Method and apparatus for determining the location of a sound source
First Claim
1. An apparatus for determining the location of a sound source, said apparatus comprising:
- a first detector, located at a first location remote from said sound source, converting sound from said sound source into a first signal;
a second detector, located at a second location remote from said sound source, converting sound from said sound source into a second signal;
a first transform means for calculating first phase angles of a plurality of frequency components of said first signal;
a second transform means for calculating second phase angles of a plurality of frequency components of said second signal;
a phase difference calculating means for calculating phase differences between said first phase angles and said second phase angles at each of a plurality of frequencies and for converting said phase differences into a plurality of time lags;
a multiple means for adding to each time lag of said plurality of time lags integer multiples of one of a plurality of periods to form a plurality of potential time delays at each of said plurality of frequencies;
selection means for determining which time delay occurs most frequently among said plurality of potential time delays at said plurality of frequencies; and
location calculating means for calculating said location of said sound source utilizing said most frequency occurring time delay.
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Abstract
An apparatus and method for determining the location of a pipe leak detects the pipe leak sound at a first remote location and at a second remote location, and generates first and second signals indicative of the sound. A time lay between the first and second signals is calculated at each of a plurality of frequencies. Integer multiplies of an associated period are added to each time lag to form a plurality of potential time delays at each of the plurality of frequencies. The plurality of potential time delays at all of the plurality of frequencies are stored in a memory. The time delay value which occurs most frequently is selected from the memory and is utilized to calculate the location of the sound source relative to the first and second locations. The invention can also be employed to determined the location of a sound source other than a pipe leak.
62 Citations
37 Claims
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1. An apparatus for determining the location of a sound source, said apparatus comprising:
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a first detector, located at a first location remote from said sound source, converting sound from said sound source into a first signal; a second detector, located at a second location remote from said sound source, converting sound from said sound source into a second signal; a first transform means for calculating first phase angles of a plurality of frequency components of said first signal; a second transform means for calculating second phase angles of a plurality of frequency components of said second signal; a phase difference calculating means for calculating phase differences between said first phase angles and said second phase angles at each of a plurality of frequencies and for converting said phase differences into a plurality of time lags; a multiple means for adding to each time lag of said plurality of time lags integer multiples of one of a plurality of periods to form a plurality of potential time delays at each of said plurality of frequencies; selection means for determining which time delay occurs most frequently among said plurality of potential time delays at said plurality of frequencies; and location calculating means for calculating said location of said sound source utilizing said most frequency occurring time delay. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A method of determining the location of a sound source comprising the steps of:
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(a) detecting sound at a first location and generating a first signal indicative of sound at said first location; (b) detecting sound at a second location and generating a second signal indicative of sound at said second location; (c) performing a Fast Fourier Transform of said first signal to generate a first phase angle of a first frequency component and a third phase angle of a second frequency component; (d) performing a Fast Fourier Transform of said second signal to generate a second phase angle of said first frequency component and a fourth phase angle of said second frequency component; (e) calculating a difference between said first phase angle and said second phase angle to generate a first time lag; (f) generating a plurality of first possible time delays by adding integer multiples of a first period to said first time lag; (g) calculating a difference between said third phase angle and said fourth phase angle to generate a second time lag; (h) generating a plurality of second possible time delays by adding integer multiples of a second period to said second time lag; and (i) utilizing a most frequently occurring time delay from among said first and second possible time delays to calculate said location of said sound source.
