Remote monitoring of water distribution system
A liquid monitoring system includes a remote measurement device located at a location of the fire hydrant that is in contact with water provided by a water main. The remote measurement device has sensors that measure characteristics of the water, energy characteristics and/or acoustic vibrations in the water and a communication interface that transmits measured information to a communication network device that may be located elsewhere on the fire hydrant. The communication network device communicates measurements, including event-related data, with a communication network to a central monitoring system.
1 . A method for detecting energy characteristics in a water distribution system, the method comprising:
continuously sampling water pressure with a pressure sensor in a fire hydrant of the water distribution system, the pressure sensor positioned in contact with water of the water distribution system, and wherein the pressure sensor samples the water pressure at a predetermined sample rate of at least 64 samples per second;
determining whether a value of the sampled water pressure satisfies a trigger condition for the water distribution system;
storing the values of the sampled water pressure in a first buffer until an energy pulse event based on the trigger condition is declared, wherein the first buffer is a circular buffer having a predetermined number of cells to store the values of the sampled water pressure, and the individual stored values of sampled water pressure in a corresponding cell of the predetermined number of cells are replaced after a predetermined time period has elapsed, such that a stored value is replaced at least 64 times every second once the predetermined number of cells in the circular buffer have been filled;
locking the first buffer and storing the values of the post-event sampled water pressure in a second buffer upon the energy pulse event having been declared;
collecting and storing additional values of sampled water pressure in the second buffer, after the energy pulse event has been declared, until the second buffer has been filled with values of post-event sampled water pressure; and
transmitting the stored values of sampled water pressure in the first buffer and the second buffer to a central monitoring system upon the second buffer being filled with values, wherein the stored values of sampled water pressure in the first buffer and the second buffer are used to provide an energy characteristic profile of the energy pulse event.
2 . The method of claim 1 , further comprising
resetting the first buffer and the second buffer after the transmitting of the stored values, wherein resetting the first buffer and the second buffer includes resetting a write pointer for each of the first buffer and the second buffer to a first cell of the first buffer and the second buffer.
3 . The method of claim 1 , wherein the first buffer and the second buffer have an equal number of cells.
4 . The method of claim 1 , further comprising resuming storage of values of the sampled water pressure in the first buffer after transmission of the stored values of sampled water pressure in the first buffer to the central monitoring system is complete.
5 . The method of claim 1 , wherein the predetermined sample rate is a first predetermined sample rate and the method further comprising:
sampling water pressure with the pressure sensor at a second predetermined sample rate even while the first buffer is locked, wherein the second predetermined sample rate is slower than the first predetermined sample rate;
storing the sampled water pressure at the second predetermined sample rate in a memory device, wherein the memory device is separate from the first buffer and the second buffer;
sampling at least one physical characteristic of the water with a corresponding sensor at the second predetermined sample rate even while the first buffer is locked; and
storing the sampled at least one physical characteristic in the memory device.
6 . The method of claim 2 , further comprising:
collecting and storing additional values of sampled water pressure in the first buffer after resetting the first buffer; and
determining whether the declared event has ended based on a comparison of the additional values of sampled water pressures to a predetermined range of values for the water pressure.
7 . The method of claim 1 , wherein the predetermined sample rate is a first predetermined sample rate and the method further comprising:
sampling water pressure with the pressure sensor at a second predetermined sample rate, wherein the second predetermined sample rate is slower than the first predetermined sample rate; and
storing the sampled water pressure at the second predetermined sample rate in a memory device, wherein the memory device is separate from the first buffer and the second buffer.
8 . The method of claim 7 , further comprising:
sampling at least one physical characteristic of the water with a corresponding sensor at the second predetermined sample rate; and
storing the sampled at least one physical characteristic in the memory device.
9 . The method of claim 1 , further comprising:
resetting a write pointer for the first buffer to a first cell of the first buffer upon the first buffer being filled with values; and
overwriting the values of the sampled water pressure in the first cell of the first buffer.
10 . The method of claim 9 , further comprising:
adjusting the write pointer for the first buffer to a subsequent cell of the first buffer upon a prior cell of the first buffer being overwritten with values of the sampled water pressure;
adjusting a read pointer for the first buffer to the subsequent cell of the first buffer; and
reading the values of the sampled water pressure from the first buffer based on the read pointer.
11 . The method of claim 1 , further comprising uploading to a database the stored values of sampled water pressure in the first buffer and the second buffer transmitted to the central monitoring system.
12 . The method of claim 1 , further comprising declaring an energy pulse event upon the trigger condition being satisfied for a predetermined number of consecutive values of the sampled water pressure.
13 . A system to monitor energy characteristics of a water distribution system at a fire hydrant, the system comprising:
a pressure sensor positioned in the fire hydrant to be in contact with the water of the water distribution system, the pressure sensor is configured to continuously output a pressure signal based on a pressure of the water within the water distribution system, wherein the pressure sensor outputs the pressure signal at a predetermined rate of at least 64 outputs per second; and
a monitoring system in communication with the pressure sensor, the monitoring system comprising:
a processor configured to receive the pressure signal from the pressure sensor and determine a pressure value based on the pressure signal, the processor configured to determine whether the pressure value satisfies a trigger condition for an energy pulse event in the water distribution system;
a first memory device having a predetermined number of cells and configured to store pressure values until the energy pulse event based on the trigger condition is declared, wherein the individual stored pressure values are replaced after a predetermined time period has elapsed, such that a stored pressure value is replaced at least 64 times every second once the first memory device has been filled, and wherein the first memory device is locked after the energy pulse event is declared;
a second memory device having a predetermined number of cells and configured to store post event pressure values upon the energy pulse event being declared; and
a wireless communication interface coupled to the processor to transmit, via a wireless communication network, the plurality of pressure values stored in the first memory device and the second memory device to a central monitoring system upon the second memory device being filled with stored pressure values, wherein the stored pressure values in the first memory device and the second memory device are used to provide an energy characteristic profile of the energy pulse event.
