Sewerage network environment monitoring device, sewerage network environment monitoring method, and sewerage network environment monitoring program

Abstract

To efficiently monitor a sewerage network.SOLUTION: An upstream side main pipe and a downstream side main pipe are connected by at least one branch pipe in a sewerage network. The sewerage network comprises: a first acquisition part to acquire an upstream side first sensor data and a downstream side first sensor data, which indicate environments of the upstream side main pipe and the downstream side main pipe near a position at which the upstream side first sensor and the downstream side first sensor are fitted, from the upstream side first sensor fitted to an upstream side main pipe manhole and the downstream side first sensor fitted to a downstream side main pipe manhole; a second acquisition part to acquire a second sensor data stored in a second sensor fitted to a manhole disposed on the branch pipe from a storage medium for storing the second sensor data for a prescribed period in the manhole of the branch pipe, when difference is detected by monitoring the upstream side first sensor data and the downstream side first sensor data in real time; and a specification part to specify cause of the difference by analyzing the acquired second sensor data.SELECTED DRAWING: Figure 2A

Description

[Technical field]

[0001] The present invention relates to a sewer network environment monitoring device, a sewer network environment monitoring method, and a sewer network environment monitoring program. [Background technology]

[0002] In the above-mentioned technical field, Patent Document 1 discloses a remote monitoring system that changes the frequency at which a sensor installed in a sewer network, etc. acquires sensor data and the frequency at which the sensor transmits the sensor data to a server depending on the sensor data acquired by the sensor (see paragraphs

[0027] and

[0028] , claim 1, etc. of the same document). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special table 2022-525560 publication Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology described in Patent Document 1 requires that all sensors and the server be in constant communication with each other, which requires excessive energy (electricity) for storing and communicating sensor data. Due to the economic burden, it becomes difficult to perform practical monitoring, especially in larger sewer networks. [Means for solving the problem]

[0005] In order to achieve the above object, the sewer network environment monitoring device according to the present invention comprises: A sewer network environment monitoring device that monitors the environment of a sewer network installed in a specified area, The sewer network is a sewer network in which an upstream main pipe and a downstream main pipe are connected by at least one branch pipe, a first acquisition unit that acquires upstream first sensor data and downstream first sensor data indicating the environment of the upstream main pipe and the downstream main pipe in the vicinity of the positions where the upstream first sensor and the downstream first sensor are installed from an upstream first sensor attached to an upstream main pipe manhole provided near the connection between the upstream main pipe and one end of the at least one branch pipe and a downstream first sensor attached to a downstream main pipe manhole provided near the connection between the downstream main pipe and the other end of the at least one branch pipe; a detection unit that monitors the upstream first sensor data and the downstream first sensor data in real time and detects a difference between the upstream first sensor data and the downstream first sensor data; a second acquisition unit that acquires, when the difference is detected by the detection unit, second sensor data recorded in a second sensor attached to a manhole provided in at least one of the branch pipes connected to the upstream main pipe and the downstream main pipe, from a storage medium in a manhole of the branch pipe in which the second sensor data has been recorded for a certain period of time; Equipped with.

[0006] In order to achieve the above object, a sewer network environment monitoring method according to the present invention includes: A sewer network environment monitoring method for monitoring the environment of a sewer network provided in a predetermined area, comprising: The sewer network is a sewer network in which an upstream main pipe and a downstream main pipe are connected by at least one branch pipe, a first acquisition step of acquiring upstream first sensor data and downstream first sensor data indicating the environment of the upstream main pipe and the downstream main pipe in the vicinity of the positions where the upstream first sensor and the downstream first sensor are installed from an upstream first sensor attached to an upstream main pipe manhole provided near the connection between the upstream main pipe and one end of the at least one branch pipe and a downstream first sensor attached to a downstream main pipe manhole provided near the connection between the downstream main pipe and the other end of the at least one branch pipe; a detection step of monitoring the upstream first sensor data and the downstream first sensor data in real time and detecting a difference between the upstream first sensor data and the downstream first sensor data; a second acquisition step of acquiring second sensor data recorded in a second sensor attached to a manhole provided in at least one of the branch pipes connected to the upstream main pipe and the downstream main pipe from a storage medium in a manhole of the branch pipe in which the second sensor data has been recorded for a certain period of time when the difference is detected by the detection step; An identifying step of analyzing the acquired second sensor data to identify a cause of the detected difference; Includes.

[0007] Furthermore, in order to achieve the above object, the sewer network environmental monitoring program according to the present invention comprises: A sewer network environment monitoring program for monitoring the environment of a sewer network provided in a specified area, The sewer network is a sewer network in which an upstream main pipe and a downstream main pipe are connected by at least one branch pipe, a first acquisition step of acquiring upstream first sensor data and downstream first sensor data indicating the environment of the upstream main pipe and the downstream main pipe in the vicinity of the positions where the upstream first sensor and the downstream first sensor are installed from an upstream first sensor attached to an upstream main pipe manhole provided near the connection between the upstream main pipe and one end of the at least one branch pipe and a downstream first sensor attached to a downstream main pipe manhole provided near the connection between the downstream main pipe and the other end of the at least one branch pipe; a detection step of monitoring the upstream first sensor data and the downstream first sensor data in real time and detecting a difference between the upstream first sensor data and the downstream first sensor data; a second acquisition step of acquiring second sensor data recorded in a second sensor attached to a manhole provided in at least one of the branch pipes connected to the upstream main pipe and the downstream main pipe from a storage medium in a manhole of the branch pipe in which the second sensor data has been recorded for a certain period of time when the difference is detected by the detection step; An identifying step of analyzing the acquired second sensor data to identify a cause of the detected difference; to be executed by the computer. Effect of the Invention

[0008] The invention allows practical monitoring of a sewer network within a given area. [Brief description of the drawings]

[0009] [Figure 1A] 1 is a diagram for explaining an outline of the operation of a sewer network environment monitoring device according to a preferred embodiment of the present invention. FIG. [Figure 1B] 1 is a diagram for explaining the configuration of a first sensor used in a sewer network environment monitoring device according to a preferred embodiment of the present invention. FIG. [Figure 1C] FIG. 2 is a diagram for explaining the configuration of a second sensor used in the sewer network environment monitoring device according to the preferred embodiment of the present invention. [Figure 1D] FIG. 2 is a diagram for explaining the configuration of a water level meter of a second sensor used in the sewer network environment monitoring device according to a preferred embodiment of the present invention. [Figure 1E] FIG. 2 is a schematic cross-sectional view of a water level gauge of a second sensor used in the sewer network environment monitoring device according to a preferred embodiment of the present invention. [Figure 1F] 1 is a schematic cross-sectional view of an optical fiber having a heterocore portion in a water level gauge of a second sensor used in a sewer network environment monitoring device according to a preferred embodiment of the present invention. FIG. [Figure 1G] FIG. 13 is a diagram showing a state in which the diaphragm of the second sensor is deflected. [Figure 2A]1 is a block diagram for explaining the configuration of a sewer network environment monitoring device according to a preferred embodiment of the present invention. [Figure 2B] 1 is a diagram for explaining a specific criterion referred to by a specific unit of a sewer network environment monitoring device according to a preferred embodiment of the present invention. FIG. [Diagram 3] 2 is a diagram for explaining an example of a first sensor data increase / decrease threshold table and a second sensor data fluctuation threshold table possessed by the sewerage network environment monitoring device according to the preferred embodiment of the present invention. FIG. [Figure 4] 1 is a diagram for explaining a hardware configuration of a sewer network environment monitoring device according to a preferred embodiment of the present invention. [Diagram 5] 2 is a flowchart for explaining a processing procedure of a sewer network environment monitoring device according to a preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. However, the configurations, numerical values, process flows, functional elements, etc. described in the following embodiments are merely examples, and are free to be modified or changed, and are not intended to limit the technical scope of the present invention to the following description.