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18. A method of determining the location of a sound source comprising the steps of:
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(a) detecting sound at a first location and generating a first signal indicative of sound at said first location; (b) detecting sound at a second location and generating a second signal indicative of sound at said second location; (c) calculating a time lag between said first and second signals for each of a plurality of frequency components; (d) adding integer multiples of one of a plurality of periods to each time lag to form a plurality of potential time delays at each of a plurality of frequencies; (e) storing said plurality of potential time delays of all of said plurality of frequencies in a memory; (f) selecting from said memory a time delay value which occurs most frequently; and (g) utilizing said time delay value which occurs most frequently to calculate said location of said sound source. - View Dependent Claims (19, 20, 21)
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22. An apparatus for determining the location of a fluid leak, said apparatus comprising:
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a first detector, located at a first location, converting sound from said fluid leak into a first signal; a second detector, located at a second location, converting sound from said fluid leak into a second signal; a phase difference calculating means for calculating phase differences between said first signal and said second signal at at least one specific frequency; and location determining means for deriving said location of said fluid leak utilizing said phase differences. - View Dependent Claims (23, 24, 25, 26)
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27. An apparatus for determining the location of a sound, said apparatus comprising:
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a first detector, located at a first location, converting sound from said sound source into a first signal; a second detector, located at a second location, converting sound from said sound source into a second signal; a phase difference calculating means for calculating phase differences between said first signal and said second signal at at least one specific frequency; location determining means for deriving said location of said sound source utilizing said phase differences; and a frequency selecting means for selecting frequencies based on phase difference versus frequency information.
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28. A method of determining the location of a fluid leak comprising the steps of:
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(a) detecting sound of a fluid leak at a first location and generating a first signal indicative of sound at said first location; (b) detecting sound of said fluid leak at a second location and generating a second signal indicative of sound at said second location; (c) deriving phase differences between said first and second signals at at least one specific frequency; and (d) utilizing said phase differences to derive said location of said fluid leak. - View Dependent Claims (29, 30, 31, 33)
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32. A method of determining the location of a sound source comprising the steps of:
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(a) detecting sound at a first location and generating a first signal indicative of sound at said first location; (b) detecting sound at a second location and generating a second signal indicative of sound at said second location; (c) deriving phase differences between said first and second signals at at least one specific frequency; (d) utilizing said phase differences to derive said location of said sound source; and (e) selecting frequencies based on phase difference versus frequency information.
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34. An apparatus for determining the location of a sound source, said apparatus comprising:
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a first detector, located at a first location remote from said sound source, which converts sound from said sound source into a first signal; a second detector, located at a second location remote from said sound source, which converts sound from said sound source into a second signal; a first transform calculation unit which calculates first phase angles of a plurality of frequency components of said first signal; a second transform calculation unit which calculates second phase angles of a plurality of frequency components of said second signal; a phase difference calculation unit which calculates phase differences between said first phase angles and said second phase angles at each of a plurality of frequencies and which converts said phase differences into a plurality of time lags; a multiple calculation unit which adds to each time lag of said plurality of time lags integer multiples of one of a plurality of periods to form a plurality of potential time delays at each of said plurality of frequencies; a selection unit which determines which time delay occurs most frequently among said plurality of potential time delays at said plurality of frequencies; and a location calculation unit which calculates said location of said sound source utilizing said most frequently occurring time delay.
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35. An apparatus for determining the location of a fluid leak, said apparatus comprising:
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a first detector, located at a first location remote from said fluid leak, which converts sound from said fluid leak into a first signal; a second detector, located at a second location remote from said fluid leak, which converts sound from said fluid leak into a second signal; a first transform calculation unit which calculates first phase angles of a plurality of frequency components of said first signal; a second transform calculation unit which calculates second phase angles of a plurality of frequency components of said second signal; a phase difference calculation unit which calculates phase differences between said first phase angles and said second phase angles at each of a plurality of frequencies and which converts said phase differences into a plurality of time lags; a multiple calculation unit which adds to each time lag of said plurality of time lags integer multiples of one of a plurality of periods to form a plurality of potential time delays at each of said plurality of frequencies; a selection unit which determines which time delay occurs most frequently among said plurality of potential time delays at said plurality of frequencies; and a location calculation unit which calculates said location of said fluid leak utilizing said most frequently occurring time delay.
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36. An apparatus for determining the distance to a sound source, said apparatus comprising:
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a first detector which converts sound from said sound source into a first signal; a second detector which converts sound from said sound source into a second signal; a calculation unit which utilizes said first and second signals to generate a plurality of potential time delays; a selection processor which determines which time delay occurs most frequently among said plurality of potential time delays; and a distance calculator which calculates a distance to said sound source utilizing said most frequently occurring time delay. - View Dependent Claims (37)
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Specification