Acoustic location and enhancement

• US 20070159924A1
• Filed: 01/06/2006
• Published: 07/12/2007
• Est. Priority Date: 01/06/2006
• Status: Active Grant

• Current Assignee: Agilent Technologies, Inc.
• Original Assignee: Agilent Technologies, Inc.
• Inventors: Hamilton, Bruce, Burch, Jefferson, Fernandez, Andrew, Vook, Dieterich
• Granted Patent: US 7,558,156 B2
• Time in Patent Office: Days
• US Class Current: 367/127
• CPC Class Codes: G01S 5/28 by co-ordinating position lines of different shape, e.g. hyperbolic, circular, elliptical or radial
• CPC Class Codes: G08B 13/1672 using sonic detecting means, e.g. a microphone operating in the audio frequency range
• CPC Class Codes: H04J 3/0667 Bidirectional timestamps, e.g. NTP or PTP for compensation of clock drift and for compensation of propagation delays arrangements for monitoring round trip delays in packet switching networks H04L43/0864
• CPC Class Codes: H04J 3/0697 Synchronisation in a packet node
• CPC Class Codes: H04R 1/406 microphones
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407
• CPC Class Codes: Y10S 367/906 Airborne shock-wave detection

Abstract

A method of locating an acoustic source, the method comprising sampling said acoustic source at a plurality of acoustic receivers having different locations, each acoustic receiver time-stamping a respective received acoustic sample using a system time, each acoustic receiver sending said time-stamped acoustic sample to a central controller, the central controller determining the location of the acoustic source in response to receiving the time-stamped sound source samples from the plurality of receivers.

Claims

1. A method of locating an acoustic source, the method comprising:

sampling said acoustic source at a plurality of acoustic receivers;

each acoustic receiver time-stamping a respective received acoustic sample using a system time;

each acoustic receiver sending said time-stamped acoustic sample to a central controller;

the central controller determining the location of the acoustic source in response to receiving the time-stamped acoustic samples from the plurality of receivers.

2. A method as claimed in claim 1, wherein each acoustic receiver is synchronized to the system time using the Precision Time Protocol.

3. A method as claimed in claim 1, wherein the time-stamped acoustic samples are sent over a communications path having a non-characterized delay.

4. A method as claimed in claim 1, wherein sampling the acoustic source is in response to detecting a predetermined acoustic pattern.

5. A method as claimed in claim 1, wherein determining the location of the acoustic source comprises:

determining acoustic signal time of arrival differences between the acoustic receivers;

calculating the relative distance from the acoustic source to each acoustic receiver based on said time of arrival differences;

determining the location of the acoustic source using said relative distances.

6. A method as claimed in claim 1, further comprising coherently combining the received acoustic samples according to their respective time stamps and the location of the acoustic source in order to generate an enhanced acoustic source signal.

7. A method as claimed in claim 1, further comprising:

sampling said acoustic source at the acoustic receivers at respective acoustic receiver sampling times;

each acoustic receiver sending said acoustic samples to the central controller;

the central controller combining the received acoustic samples in order to generate an enhanced the acoustic source signal.

8. A method as claimed in claim 7, further comprising:

the central controller determining the relative distances between each acoustic receiver and the acoustic source based on the determined acoustic source location;

calculating the respective receiver times dependent on the distance from the acoustic source to the respective acoustic receiver; and

sending the respective acoustic receiver times to the respective acoustic receivers.

9. A carrier medium carrying a computer program which when executed on a computer is arranged to carry out the method of claim 1.

10. A method of receiving samples from an acoustic source, the method comprising:

sampling said acoustic source at a plurality of acoustic receivers having different locations and at respective acoustic receiver sampling times, said acoustic receivers having been synchronized to a common system time;

each acoustic receiver sending said acoustic sample to a central controller;

the central controller coherently combining the acoustic samples received from the plurality of acoustic receivers.

11. A method as claimed in claim 10, wherein the respective acoustic receiver sampling times are dependent on the distance from the acoustic source to the respective acoustic receiver.

12. A method as claimed in claim 10, wherein the acoustic receivers are synchronized to the system time using the Precision Time Protocol.

13. A method as claimed in claim 10, wherein combining the acoustic samples comprises coherently averaging said samples.

14. A method as claimed in claim 10, wherein the acoustic samples are sent over a digital communications path having a non-characterized delay.

15. A carrier medium carrying a computer program which when executed on a computer is arranged to carry out the method of claim 10.

16. An acoustic receiver comprising:

an acoustic transducer for transducing acoustic signals received from an acoustic source;

a local clock synchronized to an external system time;

a communications interface arranged to interface with a communications path having a non-characterized delay; and

a processor arranged to sample the received acoustic signals from the acoustic source, and to transmit said samples onto the communications path having the non characterized delay.

17. An acoustic receiver as claimed in claim 16, wherein the local clock is synchronized to the external system time using the Precision Time Protocol.

18. An acoustic receiver as claimed in claim 16, wherein the processor is further arranged to time-stamp the samples using the local clock, and wherein the transmitted samples are time-stamped.

19. An acoustic receiver as claimed in claim 16, wherein the processor is further arranged to sample the received acoustic signals at a respective acoustic receiver sampling time in response to receiving corresponding instructions.