JP7177584B2 - Water usage time measuring device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a device for measuring the continuous usage time of tap water.

In order to detect water leaks due to forgetting to tighten the water faucet or loose water pipe joints, it is necessary to determine whether the changes in pressure and flow velocity that occur in the water pipe are due to normal water use. It is necessary to examine whether or not Therefore, we monitor the usage of water in the home using pressure sensors and flow rate sensors, and if we detect that the water is being used for more than a predetermined amount of time, which is unpredictable for domestic use, we determine that there is a water leak. can be considered.

U.S. Pat. No. 6,216,267

However, in general households, water may be used at a plurality of locations at the same time. Therefore, in the case of the above assumed technology, the continuous use time of water is from the time when the use of water is started at the first place to the time when the use of water is finished at the last place. As a result, there is a possibility that the water leakage determination time set in advance may be exceeded and the water leakage may be erroneously determined against the user's intention.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to appropriately determine the continuous water usage time for judging the state of forgetting to turn off the faucet even when water is used in a plurality of places at the same time. To provide a water supply usage time measuring device capable of measuring.

According to the water supply usage time measuring device of claim 1, the control unit monitors the water pressure or flow velocity in the water pipe via the pressure sensor or the flow velocity sensor arranged in the water pipe. Then, the sensor signal output from the sensor is sampled at predetermined intervals to obtain the differential value and variance value of the signal. When it is determined that the use of water has started at any water supply point by evaluating the differential value and the variance value, the counter starts counting operation, and it is determined that the use of water has ended at any water supply point. Clear the counter if This measures the continuous use time of water.

In a water pipe where water is used at multiple locations, if it is detected that the water pressure has decreased or the flow velocity has increased and the variation in the pressure or flow velocity has decreased, whether the use of water has started at another location or Alternatively, it can be determined that the amount of water used has increased at the same location. Conversely, if it is detected that the water pressure has increased or the flow velocity has decreased, and the variation in pressure or flow velocity has increased, it can be determined that the amount of water used at a certain location has decreased. Furthermore, if it is detected that the water pressure has increased or the flow velocity has decreased and the variation in the pressure or flow velocity has decreased, it can be determined that the use of water at a certain point has ended.

The "continuous use time of water" in the present invention is time measured by a counter as follows.
- Measurement is started when water is started to be used at at least one of the plurality of water supply points.
・After that, if the number of places where water is used increases, continue to measure.
・When it is determined that the number of places where water is used has decreased, the measurement is cleared at that point, and then the measurement is resumed.

Therefore, the "continuous use time of water" is defined as, in the case where the use of water is started at multiple places without interruption after the start of use of water at any one place, the last remaining use of water is It is the continuous use time of water at the location. That is, if the control unit controls the operation of the counter as described above, it is possible to avoid measuring the state in which the user intentionally uses water at a plurality of locations at the same time as the "continuous use time". Then, a state in which the faucet is left untightened at the last point can be measured as the continuous use time.

According to the water supply usage time measuring device of claim 2, after the control unit determines that water use has started and starts the counting operation of the counter, the variance value is equal to or less than the water pressure stability determination threshold value. If so, the counter is cleared when the differential value exceeds the clear determination threshold, which is a positive value . Further, when the variance value exceeds the hydraulic stability determination threshold value, the differential value exceeds the clear determination threshold value , and the variance value recalculated by acquiring the sensor signal is the variance value before recalculation. Clear the counter when exceeded.

Here, the amount of water used is classified into three levels of "large", "medium", and "small" for convenience. When the amount of water used in the water service is "large", the variation in pressure or flow velocity is relatively small. Therefore, when the amount of use is in the state of "medium", it becomes more difficult to determine whether the amount of use is increased or decreased based on that state. Therefore, by comparing the variance value of the sensor signal with the water pressure stability determination threshold value, it is determined whether the amount of water used is "large" or "medium", and the conditions for clearing the counter are changed according to the determination result.

That is, if the dispersion value is equal to or less than the water pressure stability determination threshold value, it can be determined that the amount of water used is "large", so the counter is cleared only under the condition that the differential value exceeds the clear determination threshold value. Also, if the dispersion value exceeds the hydraulic stability determination threshold, it can be determined that the amount of water used is "medium". In this case, in addition to the condition that the differential value exceeds the clear determination threshold value, the counter is cleared under the condition that the variance value recalculated by acquiring the sensor signal exceeds the variance value before recalculation. As a result, even when the amount of water used is "medium", it is possible to detect a change in the amount of water used to decrease and clear the counter.