14 . The system of claim 13 , wherein a write pointer for each of the first memory device and the second memory device is reset to point to a first cell of each of the first memory device and the second memory device after the plurality of pressure values stored in the first memory device and the second memory device are transmitted to the central monitoring system and the processor is configured to overwrite the pressure values stored in the first cell of the first memory device with new pressure values.
15 . The system of claim 13 , wherein the first memory device and the second memory device have an equal number of cells.
16 . The system of claim 14 , wherein the processor is configured to determine whether the declared event has ended based on a comparison of the new pressure values to a predetermined range of values for the water pressure.
17 . The system of claim 13 , wherein the processor is configured to resume storage of pressure values in the first memory device after the plurality of pressure values stored in the first memory device and the second memory device are transmitted to the central monitoring system.
18 . The system of claim 13 , wherein the processor is configured to prevent storage of pressure values in the first memory device after an event is declared until the plurality of pressure values stored in the first memory device and the second memory device are transmitted to the central monitoring system.
19 . The system of claim 18 , further comprising:
a third memory device separate from the first memory device and the second memory device;
wherein the predetermined rate is a first predetermined rate and the pressure sensor is configured to output the pressure signal at a second predetermined rate slower than the first predetermined rate even while the processor is prevented from storing pressure values in the first memory device;
a sensor configured to sample a physical characteristic of the water at the second predetermined sample rate; and
the processor is configured to store, in the third memory device, pressure values output at the second predetermined rate and the sample of the physical characteristic.
20 . The system of claim 13 , further comprising a third memory device separate from the first memory device and the second memory device, wherein the predetermined rate is a first predetermined rate and the processor is configured to store pressure values in the third memory device at a second predetermined rate slower than the first predetermined rate.
21 . The system of claim 20 , further comprising a sensor configured to sample a physical characteristic of the water at the second predetermined sample rate, and wherein the processor is configured to store the sample of the physical characteristic in the third memory device.
22 . The system of claim 13 , wherein the stored values of sampled water pressure in the first memory device and the second memory device transmitted to the central monitoring system are uploaded to a database.
23 . The system of claim 13 , wherein the processor is configured to declare an energy pulse event upon the trigger condition being satisfied for a predetermined number of consecutive values of the pressure value.
24 . The system of claim 13 , wherein the first memory device and the second memory device are corresponding buffers incorporated in the processor.
25 . The system of claim 13 , wherein the energy characteristic profile of the energy pulse event includes data from the first buffer showing changes in water pressure before the energy pulse event and data from the second buffer showing the energy pulse event and changes in water pressure after the energy pulse event.
26 . The method of claim 1 , wherein the energy characteristic profile of the energy pulse event includes data from the first buffer showing changes in water pressure before the energy pulse event and data from the second buffer showing the energy pulse event and changes in water pressure after the energy pulse event.
27 . A system to monitor energy characteristics of a water distribution system, the system comprising:
a plurality of fire hydrants located throughout the water distribution system, wherein each fire hydrant of the plurality of fire hydrants includes:
a pressure sensor positioned in contact with the water of the water distribution system, the pressure sensor is configured to continuously output a pressure signal based on a pressure of the water within the water distribution system, wherein the pressure sensor outputs the pressure signal at a predetermined rate of at least 64 outputs per second; and
a monitoring system in communication with the pressure sensor, the monitoring system comprising:
a processor configured to receive the pressure signal from the pressure sensor and determine a pressure value based on the pressure signal, the processor further configured to determine whether the pressure value satisfies a trigger condition for an energy pulse event in the water distribution system;
a first buffer having a predetermined number of cells and configured to store pressure values until the energy pulse event is declared, wherein the individual stored pressure values in a cell of the predetermined number of cells are replaced after a predetermined time period has elapsed, such that a stored pressure value is replaced at least 64 times every second once the first buffer has been filled, and wherein the first memory device is prevented from storing pressure values after the energy pulse event is declared;
a second buffer having the predetermined number of cells and configured to store post event pressure values upon the energy pulse event being declared; and
a wireless communication interface coupled to the processor to transmit, via a wireless communication network, the plurality of pressure values stored in the first buffer and the second buffer upon the second buffer being filled with stored pressure values, wherein the stored pressure values in the first buffer and the second buffer are used to provide an energy characteristic profile of the energy pulse event; and
a central monitoring system in communication with each monitoring system, wherein the central monitoring system receives, from an individual monitoring system, the plurality of pressure values stored in the first buffer and the second buffer upon the second memory device being filled with stored pressure values and the central monitoring system stores the received plurality of pressure values in a database for subsequent evaluation of the energy characteristic profiles of multiple energy pulse events.