Water level measurement system and transmitter

Abstract

Calculating the water level using a single pressure sensor. [Solution] The transmitter comprises a contact sensor that detects contact with water, a pressure sensor, a control unit for the transmitter, and a transmission circuit that transmits data to a water level monitoring device that monitors the water level. The control unit for the transmitter uses the pressure detected by the pressure sensor when water comes into contact with the contact sensor as the reference pressure, and the pressure detected by the pressure sensor after detecting the reference pressure as the flood monitoring pressure. The control unit for the transmitter transmits data from the transmission circuit that includes a value obtained by converting the difference between the reference pressure and the flood monitoring pressure into a water level.

Description

Technical Field

[0001] The present disclosure relates to a water level measurement system and a transmitter.

Background Art

[0002] The water level gauge disclosed in Patent Document 1 calculates the water level based on the water pressure measured by a water pressure sensor and the atmospheric pressure measured by an atmospheric pressure gauge.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the water level gauge of Patent Document 1, a pressure sensor used as a water pressure sensor and a pressure sensor used as an atmospheric pressure gauge are required to calculate the water level. That is, two pressure sensors are required to calculate the water level.

Means for Solving the Problems

[0005] A water level measurement system that solves the above problems comprises a transmitter and a water level monitoring device, wherein the transmitter comprises a contact sensor that detects when water comes into contact with it, a pressure sensor, a transmitter control unit that acquires pressure from the pressure sensor, and a transmission circuit that transmits data to the water level monitoring device, wherein the transmitter control unit uses the pressure detected by the pressure sensor when water comes into contact with the contact sensor as a reference pressure, and the pressure detected by the pressure sensor after detecting the reference pressure as the flood monitoring pressure, and transmits data from the transmission circuit including the reference pressure, the flood monitoring pressure, the difference between the reference pressure and the flood monitoring pressure, or a value obtained by converting the difference into a water level, and the water level monitoring device comprises a receiving circuit that receives the data and a control unit, wherein the control unit recognizes the water level based on the reference pressure, the flood monitoring pressure, the difference, or a value obtained by converting the difference into a water level.

[0006] The reference pressure can be considered as the pressure when the water level is zero. As the water level rises, the flood monitoring pressure also rises. Therefore, the difference between the reference pressure and the flood monitoring pressure can be attributed to the rise in water level, and the water level can be calculated from this difference. By using a contact sensor, the water level can be calculated using a single pressure sensor.

[0007] Regarding the above water level measurement system, the water level monitoring device may be a server, and the transmission circuit may transmit the data to the server. A transmitter that solves the above problems comprises a contact sensor that detects contact with water, a pressure sensor, a transmitter control unit that acquires pressure from the pressure sensor, and a transmission circuit that transmits data to a water level monitoring device that monitors the water level. The transmitter control unit uses the pressure detected by the pressure sensor when water comes into contact with the contact sensor as a reference pressure, and the pressure detected by the pressure sensor after detecting the reference pressure as the flood monitoring pressure. The transmitter control unit transmits data from the transmission circuit that includes the reference pressure, the flood monitoring pressure, the difference between the reference pressure and the flood monitoring pressure, or a value obtained by converting the difference into a water level, thereby causing the water level monitoring device to recognize the water level.

[0008] By using a contact sensor, the water level can be calculated using a single pressure sensor. With respect to the above-mentioned transmitter, if the contact sensor detects contact with water, the transmitter control unit may increase the frequency at which it acquires the pressure from the pressure sensor.

[0009] With respect to the above-mentioned transmitter, if the contact sensor detects contact with water, the control unit for the transmitter may increase the frequency of data transmission. If the contact sensor does not detect contact with water in the above-mentioned transmitter, the control unit for the transmitter may transmit the data including information indicating that water is not in contact with the contact sensor.

[0010] Regarding the above-mentioned transmitter, the pressure sensor may be positioned at the same height as the contact sensor. Regarding the above transmitter, the pressure sensor may be positioned higher than the contact sensor. [Effects of the Invention]

[0011] According to the present invention, the water level can be calculated using a single pressure sensor. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic diagram showing an example of a water level measurement system. [Figure 2] This is a schematic diagram of the water level measurement system. [Figure 3] This flowchart shows the control performed by the transmitter control unit. [Modes for carrying out the invention]

[0013] An embodiment of a water level measurement system and a transmitter will be described. As shown in Figure 1, the water level measurement system 10 comprises at least one transmitter 11 and a water level monitoring device 31. In this embodiment, the water level measurement system 10 comprises a plurality of transmitters 11.

