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

Abstract

To efficiently monitor a sewerage network.SOLUTION: A sewerage network environment monitoring device monitors an environment of a sewerage network provided within a prescribed area. The sewerage network environment monitoring device comprises: a first acquisition part to acquire first sensor data indicating environment of main pipes near a position at which a first sensor is fitted from the first sensor fitted to at least one manhole among a plurality of manholes disposed on the main pipes of the sewerage network; a detection part to detect change of the environment in the main pipes by monitoring variation in the first sensor data in real time; a second acquisition part to acquire second sensor data, which is continuously measured by a second sensor fitted to a manhole on a branch pipe around the position at which the first sensor is fitted among branch pipes connected to the main pipes, from a storage medium for storing the second data for a prescribed period in the manhole of the branch pipe, when the change of the environment is detected by the detection part; and a specification part to specify cause of the detected change of the environment in the main pipes 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, A first acquisition unit that acquires, from a first sensor attached to at least one manhole among a plurality of manholes provided in a main pipe of the sewer network, first sensor data indicating an environment of the main pipe at a position where the first sensor is attached; A detection unit that monitors fluctuations in the first sensor data in real time to detect changes in the environment inside the main pipe; a second acquisition unit that acquires, when a change in the environment is detected by the detection unit, second sensor data that is constantly measured by second sensors attached to a plurality of manholes provided in branch pipes that are connected to the main pipe and that surround a position where the first sensor is attached, from a storage medium in the manholes of the branch pipes in which the second sensor data is recorded for a certain period of time; An identification unit that analyzes the acquired second sensor data and identifies a cause of the detected change in the environment inside the main pipe; 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: A first acquisition step of acquiring, from a first sensor attached to at least one manhole among a plurality of manholes provided in a main pipe of the sewer network, first sensor data indicating an environment of the main pipe at a position where the first sensor is attached; A detection step of detecting a change in the environment in the main pipe by monitoring a change in the first sensor data in real time; a second acquisition step of acquiring, when a change in the environment is detected by the detection step, second sensor data constantly measured by second sensors attached to a plurality of manholes provided in branch pipes connected to the main pipe and located around a position where the first sensor is attached, from a storage medium in a manhole of the branch pipe in which the second sensor data is recorded for a certain period of time; An identification step of analyzing the acquired second sensor data to identify a cause of the detected change in the environment in the main pipe; 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, A first acquisition step of acquiring, from a first sensor attached to at least one manhole among a plurality of manholes provided in a main pipe of the sewer network, first sensor data indicating an environment of the main pipe at a position where the first sensor is attached; A detection step of detecting a change in the environment in the main pipe by monitoring a change in the first sensor data in real time; a second acquisition step of acquiring, when a change in the environment is detected by the detection step, second sensor data constantly measured by second sensors attached to a plurality of manholes provided in branch pipes connected to the main pipe and located around a position where the first sensor is attached, from a storage medium in a manhole of the branch pipe in which the second sensor data is recorded for a certain period of time; An identification step of analyzing the acquired second sensor data to identify a cause of the detected change in the environment in the main pipe; 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 fluctuation 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. [Figure 6A] FIG. 2 is a diagram for explaining the layout pattern of pipes in a sewer network in a sewer network environment monitoring device according to a preferred embodiment of the present invention. [Figure 6B] 1 is a diagram for explaining an overview of the operation of a sewer network environment monitoring device according to a preferred embodiment of the present invention with respect to another pattern of piping arrangement of a sewer network. FIG. 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 Fig. 1A to Fig. 6B. An overview of identifying the cause of an environmental change in a main pipe 111 of a sewer network using 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 identify the cause of an environmental change in the main pipe 111 of a sewer network 110 provided in a specified area.

[0012] The arrangement pattern of the pipes in the sewer network 110 is a mesh pattern, as shown in Fig. 1A. Specifically, branch pipes 112 are arranged in a mesh pattern in a plan view in a section surrounded by four main pipes 111. In Fig. 1A, the main pipes 111 are shown by solid lines, and the branch pipes 112 are shown by dashed lines. Also, in Fig. 1A, the arrows indicate the direction in which the sewage flows. Note that at least three main pipes 111 are necessary to form an enclosed section.

[0013] Manholes are provided in the main pipe 111 and the branch pipe 112. The manholes are provided at the intersections where the main pipes 111 cross each other, at the connections between the main pipes 111 and the branch pipes 112, and in the pipelines of the branch pipes 112. In FIG. 1A, "◯" represents a manhole 121 provided at the intersections where the main pipes 111 cross each other. A first sensor 131 is attached to the manhole 121 provided at the intersections of the main pipes 111. In FIG. 1A, "■" represents the first sensor 131. The first sensor 131 is a main sensor in the sewer network 110. The first sensor 131 acquires first sensor data indicating the environment inside the main pipe 111. The first sensor 131 has a wireless communication function, and the first sensor data acquired by the first sensor 131 is transmitted to the sewer network environment monitoring device 100. The first sensor 131 acquires the first sensor data at all times. The acquisition of the first sensor data by the first sensor 131 may be performed continuously or intermittently as long as it is performed at all times. 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, i.e., the first sensor data acquired over a ten-minute period, may be transmitted at one time.

