Metering system

• US 6,195,018 B1
• Filed: 02/07/1996
• Issued: 02/27/2001
• Est. Priority Date: 02/07/1996
• Status: Expired due to Term

• Current Assignee: Landis+Gyr Innovations Incorporated (Landis+Gyr Group AG)
• Original Assignee: CellNet Data Systems, Inc. (Landis+Gyr Group AG)
• Inventors: Hayes, Robert A., Ragle, Steven J., Johnson, Larsh M., King, Christopher S.
• Primary Examiner(s): Zimmerman, Brian
• Assistant Examiner(s): Edwards, Jr., Timothy
• Application Number:
  US08/597,724
• Time in Patent Office: 1,847 Days
• Field of Search: 340/870.03, 340/870.02, 340/870.07, 340/870.11, 340/870.01
• US Class Current: 340/870.01
• CPC Class Codes: G08C 15/06 successively, i.e. using time division
• CPC Class Codes: H04Q 2209/40 using a wireless architecture
• CPC Class Codes: H04Q 2209/60 for transmitting utility meters data, i.e. transmission of data from the reader of the utility meter
• CPC Class Codes: H04Q 9/00 Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom

Abstract

A metering system provides a measuring level with multiple meters and a collection level with multiple collectors. Each meter periodically measures a parameter, such as electricity consumption, and stores measurement information. Each meter periodically transmits its stored measurement information to a collector by a wireless signal. When a collector receives a transmission, it determines which meter sent the transmission, and then extracts unprocessed measurement information. The collector then processes the measurement information to generate a metered function, such as a load profile, a time-of-use profile, or a demand profile. The collector can compensate for missed transmissions and power failures. The metered functions for each meter are transmitted from the collectors to a monitoring station.

Claims

1. A data collection system comprising:

a) a plurality of telemetry devices, each including

i) a sensor configured to generate a series of successive measurements by measuring a parameter at a series of measurement times,

ii) a memory configured to store a plurality of measurements from said series of successive measurements, and

iii) a transmitter configured to transmit measurements stored in memory to a collection device at a series of transmission times, each of said transmitted measurements being transmitted at a plurality of different transmission times; and

b) a collection device having

i) a receiver configured to receive transmissions from said telemetry devices,

ii) a processor configured to extract said series of successive measurements from a series of received transmissions and further configured to generate a metered function of said parameter by analyzing said series of successive measurements, and

iii) a transmitter configured to transmit said metered function to a monitoring station.

2. The data collection system of claim 1 wherein the transmitter of each telemetry device is configured to generate wireless transmissions.

3. The data collection system of claim 1 wherein the sensor of each telemetry device includes:

a counter for storing a value,

means for incrementing said counter upon receipt of a trigger signal, and

means for storing said value from said counter in said first memory and resetting said counter at said measurement times.

4. The data collection system of claim 1 wherein each of said telemetry devices discards the oldest measurement stored in memory and stores in memory a new measurement from said sensor.

5. The data collection system of claim 1 wherein the memory of each telemetry device is configured to store eighteen measurements.

6. The data collection system of claim 1 wherein each of said telemetry devices further includes a timer having a predetermined time interval, wherein the expiration of said predetermined time interval causes said sensor to generate a measurement.

7. The data collection system of claim 6 wherein said predetermined time interval is approximately 2.5 minutes.

8. The data collection system of claim 6 wherein restoration of power following a power failure causes the sensor of each telemetry device to generate a measurement.

9. The data collection system of claim 1 wherein

said collection device further includes a memory configured to store a data object representing a given telemetry device from which the collection device receives transmissions.

10. The data collection system of claim 9 wherein

said collection device further includes a clock configured to determine a receipt time of a current transmission received from the given telemetry device,

the data object representing the given telemetry device includes a receipt time of a previous transmission from the given telemetry device, and

the processor of the collection device is configured to compare the receipt time of the current transmission received from the given telemetry device to the receipt time of the previous transmission received from the given telemetry device.

11. The data collection system of claim 9 wherein

the memory of each telemetry device is configured to store a number,

the given telemetry device increments said number each time a measurement is generated,

said stored number is transmitted by the transmitter of the given telemetry device in a current transmission,

the data object representing the given telemetry device includes a number transmitted in a previous transmission received from the given telemetry device;

and

the processor of the collection device is configured to compare the number transmitted in the current transmission to the number transmitted in the previous transmission.

12. The data collection system of claim 9 wherein

each of said telemetry devices includes means for detecting a power failure,

the memory of each telemetry device is configured to store power failure information indicating whether each stored measurement was generated following a power failure,

said power failure information is transmitted by the transmitter of the given telemetry device at said transmission times, and

the data object representing the given telemetry device includes said transmitted power failure information received by the collection device from the given telemetry device.

13. The data collection system of claim 9 wherein

said metered function is a load profile, and

the data object includes the duration of a load profile period.