[0014] <Transmitter> The transmitter 11 is located in a predetermined location. This predetermined location is a place where flooding may occur. The transmitter 11 is installed, for example, near a waterway, near a river, in a low-lying area such as a road, in a place with low drainage capacity, or in a place where it is desired to confirm whether or not flooding has occurred. Places with low drainage capacity include, for example, underpasses or underground passages. Places where it is desired to confirm whether or not flooding has occurred include, for example, evacuation shelters. The transmitter 11 is attached to a structure.

[0015] As shown in Figure 2, the transmitter 11 comprises a transmitter control unit 12, a contact sensor 15, a pressure sensor 18, a transmission circuit 20, a battery 21, and a housing 22. The transmitter control unit 12 comprises, for example, a processor 13 and a storage unit 14. The processor 13 is, for example, an MPU (Micro Processing Unit), a CPU (Central Processing Unit), or a DSP (Digital Signal Processor). The storage unit 14 includes RAM (Random Access Memory) and ROM (Read Only Memory). The storage unit 14 stores program code or instructions configured to cause the processor 13 to execute processing. The storage unit 14, i.e., the computer-readable medium, includes any available medium accessible by a general-purpose or dedicated computer. The transmitter control unit 12 may be composed of hardware circuits such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). The transmitter control unit 12, which is a processing circuit, may include one or more processors that operate according to a computer program, one or more hardware circuits such as an ASIC or FPGA, or a combination thereof. The storage unit 14 stores an ID code. The ID code is set individually for each transmitter 11.

[0016] The contact sensor 15 detects contact with water. The contact sensor 15 in this embodiment comprises two electrodes 16 and 17. For example, the contact sensor 15 may detect water contact by a change in capacitance between the two electrodes 16 and 17. The contact sensor 15 may also detect water contact by an electric current flowing between the two electrodes 16 and 17 due to rainwater.

[0017] The pressure sensor 18 includes a pressure receiving portion 19. The pressure sensor 18 detects the pressure received by the pressure receiving portion 19. The pressure sensor 18 is arranged at the same height as the contact sensor 15. Specifically, the heights of the two electrodes 16 and 17 are the same as the height of the pressure receiving portion 19. The height of the two electrodes 16 and 17 is, for example, the lowest position of the two electrodes 16 and 17. The height of the pressure receiving portion 19 is, for example, the lowest position of the pressure receiving portion 19. That is, when flooding occurs, the heights of the two electrodes 16 and 17 and the pressure receiving portion 19 are adjusted so that water contacts the two electrodes 16 and 17 and the pressure receiving portion 19 simultaneously. Note that "the same" allows for manufacturing errors, and there may be some errors in the heights of the two electrodes 16 and 17 and the height of the pressure receiving portion 19.

[0018] The transmission circuit 20 is a communication device that communicates with the water level monitoring device 31 via a network. The communication standard of the transmission circuit 20 is, for example, LPWA (Low Power Wide Area) such as LTE (Long Term Evolution), Wi-Fi (registered trademark), WiMAX (Worldwide Interoperability for Microwave Access), or LoRa (registered trademark).

[0019] The battery 21 serves as a power source for the transmitter 11 by supplying power to the transmitter 11. The battery 21 is, for example, a primary battery or a secondary battery. The housing 22 houses the transmitter control unit 12, the contact sensor 15, the pressure sensor 18, the transmission circuit 20, and the battery 21. The two electrodes 16 and 17 are exposed outside the housing 22. The pressure receiving portion 19 is exposed outside the housing 22. The housing 22 is filled with resin. Thereby, the housing 22 is sealed.

[0020] The control executed by the transmitter control unit 12 will be described. The transmitter control unit 12 executes the following control at a predetermined control cycle. As shown in FIG. 3, in step S1, the transmitter control unit 12 determines whether water has come into contact with the contact sensor 15. If the determination result in step S1 is affirmative, the transmitter control unit 12 proceeds to step S2. If the determination result in step S1 is negative, the transmitter control unit 12 proceeds to step S8.