[0011] A sewer network environment monitoring device 100 according to a preferred embodiment of the present invention will be described with reference to Figs. 1A to 5. An outline of identifying the cause of the difference between the environment of an upstream main pipe 111 and the environment of a downstream main pipe 112 by the sewer network environment monitoring device 100 according to this embodiment will be described with reference to Fig. 1A. The sewer network environment monitoring device 100 is used to monitor the environment of a sewer network provided in a specified area, in which the upstream main pipe 111 and the downstream main pipe 112 are connected by at least one branch pipe 113. Specifically, the sewer network environment monitoring device 100 detects the difference between the environment of the upstream main pipe 111 and the downstream main pipe 112, and identifies the cause of the detected difference.

[0012] As shown in FIG. 1A, the sewer network 110 has a piping arrangement pattern in which two main pipes and one branch pipe 113 are connected. Specifically, an upstream main pipe 111 and a downstream main pipe 112 are connected by two branch pipes 113. In the sewer network 110, the number of branch pipes 113 connecting the upstream main pipe 111 and the downstream main pipe 112 is two, but the number of branch pipes 113 connecting the upstream main pipe 111a and the downstream main pipe 112b may be one or three or more. In FIG. 1A, the upstream main pipe 111 and the downstream main pipe 112 are shown by solid lines, and the branch pipes 113 are shown by dashed lines. Also, in FIG. 1A, the arrows indicate the direction in which the sewage flows.

[0013] Manholes are provided in the upstream main pipe 111 and the downstream main pipe 112. In Fig. 1A, "◯" represents a manhole. The manholes are provided near the connection between the upstream main pipe 111 and the branch pipe 113, and near the connection between the downstream main pipe 112 and the branch pipe 113. Specifically, an upstream main pipe manhole 121 is provided near the connection between the upstream main pipe 111 and one end of the branch pipe 113, and a downstream main pipe manhole 122 is provided near the connection between the downstream main pipe 112 and the other end of the branch pipe 113.

[0014] A first sensor is attached to the upstream main manhole 121 and the downstream main manhole 122. In FIG. 1A, "■" represents a first sensor. The first sensor is a main sensor in the sewer network 110. An upstream first sensor 131 is attached to the upstream main manhole 121, and a downstream first sensor 132 is attached to the downstream main manhole 122. The upstream first sensor 131 acquires first sensor data indicating the environment in the upstream main 111 in the vicinity of the position where the upstream first sensor 131 is attached. The downstream first sensor 132 acquires first sensor data indicating the environment in the downstream main 112 in the vicinity of the position where the downstream first sensor 132 is attached. The upstream first sensor 131 and the downstream first sensor 132 have a wireless communication function, and the first sensor data acquired by the upstream first sensor 131 and the downstream first sensor 132 are transmitted to the sewer network environment monitoring device 100. The upstream first sensor 131 and the downstream first sensor 132 acquire the first sensor data at all times. The upstream first sensor 131 and the downstream first sensor 132 acquire the first sensor data at all times, and may acquire the first sensor data continuously or intermittently. For example, the first sensor data may be acquired at one-minute intervals, and the data may be transmitted in real time each time it is acquired. Alternatively, ten acquisition results, that is, the first sensor data acquired over a ten-minute period, may be transmitted at one time. The upstream first sensor 131 and the downstream first sensor 132 may acquire the first sensor data at the same timing and transmit the first sensor data at different timings.

[0015] A manhole is also provided in the path of the branch pipe 113. A second sensor 133 is attached to the manhole provided in the path of the branch pipe 113. In FIG. 1A, "▲" represents the second sensor 133. The second sensor 133 is a secondary sensor in the sewer network 110. The second sensor 133 acquires second sensor data indicating the environment inside the branch pipe 113. The second sensor 133 has a wired or wireless short-range communication function.

[0016] The first upstream sensor 131, the first downstream sensor 132, and the second sensor 133 may be operated by an internal power source such as a built-in battery, or may be operated by being connected to an external power source. The power source possessed by the first upstream sensor 131, the first downstream sensor 132, and the second sensor 133 may be one that generates electricity by heat, vibration, sunlight, or the like.

[0017] The sewer network environment monitoring device 100 monitors the upstream first sensor data acquired by the upstream first sensor 131 and the downstream first sensor data acquired by the downstream first sensor 132 in real time, and detects the difference between the upstream first sensor data and the downstream first sensor data. For example, when a difference between the upstream first sensor data acquired by the upstream first sensor 131a attached to a certain upstream main manhole 121a and the downstream first sensor 132a attached to a certain downstream main manhole 122a is detected, a worker moves by the vehicle 117 to the vicinity of the second sensors 133a to 133d attached to a plurality of manholes provided in the branch pipe 113a connected to the upstream main pipe 111 and the downstream main pipe 112. The vehicle 117 is provided with the position information of all the second sensors, so that it can quickly move to the installation locations of the second sensors 133a to 133d. The vehicle 117 has a communication function. Then, the vehicle 117 and the second sensors 133a to 133d communicate with each other, and the vehicle 117 collects the second sensor data recorded in the second sensors 133a to 133d from the second sensors 133a to 133d and stores the data in a medium such as a storage medium that the vehicle 117 has. The communication between the vehicle 117 and the second sensors 133a to 133d may be wired communication or wireless communication. From the viewpoint of easily acquiring the second sensor data, it is preferable that the vehicle 117 acquires the second sensor data from the second sensor 133 by wireless communication. When acquiring the second sensor data from the second sensor 133 by wired communication, it is preferable that the connection terminal of the second sensor 133 is exposed to the ground and the connection terminal of the vehicle 117 is easily connectable, from the viewpoint of easily acquiring the second sensor data.

[0018] The second sensor data from the second sensors 133a to 133d may be collected by one vehicle 117 making a round. Also, the second sensor data from the second sensors 133a to 133d may be collected by different vehicles 117, respectively.

[0019] Furthermore, it is not necessary to check the second sensor data for all second sensors 133a-133d attached to the multiple manholes provided in branch pipe 113a, and the second sensor data may be checked only for any of second sensors 133a-133d among second sensors 133a-133d attached to the multiple manholes provided in branch pipe 113a.

[0020] Then, the worker moves the vehicle 117 that collected the second sensor data to the vicinity of the location of the sewer network environment monitoring device 100. After that, the sewer network environment monitoring device 100 acquires the second sensor data from the storage medium of the vehicle 117 by wired communication or wireless communication. Then, the sewer network environment monitoring device 100 analyzes the acquired second sensor data and identifies the cause of the difference between the upstream side first sensor data and the downstream side first sensor data.

[0021] A method of identifying the cause will be described by taking as an example a case where the water level indicated by the downstream first sensor data acquired by the downstream first sensor 132a is lower than the water level indicated by the upstream first sensor data acquired by the upstream first sensor 131a. In this case, for example, if the second sensor 133a and the second sensor 133b do not detect a decrease in the water level, and the second sensor 133c and the second sensor 133d both detect a decrease in the water level, the cause of the decrease in the water level is identified to be a location between the second sensor 133b and the second sensor 133c in the branch pipe 113a, such as a location where a crack in the pipe causes sewage to leak or a location where the pipe is clogged and the flow of sewage is stagnant. In this specification, "identification" is a concept that includes an estimation with a certain degree of accuracy or rationality.

[0022] There is no particular limitation on the location where the sewer network environment monitoring device 100 is installed. The sewer network environment monitoring device 100 may be installed, for example, in a management center that manages the sewer network 110 in a specific area. In some cases, it may be installed in the vehicle 117 described above.