14. The data collection system of claim 9 wherein

said metered function is a time-of-use profile,

the data object includes a plurality of time-of-use measurements, and

the memory of the collection device is configured with a calendar to link a measurement time of a measurement to one of said time-of-use measurements.

15. The data collection system of claim 9 wherein

said metered function is a demand profile, and

the data object includes a duration of a demand profile period.

16. The data collection system of claim 1 wherein said parameter is selected from the group consisting of electrical power, fluid flow, voltage, current, temperature, pressure, and humidity.

17. The data collection system of claim 16 wherein said parameter is electrical power.

18. The data collection system of claim 16 wherein said parameter is fluid flow.

19. The data collection system of claim 18 wherein said fluid is natural gas.

20. The data collection system of claim 18 wherein said fluid is water.

21. A method of collecting data comprising the steps of:

a) generating a series of successive measurements by measuring a parameter with a telemetry device at a series of measurement times;

b) storing a plurality of said measurements in said telemetry device;

c) transmitting said stored measurements to a collection device at a series of transmission times;

d) extracting said series of successive measurements from a series of said transmissions with said collection device;

e) generating a metered function of said parameter with said collection device by analyzing said series of successive measurements; and

f) transmitting said metered function to a monitoring station.

22. The method of claim 21 further comprising the steps of:

storing an old number in said collection device,

generating a new number in said telemetry device each time a measurement is generated,

transmitting said new number with stored measurements, and

comparing said old number to said new number at said collection device to determine which measurements are new measurements which were not previously received by said collection device and whether there are missing measurements.

23. The method of claim 21 wherein said transmissions are wireless transmissions.

24. The method of claim 22 further comprising the step of storing said old number in said telemetry device, and wherein the step of generating said new number includes incrementing said old number.

25. The method of claim 24 further comprising the step of determining the measurement times for new measurements received by said collection device.

26. The method of claim 25 further comprising the steps of:

storing information in said telemetry device indicating whether a power failure occurred between successive measurements,

transmitting said information to said collection device, and

using said information to determine whether there are new measurements for which the measurement time cannot be determined.

27. The method of claim 26 further comprising the step of performing a recovery operation for missing measurements or new measurements for which the measurement time cannot be determined.

28. The method of claim 21 further comprising the step of waiting an alignment time following a measurement to transmit said stored measurements.

29. The method of claim 28 wherein said alignment time is selected randomly.

30. The method of claim 28 wherein said transmission occurs following an integer number of measurements.

31. The method of claim 28 further comprising the steps of:

transmitting said alignment time from said telemetry device to said collector in a transmission,

determining a receipt time representing the time said collector receives said transmission, and

subtracting said alignment time from said receipt time to generate a time representing the measurement time of the most recent measurement in the transmission.

32. The method of claim 21 wherein said parameter is selected from the group consisting of electrical power, fluid flow, voltage, current, temperature, pressure, and humidity.

33. The method of claim 32 wherein said parameter is electrical power.

34. The method of claim 32 wherein said parameter is fluid flow.

35. The method of claim 34 wherein said fluid is natural gas.

36. The method of claim 34 wherein said fluid is water.

37. A network for collecting data generated by a plurality of sensors, comprising:

a) a plurality of data generating devices, each including

i) a sensor configured to generate measurements by measuring a parameter,

ii) a memory configured to store said measurements, and

iii) a transmitter configured to transmit at a plurality of transmission times measurements stored in memory to an intermediate device; and

b) a plurality of intermediate devices, there being fewer intermediate devices than data generating devices, each of said intermediate devices including

i) a receiver configured to receive transmissions from a subset of said plurality of data generating devices,

ii) a processor configured to extract said measurements from said transmissions and further configured to generate a metered function of said parameter by analyzing said measurements, and

iii) a transmitter to transmit said metered function; and

c) a central station configured to receive said transmitted metered functions from said plurality of intermediate devices.

38. A method of collecting data comprising the steps of:

a) generating measurements by measuring a parameter with a sensor;

b) storing a plurality of said measurements in a memory;

c) transmitting said stored measurements to an intermediate device;

d) extracting said measurements from said transmissions with said intermediate device;

e) generating a metered function of said parameter with said intermediate device by analyzing said measurements; and

f) transmitting said metered function to a central station.

39. A data collection system, comprising:

a plurality of sensors each of which has a meter configured to sample a parameter value at discrete measurement times and a transmitter configured to transmit data measured by the meter; and

a collector having a receiver configured to receive data transmitted by the plurality of sensors, a processor configured to generate a summary profile of data received by the receiver from the plurality of sensors, and a transmitter configured to transmit the summary profile to a monitoring station, wherein each sensor periodically transmits a plurality of data measurements during a current data collection period and, with each transmission, each sensor transmits redundant data measurements corresponding to a prior transmission, and the collector is configured to reduce the occurrence of usage profile errors based upon the redundant data measurements contained in a received transmission.