According to the water supply usage time measuring device according to claim 3, the control unit sets the differential value to be lower than the use determination threshold value for the differential value, which is a negative value , and the variance value to be lower than the water pressure stability determination threshold value. It is determined that the use of water has started when the use determination threshold value for the variance value is exceeded, and the counter starts counting operation. In other words, when the water starts to be used, the water pressure usually decreases or the flow velocity increases compared to the state before the start of use. It may reach. When transitioning from "before use" to "after use", the dispersion value of the sensor signal changes relatively greatly. can be done.

1 is a functional block diagram showing the configuration of a water leakage detection system according to an embodiment; FIG. A diagram showing an example of changes in pressure and flow rate in a water supply system with three water supply points when the number of points where water is used increases in sequence. Flowchart showing water use determination processing executed by the controller Flowchart showing water leakage determination processing Flowchart showing continuous use time determination processing A diagram showing an example of a change in water pressure and a counting operation by a counter when the usage condition of a water supply with three water supply points A, B, and C changes.

An embodiment will be described below with reference to the drawings. FIG. 1 is a functional block diagram showing the configuration of a water leakage detection system. A water pipe 1 is for supplying water to a general household, for example, and a solenoid valve 2 and a pressure sensor 3 are arranged in the middle of the pipe. Here, 1a is the water pipe on the upstream side of the solenoid valve 2, that is, on the water source side, 1b is the water pipe between the solenoid valve 2 and the pressure sensor 3, and 1b is the water pipe on the downstream side of the pressure sensor 3, that is, on the home side. is 1c. The tip of the water pipe 1c is branched into a plurality of pipes for supplying water to various parts in the home such as a washroom, a kitchen and a toilet. A terminal portion of the water pipe 1c is closed by a water supply valve or the like such as a faucet (not shown) when the water supply is not in use.

The solenoid valve 2 switches the water pipe 1 between a fully closed state and a fully opened state, and the opening/closing control is performed by the controller 4 . The controller 4 is composed of, for example, a microcomputer or the like, and includes a software counter 5 for measuring the continuous use time of the water supply. A sensor signal output from the pressure sensor 3 is input to the controller 4 . A display device 6 is also connected to the controller 4 . The display device 6 is installed, for example, on the wall surface of the house, and displays the status information of the water pipe 1 grasped by the controller 4 using symbols, text messages, and the like.

Further, the controller 4 has a wireless communication function, and notifies the user by transmitting the information displayed on the display device 6 to, for example, a smart phone owned by the user. Only one of the display device 6 and the function of notifying information by wireless communication may be provided. A battery may be used as the driving power source for each of these components, or a power source circuit connected to a commercial AC power source may be used. In the configuration described above, the pressure sensor 3 and the controller 4 correspond to the water supply usage time measuring device.

Next, the operation of this embodiment will be described. Fig. 2 shows, for example, in a water supply with three water supply points,
Section (0): Before starting use → Section (1): Use one place → Section (2): Use two places →
Interval (3): This shows an example of changes in the pressure P and the flow rate Q when the number of places where they are used increases in sequence, such as when three places are used. As the flow rate Q gradually increases from Q0, which is _zero , to _{Q3 ,} the pressure P gradually decreases from the initial value P0 to _P3 .

Here, when the dispersion values of the pressure P corresponding to the sections (0) to (3) are assumed to be S ₀ to S ₃ respectively, and the magnitude relationship between these values is evaluated, as the flow rate Q increases, the pressure P decreases. As a result, the variance value S also becomes smaller. That is, when the faucet is not opened at all and the faucet is not used, there is no pressure drop in the first place, so the pressure dispersion value S0 is extremely small and is substantially _zero .

When the _first faucet is opened from this state, the pressure starts to drop from the high pressure _P0 and becomes unstable, and the variance value S1 increases. Furthermore, when the _second and _third faucets are opened, the pressure decreases sequentially from medium pressure P1 to P2 and _P3 . As a result, the range of reduction in pressure becomes narrower, so that the low pressures P ₂ and P ₃ are relatively stable and the dispersion values S ₂ and S ₃ become small. That is, the pressure dispersion value is large when the range of pressure that can be varied is large, such as when the first faucet is open, and is small when the range of pressure that can be varied is small, such as when the second and third faucets are open. becomes smaller in some cases. Therefore, by monitoring the pressure variance, it is possible to detect whether a new faucet has been opened in the presence of already opened faucets, or whether one of the previously open faucets has been closed.

Also, the variance values S ₂ and S ₃ of the sections (2) and (3) are substantially equal. In other words, when the amount of water used increases further from a state in which a certain amount of water is flowing and the change in pressure or flow velocity is stable, the difference between before and after the change in water volume is the pressure value or flow velocity value. Only the difference in absolute value is obtained, and there is no significant difference in variance.