[0014] A second sensor 132 is attached to a manhole provided at the connection between the main pipe 111 and the branch pipe 112 and a manhole provided in the pipeline of the branch pipe 112. In FIG. 1A, "▲" represents the second sensor 132. The second sensor 132 is a secondary sensor in the sewer network 110. The second sensor 132 constantly measures second sensor data indicating the environment inside the branch pipe 112. The second sensor 132 has a wired or wireless short-range communication function. The second sensor 132 is attached in multiple manholes provided in the branch pipe 112.

[0015] The first sensor 131 and the second sensor 132 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 sensor 131 and the second sensor 132 may generate electricity by heat, vibration, sunlight, or the like.

[0016] The sewer network environment monitoring device 100 monitors the fluctuation of the first sensor data and detects whether or not the environment in the main pipe 111 to which the first sensor 131 is attached has changed. For example, when a certain first sensor 131a installed in the main pipe 111a detects a change in the environment at that location, a worker moves by the vehicle 117 to the vicinity of the second sensors 132a, 132b attached to a plurality of manholes provided in the branch pipes 112a, 112b surrounding the location where the first sensor 131a is attached among the branch pipes 112 connected to the main pipe 111a. In this embodiment, the second sensors 132a, 132b are second sensors 132 attached to manholes at the connection parts between the branch pipes 112a, 112b and the main pipes 111a, 111b. The vehicle 117 is provided with the position information of all the second sensors, so it can quickly move to the installation locations of the second sensors 132a, 132b. The vehicle 117 has a communication function. The vehicle 117 and the second sensors 132a and 132b communicate with each other, and the vehicle 117 collects the second sensor data recorded in the second sensors 132a and 132b from the second sensors 132a and 132b 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 132a and 132b 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 132 by wireless communication. When acquiring the second sensor data from the second sensor 132 by wired communication, it is preferable that the connection terminal of the second sensor 132 is exposed to the ground and the connection terminal on the vehicle 117 side is easily connectable from the viewpoint of easily acquiring the second sensor data.

[0017] The second sensor data from both the second sensor 132a and the second sensor 132b may be collected by one vehicle 117. Also, the second sensor data from the second sensor 132a and the second sensor data from the second sensor 132b may be collected by different vehicles 117.

[0018] In this embodiment, another sewer network section (not shown) is adjacent to the periphery of the partitioned sewer network 110. In this case, when the first sensor 131a detects an environmental change, it is desirable to acquire not only the second sensor data of the second sensors 132a and 132b located upstream of the position where the first sensor 131a is attached, but also the second sensor data of the second sensor 132 located in the adjacent sewer network section. It is desirable to appropriately set the range for acquiring the second sensor data based on the type of sensor data after comparing the change rate of the first sensor data acquired from each first sensor 131 installed in the main pipe 111.

[0019] 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 to identify the cause of the change in the environment inside the main pipe 111a.

[0020] For example, if the first sensor 131a detects a decrease in the water level, and neither the second sensor 132a nor the second sensor 132b detects a decrease in the water level, the cause of the decrease in the water level, for example, a location where a crack in the pipe is causing sewage to leak or a location where a clogged pipe is causing sewage to stagnate, is identified between the first sensor 131a and the second sensor 132a, or between the first sensor 131a and the second sensor 132b in the sewer network 110. Note that "identification" in this specification is a concept that includes an estimation with a certain degree of certainty or rationality.

[0021] 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.

[0022] Here, the main pipe 111 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 111 and the branch pipe 112 can be distinguished by their inner diameters, and the pipe with a relatively larger inner diameter can be called the main pipe 111, and the pipe with a relatively smaller inner diameter can be called the branch pipe 112. 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 111, and the pipe with the relatively smaller inner diameter is the branch pipe 112. However, this is subject to the condition that the main pipe 111 is provided with a manhole 121. Therefore, when neither of the two types of pipes selected arbitrarily is provided with a manhole 121, both of the two types of pipes are branch pipes 112.

[0023] Also, two or more types of branch pipes 112 having different inner diameters may be used for one type of main pipe 111.

[0024] 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.

[0025] Examples of materials for the main pipe 111 and the branch pipes 112 include concrete such as reinforced concrete; metals such as ductile cast iron; resins such as polyvinyl chloride and polyethylene; and ceramics.

[0026] Next, the configuration of the first sensor 131 will be described with reference to FIG. 1B. The first sensor 131 may include, for example, a transceiver 141 and a water level gauge 151. The transceiver 141 can be attached to, for example, the back surface of the cover of the manhole 121. The water level gauge 151 can be installed, for example, in the 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 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. The transceiver 141 may be, for example, one that supports LTE (Long Term Evolution) communication or LPWA (Low power wide area) communication. The transceiver 141 is preferably compatible with LTE communication because 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, so that the first sensor data can be transmitted to the sewer network environment monitoring device 100 without opening the cover of the manhole 121.

