Water leakage detection system

Abstract

This water leakage detection system comprises a water meter provided for each consumer home, and a center server that can communicate with the water meter. The water meter has a flow rate measurement unit that is provided in a flow path through which water circulates and measures the flow rate of water circulating through the flow path, and a communication unit that performs communication with the center server. The center server has: a general communication unit that performs communication with the communication unit; a determination unit that when a flow rate, which is the measurement result obtained by the flow rate measurement unit, is at least a reference flow rate determined in advance on the basis of past use results or exceeds the reference flow rate, determines said flow rate as a water leakage assessment target flow rate; and a judgment unit that identifies whether the water of the water leakage assessment target flow rate is flowing for a prescribed reference duration or longer, and judges that there is water leakage when the water is flowing for the reference duration or longer.

Description

Water Leak Detection System

[0001] The present disclosure relates to a water leak detection system for detecting water leaks.

[0002] Conventionally, a control system has been known in which a control unit detects a water leak when it determines, based on the water flow rate measured by a water meter, that water has flowed through the waterworks for a predetermined continuous usable time, and notifies a waterworks information terminal or the like of the leak via a network (Patent Document 1).

[0003] JP 2023-123930 A

[0004] However, the above-mentioned conventional technology determines that a leak has occurred when water continues to flow after a specified continuous usable time has elapsed, but it was difficult to accurately determine whether a leak had occurred depending on the length of the continuous usable time setting.

[0005] Therefore, an object of the present disclosure is to provide a water leakage detection system that can improve the reliability of water leakage detection.

[0006] The water leak detection system disclosed herein is a water leak detection system comprising a water meter installed at each consumer's home and a center server capable of communicating with the water meter, wherein the water meter has a flow rate measurement unit installed in a flow path through which water flows and measures the flow rate of water flowing through the flow path, and a communication unit that communicates with the center server, and the center server has an integrated communication unit that communicates with the communication unit, a determination unit that determines the flow rate as a flow rate subject to water leak detection if the flow rate measured by the flow meter unit is equal to or exceeds a standard flow rate determined based on past usage records, and a determination unit that determines whether water at the flow rate subject to water leak detection has been flowing for a predetermined standard duration or longer, and determines that a water leak has occurred if the water has been flowing for the standard duration or longer.

[0007] According to the present disclosure, when the flow rate measured by the flowmeter unit is equal to or greater than the reference flow rate, the determination unit determines that flow rate as the flow rate subject to water leak detection. In other words, only when the measured flow rate is equal to or greater than the reference flow rate is the flow rate determined as the flow rate subject to water leak detection determined. Then, when water at the flow rate subject to water leak detection flows for a reference duration or longer, the determination unit determines that there is a water leak. This makes it possible to improve the reliability of water leak detection.

[0008] According to the present disclosure, it is possible to provide a water leakage detection system that can improve the reliability of water leakage detection.

[0009] Fig. 1 is a block diagram showing a water leak detection system according to one embodiment. Fig. 2 is a block diagram showing the detailed configuration of a customer's home and a center server in the water leak detection system of Fig. 1. Fig. 3 is a diagram showing the cumulative value of the hourly usage flow rate for each time period in a predetermined period in the past. (a) is a diagram showing the hourly usage flow rate for each time period on a certain day, and (b) is a diagram showing the hourly usage flow rate for each time period on a day different from the day in (a). Fig. 4 is a diagram showing the hourly usage frequency for each time period in a predetermined period in the past.

[0010] A water leak detection system according to an embodiment of the present disclosure will be described below with reference to the drawings. The water leak detection system described below is merely one embodiment of the present disclosure. Therefore, the present disclosure is not limited to the following embodiment, and additions, deletions, and modifications are possible within the scope of the present disclosure.

[0011] Fig. 1 is a block diagram showing a water leakage detection system 100 according to one embodiment. Fig. 2 is a block diagram showing the detailed configuration of a center server 10 and a customer's home 20 in the water leakage detection system 100 shown in Fig. 1. Fig. 3 is a diagram showing the cumulative value of hourly usage flow rate for a predetermined period in the past for each time period.

