Method and system for fluid flow rate measurement

• US 10,309,813 B2
• Filed: 06/16/2015
• Issued: 06/04/2019
• Est. Priority Date: 05/15/2015
• Status: Active Grant

• Current Assignee: Streamlabs, Inc.
• Original Assignee: Reliance Worldwide Corporation (GSA Industries Pty Limited)
• Inventors: Gestner, Brian
• Primary Examiner(s): Kundu, Sujoy K
• Assistant Examiner(s): Anderson, L.
• Application Number:
  US14/741,124
• Publication Number:
  US 20160334255A1
• Time in Patent Office: 1,449 Days
• CPC Class Codes: F17D 1/00 Pipe-line systems conveying articles or materials through a pipe- line by means of a fluid carrier B65G51/00, B65G53/00; liquids B67D; special devices for transferring liquids from bulk storage containers into vehicles or boats or vice versa, e.g. loading or unloading vehicles or portable containers B67D7/00; conveying material which has been excavated by a dredger or soil shifter through a pipe-line E02F7/10; sewer pipe-line systems E03F3/00; thermal insulation of pipe-lines F16L59/00; central heating systems F24D
• CPC Class Codes: G01F 1/66 by measuring frequency, phase shift or propagation time of electromagnetic or other waves, e.g. using ultrasonic flowmeters
• CPC Class Codes: G01F 1/667 Arrangements of transducers for ultrasonic flowmeters; Circuits for operating ultrasonic flowmeters
• CPC Class Codes: G01F 25/10 of flowmeters
• CPC Class Codes: G01M 3/28 for pipes, cables or tubes; for pipe joints or seals; for valves ; for welds

Abstract

A fluid flow meter system for monitoring fluid flow through a lumen includes a first ultrasonic transducer configured to transmit one or more versions of a transmit (TX) signal through a fluid flowing within the lumen, and a second ultrasonic transducer configured to receive one or more respective receive (RX) signals. The fluid flow meter system includes an analog-to-digital converter (ADC) configured to sample, at a first frequency, the one or more RX ultrasonic signals and a processor configured to generate a fine resolution signal based on the one or more RX ultrasonic signals. The fine resolution signal is associated with a second sampling rate higher than the first sampling rate. The processor is also configured to compute a cross-correlation signal indicative of cross-correlation between the fine resolution signal and a waveform and determine an estimated fluid flow parameter based on the computed cross-correlation signal.

Claims

1. A method of measuring fluid flow parameters of fluids flowing through lumens, the method comprising:

transmitting through a fluid flowing through a lumen, by a first transducer of a sensor secured to a structure defining the lumen, a plurality of transmit (TX) signals, each of the plurality of TX signals transmitted with a respective time delay from a clock signal of an analog-to-digital converter;

receiving, by a second transducer of the sensor, a plurality of receive (RX) signals, each one corresponding to a respective one of the plurality of transmitted TX signals;

sampling, by the analog-to-digital converter, at a first sampling rate, the plurality of RX signals received by the second transducer;

generating, by a processor, a fine resolution signal using sampled versions of the plurality of RX signals generated by the analog-to-digital converter, the fine resolution signal associated with a second sampling rate higher than the first sampling rate;

computing, by the processor, a cross-correlation signal indicative of cross-correlation between the fine resolution signal and a reference waveform; and

determining, by the processor, an estimate of a fluid flow parameter of the fluid based on the computed cross-correlation signal.

2. The method of claim 1, wherein the fluid flow parameter includes fluid flow rate or fluid flow velocity.

3. The method of claim 1, wherein the plurality of TX signals are transmitted with distinct jitter delays with respect to periods of the clock signal of the analog-to-digital converter.

4. The method of claim 3, wherein determining an estimate of the fluid flow parameter includes:

determining, by the processor, multiple first estimates of the fluid flow parameter based on the plurality of RX signals corresponding to the TX signals transmitted with distinct jitter delays with respect to the periods of the clock signal of the analog-to-digital converter; and

generating, by the processor, a final estimate of the fluid flow parameter by averaging the multiple first estimates.

5. The method of claim 1, wherein generating a fine resolution signal includes up-sampling a signal associated with the sampled versions of the plurality of RX signals, the up-sampling includes applying interpolation using a truncated sinc function.

6. The method of claim 1, wherein the plurality of TX signals are transmitted with distinct incremental delays with respect to periods of the clock signal of the analog-to-digital converter.

7. The method of claim 6, wherein generating the fine resolution signal includes interleaving samples of the plurality of RX signals corresponding to the plurality of TX signals transmitted with distinct incremental delays with respect to the periods of the clock signal of the analog-to-digital converter.

8. The method of claim 7, wherein generating the fine resolution signal further includes up-sampling an interleaved signal generated by interleaving the samples of the plurality of RX signals corresponding to the plurality of TX signals transmitted with distinct incremental delays with respect to the periods of the clock signal of the analog-to-digital converter.

9. The method of claim 1, wherein the reference waveform is associated with a RX signal received by the first transducer responsive to transmitting a TX signal by the second transducer.

10. The method of claim 1, wherein the reference waveform represents a signal component associated with the plurality of TX signals.

11. The method of claim 1, wherein the reference waveform is associated with a zero-flow RX signal.

12. The method of claim 1, wherein computing the cross-correlation signal includes:

computing a first cross-correlation signal between a first reference waveform and a signal associated with the sampled versions of the plurality of RX signals, the first reference waveform different from the reference waveform and the first cross-correlation signal different from the cross-correlation signal;

determining a time window based on the first cross-correlation signal; and

computing the cross-correlation signal by computing a plurality of cross-correlation values within the time window indicative of cross-correlations between the reference waveform and the fine resolution signal.

13. The method of claim 12, wherein determining the time window includes:

determining a first reference point associated with the first cross-correlation signal; and

determining a second reference point associated with the cross-correlation signal based on the first reference point; and

determining the time window based on the second reference point.

14. The method of claim 12, wherein samples of the first reference waveform that are less than a threshold value are nullified.

15. The method of claim 12, wherein the signal associated with the sampled versions of the plurality of RX signals includes at least one of:

a sampled version of a RX signal of the plurality of RX signals;

an up-sampled version of a RX signal of the plurality of RX signals;

an interleaved version of the sampled versions of plurality of RX signals; and

the fine resolution signal.

16. The method of claim 12 further comprising:

locating, by the processor, a maximum cross-correlation value of the plurality of cross-correlation values within the time window;

in response to locating the maximum cross-correlation value at a boundary point of the time window, shifting the time window towards that boundary point; and

in response to locating the maximum cross-correlation value inside the time window, determining a second time delay between the reference waveform and the fine resolution signal using a location of the maximum cross-correlation inside the time window.

17. The method of claim 16, wherein locating a maximum cross-correlation value inside the time window includes applying a ternary search process.

18. The method of claim 16 comprising:

determining, by the processor, the estimated fluid flow parameter based on the time delay between the reference waveform and the fine resolution signal.

19. The method of claim 18 comprising:

determining, by the processor, the estimated fluid flow parameter based on the time delay between the reference waveform and the fine resolution signal using a lookup table.

20. The method of claim 1 comprising:

determining, by the processor, multiple estimates of the fluid flow parameter based on downstream and up-stream RX signals.