[0023] Here, the main pipe in the sewer network environment monitoring device 100 of this embodiment is a pipe that constitutes a main pipeline in the sewer network 110. The main pipe and the branch pipe 113 can be distinguished by their inner diameters, and the pipe with a relatively larger inner diameter can be the main pipe, and the pipe with a relatively smaller inner diameter can be the branch pipe 113. When three or more types of pipes with different inner diameters are provided in the sewer network 110, the pipe with the relatively larger inner diameter of two types of pipes selected arbitrarily is the main pipe, and the pipe with the relatively smaller inner diameter is the branch pipe 113. However, this is subject to the condition that the main pipe has a manhole. Therefore, when neither of the two types of pipes selected arbitrarily has a manhole, both of the two types of pipes are the branch pipes 113.

[0024] Also, two or more types of branch pipes 113 having different inner diameters can be used for one type of main pipe.

[0025] Furthermore, the sewer network 110 may be a combined sewer system in which wastewater and rainwater are not separated, or a separate system in which wastewater and rainwater are separated. In this embodiment, the main pipe and the branch pipe of the sewer network may be a combined sewer pipe, or a separate wastewater pipe or a separate stormwater pipe.

[0026] Examples of materials for the main pipe and branch pipe 113 include concrete such as reinforced concrete; metals such as ductile cast iron; resins such as polyvinyl chloride and polyethylene; and ceramics.

[0027] Next, the configuration of the upstream first sensor 131 will be described with reference to FIG. 1B. The downstream first sensor 132 has a configuration similar to that of the upstream first sensor 131, and the description of the upstream first sensor 131 also applies to the downstream first sensor 132 as appropriate. The upstream first sensor 131 may include, for example, a transceiver 141 and a water level gauge 151. The transceiver 141 can be attached, for example, to the back surface of the cover of the upstream main manhole 121. The water level gauge 151 can be installed, for example, in the upstream main pipe 111. The transceiver 141 and the water level gauge 151 are connected by wire or wirelessly, and the water level of the sewage 116 in the upstream main pipe 111 measured by the water level gauge 151 is transmitted to the sewer network environment monitoring device 100 by the transceiver 141. In FIG. 1B, the dashed line connecting the transceiver 141 and the water level gauge 151 indicates that the transceiver 141 and the water level gauge 151 are connected by wire or wirelessly. The transceiver 141 is capable of communication over a wide area. For example, the transceiver 141 may be compatible with LTE (Long Term Evolution) communication or LPWA (Low power wide area) communication. The transceiver 141 is preferably compatible with LTE communication since it does not require the installation of a communication repeater. The transceiver 141 transmits the first sensor data to the sewer network environment monitoring device 100 by wireless communication, and therefore the first sensor data can be transmitted to the sewer network environment monitoring device 100 without opening the cover of the upstream main manhole 121.

[0028] The upstream first sensor 131 has a battery (not shown) attached to the back of the cover of the upstream main manhole 121 as its power source, and is capable of measuring for a period ranging from two months to approximately four years depending on the measurement frequency.

[0029] Taking advantage of the fact that the upstream first sensor 131 is capable of real-time measurement through reliable communication, it is preferable to place it at a key location in the sewer network 110 as a main device for grasping surface trends in real time.

[0030] Since the transceiver 141 is capable of communicating over a wide area, the upstream first sensor 131 tends to be large in size, and in order to install the upstream first sensor 131, a sufficient installation space may be required.

[0031] Next, the configuration of the second sensor 133 will be described with reference to FIG. 1C. The second sensor 133 may include, for example, a transceiver 142 and a water level gauge 152. In this case, a storage medium in which the second sensor data is recorded for a certain period of time is built into either the transceiver 142 or the water level gauge 152. That is, the storage medium in which the second sensor data is recorded is disposed in the manhole in which the second sensor 133 is attached. The transceiver 142 can be attached, for example, to the back surface of the cover of the upstream main manhole 121. The water level gauge 152 is installed in the branch pipe 113. The transceiver 142 and the water level gauge 152 are connected by wire or wirelessly, and the water level of the sewage 116 in the branch pipe 113 measured by the water level gauge 152 is transmitted to the outside, specifically, to the vehicle 117, by the transceiver 142. In FIG. 1C, the dashed line connecting the transceiver 142 and the water level indicator 152 indicates that the transceiver 142 and the water level indicator 152 are connected to each other by wire or wirelessly.

[0032] It is preferable to use the transceiver 142 that is compatible with, for example, LоRa (Long Range) communication. This can reduce the power consumption and cost of the transceiver 142. The communicable distance of the transceiver 142 that is compatible with LоRa communication is approximately 100 m. In addition, when the vehicle 117 travels at 50 km / h, the second sensor data can be acquired from the transceiver 142 while the vehicle 117 is traveling by setting the standby state interval of the transceiver 142 to 1182 seconds. The transceiver 142 may be compatible with NFC (Near Field Communication).

[0033] As described above, the second sensor 133 does not directly transmit the second sensor data to the sewer network environment monitoring device 100, but transmits the second sensor data to the sewer network environment monitoring device 100 via the vehicle 117. Therefore, the second sensor 133 does not need to have a communication function capable of wide-area communication such as direct communication with the sewer network environment monitoring device 100, and a sensor capable of only short-range communication can be used as the second sensor 133. Therefore, the power required for the communication function of the second sensor 133 can be reduced.

[0034] Moreover, since the second sensor data is acquired from the second sensor 133 only when a difference between the upstream first sensor data and the downstream first sensor data is detected, the second sensor 133 does not need to store the second sensor data for a long period of time. It is preferable that the storage medium provided in the second sensor 133 is capable of storing the second sensor data for a short period of time, specifically, for about several days to one month.

[0035] This makes it possible to reduce the maintenance costs, including the power consumption for storing and communicating the sensor data of the second sensor 133. In addition, the second sensor 133 can be made smaller.

[0036] The water level indicator 152 of the second sensor 133 will be described in further detail with reference to Fig. 1D. The water level indicator 152 is fixed in a state in which it is immersed in the sewage 116 flowing in the branch pipe 113 by using a substantially circular fitting-type jig 162. The water level indicator 152 is covered by a cover sheet 165.

[0037] Jig 162 can be installed, for example, at the open end of branch pipe 113 at the connection between branch pipe 113 and main pipe 111. Specifically, jig 162 is fixed inside branch pipe 113 as follows. First, jig 162 is circumferentially contracted by pipe diameter adjustment unit 163 to make the outer diameter of jig 162 smaller than the inner diameter of branch pipe 113. Then, after jig 162 is positioned inside branch pipe 113, jig 162 is circumferentially expanded by pipe diameter adjustment unit 163 to bring the outer peripheral surface of jig 162 into contact with the inner surface of branch pipe 113. Then, L-shaped bracket 164 is fixed to the wall surface of branch pipe 113.

[0038] The upper surface of the bottom surface portion 164a of the L-shaped bracket 164 is fixed to the inner peripheral surface of the jig 162 by welding, adhesive, or the like. The L-shaped bracket 164 is made of a hard material such as metal or resin. The upright side portion 164b of the L-shaped bracket 164 stands upward so as to have a flat surface on the opening side of the jig 162 to which the branch pipe 113 is opened.

[0039] The pipe diameter adjustment part 163 is a rectangular plate made of a hard material such as metal or resin, and has a plurality of through holes 163a formed at both ends in the longitudinal direction at intervals. A bolt 167 is inserted through the through hole of the L-shaped bracket 164 and an appropriately selected through hole 12a of the pipe diameter adjustment part 163, and the bolt 167 is fixed with a nut 168, thereby fixing the pipe diameter adjustment part 163 and the L-shaped bracket 164.