[0021] In step S2, the transmitter control unit 12 determines whether the reference pressure has been set. The reference pressure is the pressure detected by the pressure sensor 18 when water comes into contact with the contact sensor 15 and is the reference pressure for measuring the water level. If the determination result in step S2 is affirmative, the transmitter control unit 12 proceeds to step S5. If the determination result in step S2 is negative, the transmitter control unit 12 proceeds to step S3.

[0022] In step S3, the transmitter control unit 12 sets the pressure detected by the pressure sensor 18 as the reference pressure. That is, the transmitter control unit 12 sets the pressure detected by the pressure sensor 18 when water comes into contact with the contact sensor 15 as the reference pressure.

[0023] Next, in step S4, the transmitter control unit 12 increases the acquisition frequency of obtaining the pressure from the pressure sensor 18. For example, the transmitter control unit 12 changes the acquisition frequency of obtaining the pressure from the pressure sensor 18 from the first frequency to the second frequency. The acquisition frequency is the number of times of obtaining the pressure from the pressure sensor 18 within a predetermined time. The second frequency is higher than the first frequency.

[0024] In step S5, the transmitter control unit 12 sets the pressure detected by the pressure sensor 18 as the pressure for flooding monitoring. The pressure for flooding monitoring is the pressure received by the pressure receiving part 19 from water when flooding occurs. The pressure for flooding monitoring is the pressure detected by the pressure sensor 18 after detecting the reference pressure.

[0025] Next, in step S6, the transmitter control unit 12 calculates the water level based on the reference pressure and the flood monitoring pressure. For every 1 cm rise in the water level, the pressure applied to the pressure sensor 18 increases by 0.1 kPa. Since the water level is 0 when water comes into contact with the contact sensor 15, the reference pressure can be considered as the pressure when the water level is 0 cm. Therefore, by dividing the difference between the reference pressure and the flood monitoring pressure by 0.1 kPa, the difference between the reference pressure and the flood monitoring pressure can be converted into the water level. In this way, the transmitter control unit 12 can calculate the water level at the location where the transmitter 11 is placed.

[0026] Next, in step S7, the transmitter control unit 12 transmits data including the calculated water level and ID code from the transmission circuit 20 to the water level monitoring device 31. In addition to increasing the acquisition frequency of the pressure sensor 18 in step S4, the transmitter control unit 12 may also increase the data transmission frequency.

[0027] In step S8, the transmitter control unit 12, if a reference pressure is set, cancels the setting of the reference pressure. If no reference pressure is set, it maintains that state. When the flooding subsides and the water level falls below the contact sensor 15, the setting of the reference pressure is canceled in step S8.

[0028] Next, in step S9, if the transmitter control unit 12 has set the acquisition frequency for acquiring pressure from the pressure sensor 18 to a high setting, it resets the acquisition frequency to its original value. That is, if the second frequency is set as the acquisition frequency, it resets the second frequency to the first frequency.

[0029] If the result of step S1 is negative, the transmitter control unit 12 does not have to send data to the water level monitoring device 31, or it may send data that includes information indicating that water is not in contact with the contact sensor 15. Also, if the transmission frequency is increased when the result of step S1 is positive, the transmission frequency may be returned to its original value. In this case, the transmitter control unit 12 may set the transmission frequency to 0, i.e., not send any data. If the transmission frequency is increased when the contact sensor 15 detects water contact, the data transmission interval may be shortened. Also, data may not be sent when water contact is not detected, and data may be sent only when water contact is detected.

[0030] <Water level monitoring device> As shown in Figure 2, the water level monitoring device 31 is a server. The water level monitoring device 31 comprises a receiving circuit 32 and a server control unit 33.

[0031] The receiving circuit 32 has a hardware configuration similar to that of the transmitting circuit 20, for example. The receiving circuit 32 communicates using the same communication standard as the transmitting circuit 20. This allows the transmitter 11 and the water level monitoring device 31 to exchange information with each other.

[0032] The hardware configuration of the server control unit 33 is, for example, the same as that of the transmitter control unit 12. The server control unit 33 includes, for example, a processor 34 and a storage unit 35. The server control unit 33 is an example of a control unit.