[0012] As shown in Fig. 1, the water leakage detection system 100 includes a center server 10 and a plurality of consumer homes 20. Although Fig. 1 illustrates four consumer homes 20, the water leakage detection system 100 may include three or fewer consumer homes 20, or five or more consumer homes 20. The water flow path leading to the consumer homes 20 is connected to a water purification plant, a reservoir, or the like.

[0013] As shown in Figure 2, each consumer home 20 is provided with a water meter 13. The water meter 13 has a flow meter unit 11 and a communication unit 12. The water meter 13 may also have a storage unit (not shown) that is made up of various types of memory or a hard disk. Examples of attributes of consumer homes 20 include, but are not limited to, ordinary households, hospitals, schools, municipal facilities, nursing homes, single-family homes, multi-generational homes, elderly housing, university dormitories, and commercial facilities, and any building that can use water may be used.

[0014] Examples of methods for acquiring data on the flow rate used from the water meter 13 are given below. As a first example, as shown in FIG. 2 , data is acquired from a water meter 13 having a flow meter side unit 11 and a communication unit 12 via the communication unit 12. In this case, a message related to the flow rate value (indicator value) measured by the flow meter side unit 11 is transmitted to the center server 10 via the communication unit 12. As a second example, data is acquired from a water meter 13 that has a flow meter side unit 11 but does not have a communication unit 12. In this case, the communication unit 12 is provided independently outside the water meter 13. Note that the flow meter side unit 11 in the first and second examples is, for example, an impeller type or an ultrasonic type.

[0015] A third example involves acquiring data from a water meter 13 that has a flow meter unit 11 capable of pulse output, a communication unit 12, and no battery. In this case, the communication unit 12 is provided external to the water meter 13, converts the pulse output value from the flow meter unit 11 into a pointer value, etc., and transmits it to the center server 10. A fourth example involves attaching an attachment to a water meter 13 that does not have a communication unit 12 or a battery. In this case, the pointer value displayed on the water meter 13 is photographed by a camera provided on the attachment, and the captured image is digitized using the OCR (Optical Character Reader) function of the attachment. This digitized data is then transmitted to the center server 10 via the communication function of the attachment. The flow meter unit 11 in the third and fourth examples is, for example, an impeller type.

[0016] In this embodiment, the flowmeter unit 11 is, for example, an ultrasonic flowmeter. The flow measurement unit 11 is provided in a flow path 11a through which water flows and measures the flow rate of water flowing through the flow path 11a. Specifically, the flowmeter unit 11 measures the water flow rate based on a propagation time calculated based on an ultrasonic signal transmitted from one of two ultrasonic transmitter-receivers and received by the other ultrasonic transmitter-receiver.

[0017] The communication unit 12 has a function of wirelessly communicating with the central communication unit 5 (described later) in the center server 10. The wireless communication method between the communication unit 12 and the central communication unit 5 of the center server 10 can be, for example, a communication network such as the Internet, LAN, LPWA (Low Power Wide Area), or WI-SUN. The communication unit 12 periodically (e.g., once a day) transmits information related to a guideline value, which is information about the water usage flow rate (consumption amount) at the consumer's home 20, to the central communication unit 5 along with date information regarding use or non-use (i.e., zero usage flow rate), an ID identifying the consumer's home 20, and location information for the consumer's home 20. The information related to the guideline value transmitted from the communication unit 12 to the central communication unit 5 includes, for example, 24 pieces of information. Each of these 24 pieces of information represents the water usage flow rate for each hour of the day. The location information may be provided in the center server 10.

[0018] The center server 10 has a determination unit 1, a judgment unit 2, a notification unit 3, a storage unit 4, and an integrated communication unit 5. Of the above components of the center server 10, the determination unit 1, the judgment unit 2, and the notification unit 3 are functionally realized by a microcontroller including a CPU (Central Processing Unit) and memory (ROM (Read Only Memory) and RAM (Random Access Memory)) that stores a program, or an ASIC (Application Specific Integrated Circuit), etc. The center server 10 may also be configured as a cloud system.

[0019] When the determination unit 2 (described later) determines that there is a water leak, the notification unit 3 notifies, for example, a waterworks company, etc. In response, the waterworks company, etc. will carry out inspection and repair work on the water pipe.

[0020] The storage unit 4 is composed of, for example, various types of memory, a hard disk, etc. The storage unit 4 stores information such as the water usage flow rate at the customer's home 20 received from the communication unit 12 of the customer's home 20 via the central communication unit 5.