[0040] The fixing method using the jig 162 is easier to work with than the conventional fixing method using anchors, since it does not require fixing with anchors. In addition, repairs after removal are not required. Furthermore, since the water level gauge 152 is located at the bottom of the pipe, accurate measurement is possible even at low water levels.

[0041] The water level gauge 152 is, for example, a water level gauge using a hetero-core optical fiber having a portion with a different core diameter. The water level gauge 152 measures the deformation by detecting the degree of leakage of propagating light due to the intentionally provided portion with a different core diameter. Specifically, the water level is measured by detecting the fluctuation (curvature) caused by deformation due to the action of water pressure.

[0042] In detail, the water level meter 152 has an optical fiber 171 and a chamber 172, as shown in FIG. 1E. The optical fiber 171 has an incident end side optical fiber 171a, an emission end optical fiber 171b, and a hetero core portion HP inserted between the optical fiber 171a and 171b. The hetero core portion HP is a short single mode optical fiber having a core 181 and a clad 182 provided on the outer periphery thereof. For example, the diameter of the core 181 is 5 μm, the diameter of the clad 182 is 125 μm, and the length of the hetero core portion HP is 125 μm. On the other hand, both of the optical fiber bare wires 171a and 171b are long single mode optical fibers having a core 183 and a clad 184 provided on the outer periphery thereof. For example, the diameter of the core 183 is 9 μm, and the diameter of the clad 184 is 125 μm. In this manner, the core diameter of the hetero core portion HP is configured to be smaller than the core diameters of the optical fibers 171a and 171b.

[0043] The hetero core portion HP and the optical fiber strands 171a, 171b are joined coaxially or approximately coaxially by fusion bonding using electric discharge so that the cores 181, 183 are joined at an interface 47 perpendicular to the longitudinal direction (see FIG. 1F).

[0044] Since the hetero core portion HP is present in the middle of the optical fiber strands 171a and 171b, a part of the light leaks into the cladding 182 of the hetero core portion HP due to the difference in core diameter at the interface 47, and the transmitted light is lost. The smaller the curvature radius R of the hetero core portion HP and the optical fiber strands 171a and 171b in its vicinity, the larger the amount of light loss (leakage amount).

[0045] The chamber 172 is configured so that the overall appearance is roughly a rectangular parallelepiped by fixing the upper frame 52 and the lower frame 53 in a watertight manner. These frames 52 and 53 are formed from a hard material such as wood, metal, ceramics, etc.

[0046] The upper frame 52 and the lower frame 53 are fixed to each other with portions of the optical fibers 171a, 171b spaced apart from the hetero core portion HP between them. By fixing the two frames 52, 53, a sealed space S is formed inside the chamber 50.

[0047] A diaphragm 51 that is thinner than other portions is formed on the upper wall of the upper frame 52. In other words, a space (a space that constitutes part of the sealed space S) is provided in the upper frame 52 in its thickness direction, and the bottom of this space is made thick enough to allow the diaphragm 51 to bend.

[0048] Two support members 194, 195 are fixed at one end (upper end) with a gap L0 between them at approximately the center of the lower surface of the diaphragm 51. Here, these support members 194, 195 are made of the same material as the other parts of the upper frame 52, and are integrated with the diaphragm 51.

[0049] Each of the support members 194, 195 is an independent rectangular columnar member, and stands so as to extend downward from the lower surface of the diaphragm 51 with which the upper surface comes into contact. Predetermined portions M, N of the optical fiber strands 171a, 171b are fixed at a distance L1 to the mask surface on the other end side (lower end side) of each of the support members 194, 195. The heterocore portion HP is located between these fixed portions M, N.

[0050] In the water level gauge 152 configured as described above, when the external pressure is greater than the internal pressure, the diaphragm 51 bends and curves downwardly to become convex, in response to the pressure difference, as shown in Fig. 1G. This bending is enlarged in proportion to the vertical length of the support members 194, 195, and the interval L2 between the fixed parts M, N becomes greater than the initial interval L1 (see Fig. 1E). Therefore, compared to the case where the sensor unit SP is directly fixed to the diaphragm 51, the interval L of the sensor unit SP supported by the two support members 194, 195 changes significantly, and the curvature of the sensor unit SP changes significantly, causing a large change in the rate of leakage of light transmitted through the optical fiber 40, making it possible to detect the pressure difference with high sensitivity.

[0051] While the power consumption of a current-carrying rod-shaped water level gauge used in general water level measurement is 4 W, the power consumption of the water level gauge 152 is 0.5 W. The water level gauge 152 can reduce power consumption to 1 / 8 compared to conventional water level gauges, allowing for long-term use. In addition, the optical fiber 171 of the water level gauge 152 is made of glass, which does not require current to be passed through the sensor part, so it is highly resistant to lightning and is resistant to chemical corrosion by hydrogen sulfide and the like, ensuring long-term durability.

[0052] In this way, the second sensor 133 can reduce communication costs compared to the first sensors 131 and 132. Furthermore, the second sensor 133 can reduce the time required for installation compared to conventional sensors that are fixed by anchors. Furthermore, the second sensor 133 can significantly reduce power consumption compared to conventional rod-shaped water level gauges.

[0053] Taking advantage of the fact that second sensor 133 is inexpensive and can be installed in large numbers, it is preferable to place it between first sensors 131 and 132, which are main devices, as a backup device that complements any planar defects.

[0054] In this embodiment, by utilizing information from both the first sensors 131, 132, which are main devices, and the second sensor 133, which is a backup device (complementary device), it is possible to improve the quality of maintenance of the sewer network 110, make the maintenance work of the sewer network 110 more efficient, and reduce costs.

[0055] Next, the configuration of the sewer network environment monitoring device 100 will be described with reference to Figures 2A and 2B. The sewer network environment monitoring device 100 monitors the environment of a sewer network provided in a specified area. The device 100 includes a first acquisition unit 201, a detection unit 202, a second acquisition unit 203, and an identification unit 204.

[0056] The first acquisition unit 201 acquires upstream first sensor data and downstream first sensor data indicating the environment of the upstream main pipe 111 and the downstream main pipe 112 in the vicinity of the attachment positions of the upstream first sensor 131 and the downstream first sensor 132 from the upstream first sensor 131 attached to the upstream main pipe manhole 121 provided near the connection between the upstream main pipe 111 and one end of at least one branch pipe 113, and the downstream first sensor 132 attached to the downstream main pipe manhole 122 provided near the connection between the downstream main pipe 112 and the other end of at least one branch pipe 113. Examples of the first sensor data include water level, water flow, temperature, turbidity, odor, hydrogen sulfide concentration, and oxygen concentration, and may be data including at least one of these.

[0057] The first acquisition unit 201 constantly acquires the first sensor data. The acquisition of the first sensor data by the first acquisition unit 201 may be performed continuously or intermittently. When the first acquisition unit 201 acquires the first sensor data intermittently, the timing of acquiring the upstream first sensor data and the timing of acquiring the downstream first sensor data may be the same or different.

[0058] The detection unit 202 monitors the upstream first sensor data and the downstream first sensor data in real time to detect a difference between the upstream first sensor data and the downstream first sensor data. The detection of the difference can be performed, for example, by determining whether or not the rate of increase / decrease of the value of the downstream first sensor data relative to the value of the upstream first sensor data is equal to or greater than a predetermined threshold. Specifically, by determining that the rate of increase / decrease of the value of the downstream first sensor data relative to the value of the upstream first sensor data is equal to or greater than a threshold, it is possible to detect that a difference has occurred between the upstream first sensor data and the downstream first sensor data.

