Frequency sub-band leak detection

• US 10,539,480 B2
• Filed: 10/27/2017
• Issued: 01/21/2020
• Est. Priority Date: 10/27/2017
• Status: Active Grant

• Current Assignee: Mueller International LLC (Mueller Water Products Incorporated)
• Original Assignee: Mueller International LLC (Mueller Water Products Incorporated)
• Inventors: Burtea, Valentin Mircea
• Primary Examiner(s): Rogers, David A
• Application Number:
  US15/796,108
• Publication Number:
  US 20190128767A1
• Time in Patent Office: 816 Days
• CPC Class Codes: G01B 17/00 Measuring arrangements characterised by the use of infrasonic, sonic or ultrasonic vibrations
• CPC Class Codes: G01B 17/02 for measuring thickness
• CPC Class Codes: G01F 23/22 by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water involving the use of floats G01F23/30
• CPC Class Codes: G01F 23/2962 Measuring transit time of reflected waves
• CPC Class Codes: G01F 23/2965 Measuring attenuation of transmitted waves
• CPC Class Codes: G01F 23/2968 Transducers specially adapted for acoustic level indicators
• CPC Class Codes: G01M 3/243 for pipes
• CPC Class Codes: G01N 29/07 by measuring propagation velocity or propagation time of acoustic waves
• CPC Class Codes: G01N 29/222 Constructional or flow details for analysing fluids optoacoustic fluid cells G01N29/2425
• CPC Class Codes: G01N 29/4418 with a model, e.g. best-fit, regression analysis
• CPC Class Codes: G01N 29/4472 Mathematical theories or simulation
• CPC Class Codes: G01N 29/46 by spectral analysis, e.g. Fourier analysis or wavelet analysis spectral signal processing per se G06F17/14

Abstract

Examples of analyzing data for a distribution pipe network within a fluid distribution system are disclosed. In one example implementation according to aspects of the present disclosure, a method for analyzing data for a distribution pipe network within a fluid distribution system includes: receiving acoustic data from a plurality of nodes for a plurality of pipe segments; determining a characteristic frequency range for each pipe segment; decomposing the characteristic frequency range into a plurality of frequency sub-bands; building a leak sensitivity model based on the plurality of frequency sub-bands; and implementing a correlation schedule with the plurality of nodes based on a selection of the plurality of frequency sub-bands.

Claims

1. A method for analyzing data for a distribution pipe network within a fluid distribution system, comprising:

receiving acoustic data from a plurality of nodes for a plurality of pipe segments;

determining a characteristic frequency range for each pipe segment;

decomposing the characteristic frequency range into a plurality of frequency sub-bands;

building a leak sensitivity model based on the plurality of frequency sub-bands; and

implementing a correlation schedule with the plurality of nodes based on a selection of the plurality of frequency sub-bands.

2. The method of claim 1, further comprising:

receiving updated acoustic data from the plurality of nodes for each pipe segment;

determining an updated frequency range for each pipe segment based on the updated acoustic data;

creating an updated leak sensitivity model and an updated correlation schedule based on the updated frequency range and corresponding frequency sub-bands; and

implementing the updated correlation schedule.

3. The method of claim 1, wherein each pipe segment comprises a section of the distribution pipe network between two nodes of the plurality of nodes.

4. The method of claim 1, wherein determining the characteristic frequency range for each pipe segment is based on a pipe material and a geometry for each pipe segment.

5. The method of claim 1, wherein implementing the correlation schedule comprises the steps of:

downloading, by each node, the correlation schedule;

synchronizing time for each node based on a reference time;

recording an acoustic signal at each node for a same time and a same duration;

reading and selecting a specific sub-band signal based on the correlation schedule;

decimating and compressing the specific sub-band signal at each node; and

transmitting a compressed sub-band signal from each node to a computing host.

6. The method of claim 5, wherein compressing the specific sub-band signal comprises a quantization method of absolute pulse code modulation utilizing a nonlinear function to compress the data to 1-bit.

7. The method of claim 5, wherein compressing the specific sub-band signal comprises utilizing 1-bit quantization.

8. The method of claim 5, further comprising:

receiving, by the computing host, the compressed sub-band signal from each node;

determining, by the computing host, correlation pairs based on adjacencies from each node, wherein the adjacencies are based on geographic information system data from each node; and

detecting, by the computing host, coherent sources for each determined correlation pair by correlating the compressed sub-band signals of each correlation pair.