[0033] The server control unit 33 acquires the water level calculated by the transmitter 11 via the receiving circuit 32. This allows the server control unit 33 to recognize the water level. By pre-associating an ID code with the location of the transmitter 11, the server control unit 33 can recognize the water level for each location of the transmitter 11.

[0034] The server control unit 33 may provide the user terminal with water levels for each location of the transmitter 11 via at least one of a web browser, an application, and email. The water levels may be provided as text or as a heatmap corresponding to the water level height.

[0035] [Effects of this embodiment] (1) The reference pressure can be considered as the pressure when the water level is 0. As the water level rises, the flood monitoring pressure increases. Therefore, the difference between the reference pressure and the flood monitoring pressure can be said to have been caused by the rise in water level, and this difference can be converted to the water level. By using the contact sensor 15, the water level can be calculated using one pressure sensor 18.

[0036] By using one pressure sensor 18, power consumption can be reduced compared to using two pressure sensors. Furthermore, manufacturing costs can be reduced compared to using two pressure sensors.

[0037] When using two pressure sensors, one is used for detecting water pressure and the other for detecting atmospheric pressure. In this case, the pressure sensor for detecting atmospheric pressure needs to be placed at a high location where it will not be reached even if flooding occurs. Furthermore, if these pressure sensors are connected by wire, it will increase the size of the water level measurement system. In contrast, by using a single pressure sensor 18, it is not necessary to place the two pressure sensors far apart from each other. Therefore, the size of the water level measurement system 10 can be suppressed.

[0038] (2) The water level monitoring device 31 is a server, and the transmitter 11 transmits data to the server. Therefore, compared to the case where data is transmitted to the server via a relay device, the relay device can be omitted, and the number of parts can be reduced.

[0039] (3) When the contact sensor 15 detects contact with water, the transmitter control unit 12 increases the frequency of acquiring pressure from the pressure sensor 18. When water comes into contact with the contact sensor 15, there is a high probability that the water level will rise thereafter. For this reason, it is necessary to monitor the rise in water level at a high frequency. By keeping the frequency of acquiring pressure from the pressure sensor 18 low until water contact is detected by the contact sensor 15, the consumption of the battery 21 is suppressed, and by increasing the frequency of acquiring pressure once water contact is detected, the rise in water level can be monitored in detail.

[0040] (4) The pressure sensor 18 is positioned at the same height as the contact sensor 15. This reduces the difference between the timing at which water comes into contact with the contact sensor 15 due to the rise in water level and the timing at which water comes into contact with the pressure receiving section 19. Therefore, the accuracy of the reference pressure can be improved.

[0041] (5) When the contact sensor 15 detects contact with water, the transmitter control unit 12 increases the data transmission frequency. By keeping the transmission frequency low until the contact sensor 15 detects contact with water, the consumption of the battery 21 is suppressed, and by increasing the transmission frequency when contact with water is detected, the rise in water level can be monitored in detail.

[0042] (6) If the contact sensor 15 does not detect water contact, the transmitter control unit 12 transmits data to the contact sensor 15 that includes information indicating that water is not in contact with it. This allows the water level monitoring device 31 to recognize whether or not flooding is occurring.

[0043] [Example of changes] The embodiment can be implemented with the following modifications. The embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0044] The transmitter control unit 12 may transmit data including reference pressure and flood monitoring pressure instead of water level to the water level monitoring device 31. In this case, the water level monitoring device 31 can calculate the water level. For example, when the server control unit 33 obtains the reference pressure and flood monitoring pressure, it calculates the difference between the reference pressure and the flood monitoring pressure. The server control unit 33 then recognizes the water level by converting the difference between the reference pressure and the flood monitoring pressure into water level.

[0045] The transmitter control unit 12 may transmit data to the water level monitoring device 31 that includes the difference between the reference pressure and the flood monitoring pressure instead of the water level. In this case, the water level monitoring device 31 can calculate the water level. For example, when the server control unit 33 obtains the difference between the reference pressure and the flood monitoring pressure, it recognizes the water level by converting this difference into a water level.

