, but the application target of the submersion monitoring system is not limited thereto. For example, as shown in FIG. 10, a system for monitoring the water level of a river can be constructed by applying the above-mentioned flood monitoring system to a river bank. In this case, by fixing the plurality of radar reflectors 9 to the side surface 21 facing the river 20 of the embankment, the water level can be accurately detected, and the flooding of the river can be grasped in advance.

  In addition, as shown in FIG. 11, a system for monitoring overtopping caused by a typhoon or a storm can be constructed by applying the above-mentioned submergence monitoring system to a breakwater or tide bank along the coast. In this case, by fixing the plurality of radar reflectors 9 at positions where the altitude is higher than the height of the breakwater 22, it is possible to accurately detect the high waves that enter the road 23 in the bank beyond the breakwater 22.

When a plurality of radar reflectors 9 are fixed to the breakwater 22, the fixed heights of the respective radar reflectors 9 may be different. However, as shown by the broken line in FIG. May be. By providing each radar reflector 9 at a position where the distance to the submersion monitoring device 10 is different, it is possible to accurately identify the position where overtopping has occurred.
Alternatively, the radar reflectors 9 may be fixed to the side surface of the breakwater 22 on the sea side, and the radar reflectors 9 may be monitored from the sea surface side. In this case, it is possible to detect the height of the wave that collides with the breakwater 22, that is, it is possible to accurately detect waves and waves that do not reach the breakwater 22.

The radar reflector 9 can be submerged under the water surface in the case of flooding on the road surface or rivers, whereas the radar reflector 9 is not necessarily submerged under the water surface in the case of overtopping. The reflection intensity E _{R of the} reflected wave decreases only during a few seconds when the water is wet. Therefore, the condition for determining that the radar reflector 9 has been _flooded is “the number of times that the reflection intensity E _R becomes equal to or less than the threshold value E _RTH1 during a predetermined time is equal to or greater than the predetermined number”, and this condition is When established, it may be determined that a high wave has exceeded the breakwater 22.

1 Radar part (reception means)
2 Signal processing section 3 Storage section (storage means)
4 Judgment part (identification means, identification means)
5 Display section (output means, notification means, alarm means)
6 communication part (output means, rescue means)
9 Radar reflector 10 Flood monitoring device

Claims (11)

Receiving means for radiating radio waves toward a predetermined area where a plurality of radar reflectors are installed and receiving reflected waves from the plurality of radar reflectors;
Storage means for storing a reference value corresponding to the intensity of the reflected wave when the radar reflector is submerged for each of the plurality of radar reflectors;
Identifying means for identifying the submerged radar reflector as a submerged reflector by comparing the intensity of the reflected wave received by the receiving means with the reference value stored in the storage means;
An inundation monitoring apparatus comprising: output means for outputting information indicating that the installation point of the inundation reflector specified by the specifying means is submerged. The flood monitoring apparatus according to claim 1, wherein the plurality of radar reflectors are installed at positions different from each other with respect to the receiving unit. The inundation monitoring apparatus according to claim 1, wherein the plurality of radar reflectors are installed at positions having different altitudes. The receiving means receives a second reflected wave from a vehicle traveling in the predetermined area,
4. The flood monitoring apparatus according to claim 1, wherein the specifying unit detects a position and a speed of the vehicle based on the second reflected wave received by the receiving unit. 5. . Informing means for informing the vehicle of the occurrence of the flooding when the output means receives the second reflected wave by the receiving means and the flooding reflector is identified by the identifying means. The inundation monitoring apparatus according to claim 4, comprising: The said output means has a rescue means which outputs a rescue signal when the said vehicle stops at a place lower than the installation point of the said submerged reflector specified by the specifying means. 5. The flood monitoring apparatus according to 5. The specifying means specifies the submerged water level in the predetermined area based on the height of the installation point of the submerged reflector,
The output means includes alarm means for outputting an alarm display for restricting vehicle entry to the predetermined area in accordance with the flood level specified by the specifying means. The flood monitoring apparatus according to any one of 6. The identification unit detects a failure of the receiving unit by comparing a temporal change in intensity of the reflected wave received by the receiving unit and a temporal change in intensity of the second reflected wave. Item 8. The flood monitoring apparatus according to any one of Items 4 to 7. 9. The radar device according to claim 4, wherein the specifying unit detects damage of the radar reflector based on a change with time of the intensity of the reflected wave received by the receiving unit and a speed of the vehicle. The flood monitoring apparatus according to claim 1. The said specifying means specifies the said submerged reflector based on the time and the frequency | count that the intensity | strength of the said reflected wave received by the said receiving means fell below the said reference value memorize | stored in the said memory | storage means, It is characterized by the above-mentioned. Item 10. The flood monitoring apparatus according to any one of Items 1 to 9. A submergence monitoring system for monitoring submergence conditions on a road surface,
A plurality of radar reflectors installed in a predetermined area on the road surface;
A radar device that radiates radio waves toward the predetermined region and receives a first reflected wave from the plurality of radar reflectors and a second reflected wave from a vehicle traveling on the road surface;
The radar device is
Identifying means for identifying the first reflected wave and the second reflected wave;
Storage means for storing a reference value corresponding to the intensity of the reflected wave when the radar reflector is submerged for each of the plurality of radar reflectors;
Identifying means for identifying the submerged radar reflector as a submerged reflector by comparing the reference value stored in the storage means with the intensity of the first reflected wave and the second reflected wave;
An inundation monitoring system comprising: output means for transmitting information to the road manager that the installation point of the inundation reflector specified by the specifying means is submerged.

Images