[0021] The central communication unit 5 communicates with the communication unit 12 of each consumer's home 20. The communication method of the central communication unit 5 is the same as the above-mentioned communication method of the communication unit 12. The central communication unit 5 periodically (for example, once a day) receives information related to guideline values, which are information on the water usage flow rate (consumption amount) at the consumer's home 20, from the communication unit 12. The information received by the central communication unit 5 is stored in the memory unit 4.

[0022] When the water usage flow rate measured by the flowmeter unit 11 is equal to or greater than a predetermined reference flow rate, the determination unit 1 determines the usage flow rate as a leak detection target flow rate. The leak detection target flow rate refers to a flow rate that is used to determine whether or not there is a leak.

[0023] The determination unit 1 calculates the cumulative hourly flow rate (e.g., cumulative daily hourly flow rate) for each time period over a predetermined period of time in the past (e.g., one month) based on the water usage flow rate measured by the flowmeter unit 11. This yields information such as that shown in FIG. 3. In this case, the maximum flow rate (maximum hourly flow rate) over the predetermined period of time in the past, during the time period in which the cumulative hourly flow rate over the predetermined period of time is the smallest, is used as the reference flow rate. Specifically, 20 liters is used as an example of the reference flow rate. This value of 20 liters takes into account toilet usage.

[0024] 3, the time period in which the cumulative value of the hourly usage flow rate over one month is the smallest is 2:00 AM. The determination unit 1 obtains the maximum flow rate over one month at 2:00 AM based on the measurement results by the flowmeter unit 11. Then, if the water usage flow rate measured by the flowmeter unit 11 is equal to or greater than the maximum flow rate obtained above, the determination unit 1 determines that the usage flow rate is the flow rate subject to water leak detection.

[0025] The determination unit 2 determines whether water at the leak detection target flow rate has been flowing for a predetermined reference duration or longer. If water at the leak detection target flow rate has been flowing for the reference duration or longer, the determination unit 2 determines that there is a leak downstream. The reference duration is a time determined based on the duration of time during which the flow rate used per hour has continued to be equal to or greater than the minimum value of the flow rate used per hour over a predetermined period of time in the past (e.g., one month). For example, if the flow rate used per hour has continued to be equal to or greater than the minimum value of the flow rate used per hour over a one-month period for 20 consecutive hours during that month, the reference duration may be set to 24 hours, etc. The reference duration may be determined by the user, or may be determined by learning using an artificial intelligence function provided in the determination unit 2.

[0026] A reference flow rate Qth may be adopted that takes into account a margin (surplus) α relative to the above-mentioned maximum flow rate. In this case, if the above-mentioned maximum flow rate is Qmax, the reference flow rate Qth is expressed as Qmax × (1 + α). The margin α may be set appropriately based on the attributes of each consumer home 20 or the daily variation in flow rate used at each consumer home 20. The margin α is a variable that is set based on the length of the learning period by the artificial intelligence function of the determination unit 2. If the learning period is longer, the reliability of the leak determination by the determination unit 2 increases, and therefore the margin α can be set larger.

[0027] Here, as an aspect related to a modified example, when the minimum flow rate per hour for each day based on the measurement results by the flowmeter side unit 11 exceeds the reference flow rate, the determination unit 1 may determine the minimum flow rate as the flow rate subject to water leakage detection. Figure 4(a) is a diagram showing the flow rate usage per hour for each time period on a certain day, and (b) is a diagram showing the flow rate usage per hour for each time period on a day different from the day in (a).

[0028] In this embodiment, the reference flow rate is 0 m ３The determination unit 1 obtains the hourly usage flow rate for each time period for a certain day based on the measurement results by the flowmeter unit 11. The determination unit 1 then obtains the maximum and minimum values ​​of the obtained hourly usage flow rate. As a specific example, as shown in FIG. 4(a), the determination unit 1 obtains the usage flow rate of 0.558 m3 at 6:00 p.m. on a certain date. ３ is taken as the maximum value, and the flow rate is 0 m at 1:00 and 3:00 on the same day. ３ As shown in FIG. 4B, the determining unit 1 obtains a minimum flow rate of 0.603 m3 at 15:00 on month and day. ３ is taken as the maximum value, and the flow rate used at 22:00 on the same day is 0.03 m ３ In this case, the determination unit 1 acquires the minimum value of the flow rate used of 0.03 m on △ month and △ day at 22:00. ３ is determined as the leakage detection target flow rate.