[0027] The first sensor 131 has a battery (not shown) attached to the back surface of the cover of the manhole 121 as its power source, and is capable of measurement for a period ranging from two months to about four years depending on the measurement frequency.

[0028] Taking advantage of the fact that the first sensor 131 is capable of real-time measurement through reliable communication, it is preferable to place the first sensor 131 at key locations in the sewer network 110 as a main device for grasping surface trends in real time.

[0029] Since the transceiver 141 is capable of communicating over a wide area, the first sensor 131 tends to be large in size, and in order to install the first sensor 131, a sufficient installation space may be required.

[0030] Next, the configuration of the second sensor 132 will be described with reference to FIG. 1C. The second sensor 132 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 132 is attached. The transceiver 142 can be attached, for example, to the back surface of the cover of the manhole 121. The water level gauge 152 is installed in the branch pipe 112. 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 112 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.

[0031] 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).

[0032] As described above, the second sensor 132 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 132 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 132. Therefore, the power required for the communication function of the second sensor 132 can be reduced.

[0033] In addition, since the second sensor data is acquired from the second sensor 132 only when an abnormality is detected in the first sensor 131, the second sensor 132 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 132 be capable of storing the second sensor data for a short period of time up to the present, specifically, for about several days to one month.

[0034] This makes it possible to reduce the maintenance costs, including the power consumption for storing and communicating the sensor data of the second sensor 132. In addition, the second sensor 132 can be made smaller.

[0035] The water level indicator 152 of the second sensor 132 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 112 by using a substantially circular fitting-type jig 162. The water level indicator 152 is covered by a cover sheet 165.

[0036] Jig 162 can be installed, for example, at the open end of branch pipe 112 at the connection between branch pipe 112 and main pipe 111. Specifically, jig 162 is fixed inside branch pipe 112 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 112. Then, after jig 162 is positioned inside branch pipe 112, jig 162 is circumferentially expanded by pipe diameter adjustment unit 163 to bring the outer circumferential surface of jig 162 into contact with the inner surface of branch pipe 112. Then, L-shaped bracket 164 is fixed to the wall surface of branch pipe 112.

[0037] 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 branch pipe 112 of the jig 162.

[0038] 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 using a nut 168, thereby fixing the pipe diameter adjustment part 163 and the L-shaped bracket 164.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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).

[0043] 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).

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] In this way, the second sensor 132 can reduce communication costs compared to the first sensor 131. Furthermore, the second sensor 132 can shorten the time required for installation compared to conventional sensors that are fixed by anchors. Furthermore, the second sensor 132 can also significantly reduce power consumption compared to conventional rod-shaped water level gauges.

[0052] Taking advantage of the fact that second sensors 132 are inexpensive and can be installed in large numbers, they are preferably disposed between first sensors 131, which are main devices, as backup devices that complement planar missing parts.

[0053] In this embodiment, by utilizing information from both the first sensor 131, which is the main device, and the second sensor 132, which is the 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.

[0054] Next, the configuration of the sewer network environment monitoring device 100 will be described with reference to Fig. 2A. 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.

[0055] The first acquisition unit 201 acquires, from a first sensor 131 attached to at least one manhole 121 among a plurality of manholes 121 provided in the main pipe 111 of the sewer network 110, first sensor data indicating the environment of the main pipe 111 at the position where the first sensor 131 is attached. 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.

[0056] The first acquisition unit 201 constantly acquires the first sensor data. The first acquisition unit 201 may acquire the first sensor data continuously or intermittently.

[0057] The detection unit 202 monitors the fluctuation of the first sensor data in real time to detect a change in the environment in the main pipe 111. The detection of the environmental change can be performed, for example, by determining whether or not the fluctuation rate of the first sensor data is equal to or greater than a predetermined threshold value. Specifically, by determining that the fluctuation rate of the first sensor data is equal to or greater than a threshold value, it is possible to detect that the environment in the main pipe 111 to which the first sensor 131 that acquired the first sensor data is attached has changed. The fluctuation rate of the first sensor data can be determined based on the first sensor data at any two points in time. The fluctuation rate of the first sensor data may be, for example, a fluctuation rate of the value of the latest first sensor data relative to the value of the past first sensor data, for example, the first sensor data 10 minutes ago. It may also be a fluctuation rate of the value of the first sensor data after the first sensor data relative to the value of the first sensor data at a certain point in the past.

[0058] Furthermore, the detection of an environmental change may be performed by determining whether or not a rate of change in the first sensor data at any one point in time exceeds a threshold value.