[0059] When the environment in the upstream main pipe 111 changes and the upstream first sensor data fluctuates, it is considered that there is a time lag before the change in the environment in the upstream main pipe 111 affects the environment in the downstream main pipe 112 and the downstream first sensor data fluctuates. Therefore, it is preferable that the downstream first sensor data used for the difference detection is acquired later than the upstream first sensor data. The time point at which data is used as the upstream first sensor data and the downstream first sensor data used for the difference detection can be determined in consideration of the distance between the upstream first sensor 131 and the downstream first sensor 132 in the sewer network 110.

[0060] The detection unit 202 may detect that a difference has occurred between the upstream first sensor data and the downstream first sensor data by calculating a difference between the value of the upstream first sensor data and the value of the downstream first sensor data and determining whether the calculated difference is equal to or greater than a predetermined threshold. At this time, the value of the downstream first sensor data may be subtracted from the value of the upstream first sensor data, or the value of the upstream first sensor data may be subtracted from the value of the downstream first sensor data.

[0061] When the detection unit 202 detects a difference, the second acquisition unit 203 acquires the second sensor data recorded in the second sensor 133 attached to a manhole provided in at least one branch pipe 113 connected to the upstream main pipe 111 and the downstream main pipe 112 from a storage medium in the manhole of the branch pipe in which the second sensor data was recorded for a certain period of time. In this embodiment, the second sensor data recorded in the storage medium in the manhole of the branch pipe 113 is first transmitted to a storage medium possessed by the vehicle 117. The second acquisition unit 203 acquires the second sensor data from the storage medium possessed by the vehicle 117. As the storage medium in the manhole of the branch pipe 113 and the storage medium possessed by the vehicle 117, a hard disk drive (HDD), a solid state drive (SSD), a universal serial bus (USB) memory, etc. can be used. The storage medium in the manhole of the branch pipe 113 and the storage medium possessed by the vehicle 117 may be the same or different. The second sensor data may include, for example, water level, water flow, temperature, turbidity, odor, hydrogen sulfide concentration, and oxygen concentration, and may include at least one of these.

[0062] The identification unit 204 analyzes the acquired second sensor data and identifies the cause of the detected difference. When a difference occurs between the upstream first sensor data and the downstream first sensor data, it is considered that the increase or decrease in one is larger than the increase or decrease in the other. Examples of causes of the increase or decrease in the upstream first sensor data or the downstream first sensor data are shown in FIG. 2B for each detection item listed as the upstream first sensor data and the downstream first sensor data. In FIG. 2B, "+" indicates that the upstream first sensor data or the downstream first sensor data has increased, and "-" indicates that the upstream first sensor data or the downstream first sensor data has decreased. In addition, in FIG. 2B, "○" indicates that the second sensor data needs to be acquired. Note that this figure is merely an example and is appropriately changed according to the attributes and conditions of the area to be monitored.

[0063] A specific method for identifying the cause of the difference by the identifying unit 204 will be described below.

[0064] (1) When the detection item is water level (i) When the upstream first sensor data is greater than the downstream first sensor data (when the difference is positive or the rate of increase / decrease is positive)

[0065] The upstream first sensor data may be greater than the downstream first sensor data, the upstream first sensor data may increase more than the downstream first sensor data, or the downstream first sensor data may decrease more than the upstream first sensor data. Causes of an increase in the upstream first sensor data (water level) include an increase in rainfall, downstream pipe clogging, inflow of groundwater due to upstream pipe damage, and connection of a new branch pipe upstream (see the case in FIG. 2B where the "detection item" column is "water level" and the "increase / decrease" column is "+"). Causes of a decrease in the downstream first sensor data (water level) include loss of water (outflow to the outside) due to upstream pipe damage, upstream pipe clogging, and reinforcement of the main pipe 111 downstream (laying a new line, replacing with an expanded pipe) (see the case in FIG. 2B where the "detection item" column is "water level" and the "increase / decrease" column is "-").

[0066] In order to identify the location of the cause of the difference, it is preferable to refer to the second sensor data of the second sensor 133 located between the upstream first sensor 131 and the downstream first sensor 132. For example, when the upstream first sensor data is increasing and the downstream first sensor data and the second sensor data are not fluctuating, it is considered that a blockage of the pipe has occurred between the upstream first sensor 131 that acquired the upstream first sensor data and the second sensor 133 that acquired the second sensor data. In addition, when the upstream first sensor data and the second sensor data are not fluctuating and the downstream first sensor data is decreasing, it is considered that the location of the cause is in the downstream main pipe 112.

[0067] (ii) When the downstream first sensor data is greater than the upstream first sensor data (when the difference is negative or the rate of increase / decrease is negative)

[0068] Possible cases include a case where the downstream first sensor data is greater than the upstream first sensor data, a case where the increase in the upstream first sensor data is smaller than the downstream first sensor data, and a case where the decrease in the downstream first sensor data is smaller than the upstream first sensor data. Causes of an increase or decrease in the sensor data (water level) are similar to those of the case where the difference is positive, as described above. In order to identify the location of the cause of the difference, it is preferable to refer to the second sensor data of the second sensor 133 located between the upstream first sensor 131 and the downstream first sensor 132. The location of the cause of the difference can be identified based on the manner in which the second sensor data increases or decreases, as described above.

[0069] (2) When the detection item is temperature (i) When the upstream first sensor data is greater than the downstream first sensor data (when the difference is positive or the rate of increase / decrease is positive) The upstream first sensor data may be greater than the downstream first sensor data, the upstream first sensor data may increase more than the downstream first sensor data, or the downstream first sensor data may decrease more than the upstream first sensor data. The cause of an increase or decrease in sensor data (temperature increase or decrease) may be a change in the type of inflow water. When the temperature increases, the change in the type of inflow water may be caused by high-temperature water flowing in from a restaurant or other establishment upstream of the sensor data acquisition position (see FIG. 2B, where the "Detection Item" column is "Temperature" and the "Increase / Decrease" column is "+"). Detecting an increase in temperature may be used to detect the deterioration rate of a pipe due to a change in the temperature inside the pipe. Examples of deterioration of the pipe include corrosion of the pipe. When the temperature decreases, the change in the type of inflow water may be caused by low-temperature water flowing in from a restaurant or other establishment upstream of the sensor data acquisition position (see FIG. 2B, where the "Detection Item" column is "Temperature" and the "Increase / Decrease" column is "-"). In order to identify the location of the cause of the difference, it is preferable to refer to the second sensor data of the second sensor 133 located between the upstream first sensor 131 and the downstream first sensor 132. As described above, the location of the cause of the difference can be identified based on how the second sensor data increases or decreases.

[0070] (ii) When the downstream first sensor data is greater than the upstream first sensor data (when the difference is negative or the rate of increase / decrease is negative) The downstream first sensor data may be greater than the upstream first sensor data, the upstream first sensor data may increase less than the downstream first sensor data, or the downstream first sensor data may decrease less than the upstream first sensor data. Causes of an increase or decrease in sensor data (temperature increase or decrease) may be the same as those of the case where the difference is positive, as described above. In order to identify the location of the cause of the difference, it is preferable to refer to the second sensor data of the second sensor 133 located between the upstream first sensor 131 and the downstream first sensor 132. The location of the cause of the difference can be identified based on the manner in which the second sensor data increases or decreases, as described above.