[0046] The water level monitoring device may include a relay device and a server. The relay device receives data transmitted from multiple transmitters 11 and transmits it to the server. In this case, the water level may be calculated in the relay device.

[0047] The pressure sensor 18 may be positioned higher than the contact sensor 15. When flooding occurs, the water surface is rippling. Therefore, at the time when the contact sensor 15 detects water contact, the water level may not actually have reached the pressure receiving unit 19. By positioning the pressure sensor 18 higher than the contact sensor 15, the effect of waves can be reduced. In this case, the transmitter control unit 12 may correct the water level calculated according to the height difference between the pressure sensor 18 and the contact sensor 15. For example, if the pressure sensor 18 is positioned 1 cm higher than the contact sensor 15, 1 cm may be added to the calculated water level.

[0048] The pressure sensor 18 may be positioned lower than the contact sensor 15. In this case, the transmitter control unit 12 may correct the water level calculated according to the height difference between the pressure sensor 18 and the contact sensor 15. For example, if the pressure sensor 18 is positioned 1 cm lower than the contact sensor 15, 1 cm may be subtracted from the calculated water level.

[0049] The contact sensor 15 may be a float switch. The float switch includes a float that rises as the water level rises, and a reed switch that switches between on and off when the float rises. The transmitter control unit 12 detects water contact by the switching of the reed switch between on and off.

[0050] The transmitting circuit 20 may be a device that communicates with the water level monitoring device 31 via a wire. [Explanation of symbols]

[0051] 10...Water level measurement system, 11...Transmitter, 12...Control unit for transmitter, 15...Contact sensor, 18...Pressure sensor, 20...Transmission circuit, 31...Water level monitoring device, 32...Receiver circuit, 33...Server control unit, which is an example of a control unit.

Claims

1. Transmitter and Equipped with a water level monitoring device, The transmitter includes a contact sensor that detects contact with water, Pressure sensor and, A control unit for a transmitter that acquires pressure from the pressure sensor, The system includes a transmission circuit that transmits data to the water level monitoring device, The control unit for the transmitter is, The pressure detected by the pressure sensor when water comes into contact with the contact sensor is used as the reference pressure, and the pressure detected by the pressure sensor after the reference pressure has been detected is used as the water infiltration monitoring pressure. The transmission circuit transmits the data including the reference pressure and the flood monitoring pressure, the difference between the reference pressure and the flood monitoring pressure, or the value obtained by converting the difference into a water level. The water level monitoring device is, A receiving circuit that receives the aforementioned data, It comprises a control unit and, The control unit, A water level measurement system that recognizes the water level based on the aforementioned reference pressure, the aforementioned flood monitoring pressure, the aforementioned difference, or a value obtained by converting the aforementioned difference into a water level.

2. The water level monitoring device is a server, The water level measurement system according to claim 1, wherein the transmission circuit transmits the data to the server.

3. A contact sensor that detects contact with water, Pressure sensor and, A control unit for a transmitter that acquires pressure from the pressure sensor, It includes a transmission circuit that transmits data to a water level monitoring device that monitors the water level, The control unit for the transmitter is, The pressure detected by the pressure sensor when water comes into contact with the contact sensor is used as the reference pressure, and the pressure detected by the pressure sensor after the reference pressure has been detected is used as the water infiltration monitoring pressure. A transmitter that causes the water level monitoring device to recognize the water level by transmitting data from the transmission circuit, including the reference pressure, the flood monitoring pressure, the difference between the reference pressure and the flood monitoring pressure, or a value obtained by converting the difference into a water level.

4. The transmitter according to claim 3, wherein when the contact sensor detects contact with water, the transmitter control unit increases the frequency of acquiring the pressure from the pressure sensor.

5. The transmitter according to claim 3 or 4, wherein when the contact sensor detects contact with water, the transmitter control unit increases the frequency of data transmission.

6. The transmitter according to claim 3 or 4, wherein if the contact sensor does not detect contact with water, the control unit for the transmitter transmits the data including information indicating that water is not in contact with the contact sensor.

7. The transmitter according to claim 3 or 4, wherein the pressure sensor is positioned at the same height as the contact sensor.

8. The transmitter according to claim 3 or 4, wherein the pressure sensor is positioned higher than the contact sensor.

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