[0059] When the detection unit 202 detects an environmental change, the second acquisition unit 203 acquires second sensor data, which is constantly measured by the second sensor 132 attached to a plurality of manholes provided in the branch pipe 112 surrounding the position where the first sensor 131 is attached among the branch pipes 112 connected to the main pipe 111, from a storage medium in the manhole of the branch pipe 112 in which the second sensor data is 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 112 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 112 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 112 may be the same as or different from the storage medium possessed by the vehicle 117. Examples of the second sensor data include water level, water flow, temperature, turbidity, odor, hydrogen sulfide concentration, and oxygen concentration, and the data may include at least one of these.

[0060] The identification unit 204 analyzes the acquired second sensor data to identify the cause of the detected environmental change in the main pipe 111. In this embodiment, the identification unit 204 may further identify at least one of the location of the cause of the detected environmental change in the main pipe 111 and the range of influence of the detected environmental change in the main pipe 111 in the sewer network 110. FIG. 2B shows examples of possible causes of changes in each detection item listed as the first sensor data and the second sensor data. FIG. 2B also shows the branch pipe 112 from which the second sensor data should be acquired when a change is detected in the main pipe 111, as a "reference branch pipe", divided into the upstream side and the downstream side with respect to the main pipe 111. In FIG. 2B, "+" indicates that the change in the detection item is an increase change, and "-" indicates that the change in the detection item is a decrease change. In FIG. 2B, "○" indicates that the acquisition of the second sensor data is necessary, and "-" indicates that the acquisition of the second sensor data is unnecessary. Note that this diagram is merely an example and may be modified as appropriate depending on the attributes and conditions of the area to be monitored.

[0061] 2B, the identification unit 204 sequentially analyzes the second sensor data acquired by the surrounding second sensor 132 at the installation position of the first sensor 131 where a change was detected, starting from the data from the closest position. Hereinafter, a method for analyzing the second sensor data and identifying the cause of the environmental change, the location where the cause of the environmental change occurred, and the range of influence of the environmental change will be described.

[0062] (1) When the detection item is water level (i) When the value of the first sensor data is increasing For example, when the first sensor data increases, the causes include an increase in rainfall, a clogged pipe downstream, an inflow of groundwater due to damage to a pipe upstream, and the connection of a new branch pipe upstream. When the first sensor data, which is a water level, increases, the increase in the water level is typically caused by the upstream, but may also be caused by the downstream. Therefore, when the first sensor data increases, in order to identify the location of the cause of the environmental change, it is preferable to refer to the second sensor data of the branch pipes 112 both upstream and downstream from the acquisition position of the first sensor data. Also, in order to identify the range of influence of the environmental change, the second sensor data of the branch pipes 112 both upstream and downstream from the acquisition position of the first sensor data is referred to.

[0063] For example, if the first sensor data is increasing, the second sensor data on the upstream side remains unchanged, and the second sensor data on the downstream side increases, there is a strong possibility that the pipe is clogged downstream of the acquisition position of the increased second sensor data. In this case, by referring to the increases and decreases in the second sensor data at multiple positions connected further downstream, the location where the increase turns to a decrease can be identified as the clogged location. Conversely, if the second sensor data is increasing both upstream and downstream, there is a strong possibility that unexpected water is flowing in further upstream. In this case, by referring to the increases and decreases in the second sensor data at multiple positions connected further upstream, the location where the increase turns to no change can be identified as the location where the unexpected inflow occurred. As a result of the above, the range of influence of the detected change in the first sensor data can be automatically grasped.

[0064] (ii) When the value of the first sensor data is decreasing For example, when the first sensor data is decreased, the causes include water leakage (flowing out) due to damage to the pipe upstream, clogging of the pipe upstream, and reinforcement of the main pipe 111 downstream (laying a new line, replacing with an enlarged pipe). When the first sensor data is decreased, in order to identify the location of the occurrence of the cause of the environmental change, the second sensor data of the branch pipes 112 both upstream and downstream from the acquisition position of the first sensor data is referenced. Also, in order to identify the range of influence of the environmental change, the second sensor data of the branch pipes 112 both upstream and downstream from the acquisition position of the first sensor data is referenced. As described above, the range of influence of the environmental change can be identified based on the location where the increase and decrease of the second sensor data is changing.

[0065] (2) When the detection item is temperature (i) When the value of the first sensor data is increasing For example, if the first sensor data increases, the cause may be a change in the type of inflowing water. Specifically, it is highly likely that high-temperature water has flowed in from a restaurant or other establishment upstream of the acquisition position of the first sensor data. Detecting an increase in the first sensor data, which is temperature, can be used to detect the rate of deterioration of the pipe due to changes in temperature inside the pipe. Examples of pipe deterioration include corrosion of the pipe.