Since the dispersion value S0 of the pressure P in the section ( ₀ ) in which water is not used is extremely small, the threshold value of the dispersion value for judging that water is not used _, which is the dispersion values _S3 and S0 in FIG. By providing a threshold value, it is possible to determine whether the use of water has ended completely or only at some locations.

In addition, since the differential value of pressure indicates the magnitude of change in pressure, the differential value indicates a significant change at the timing when the amount of water used increases or decreases. Therefore, by evaluating a combination of the differential value and the variance value of pressure, it is possible to more reliably determine when the use of water started, when the amount of water used increased or decreased, and when the use of water finally ended. can be distinguished.

FIG. 3 is a flow chart showing the water usage determination process executed by the controller 4. As shown in FIG. First, the sensor signal of the pressure sensor 3 is A/D converted and read (S1), and the differential value of the pressure value is calculated (S2). A sampling interval of the sensor signal is, for example, 0.2 seconds. Then, the differential value is compared with a negative threshold (S3). If the differential value is greater than or equal to the threshold (NO), the process returns to step S1. On the other hand, if the differential value is less than the threshold value (YES), the variance value _SS of the pressure values is calculated (S4), and the variance value _SS is compared with the threshold value for determining water usage (S5). The threshold is set to, for example, about "0.004". If the variance value is equal to or less than the threshold value (NO), the process returns to step S1, and if the variance value exceeds the threshold value (YES), water leakage determination processing is executed (S6).

FIG. 4 is a flowchart showing water leakage determination processing. First, the count value t of the continuous use time of water measured by the counter 5 is incremented (S11). Then, the sensor signal of the pressure sensor 3 is A/D converted and read (S12), and the dispersion value _S0 of the pressure values is calculated (S2). It should be noted that this has nothing to do with the variance value S0 shown in FIG. ₂ , and the same applies to subsequent variance values with the same sign. Then, the variance value _S0 is compared with the threshold value for judging water usage (S14), as in step S5.

If the variance value S0 is equal to or less than the threshold value (NO), the counter ₅ is cleared (S18), and the process proceeds to the water usage determination process shown in FIG. 3 (S19). On the other hand, if the variance value _S0 exceeds the threshold value (YES), continuous use time determination processing is performed (S15). When this process is executed, the count value t of the counter 5 is compared with the threshold value for water leakage determination (S16), and if the count value t is equal to or less than the threshold value (NO), the process proceeds to step S11. On the other hand, if the count value t exceeds the threshold (YES), it is determined that there is water leakage (S17). In this case, the controller 4 closes the electromagnetic valve 2, causes the display device 6 to display that effect, and performs water leakage countermeasure processing such as wirelessly notifying the user's smart phone of that effect.

FIG. 5 is a flow chart showing the continuous use time determination process. First, the differential value ΔP of the pressure value is calculated (S21), and the variance value _S0 is compared with the threshold value for judging hydraulic stability (S22). The threshold is set to, for example, about "0.02". If the variance value _S0 is equal to or less than the threshold value (NO), it is determined that the amount of water used is "large". Then, the differential value ΔP is compared with a positive threshold value (S28), and if the threshold value is exceeded (YES), it is determined that the amount of water used has decreased, and the counter value t of the counter 5 is cleared (S27). End the process. If the differential value ΔP is equal to or less than the threshold (NO), the process is terminated.

On the other hand, in step S22, if the variance value _S0 exceeds the threshold (YES), it is determined that the amount of water used is "medium". In this case, the same determination as in step S28 is made (S23), and if the differential value ΔP is equal to or less than the threshold value (NO), the process ends. If the differential value ΔP exceeds the threshold (YES), the sensor signal from the pressure sensor ₃ is read again (S24), and its variance S1 is calculated (S25). Then, the variance values S ₁ and S ₀ are compared (S26), and if (S ₁ ≤ S ₀ ) (NO) the process is terminated, and if (S ₁ >S ₀ ) (YES) go to step S27 Transition.

FIG. 6 shows an example of the change in water pressure and the counting operation of the counter 5 when the use condition of water supply points A, B, and C changes by executing the above processing. The counting operation by the counter 5 is continued when the number of places where water is used increases in order of A→(A+B)→(A+B+C). On the other hand, the counting operation is reset at the time when the number of places where water is used decreases in order of (A+B+C)→(A+B)→A. Therefore, finally, the continuous use time t for the only remaining water supply point A is counted. Then, when the continuous use time t exceeds the threshold value, "YES" is obtained in step S16 in the water leakage determination process, and water leakage is detected. Then, the controller 4 performs water leakage countermeasure processing in step S27.