[0029] Then, the determination unit 2 determines the leakage determination target flow rate (i.e., 0 m ３ The determination unit 2 determines whether or not the water (usage flow rate exceeding 0 m) has been flowing for a reference duration, for example, a predetermined number of days (or a predetermined time). ３ If a water usage rate exceeding this is detected for two consecutive days, it is determined that there is a leak.

[0030] In the above, the determining unit 1 has been described as acquiring the maximum flow rate in a predetermined period in the time period in which the cumulative value of the hourly usage flow rate in the past is the smallest, as the reference flow rate. However, a modified example will now be described. Fig. 5 is a diagram showing the hourly usage frequency for each time period in the past.

[0031] The determination unit 1 calculates the hourly usage frequency for each time period over a predetermined period (e.g., one month) based on the water usage flow rate measured by the flowmeter unit 11. This results in information such as that shown in FIG. 5 . In this case, the reference flow rate is the maximum flow rate (maximum hourly flow rate) over the predetermined period during the minimum time period, which is the time period during which the hourly usage frequency over the predetermined period is the lowest. The usage frequency is a ratio calculated for each time period and is the ratio of the total number of days in the predetermined period (e.g., 30 days) on which the hourly usage flow rate exceeds zero to the total number of days included in the predetermined period. To explain the usage frequency using an example shown in FIG. 5 , assume that there are two days during the 30-day period when the usage flow rate exceeds zero at 2:00 a.m. In this case, the usage frequency is calculated as 2 / 30, resulting in approximately 7%.

[0032] In Fig. 5, the minimum time period is 2:00 AM. The determination unit 1 obtains the maximum flow rate over 30 days at 2:00 AM based on the measurement results from the flowmeter unit 11. Then, when the water usage flow rate measured by the flowmeter unit 11 is equal to or greater than the maximum flow rate obtained above, the determination unit 1 determines that the usage flow rate is the flow rate subject to water leak detection.

[0033] As described above, the determination unit 1 acquires, as the reference flow rate, the maximum flow rate during a time period in which the cumulative value of the hourly usage flow rate during that time period is the smallest, or the maximum flow rate during a time period in which the frequency of usage during that time period is the smallest. When the continuous water usage time is equal to or longer than a predetermined time (e.g., 25 hours), the determination unit 1 can adopt either of the two maximum flow rates. This can shorten the time required to determine whether or not there is a water leak, even in cases where the continuous usage time tends to be relatively long, such as for industrial water, where the time required for the determination may be long.

[0034] On the other hand, instead of or in addition to performing a water leak determination using the two maximum flow rates as the reference flow rate, a water leak determination may be performed using the maximum time of continuous water usage over a predetermined period in the past. In this case, the determination unit 1 obtains the water usage flow rate from the flowmeter unit 11 and obtains the continuous usage time based on the usage flow rate. The determination unit 2 may then compare the continuous usage time with the maximum time and determine that a water leak has occurred if the continuous usage time exceeds the maximum time. In this embodiment, a margin (allowance) α may be taken into account for the maximum time, just as in the above embodiment in which a reference flow rate Qth is used that takes into account a margin (allowance) α for the maximum flow rate.

[0035] As described above, according to the water leak detection system 100 of this embodiment, when the flow rate measured by the flowmeter unit 11 is equal to or greater than the reference flow rate, the determining unit 1 determines that flow rate as the flow rate subject to water leak detection. In other words, when the measured flow rate is equal to or greater than the reference flow rate, the flow rate is determined as the flow rate subject to water leak detection for the first time. Then, when water at the flow rate subject to water leak detection flows for a reference duration or longer, the determining unit 2 determines that there is a leak. This makes it possible to improve the reliability of water leak detection.

[0036] In this embodiment, the water meter 13 may be, for example, an electronic meter. In this case, the hourly flow rate (accumulated amount) may be calculated in the water meter 13 as described above. The water meter 13 may also be, for example, a mechanical meter capable of pulse output. In this case, a wireless device externally connected to the water meter 13 converts the pulse output value from the water meter 13 to calculate the hourly flow rate. Furthermore, all indicator values ​​measured by the flow meter unit 11 may be transmitted to the center server 10, and the center server 10 may calculate the hourly flow rate.