[0066] When the first sensor data increases, the second sensor data of the branch pipe 112 upstream of the acquisition position of the first sensor data is referenced in order to identify the location of the cause of the environmental change. Also, in order to identify the range of influence of the environmental change, the second sensor data of the branch pipe 112 upstream of the acquisition position of the first sensor data is referenced. As described above, the range of influence of the environmental change can be identified based on the location where the way in which the second sensor data increases and decreases changes. In the sewer network 110, it is generally unlikely that a temperature change on the downstream side propagates to the upstream side, so it is not necessarily necessary to reference the second sensor data of the branch pipe 112 downstream of the acquisition position of the first sensor data.

[0067] (ii) When the value of the first sensor data is decreasing For example, when the first sensor data is decreased, the cause may be a change in the type of inflow water. Specifically, it is highly likely that cold water has flowed in from a restaurant or the like upstream of the acquisition position of the first sensor data. When the first sensor data is decreased, in order to identify the location of the cause of the environmental change, the second sensor data of the branch pipe 112 upstream of the acquisition position of the first sensor data is referenced. In addition, in order to identify the range of influence of the environmental change, the second sensor data of the branch pipe 112 upstream of the acquisition position of the first sensor data is referenced. As described above, the range of influence of the environmental change can be identified based on the location where the way in which the second sensor data increases and decreases changes. In the sewer network 110, it is generally difficult to imagine that a temperature change on the downstream side propagates to the upstream side, so it is not necessarily necessary to reference the second sensor data of the branch pipe 112 downstream of the acquisition position of the first sensor data.

[0068] (3) When the detection item is turbidity (i) When the value of the first sensor data is increasing For example, when the first sensor data increases, the causes include an inflow of soil and sand due to damage to an upstream pipe, flooding from the ground (road) during heavy rain, and a clogged pipe upstream. When the first sensor data increases, in order to identify the location of the cause of the environmental change, the second sensor data of the branch pipes 112 both upstream and downstream from the acquisition position of the first sensor data is referenced. In addition, in order to identify the range of influence of the environmental change, the second sensor data of the branch pipes 112 both upstream and downstream from the acquisition position of the first sensor data is referenced. As described above, the range of influence of the environmental change can be identified based on the location where the increase and decrease of the second sensor data changes.

[0069] (ii) When the value of the first sensor data is decreasing For example, when the first sensor data is decreased, the cause may be a change in the inflow water, infiltration of groundwater due to damage to the pipe, etc. When the first sensor data is decreased, in order to identify the location of the cause of the environmental change, the second sensor data of the branch pipe 112 upstream of the acquisition position of the first sensor data is referenced. In the sewer network 110, it is generally unlikely that turbidity on the downstream side propagates to the upstream side, so it is not necessarily necessary to reference the second sensor data of the branch pipe 112 downstream of the acquisition position of the first sensor data. In addition, in order to identify the range of influence of the environmental change, the second sensor data of the branch pipe 112 both upstream and downstream of the acquisition position of the first sensor data is referenced. As described above, the range of influence of the environmental change can be identified based on the location where the increase and decrease of the second sensor data is changing.

[0070] (4) When the detection item is odor (i) When the value of the first sensor data is increasing For example, when the first sensor data increases, the causes include deterioration of the inflow wastewater, progression of the corrosive environment, etc. When the first sensor data increases, in order to identify the location of the cause of the environmental change, the second sensor data of the branch pipes 112 both upstream and downstream of the acquisition position of the first sensor data is referenced. Also, in order to identify the range of influence of the environmental change, the second sensor data of the branch pipes 112 both upstream and downstream of the acquisition position of the first sensor data is referenced. As described above, the range of influence of the environmental change can be identified based on the location where the way in which the second sensor data increases and decreases changes.

[0071] The extent to which the second sensor data is acquired in the sewer network 110 can be appropriately determined according to the arrangement pattern of the pipes in the sewer network 110, the thickness of the pipes, the water force in the pipes, and the like. For example, when the water force in the pipes is strong, the air in the pipes is likely to flow from upstream to downstream accompanied by the sewage flowing in the pipes. Therefore, when the water force in the pipes is strong, the second sensor data upstream of the acquisition position of the first sensor data is more important than the second sensor data downstream. In other words, when the water force in the pipes is strong, the second sensor data downstream of the acquisition position of the first sensor data does not necessarily need to be acquired. On the other hand, when the air in the pipes is stagnant due to reasons such as weak water force in the pipes or narrow pipes, the fluctuation of the odor in the pipes may be transmitted to both the upstream and downstream sides. Therefore, when the air in the pipes is stagnant, it is preferable to refer to the second sensor data of the branch pipes 112 both upstream and downstream of the acquisition position of the first sensor data.

[0072] (ii) When the value of the first sensor data is decreasing For example, when the first sensor data decreases, the cause may be improvement of inflow wastewater, improvement of corrosive environment, etc. When the first sensor data increases, in order to identify the location of the cause of the environmental change, the second sensor data of the branch pipes 112 both upstream and downstream from the acquisition position of the first sensor data is referenced. Also, in order to identify the range of influence of the environmental change, the second sensor data of the branch pipes 112 both upstream and downstream from the acquisition position of the first sensor data is referenced. As described above, the range of influence of the environmental change can be identified based on the location where the increase and decrease of the second sensor data changes.