As described above, according to the present embodiment, the controller 4 detects the pressure in the water pipe 1 via the pressure sensor 3 arranged in the water pipe 1 on the upstream side of the branch point where the pipes heading for a plurality of water supply points branch. monitor water pressure. Then, by sampling the sensor signal output from the pressure sensor 3 at predetermined intervals, the differential value and variance value of the signal are obtained. The differential value and the variance value are evaluated, and when it is determined that the use of water has started at any water supply point, the counter 5 is caused to start the counting operation, and when it is determined that the use of water has ended at any water supply point. Clear counter 5. Thereby, the continuous use time t of water is measured.

As a result, in the case where the use of water is started at a plurality of places without interruption after the time when the use of water is started at any one place, the continuous use time t is the last remaining place of use. It is the continuous use time of water in Therefore, if the controller 4 controls the operation of the counter 5 as described above, it is possible to avoid measuring the state in which the user intentionally uses water at a plurality of places at the same time as the "continuous use time." Then, a state in which the faucet is left untightened at the last point can be measured as the continuous use time t.

Specifically, when the controller 4 determines that the use of water has started and starts the counting operation of the counter ₅ , if the variance value S0 is equal to or less than the water pressure stability determination threshold value, the differential value ΔP If the positive clear determination threshold is exceeded, the counter 5 is cleared. Further, if the variance value S ₀ exceeds the hydraulic stability determination threshold value, the differential value ΔP exceeds the positive clear determination threshold value, and the variance value S ₁ recalculated by acquiring the sensor signal is If it exceeds the pre-calculated variance value S0, the counter ₅ is cleared.

That is, if the dispersion value _S0 is equal to or less than the water pressure stability determination threshold value, it can be determined that the amount of water used is "large", so the counter 5 is cleared only under the condition that the differential value ΔP exceeds the clear determination threshold value. Further, if the dispersion value _S0 exceeds the hydraulic stability determination threshold, it can be determined that the amount of water used is "medium". In this case, in addition to the condition that the differential value ΔP exceeds the clear determination threshold value, the counter ₅ is cleared under the condition that the variance value S1 recalculated by acquiring the sensor signal exceeds the variance value _S0 . As a result, even when the amount of water used is "medium", the counter 5 can be cleared by capturing the change in the direction of decreasing the amount of water used.

In addition, the controller 4 determines that the use of water has started when the differential value ΔP is below the negative use determination threshold and the dispersion value _SS exceeds the use determination threshold set lower than the water pressure stability determination threshold. to cause the counter 5 to start counting. In other words, when the water starts to be used, the water pressure usually decreases or the flow velocity increases compared to the state before the start of use. It may reach. When transitioning from "before use" to "after use", the variance value _SS of the sensor signal changes relatively greatly. It can be carried out.

The present invention is not limited to the embodiments described above or illustrated in the drawings, but can be modified or expanded as follows.
Whether to start using water may be determined based on only the differential value of the pressure or based on the absolute value depending on the required accuracy.
A flow velocity sensor may be used in place of the pressure sensor 3, and similar use time measurement may be performed based on the flow velocity instead of the pressure.
The specific numerical values of the threshold for determining water usage and the threshold for determining hydraulic stability may be appropriately set according to the system to be applied under the condition that the former is smaller than the latter.

In the drawings, 1 is a water pipe, 2 is an electromagnetic valve, 3 is a pressure sensor , 4 is a controller, 5 is a counter, and 6 is a display.

Claims (3)

a pressure sensor or flow velocity sensor placed in the water pipe;
a counter for measuring water usage time;
A water service usage time measuring device comprising a control unit for measuring continuous water usage time,
The control unit
sampling the sensor signal output from the pressure sensor or the flow velocity sensor at predetermined intervals to obtain a differential value and a variance value of the sensor signal;
When it is determined that the use of water has started at any water supply point by evaluating the differential value and the variance value, the counter starts the counting operation, and the use of water has ended at any water supply point. A water supply usage time measuring device that clears the counter when it is determined that After determining that the use of water has started and causing the counter to start counting,
if the variance value is equal to or less than the hydraulic stability determination threshold value, clearing the counter when the differential value exceeds a clear determination threshold value that is a positive value ;
When the variance value exceeds the hydraulic stability determination threshold value, the differential value exceeds the clear determination threshold value , and the variance value recalculated by acquiring the sensor signal is the variance value before recalculation 2. The water service usage time measuring device according to claim 1 , wherein the counter is cleared when the time exceeds. The control unit is configured such that the differential value is below a differential value use determination threshold value that is a negative value, and the variance value is a variance value use determination threshold value that is set lower than the hydraulic stability determination threshold value. 3. The water supply usage time measuring device according to claim 2, wherein it is determined that the use of water has been started when the time exceeds , and the counter starts counting operation.

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