[0071] (3) When the detection item is turbidity (i) When the upstream first sensor data is greater than the downstream first sensor data (when the difference is positive or the rate of increase / decrease is positive) There are two possible cases: the upstream first sensor data is greater than the downstream first sensor data, and the downstream first sensor data is greater in decrease than the upstream first sensor data. The causes of an increase in sensor data (turbidity) include inflow of soil and sand due to damage to the upstream pipe, flooding from the ground (road) during heavy rain, and blockage of the upstream pipe (see the case in FIG. 2B where the "detection item" column is "turbidity" and the "increase / decrease" column is "+"). The causes of a decrease in sensor data (turbidity) include changes in inflow water, infiltration of groundwater and the like due to damage to the pipe (see the case in FIG. 2B where the "detection item" column is "turbidity" and the "increase / decrease" column is "-"). In order to identify the location of the cause of the difference, it is preferable to refer to the second sensor data of the second sensor 133 located between the upstream first sensor 131 and the downstream first sensor 132. As described above, the location of the cause of the difference can be identified based on the manner in which the second sensor data increases or decreases. In general, it is unlikely that downstream turbidity will propagate to the upstream side in the sewer network 110. Therefore, when a plurality of second sensors 133 are installed in the path of the branch pipe 113 connecting the upstream main pipe 111 and the downstream main pipe 112, and the second sensor data of a certain second sensor 133 among the plurality of second sensors 133 is not increasing, it is not necessarily necessary to refer to the second sensor data of the second sensor 133 located upstream of the second sensor 133 whose second sensor data is not increasing.

[0072] (ii) If the difference is negative When the difference is negative, it is possible that the increase in the upstream first sensor data is smaller than the downstream first sensor data, or that the decrease in the downstream first sensor data is smaller than the upstream first sensor data. Causes of an increase or decrease in the sensor data (turbidity) are similar to those of the case where the difference is positive, as described above. In order to identify the location of the cause of the difference, it is preferable to refer to the second sensor data of the second sensor 133 located between the upstream first sensor 131 and the downstream first sensor 132. The location of the cause of the difference can be identified based on the manner in which the second sensor data increases or decreases, as described above.

[0073] (4) When the detection item is odor (i) When the upstream first sensor data is greater than the downstream first sensor data (when the difference is positive or the rate of increase / decrease is positive) The following cases are considered: the upstream first sensor data is greater than the downstream first sensor data; the upstream first sensor data increases more than the downstream first sensor data; and the downstream first sensor data decreases more than the upstream first sensor data. Causes of an increase in sensor data (odor) include deterioration of inflow sewage and progression of a corrosive environment (see FIG. 2B, where the "detection item" column is "odor" and the "increase / decrease" column is "+"). Causes of a decrease in sensor data (odor) include improvement of inflow sewage and improvement of a corrosive environment (see FIG. 2B, where the "detection item" column is "odor" and the "increase / decrease" column is "-"). In order to identify the location of the cause of the difference, it is preferable to refer to the second sensor data of the second sensor 133 located between the upstream first sensor 131 and the downstream first sensor 132. As described above, the location of the cause of the difference can be identified based on the manner in which the second sensor data increases or decreases.

[0074] When a plurality of second sensors 133 are installed in the path of the branch pipe 113 connected to the upstream main pipe 111 and the downstream main pipe 112, which of the plurality of second sensors 133 the second sensor data should be acquired from can be appropriately determined according to the thickness of the branch pipe 113, the water force in the branch pipe 113, and the like. For example, when the water force in the branch pipe 113 is strong, the air in the branch pipe 113 is likely to flow from upstream to downstream accompanied by the wastewater flowing in the branch pipe 113. Therefore, when the water force in the branch pipe 113 is strong, the second sensor data of the second sensor 133 located relatively downstream is more important. Therefore, the second sensor data may be acquired only from the second sensor 133 located relatively downstream, for example, near the downstream first sensor 132. On the other hand, when air is stagnant in the pipe due to weak water force in the pipe, thin pipe, or the like, odor fluctuations in the pipe may be transmitted to both the upstream and downstream sides. Therefore, in this case, it is preferable to acquire second sensor data from all second sensors 133. In this manner, it is possible to determine up to which of the multiple second sensors 133 the second sensor data is to be acquired depending on the size of branch pipe 113, the water pressure in branch pipe 113, and the like.

[0075] (ii) When the downstream first sensor data is greater than the upstream first sensor data (when the difference is negative or the rate of increase / decrease is negative) Possible cases include a case where the downstream first sensor data is greater than the upstream first sensor data, a case where the increase in the upstream first sensor data is smaller than the downstream first sensor data, and a case where the decrease in the downstream first sensor data is smaller than the upstream first sensor data. Causes of an increase or decrease in sensor data (odor) are similar to those of the case where the difference is positive, as described above. In order to identify the location where the cause of the difference occurs, it is preferable to refer to the second sensor data of the second sensor 133 located between the upstream first sensor 131 and the downstream first sensor 132. As described above, the location where the cause of the difference occurs can be identified based on the manner in which the second sensor data increases or decreases.

[0076] (5) When the detection item is hydrogen sulfide concentration (i) When the upstream first sensor data is greater than the downstream first sensor data (when the difference is positive or the rate of increase / decrease is positive) The upstream first sensor data may be greater than the downstream first sensor data, the upstream first sensor data may increase more than the downstream first sensor data, or the downstream first sensor data may decrease more than the upstream first sensor data. The cause of the increase in the sensor data (hydrogen sulfide concentration) may be the progression of a corrosive environment (see FIG. 2B, where the "detection item" column is "hydrogen sulfide" and the "increase / decrease" column is "+"). For example, in a pressure pipe or the like, when an anaerobic state occurs, sulfates contained in the sewage may be reduced by sulfate-reducing bacteria or the like, generating hydrogen sulfide. The cause of the decrease in the sensor data (hydrogen sulfide concentration) may be the improvement of the corrosive environment (see FIG. 2B, where the "detection item" column is "hydrogen sulfide" and the "increase / decrease" column is "-"). In order to identify the location where the cause of the difference occurs, it is preferable to refer to the second sensor data of the second sensor 133 located between the upstream first sensor 131 and the downstream first sensor 132. The location where the cause of the difference occurs can be identified based on the manner in which the second sensor data increases or decreases, as described above. As in the case where the detection item is odor, which of the multiple second sensors 133 should acquire the second sensor data can be appropriately determined based on the diameter of the branch pipes 113 of the sewer network 110, the water pressure in the branch pipes 113, and the like.

[0077] (ii) When the downstream first sensor data is greater than the upstream first sensor data (when the difference is negative or the rate of increase / decrease is negative) Possible cases include a case where the downstream first sensor data is greater than the upstream first sensor data, a case where the increase in the upstream first sensor data is smaller than the downstream first sensor data, and a case where the decrease in the downstream first sensor data is smaller than the upstream first sensor data. Causes of an increase or decrease in the sensor data (hydrogen sulfide concentration) are similar to those of the case where the difference is positive, as described above. In order to identify the location of the cause of the difference, it is preferable to refer to the second sensor data of the second sensor 133 located between the upstream first sensor 131 and the downstream first sensor 132. The location of the cause of the difference can be identified based on the manner in which the second sensor data increases or decreases, as described above.

[0078] (6) When the detection item is oxygen concentration (i) When the upstream first sensor data is greater than the downstream first sensor data (when the difference is positive or the rate of increase / decrease is positive) The following cases are considered: the upstream first sensor data is greater than the downstream first sensor data; the upstream first sensor data increases more than the downstream first sensor data; and the downstream first sensor data decreases more than the upstream first sensor data. In the sewer network 110, the oxygen concentration is always about 20.9%, and it is generally difficult to imagine that the oxygen concentration increases (see the case in FIG. 2B where the "detection item" column is "oxygen concentration" and the "increase / decrease" column is "+"). The sensor data (oxygen concentration) decreases due to the progression of a corrosive environment, etc. (see the case in FIG. 2B where the "detection item" column is "oxygen concentration" and the "increase / decrease" column is "-"). The progression of a corrosive environment typically occurs in pipelines that have not been inspected for a long time, in sludge that has accumulated in pipelines, near pressure pipes, etc. The progression of a corrosive environment is specifically caused by the decay of organic matter, reactions by bacteria that consume oxygen, etc. Near the outlet of the pressure pipe, hydrogen sulfide generated in the pressure pipe is released into the gas phase, where a biochemical reaction caused by aerobic bacteria etc. produces sulfuric acid, which accelerates concrete corrosion. In order to identify the location of the cause of the difference, it is preferable to refer to the second sensor data of the second sensor 133 located between the upstream first sensor 131 and the downstream first sensor 132. As described above, the location of the cause of the difference can be identified based on the manner in which the second sensor data increases or decreases.

