Automated utility meter reading system with variable bandwidth receiver

• US 7,079,962 B2
• Filed: 10/20/2004
• Issued: 07/18/2006
• Est. Priority Date: 10/20/2004
• Status: Active Grant

• Current Assignee: Itron, Inc.
• Original Assignee: Itron, Inc.
• Inventors: Cornwall, Mark K., Weyrauch, Bruce N.
• Primary Examiner(s): Barlow, John
• Assistant Examiner(s): VO, HIEN XUAN
• Application Number:
  US10/970,738
• Publication Number:
  US 20060085147A1
• Time in Patent Office: 636 Days
• Field of Search: 702 60- 64, 702/77, 702/80, 702/57, 340/870.02, 340/870.1, 340/870.05, 340/870.01, 340/870.03, 340/870.04, 340/870.06, 340/870.07
• US Class Current: 702/62
• CPC Class Codes: G01D 4/006 Remote reading of utility meters to a non-fixed location, i.e. mobile location
• CPC Class Codes: H04Q 2209/50 using a mobile data collecting device, e.g. walk by or drive by
• 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
• CPC Class Codes: Y02B 90/20 Smart grids as enabling technology in buildings sector smart grids supporting the management or operation of end-user stationary applications in general, or like technologies with no associated climate change mitigation effect Y04S20/00
• CPC Class Codes: Y04S 20/30 Smart metering, e.g. specially adapted for remote reading

Abstract

Methods and apparatus are disclosed for Automated Meter Reading (AMR) systems for determining quantities of a consumed utility product including electric, gas, and water service, using wireless data transfer. To compensate for the frequency drifts of the transmitters, these methods and apparatus, with minimum pre-processing of the received data, allow for on-the-fly adjustability of receiver bandwidth by merely changing a pre-calculated weighting function. As such, it is possible to use a fixed size Discrete Fourier Transform (DFT), or in particular a fixed N-point Fast Fourier Transform, for signals of different bandwidths.

Claims

1. In a utility meter reading system having multiple utility meters wirelessly transmitting utility meter data to a mobile or fixed wireless receiver, an adjustable bandwidth automated meter reading system, comprising:

an encoder-receiver-transmitter (ERT) connected to each of the utility meters, wherein the ERT is configured to receive and wirelessly transmit utility metering data with respect to consumption of at least one utility resource; and

a mobile or fixed data collection unit comprising a receiver and a signal processing resource, wherein the receiver is configured to wirelessly receive the transmitted utility metering data, and wherein the signal processing resource is configured for performing N-point Fast Fourier Transformation (FFT), wherein the data collection unit;

stores the received data into an M×

N long buffer, where M is an integer;

multiplies the buffered utility meter data by a window function, wherein the window function contains no zeros, one zero, or a plurality of zeros depending on how much the bandwidth is to be adjusted;

partitions the multiplied data into M equal segments, where each segment has N points;

adds similarly positioned points of all the segments together such that the most significant points of all the M segments are added together, the second most significant points of all the segments are added together, and likewise adds together other similarly situated points of the segments; and

performs N-point FFT on the N-point results of the additions to enable the adjustable bandwidth meter reading system to carry out signal processing on narrow bandwidth data to broadband data up to M×

N points long.

2. The adjustable bandwidth automated meter reading system of claim 1, wherein N represents the widest bandwidth of the receiver.

3. An adjustable bandwidth automated wireless utility meter reading system, comprising:

a transmitter connected to the utility meter; and

a receiver;

wherein the receiver includes an N-point Fast Fourier Transform (FFT) signal processing resource configured to;

receive the utility meter data provided by the transmitter;

store the received data into an M×

N long buffer;

multiply the buffer data by a window function, wherein the window function contains no zeros, one zero, or a plurality of zeros depending on how much the bandwidth is to be adjusted;

partition the multiplied data into M equal segments, where each segment has N points;

add similarly positioned points of all the segments together to form an N-point result, such that the 1^st, (N+1)^th, (2N+1)^th, . . . , [(M−

1)N+1)]^th points of the buffered data are added together, the 2^nd, (N+2)^th, (2N+2)^th, . . . , [(M−

1)N+2)]^th points are added together, the 3^rd, (N+3)^th, (2N+3)^th, . . . , [(M−

1)N+3)]^th points are added together, up to and including N^th, (N+N)^th, (2N+N)^th, . . . , [(M−

1)N+N)]^th points of the buffered data; and

perform N-point FFT on the N-point results of the additions, which enables the utility meter reading system to carry out signal processing on any data of up to M×

N points long.