[0073] (5) When the detection item is hydrogen sulfide concentration (i) When the value of the first sensor data is increasing For example, when the first sensor data increases, the cause may be the progression of a corrosive environment. When the first sensor data increases, in order to identify the location of the cause of the environmental change, the second sensor data of the branch pipes 112 both upstream and downstream of the acquisition position of the first sensor data is referenced. In addition, in order to identify the range of influence of the environmental change, the second sensor data of the branch pipes 112 both upstream and downstream of the acquisition position of the first sensor data is referenced. As described above, the range of influence of the environmental change can be identified based on the location where the manner of increase and decrease of the second sensor data changes. Also, as in the case where the detection item is odor, the extent to which the second sensor data is acquired in the sewer network 110 can be appropriately determined depending on the arrangement pattern of the pipes of the sewer network 110, the thickness of the pipes, the water pressure in the pipes, and the like.

[0074] (ii) When the value of the first sensor data is decreasing For example, when the first sensor data decreases, the cause may be an improvement in the corrosive environment. When the first sensor data increases, in order to identify the location of the cause of the environmental change, the second sensor data of the branch pipes 112 both upstream and downstream of the acquisition position of the first sensor data is referenced. In addition, in order to identify the range of influence of the environmental change, the second sensor data of the branch pipes 112 both upstream and downstream of the acquisition position of the first sensor data is referenced. As described above, the range of influence of the environmental change can be identified based on the location where the increase and decrease of the second sensor data changes.

[0075] (6) When the detection item is oxygen concentration (i) When the value of the first sensor data is increasing In the sewer network 110, the oxygen concentration is always about 20.9%, and it is generally unlikely that the oxygen concentration will increase. Therefore, it is not necessarily necessary to detect an increase in the value of the first sensor data. Furthermore, when the detection unit 202 detects an increase in the oxygen concentration, the identification unit 204 does not necessarily need to identify the cause of the environmental change, etc. Therefore, when the first sensor data increases, it is not necessarily necessary to identify the location where the cause of the environmental change occurred or the extent of the influence of the environmental change. In other words, it is not necessarily necessary to acquire the second sensor data.

[0076] (ii) When the value of the first sensor data is decreasing For example, when the first sensor data is decreased, the cause may be the progression of a corrosive environment. The progression of a corrosive environment typically occurs in a pipeline that has not been inspected for a long time, in sludge that accumulates in the pipeline, or in the vicinity of a pressure pipe. Specific examples of the progression of a corrosive environment include the decay of organic matter and reactions caused by bacteria that consume oxygen. When the first sensor data is increased, in order to identify the location of the cause of the environmental change, the second sensor data of the branch pipes 112 both upstream and downstream of the acquisition position of the first sensor data is referenced. In addition, in order to identify the range of influence of the environmental change, the second sensor data of the branch pipes 112 both upstream and downstream of the acquisition position of the first sensor data is referenced. As described above, the range of influence of the environmental change can be identified based on the location where the increase and decrease of the second sensor data is changing.

[0077] The cause of the change in the environment inside the main pipe 111 identified by the identification unit 204 is displayed, for example, on a display device (not shown) provided in the sewer network environment monitoring device 100. Alternatively, the cause is notified to a worker riding in the vehicle 117. The location of the occurrence, etc. may be displayed or notified together with the cause.

[0078] 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.

[0079] FIG. 3 is a diagram for explaining an example of the first sensor data fluctuation rate 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 fluctuation rate threshold table 301 is a table that stores a threshold value of the fluctuation rate of the first sensor data. The item 311 is a type of the first sensor data. The fluctuation rate 312 is a threshold value of the fluctuation rate for each type of the first sensor data. The "●" in the fluctuation rate 312 is the value, and a different value is set for each type of the first sensor data. The first sensor data fluctuation rate threshold table 301 is possessed by, for example, the detection unit 202. The detection unit 202 refers to the first sensor data fluctuation rate threshold table 301 and determines whether the fluctuation rate of the first sensor data is equal to or greater than a predetermined threshold. The detection unit 202 detects a change in the environment in the main pipe 111 depending on the presence or absence of the item 311 that is determined to have a fluctuation rate equal to or greater than the threshold. Specifically, when an item 311 is determined to have a fluctuation rate equal to or greater than the threshold, the detection unit 202 determines that an environmental change in the main pipe 111 has been detected. The second sensor data fluctuation rate threshold table 302 is a table that stores a threshold value of the fluctuation rate of the second sensor data. The item 321 is the type of second sensor data. The fluctuation rate 322 is the threshold value of the fluctuation rate for each type of second sensor data. The "◆" in the fluctuation rate 322 is the value, and a different value is set for each type of second sensor data. The second sensor data fluctuation rate threshold table 302 is held 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.

[0080] 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 transmission / reception data 444 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.