[0079] (ii) When the downstream first sensor data is greater than the upstream first sensor data (when the difference is negative or the rate of increase / decrease is negative) Possible cases include a case where the downstream first sensor data is greater than the upstream first sensor data, a case where the upstream first sensor data increases less than the downstream first sensor data, and a case where the downstream first sensor data decreases less than the upstream first sensor data. Causes of the decrease in sensor data (oxygen concentration) are similar to those of the case where the difference is positive, as described above. In order to identify the location of the cause of the difference, it is preferable to refer to the second sensor data of the second sensor 133 located between the upstream first sensor 131 and the downstream first sensor 132. The location of the cause of the difference can be identified based on the manner in which the second sensor data increases or decreases, as described above.

[0080] The cause of the difference identified by the identification unit 204 is displayed, for example, on a display device (not shown) provided in the sewerage network environment monitoring device 100. Alternatively, the cause is notified to a worker riding in the vehicle 117. The location of occurrence, etc. may be displayed or notified together with the cause.

[0081] The sewerage network environment monitoring device 100 may have a suggestion unit that proposes a solution to the cause identified by the identification unit 204.

[0082] In addition, the sewerage network environment monitoring device 100 does not necessarily have to have the identification unit 204.

[0083] FIG. 3 is a diagram for explaining an example of the first sensor data increase / decrease threshold table 301 and the second sensor data fluctuation rate threshold table 302 possessed by the sewer network environment monitoring device 100. The first sensor data increase / decrease threshold table 301 is a table for storing a threshold of an increase / decrease rate of the value of the downstream side first sensor data with respect to the value of the upstream side first sensor data. An item 311 is a type of the first sensor data. An increase / decrease rate 312 is a threshold of an increase / decrease rate of the value of the downstream side first sensor data with respect to the value of the upstream side first sensor data. The "●" in the increase / decrease rate 312 is the value, and a different value is set for each type of the first sensor data. The first sensor data increase / decrease threshold table 301 is possessed by, for example, the detection unit 202. The detection unit 202 refers to the first sensor data increase / decrease threshold table 301 and determines whether or not the increase / decrease rate of the value of the downstream side first sensor data with respect to the value of the upstream side first sensor data is equal to or greater than a predetermined threshold. Depending on the presence or absence of the item 311 determined to have an increase / decrease rate equal to or greater than the threshold, the detection unit 202 detects the difference between the upstream first sensor data and the downstream first sensor data. Specifically, when the item 311 determined to have an increase / decrease rate equal to or greater than the threshold exists, the detection unit 202 determines that the difference between the upstream first sensor data and the downstream first sensor data has been detected. The second sensor data fluctuation rate threshold table 302 is a table that stores the threshold value of the fluctuation rate of the second sensor data. The item 321 is the type of the second sensor data. The fluctuation rate 322 is the threshold value of the fluctuation rate of the second sensor data. The "◆" in the fluctuation rate 322 is the value, and a different value is set for each type of the second sensor data. The second sensor data fluctuation rate threshold table 302 is possessed by, for example, the identification unit 204. The identification unit 204 refers to the second sensor data fluctuation rate threshold table 302 and determines whether the fluctuation rate of the second sensor data is equal to or greater than a predetermined threshold.

[0084] The hardware configuration of the sewer network environment monitoring device 100 will be described with reference to FIG. 4. The CPU (Central Processing Unit) 410 is a processor for arithmetic control, and executes a program to realize each functional configuration of the sewer network environment monitoring device 100 in FIG. 2A. The CPU 410 may have multiple processors and execute different programs, modules, tasks, threads, etc. in parallel. The ROM (Read Only Memory) 420 stores fixed data such as initial data and programs, and other programs. The network interface 430 communicates with other devices, etc., via a network. The CPU 410 is not limited to one, and may be multiple CPUs or may include a GPU (Graphics Processing Unit) for image processing. The network interface 430 preferably has a CPU independent of the CPU 410 and writes or reads transmitted / received data in an area of ​​the RAM (Random Access Memory) 440. It is also preferable to provide a DMAC (Direct Memory Access Controller) for transferring data between the RAM 440 and the storage 450 (not shown). Furthermore, the CPU 410 processes the data upon recognizing that the data has been received or transferred to the RAM 440. The CPU 410 also prepares the processing results in the RAM 440, and leaves the subsequent transmission or transfer up to the network interface 430 or DMAC.

[0085] The RAM 440 is a random access memory used by the CPU 410 as a work area for temporary storage. A storage area for storing data necessary for implementing this embodiment is secured in the RAM 440. The first sensor data 441 is data acquired by the first acquisition unit 201 from the first sensor 131. The second sensor data 442 is data acquired by the second acquisition unit 203 from the second sensor 133. The threshold data 443 is data developed from the first sensor data increase / decrease threshold table 301 and the second sensor data fluctuation rate threshold table 302 shown in FIG. 3.

[0086] The transmitted / received data 444 is data that is transmitted and received via the network interface 430. The RAM 440 also has an application execution area 445 for executing various application modules.

[0087] The storage 450 stores a database, various parameters, or the following data or programs required to realize this embodiment. The storage 450 stores a first sensor data increase / decrease threshold table 301, a second sensor data fluctuation rate threshold table 302, and a cause identification table 303. The first sensor data increase / decrease threshold table 301 is a table that manages the relationship between the item 311 and the increase / decrease rate 312 shown in Fig. 3. The second sensor data fluctuation rate threshold table 302 is a table that manages the relationship between the item 321 and the fluctuation rate 322 shown in Fig. 3.

[0088] The storage 450 further stores a first acquisition module 451, a detection module 452, a second acquisition module 453, and an identification module 454. The first acquisition module 451 is a module that acquires first sensor data. The detection module is a module that monitors fluctuations in the first sensor data and detects changes in the environment in the main pipe 111. The second acquisition module is a module that acquires second sensor data stored in the second sensor 133. The identification module 454 is a module that identifies a cause in the main pipe 111 based on the acquired second sensor data. These modules 451 to 454 are read by the CPU 410 into the application execution area 445 of the RAM 440 and executed. The control program 455 is a program for controlling the entire sewer network environment monitoring device 100.

[0089] The input / output interface 460 interfaces input / output data with input / output devices. A display unit 461 and an operation unit 462 are connected to the input / output interface 460. A storage medium 464 may be further connected to the input / output interface 460. A speaker 463 serving as an audio output unit, a microphone (not shown) serving as an audio input unit, or a GPS position determination unit may be further connected. Note that the RAM 440 and storage 450 shown in FIG. 4 do not show programs and data relating to the general-purpose functions of the sewer network environment monitoring device 100 or other feasible functions.

[0090] Next, a processing procedure of the sewer network environment monitoring device 100 will be described with reference to the flowchart shown in Fig. 5. This flowchart is executed by the CPU 410 in Fig. 4 using the RAM 440, and realizes each functional configuration of the sewer network environment monitoring device 100 in Fig. 2.