[0037] Although several modifications have been given in the above-described embodiment, the following modifications can also be adopted without departing from the gist of the present disclosure.

[0038] In the above embodiment, the determination unit 1 and the judgment unit 2 are provided in the center server 10, but the present invention is not limited to this. The determination unit 1 and the judgment unit 2 may also be provided in the water meter 13.

[0039] In the above embodiment, the reference duration may be shortened or extended depending on the reference flow rate.

[0040] In the above embodiment, if the stop of water use is detected before the notification by the notification unit 3, the notification may not be made.

[0041] In addition, in the above embodiment, when using as the reference flow rate either the maximum flow rate during a specified period in the time zone in which the cumulative value of the hourly usage flow rate during a specified period in the past is the smallest, or the maximum flow rate during a specified period in the minimum time zone in which the frequency of usage per hour during a specified period in the past is the smallest, the one maximum flow rate may be selected based on the attributes of the consumer's home 20.

[0042] Furthermore, in the above embodiment, of the maximum flow rate during a specified period in the past during a time period when the cumulative value of the hourly usage flow rate during that specified period is the smallest, and the maximum flow rate during a specified period in the past during a minimum time period when the frequency of usage per hour during that specified period is the smallest, the former maximum flow rate may be used as the reference flow rate in the early stages of use of the water meter 13.

[0043] (Additional Notes) The above description of the embodiments discloses the following techniques.

[0044] (Technology 1) A water leak detection system comprising a water meter provided at each consumer's home and a center server capable of communicating with the water meter, wherein the water meter has a flow rate measurement unit provided in a flow path through which water flows and measures the flow rate of water flowing through the flow path, and a communication unit that communicates with the center server, and the center server has an integrated communication unit that communicates with the communication unit, a determination unit that determines the flow rate as a flow rate subject to water leak detection if the flow rate measured by the flow meter unit is equal to or exceeds a predetermined standard flow rate, and a determination unit that determines whether water at the flow rate subject to water leak detection has been flowing for a predetermined standard duration or longer, and determines that a leak has occurred if the water has been flowing for the standard duration or longer.

[0045] With this configuration, when the flow rate measured by the flowmeter unit is equal to or greater than the reference flow rate, the determination unit determines that flow rate as the flow rate subject to leak detection. In other words, only when the measured flow rate is equal to or greater than the reference flow rate is the flow rate determined as the flow rate subject to leak detection. Then, when water at the leak detection flow rate flows for a reference duration or longer, the determination unit determines that there is a leak. This makes it possible to improve the reliability of leak detection.

[0046] (Technology 2) A water leak detection system according to Technology 1, wherein the reference flow rate is the maximum flow rate during a predetermined period of time in the past, during a time period when the cumulative value of the hourly flow rate during the predetermined period of time is the smallest.

[0047] This configuration significantly improves the reliability of water leak detection. In addition, since it is difficult to calculate the frequency of water use in the early stages of use of the flow meter side of the water meter, the maximum flow rate can be effectively used as the reference flow rate in such cases.

[0048] (Technology 3) A water leak detection system according to Technology 1, wherein the reference flow rate is the maximum flow rate during a predetermined period in the past during a time period when the frequency of use per hour during that period is the lowest.

[0049] This configuration can significantly improve the reliability of water leakage detection.

[0050] (Technology 4) The water leak detection system described in Technology 3, wherein the frequency of use is a ratio calculated for each time period, and is the ratio of the total number of days on which the hourly flow rate exceeds zero to the total number of days included in the specified past period.

[0051] This configuration makes it easier to clarify the water usage trends at the customer's home, thereby improving the accuracy of water leak detection.

[0052] (Technology 5) A water leak detection system according to Technology 3, wherein the determination unit uses the maximum flow rate as the reference flow rate when the continuous water usage time measured by the flow rate measurement unit is equal to or longer than a predetermined time.

[0053] This configuration can reduce the time required to determine whether or not there is a leak.