[0081] 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 132. The threshold data 443 is data developed from the first sensor data fluctuation rate threshold table 301 and the second sensor data fluctuation rate threshold table 302 shown in FIG. 3.

[0082] 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.

[0083] 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 fluctuation rate threshold table 301 and a second sensor data fluctuation rate threshold table 302. The first sensor data fluctuation rate threshold table 301 is a table that manages the relationship between the item 311 and the fluctuation 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.

[0084] 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 132. 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.

[0085] 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.

[0086] 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.

[0087] In step S501, the first acquisition unit 201 acquires the first sensor data. In step S503, the detection unit 202 monitors the fluctuation of the first sensor data and determines whether the environment in the main pipe 111 has changed. If the detection unit 202 detects a change in the environment (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 environmental change in the main pipe 111. In step S509, the identification unit 204 analyzes the second sensor data and identifies the location of the cause of the environmental change in the main pipe 111. In step S511, the identification unit 204 analyzes the second sensor data and identifies the range of influence of the environmental change in the main pipe 111 in the sewer network 110. After step S511, step S513 is performed to propose a solution. Note that steps S509, S511, and S513 do not necessarily need to be performed.

[0088] 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.

[0089] Steps S507, S509, and S511 can be performed in any order. For example, steps S507, S509, and S511 may be performed in this order. By performing steps S507, S509, and S511 in this order, the cause of the environmental change in the main pipe 111 can be identified quickly, making it possible to quickly respond to the environmental change. In addition, the importance of the environmental change, such as whether serious damage has occurred to the sewer network 110, can also be grasped.

[0090] Alternatively, steps S511, S507, and S509 may be performed in this order. By performing the steps in this order, the extent of the impact of the environmental change in the main pipe 111 on the sewer network 110 can be quickly identified, making it easier to grasp the scope and scale of repair work and the like on the sewer network 110 and to plan the work. Also, inspection and maintenance of the sewer network 110 can be performed efficiently. Also, it is possible to prevent an unnecessarily wide range of the environment in the sewer network 110 from being monitored. Therefore, more effective monitoring of the sewer network 110 can be performed.

[0091] 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, only the first sensor 131 is normally monitored, and when the first sensor 131 detects an abnormality, it is only necessary to check the second sensor data of the second sensor 132, so that it is possible to practically and efficiently monitor the sewer network 110.

[0092] In addition, since a sensor with low power consumption and low cost can be used as the second sensor 132, the maintenance costs of the sewer network environment monitoring device 100 can be reduced.

[0093] In addition, while the first sensor 131 is prone to becoming large, the second sensor 132 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 132 in the sewer network 110 provided in a specific area, the sewer network 110 can be comprehensively monitored.

[0094] 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.

[0095] [Variations] The arrangement pattern of the piping of the sewer network 110 is not limited to the example shown in FIG. 1A. For example, as shown in FIG. 6A, the sewer network 110 may be a mesh-like sewer network 601, a dendritic sewer network 602, a radial sewer network 603, or a ladder-like sewer network 604. In the sewer network 601, a main pipe 111 and branch pipes 112 are arranged in a mesh-like manner in a plan view. In the sewer network 602, a plurality of branch pipes 112 are connected to one main pipe 111. The sewer network 602 may have a branch pipe (not shown) that further branches off from the branch pipe 112. In the sewer network 604, an upper main pipe 111a and a lower main pipe 111b in the figure may be connected by a plurality of branch pipes 112. In the sewer network 604 shown in Fig. 6B, the number of branch pipes 112 connecting the upper main pipe 111a and the lower main pipe 112b is three, but the number of branch pipes 112 connecting the upper main pipe 111a and the lower main pipe 112b may be two or four or more. In Fig. 6A, the solid lines, dashed lines, and arrows have the same meanings as in Fig. 1A.

[0096] Hereinafter, the sewer network 605 will be described in detail with reference to FIG. 6B. The sewer network 605 differs from the sewer network 604 shown in FIG. 6A in that the number of branch pipes 112 connecting the upper main pipe 111a and the lower main pipe 112b is one. In FIG. 6B, the same reference numerals as in FIG. 1A are used to indicate the same functions as those described in FIG. 1A. As shown in FIG. 6B, the sewer network 605 has a piping arrangement pattern in which two main pipes and one branch pipe 112 are connected. Specifically, the upper main pipe 111a and the lower main pipe 112b are connected by one branch pipe 112. In FIG. 6B, the upper main pipe 111a and the lower main pipe 112b are shown by solid lines, and the branch pipe 112 is shown by dashed lines. Also, in FIG. 6B, the arrows indicate the direction of sewage flow. The upper main pipe 111a means a main pipe located upstream of the branch pipe 112, and the lower main pipe 111b means a main pipe located downstream of the branch pipe 112. In the following description, the upper main pipe 111a and the lower main pipe 111b have the same meanings.