[0091] In step S501, the first acquisition unit 201 acquires the upstream first sensor data and the downstream first sensor data. In step S503, the detection unit 202 monitors the fluctuation of the first sensor data and detects whether or not a difference occurs between the upstream first sensor data and the downstream first sensor data. When the detection unit 202 detects a difference between the upstream first sensor data and the downstream first sensor data (YES in step S503), the sewer network environment monitoring device 100 proceeds to step S505. In step S505, the second acquisition unit 203 acquires the second sensor data. Then, in step S507, the identification unit 204 analyzes the second sensor data and identifies the cause of the difference between the upstream first sensor data and the downstream first sensor data. In step S509, the identification unit 204 analyzes the second sensor data and identifies the location where the cause of the detected difference occurs. After step S509, step S511 is performed to identify the cause and then propose a solution. It should be noted that it is not always necessary to perform steps S507, S509, and S511.

[0092] If the detection unit 202 has not detected a change in the environment (NO in step S503), the sewer-network environment monitoring device 100 returns to step S501.

[0093] According to this embodiment, since it is not necessary to constantly monitor all the sensors installed in the sewer network 110, it is possible to practically and efficiently monitor the sewer network 110. In other words, under normal circumstances, only the first sensor 131 is monitored, and when the first sensor 131 detects an abnormality, it is only necessary to check the second sensor data of the second sensor 133, so that it is possible to practically and efficiently monitor the sewer network 110.

[0094] In addition, since a sensor with low power consumption and low cost can be used as the second sensor 133, the maintenance costs of the sewer network environment monitoring device 100 can be reduced.

[0095] In addition, while the first sensor 131 tends to be large, the second sensor 133 can be made small, consumes less power, and is low cost. Therefore, by installing a small number of first sensors 131 and a large number of second sensors 133 in the sewer network 110 provided in a specific area, the sewer network 110 can be comprehensively monitored.

[0096] In this way, according to the sewer network environment monitoring device 100 of this embodiment, practical monitoring of the sewer network 110 can be performed.

[0097] [others] In this embodiment, instead of collecting the second sensor data of the second sensor 133 by the vehicle 117 having a communication function and a storage medium, the second sensor data of the second sensor 133 may be collected by a small device that an operator can carry, such as a smartphone. Also, the second sensor data may be collected by connecting a USB (Universal Serial Bus) memory or the like to the second sensor 133.

[0098] Also, the second sensor data may be collected by a worker removing a storage medium storing the second sensor data from the second sensor 133. In this case, after the worker removes the storage medium from the second sensor 133, the worker carries the storage medium to the vicinity of the sewer network environment monitoring device 100. Thereafter, the sewer network environment monitoring device 100 acquires the second sensor data from the storage medium collected by the worker through wired communication or wireless communication. In this case, the second sensor 133 does not need to have a communication function.

[0099] [Other embodiments] Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the above embodiments. Various modifications that can be understood by a person skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention. For example, as in the present embodiment, all of the various judgments and the like may be performed by computer resources, or some of the detection of the difference between the upstream first sensor data and the downstream first sensor data, the analysis of the second sensor data, and the identification of the cause of the detected difference and the location where it occurs may be performed by something other than computer resources. In addition, systems or devices in which the separate features included in each embodiment are combined in any way are also included in the scope of the present invention.

[0100] The present invention may be applied to a system consisting of multiple devices, or to a single device. Furthermore, the present invention is also applicable to a case where an information processing program for realizing the functions of the embodiments is supplied directly or remotely to a system or device. Therefore, the scope of the present invention also includes a program installed on a computer to realize the functions of the present invention by a computer, a medium storing the program, and a WWW (World Wide Web) server for downloading the program. In particular, the scope of the present invention includes at least a non-transitory computer readable medium storing a program for causing a computer to execute the processing steps included in the above-mentioned embodiments.

Claims

1. A sewer network environment monitoring device that monitors the environment of a sewer network installed in a specified area, The sewer network is a sewer network in which an upstream main pipe and a downstream main pipe are connected by at least one branch pipe, a first acquisition unit that acquires upstream first sensor data and downstream first sensor data indicating the environments of the upstream main pipe and the downstream main pipe in the vicinity of the positions where the upstream first sensor and the downstream first sensor are installed from an upstream first sensor attached to an upstream main pipe manhole provided near the connection between the upstream main pipe and one end of the at least one branch pipe and a downstream first sensor attached to a downstream main pipe manhole provided near the connection between the downstream main pipe and the other end of the at least one branch pipe; a detection unit that monitors the upstream first sensor data and the downstream first sensor data in real time and detects a difference between the upstream first sensor data and the downstream first sensor data; a second acquisition unit that acquires, when the difference is detected by the detection unit, second sensor data recorded in a second sensor attached to a manhole provided in at least one of the branch pipes connected to the upstream main pipe and the downstream main pipe, from a storage medium in a manhole of the branch pipe in which the second sensor data has been recorded for a certain period of time; A sewer network environmental monitoring device equipped with the above.

2. The sewer network environment monitoring device according to claim 1 , further comprising an identification unit that analyzes the acquired second sensor data and identifies a cause of the detected difference.

3. The sewer network environment monitoring device of claim 2 , wherein the identification unit analyzes the acquired second sensor data to identify a location where a cause of the detected difference occurs.

4. The sewer network environment monitoring device according to claim 1 , wherein the first sensor data and the second sensor data include at least one of a water level, a temperature, a turbidity, an odor, a hydrogen sulfide concentration, and an oxygen concentration.

5. A sewer network environment monitoring method for monitoring the environment of a sewer network provided in a predetermined area, comprising: The sewer network is a sewer network in which an upstream main pipe and a downstream main pipe are connected by at least one branch pipe, a first acquisition step of acquiring upstream first sensor data and downstream first sensor data indicating the environment of the upstream main pipe and the downstream main pipe in the vicinity of the positions where the upstream first sensor and the downstream first sensor are installed from an upstream first sensor attached to an upstream main pipe manhole provided near the connection between the upstream main pipe and one end of the at least one branch pipe and a downstream first sensor attached to a downstream main pipe manhole provided near the connection between the downstream main pipe and the other end of the at least one branch pipe; a detection step of monitoring the upstream first sensor data and the downstream first sensor data in real time and detecting a difference between the upstream first sensor data and the downstream first sensor data; a second acquisition step of acquiring second sensor data recorded in a second sensor attached to a manhole provided in at least one of the branch pipes connected to the upstream main pipe and the downstream main pipe from a storage medium in a manhole of the branch pipe in which the second sensor data has been recorded for a certain period of time when the difference is detected by the detection step; an identifying step of analyzing the acquired second sensor data to identify a cause of the detected difference; A sewer network environmental monitoring method comprising:

6. A sewer network environment monitoring program for monitoring the environment of a sewer network provided in a specified area, The sewer network is a sewer network in which an upstream main pipe and a downstream main pipe are connected by at least one branch pipe, a first acquisition step of acquiring upstream first sensor data and downstream first sensor data indicating the environment of the upstream main pipe and the downstream main pipe in the vicinity of the positions where the upstream first sensor and the downstream first sensor are installed from an upstream first sensor attached to an upstream main pipe manhole provided near the connection between the upstream main pipe and one end of the at least one branch pipe and a downstream first sensor attached to a downstream main pipe manhole provided near the connection between the downstream main pipe and the other end of the at least one branch pipe; a detection step of monitoring the upstream first sensor data and the downstream first sensor data in real time and detecting a difference between the upstream first sensor data and the downstream first sensor data; a second acquisition step of acquiring second sensor data recorded in a second sensor attached to a manhole provided in at least one of the branch pipes connected to the upstream main pipe and the downstream main pipe from a storage medium in a manhole of the branch pipe in which the second sensor data has been recorded for a certain period of time when the difference is detected by the detection step; an identifying step of analyzing the acquired second sensor data to identify a cause of the detected difference; A sewer network environmental monitoring program that causes a computer to execute the above.

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