4. A wireless utility data communication system for automatic utility meter reading, the data communication system comprising:

a receiver for receiving encoded utility meter data; and

a signal processing facility with a mathematical transformation capability, wherein the signal processing facility is configured or programmed to;

read the received utility meter data into a buffer;

mathematically manipulate the buffered utility meter data, wherein the mathematical manipulation comprises multiplication of the buffer data by a weighting function;

partition the manipulated utility meter data into segments;

combine the segmented and partitioned utility meter data; and

mathematically transform the combined utility meter data.

5. The wireless utility data communication system of claim 4, wherein the signal processing facility is a digital signal processor (DSP).

6. The wireless utility data communication system of claim 4, wherein the mathematical transformation is an N-point Fast Fourier Transform operation.

7. The wireless utility data communication system of claim 4, wherein the data buffer is M×

N long and the utility meter data is partitioned into M equal segments of N-point data, and wherein N represents the widest bandwidth of the receiver.

8. The wireless utility data communication system of claim 4, wherein the combination of the partitioned data of the M segments comprise adding together similarly positioned points of all the M segments, such as adding the least significant points of all the segments together, and the most significant points of all the segments together, and likewise the other similarly situated points of all the segments.

9. The wireless utility data communication system of claim 4, wherein the mathematical transformation of the combined data comprises a Fourier Transform operation on the combined data.

10. In a utility meter reading system having multiple utility meters wirelessly transmitting utility meter data to a wireless receiver, a combination of elements for providing an adjustable bandwidth receiver comprising:

a step for receiving utility meter data from at least one of the multiple utility meters;

a step for manipulating the received utility meter data;

a step for parsing the manipulated data into segments;

a step for combining the segmented data; and

a step for performing mathematical transformation on the combined data, wherein the step for performing mathematical transformation on the combined data comprises performing Fast Fourier Transform on the combined data.

11. The combination of elements of claim 10, wherein the step for manipulating the received utility meter data comprises multiplying the data by a weighting function, and wherein the window function contains no zeros, one zero, or a plurality of zeros depending on how much the bandwidth is to be adjusted.

12. The combination of elements of claim 10, wherein the step for parsing the manipulated data into segments comprises dividing the data into M groups of N-point data, wherein M is an integer and N represents the widest bandwidth of the receiver.

13. The combination of elements of claim 10, wherein the step for combining the segmented data comprises adding together the similarly positioned bits of all the segments, such as adding the least significant bits of all the segments together, and the most significant bits of all the segments together, and likewise the other similarly situated points of all the segments.

14. An adjustable bandwidth wireless data communication method for use with an automated utility meter data reading system, comprising:

receiving the utility meter data;

storing the received utility meter data into a buffer;

mathematically manipulating the stored data by multiplying the buffer data with a weighting function;

partitioning the manipulated data into segments;

combining the partitioned data by adding the partitioned data together point-by-point; and

mathematically transforming the combined data through Fourier Transformation.

15. The method of claim 14, wherein the window function contains no zeros, one zero, or a plurality of zeros depending on how much the bandwidth is to be adjusted.

16. The method of claim 14, wherein partitioning the data into segments comprises dividing the data into M groups of N-point data, wherein M and N are integers.

17. The method of claim 14, wherein adding the partitioned data point-by-point comprises adding together the similarly positioned points of all the segments, such as adding the least significant points of all the segments together, and the most significant points of all the segments together, and likewise the other similarly situated points of the segments.

18. The method of claim 14, wherein Fourier Transformation of the combined data comprises performing Discrete Fourier Transformation on the combined data.

19. A wireless automated utility meter data reading system, comprising:

a means for receiving the utility meter data;

a means for storing the received utility meter data;

a means for mathematically manipulating the stored data, wherein the mathematical manipulation comprises multiplication of the stored data by a weighting function;

a means for partitioning the manipulated data into segments;

a means for combining the partitioned data; and

a means for mathematically transforming the combined data, wherein the means for mathematically transforming the combined data comprises performing Fast Fourier Transform on the combined data.

20. An adjustable bandwidth wireless data communication method for use with an automated utility meter data reading system, comprising:

receiving the utility meter data;

sampling or digitizing the received data

storing the sampled or digitized data into an M×

N long buffer;

multiplying the buffer data by a weighting function;

partitioning the data into M groups, where each group includes N points;

adding together the similarly positioned points of all the segments to form an N-point result, wherein each n^th point of the N-point result, where n=1, 2, 3, . . . , N, is computed using;