9. The method of claim 8, further comprising the steps of, responsive to a determination that the correlating of the compressed sub-band signals of a particular correlation pair is positive between a first node and a second node:

determining, by the computing host, a time delay between the first node and the second node; and

calculating, by the computing host, a leak location based on the time delay and the particular correlation pair.

10. A system for analyzing data for a distribution pipe network within a fluid distribution system, comprising:

a computing host in communication with the fluid distribution system and configured to create a correlation schedule based on a selection of frequency sub-bands; and

a plurality of nodes in communication with the computing host and configured to acquire acoustic data in the fluid distribution system, each node programmed to perform steps comprising

downloading the correlation schedule;

synchronizing time with a reference time;

recording an acoustic signal, wherein each node records acoustic data at a same time and for a same duration;

reading the correlation schedule to determine a plurality of specific frequency sub-bands for each recording;

selecting a specific sub-band signal for each of the plurality of specific frequency sub-bands;

decimating the specific sub-band signal for each of the plurality of specific frequency sub-bands;

compressing the specific sub-band signal for each of the plurality of specific frequency sub-bands utilizing a quantization method; and

transmitting, as one file, a plurality of compressed sub-band signals to the computing host.

11. The system of claim 10, wherein selecting the specific sub-band signal for the specific frequency sub-band comprises the steps of:

decomposing the specific sub-band signal into a plurality of symmetric sub-bands; and

selecting only the specific frequency sub-band of the specific sub-band signal as determined by the correlation schedule.

12. The system of claim 10, wherein selecting the specific sub-band signal for the specific frequency sub-band comprises the steps of:

applying a pass-band filter to the specific sub-band signal to retain a desired energy in the specific sub-band signal.

13. The system of claim 10, wherein the quantization method comprises clipping to 1-bit compression.

14. The system of claim 10, wherein the quantization method comprises an absolute pulse code modulation utilizing a nonlinear function to compress the data to 1-bit.

15. The system of claim 10, wherein the quantization method comprises a non-linear pulse code modulation utilizing a nonlinear function.

16. The system of claim 10, wherein creating the correlation schedule by the computing host comprises the steps of:

receiving acoustic data from the plurality of nodes for a plurality of pipe segments;

determining a characteristic frequency range for each pipe segment;

decomposing the characteristic frequency range into a plurality of frequency sub-bands;

building a leak sensitivity model based on the plurality of frequency sub-bands by aggregating data from every pipe segment; and

configuring the correlation schedule to maximize sensitivity to leak detection of an acoustic propagation detection system based on the selecting of the specific sub-band signal for the specific frequency sub-band.

17. The system of claim 16, wherein the computing host is further configured to:

receive the compressed sub-band signal from each node;

determine correlation pairs based on adjacencies from each node, wherein the adjacencies are based on geographic information system data from each node; and

detect coherent sources for each determined correlation pair by correlating the compressed sub-band signals of each correlation pair.

18. A non-transitory computer-readable storage medium storing instructions that, when executed by a processing resource, cause the processing resource to perform steps comprising:

receiving acoustic data from a plurality of nodes for a plurality of pipe segments;

determining a characteristic frequency range for each pipe segment;

decomposing the characteristic frequency range into a plurality of frequency sub-bands;

building a leak sensitivity model based on the plurality of frequency sub-bands; and

implementing a correlation schedule with the plurality of nodes based on a selection of the plurality of frequency sub-bands.

19. The non-transitory computer-readable storage medium of claim 18, wherein implementing the correlation schedule comprises the steps of:

downloading, by each node, the correlation schedule;

synchronizing time for each node based on a reference time;

recording an acoustic signal at each node for a same time and a same duration;

reading and selecting a specific sub-band signal based on the correlation schedule;

decimating and compressing the specific sub-band signal at each node; and

transmitting a compressed sub-band signal from each node to a computing host.

20. The non-transitory computer-readable storage medium of claim 19, wherein compressing the specific sub-band signal comprises clipping to 1-bit compression.