[0097] Manholes are provided in the upper main pipe 111a and the lower main pipe 11b. In Fig. 6B, "◯" represents a manhole. The manholes are provided at the connection between the upper main pipe 111a and the branch pipe 112, and at the connection between the lower main pipe 111b and the branch pipe 112. Specifically, an upper main pipe manhole 121a is provided at the connection between the upper main pipe 111a and one end (upstream side) of the branch pipe 112, and a lower main pipe manhole 121b is provided near the connection between the lower main pipe 111b and the other end (downstream side) of the branch pipe 112.

[0098] A first sensor is attached to the upper main manhole 121a and the lower main manhole 121b. In FIG. 6B, "■" represents a first sensor. The first sensor is a main sensor in the sewer network 605. An upper first sensor 131a is attached to the upper main manhole 121a, and a lower first sensor 131b is attached to the lower main manhole 121b. The upper first sensor 131a acquires first sensor data indicating the environment in the upper main 111a at the position where the upper first sensor 131a is attached. The lower first sensor 131b acquires first sensor data indicating the environment in the lower main 111b at the position where the lower first sensor 131b is attached.

[0099] A manhole is also provided in the path of the branch pipe 112. A second sensor 132 is attached to the manhole provided in the path of the branch pipe 112. In FIG. 6B, "▲" represents the second sensor 132. The second sensor 132 is a secondary sensor in the sewer network 110. The second sensor 132 acquires second sensor data indicating the environment inside the branch pipe 112.

[0100] In addition, in this embodiment, instead of collecting the second sensor data of the second sensor 132 by the vehicle 117 having a communication function and a storage medium, the second sensor data of the second sensor 132 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 132.

[0101] Alternatively, the second sensor data may be collected by a worker removing a storage medium storing the second sensor data from the second sensor 132. In this case, after the worker removes the storage medium from the second sensor 132, 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 132 does not need to have a communication function.

[0102] [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, all of the various judgments, etc. may be performed by computer resources as in the present embodiment, or some of the judgment of the change in the first sensor data and the second sensor data, the identification of the cause and the location of the detected change in the first sensor data, and the identification of the range of influence of the change may be performed by something other than computer resources. In addition, a system or device in which the separate features included in each embodiment are combined in any way is also included in the scope of the present invention.

[0103] 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, A first acquisition unit that acquires, from a first sensor attached to at least one manhole among a plurality of manholes provided in a main pipe of the sewer network, first sensor data indicating an environment of the main pipe at a position where the first sensor is attached; A detection unit that detects a change in the environment in the main pipe by monitoring a change in the first sensor data in real time; a second acquisition unit that acquires, when a change in the environment is detected by the detection unit, second sensor data that is constantly measured by second sensors attached to a plurality of manholes provided in branch pipes that are connected to the main pipe and that surround a position where the first sensor is attached, from a storage medium in the manholes of the branch pipes in which the second sensor data is recorded for a certain period of time; An identification unit that analyzes the acquired second sensor data and identifies a cause of the detected change in the environment in the main pipe; A sewer network environmental monitoring device equipped with the above.

2. The sewer network environment monitoring device according to claim 1 , wherein the identification unit analyzes the acquired second sensor data to identify a location where a cause of the detected change in the environment in the main pipe has occurred.

3. The sewer network environment monitoring device according to claim 1 or 2, wherein the identification unit analyzes the acquired second sensor data to identify an extent of influence of the detected change in the environment in the main pipe in the sewer network.

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: A first acquisition step of acquiring, from a first sensor attached to at least one manhole among a plurality of manholes provided in a main pipe of the sewer network, first sensor data indicating an environment of the main pipe at a position where the first sensor is attached; A detection step of detecting a change in the environment in the main pipe by monitoring a change in the first sensor data in real time; a second acquisition step of acquiring, when a change in the environment is detected by the detection step, second sensor data constantly measured by second sensors attached to a plurality of manholes provided in branch pipes connected to the main pipe and located around a position where the first sensor is attached, from a storage medium in the manholes of the branch pipes in which the second sensor data is recorded for a certain period of time; An identification step of analyzing the acquired second sensor data to identify a cause of the detected change in the environment in the main pipe; 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, A first acquisition step of acquiring, from a first sensor attached to at least one manhole among a plurality of manholes provided in a main pipe of the sewer network, first sensor data indicating an environment of the main pipe at a position where the first sensor is attached; A detection step of detecting a change in the environment in the main pipe by monitoring a change in the first sensor data in real time; a second acquisition step of acquiring, when a change in the environment is detected by the detection step, second sensor data constantly measured by second sensors attached to a plurality of manholes provided in branch pipes connected to the main pipe and located around a position where the first sensor is attached, from a storage medium in the manholes of the branch pipes in which the second sensor data is recorded for a certain period of time; An identification step of analyzing the acquired second sensor data to identify a cause of the detected change in the environment in the main pipe; A sewer network environmental monitoring program that causes a computer to execute the above.

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