[0054] (Technology 6) A water leak detection system described in any one of technologies 1 to 5, wherein the reference duration is a time determined based on the duration during which the flow rate used continues to be equal to or greater than the minimum flow rate used per hour during a specified period in the past.

[0055] This configuration can further improve the accuracy of water leakage detection.

[0056] (Technology 7) A water leak detection system described in any one of technologies 1 to 6, wherein the determination unit determines the minimum flow rate as the flow rate to be subject to leak detection when the minimum flow rate per hour per day based on the measurement results by the flow meter unit exceeds the reference flow rate, and the judgment unit determines whether water at the flow rate to be subject to leak detection has been flowing for a predetermined number of days or more as the reference duration, and determines that there is a leak if the water has been flowing for the predetermined number of days or more.

[0057] This configuration makes it easier to identify the presence or absence of water leakage on a daily basis.

[0058] (Technology 8) A water leak detection system described in any one of technologies 1 to 7, wherein when the flow rate measured by the flow meter side unit is equal to or exceeds the standard flow rate, the determination unit determines the flow rate to be subject to water leak detection to be the flow rate plus a predetermined margin based on the attributes of the consumer's home or the daily flow rate variation at the consumer's home.

[0059] When the period of past usage history that can be obtained is short, the reliability of the judgment of the judgment unit regarding the presence or absence of a water leak may be relatively low. However, by setting the flow rate subject to water leak judgment to the flow rate obtained by adding a predetermined margin to the flow rate as in the above configuration, it is possible to prevent or suppress erroneous judgment of the presence or absence of a water leak by the judgment unit in each consumer's home.

[0060] REFERENCE SIGNS LIST 1 determination unit 2 judgment unit 3 notification unit 4 storage unit 5 general communication unit 10 center server 11 flow meter side unit 11a flow path 12 communication unit 13 water meter 20 customer's house 100 water leakage detection system

Claims

1. A water leak detection system comprising a water meter installed at each consumer's home and a center server capable of communicating with said water meter, wherein said water meter has: a flow measurement unit installed in a flow path through which water flows and measuring the flow rate of water flowing through said flow path; and a communication unit for communicating with said center server, and said center server has: an integrated communication unit for communicating with said communication unit; a determination unit for determining, when the flow rate measured by said flow meter unit is equal to or exceeds a standard flow rate determined based on past usage records, that the flow rate is a flow rate subject to water leak detection; and a determination unit for determining whether water at the flow rate subject to water leak detection has been flowing for a predetermined standard duration or longer, and determining that a water leak has occurred if the water has been flowing for the standard duration or longer.

2. A water leak detection system as described in claim 1, wherein the reference flow rate is the maximum flow rate during a specified period of time in the past during the time period when the cumulative value of the hourly flow rate used during the specified period of time is the smallest.

3. A water leak detection system as described in claim 1, wherein the reference flow rate is the maximum flow rate during a predetermined period in the past during a time period when the frequency of use per hour during the predetermined period is the lowest.

4. The water leak detection system of claim 3, wherein the frequency of use is a ratio shown for each time period, and is the ratio of the total number of days in which the hourly flow rate exceeds zero to the total number of days included in the specified past period.

5. A water leak detection system as described in claim 3, wherein the determination unit uses the maximum flow rate as the reference flow rate when the continuous water use time measured by the flow rate measurement unit is equal to or longer than a predetermined time.

6. A water leak detection system as described in claim 1, wherein the reference duration is determined based on the duration during which the flow rate used per hour is equal to or greater than the minimum value of the flow rate used per hour during a specified period in the past.

7. The water leak detection system according to claim 1, wherein the determination unit determines the minimum flow rate as the flow rate subject to leak detection when the minimum flow rate per hour per day based on the measurement results from the flow meter unit exceeds the reference flow rate, and the judgment unit determines whether water at the flow rate subject to leak detection has been flowing for a predetermined number of days or more as the reference duration, and determines that a leak has occurred if the water has been flowing for a predetermined number of days or more.

8. The water leak detection system of claim 1, wherein when the flow rate measured by the flow meter side unit is equal to or exceeds the standard flow rate, the determination unit determines the flow rate to be subject to water leak detection to be the flow rate to which a predetermined margin is added based on the attributes of the consumer's home or the daily flow rate fluctuations at the consumer's home.

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