Proximity detecting apparatus and method based on audio signals

• US 9,097,795 B2
• Filed: 11/12/2010
• Issued: 08/04/2015
• Est. Priority Date: 11/12/2010
• Status: Active Grant

• Current Assignee: Piece Future Pte., Ltd.
• Original Assignee: Nokia Technologies Oy (Nokia Corporation)
• Inventors: Ojala, Pasi, Kirkeby, Ole
• Primary Examiner(s): Nguyen, Hung T
• Application Number:
  US13/883,660
• Publication Number:
  US 20130223188A1
• Time in Patent Office: 1,726 Days
• Field of Search: 367/93, 367/95, 367/96, 367/99, 367/118, 367/127, 455/90.1, 455/90.3, 455/355, 455/569.1, 455/456, 455/456.1, 455/569
• US Class Current: 1/1
• CPC Class Codes: G01S 15/003 Bistatic sonar systems; Multistatic sonar systems
• CPC Class Codes: G01S 15/04 Systems determining presence of a target
• CPC Class Codes: H04M 1/6008 in the transmitter circuit
• CPC Class Codes: H04M 2250/12 including a sensor for measuring a physical value, e.g. temperature or motion
• CPC Class Codes: H04M 9/08 Two-way loud-speaking telephone systems with means for conditioning the signal, e.g. for suppressing echoes for one or both directions of traffic
• CPC Class Codes: H04M 9/082 using echo cancellers echo cancellers per se H04B3/23

Abstract

Apparatus comprising at least one processor and at least one memory including computer code, the at least one memory and the computer code configured to with the at least one processor cause the apparatus to at least perform: determining at least one impulse response model pulse train from at least one audio signal; and determining an presence of an object from the at least one impulse model pulse train.

Claims

1. An apparatus comprising:

at least one processor; and

at least one memory including computer code, the at least one memory and the computer code configured, with the at least one processor, to cause the apparatus to;

transmit from a first speaker a first audio signal;

transmit from a second speaker a second audio signal;

receive at least one audio signal using at least one microphone, wherein the at least one audio signal comprises a combination of a direct pathway and a reflected pathway first and second audio signals;

determine a distance value based on the received at least one audio signal; and

determine a presence of an object from the distance value.

2. The apparatus as claimed in claim 1, wherein determine a presence of an object comprises:

determine at least one impulse response model;

determine an object reflection delay value; and

determine an object reflection distance based on the object reflection delay value.

3. The apparatus as claimed in claim 2, wherein determine a presence of an object further comprises:

determine the object reflection distance is less than a first defined value; and

control a function of the apparatus dependent on the determined object reflection distance.

4. The apparatus as claimed in claim 3, wherein control a function of the apparatus comprises at least one of:

control a speaker output level; and

wake the apparatus from standby.

5. The apparatus as claimed in claim 2, wherein determine at least one impulse response model comprises determine at least two distinguishable signal impulse models, and wherein determine a presence of an object from the at least one impulse model comprises:

determine an object reflection delay value for each impulse model;

determine an object location based on the object reflection delay value for each impulse model; and

determine a motion of the object based on the determined object location.

6. The apparatus as claimed in claim 2, wherein determine the at least one impulse response model comprises:

transform the at least one audio signal into a sparse representation domain; and

sparse sense the at least one audio signal in the sparse representation domain to determine the impulse response model.

7. The apparatus as claimed in claim 6, wherein transform the at least one audio signal into the sparse representation domain comprises at least one of:

cross-correlate the at least one audio signal against a reference signal; and

frame the at least one audio signal before the at least one audio signal is cross-correlated.

8. The apparatus as claimed in claim 6, wherein sparse sense comprises at least one of:

discrete Fourier transform the cross-correlated at least one audio signal;

organize the discrete Fourier transform products into a Toeplitz form;

determine the annihilating filter roots associated with the Toeplitz form discrete Fourier transform products; and

determine the impulse response model pulse times and amplitudes based on the annihilating filter root values.

9. The apparatus as claimed in claim 8, wherein the at least one memory and the computer code are further configured, with the at least one processor, to cause the apparatus to:

denoise the Toeplitz form discrete Fourier transform products before determining the annihilating filter roots.

10. A method comprising:

transmitting from a first speaker a first audio signal;

transmitting from a second speaker a second audio signal;

receiving at least one audio signal using at least one microphone, wherein the at least one audio signal comprises combination of a direct pathway and a reflected pathway first and second audio signals;

determining a distance value based on the received at least one audio signal; and

determining a presence of an object from the distance value.

11. The method as claimed in claim 10, wherein determining a presence of an object comprises:

determining at least one impulse response model;

determining an object reflection delay value; and

determining an object reflection distance based on the object reflection delay value.

12. The method as claimed in claim 11, wherein determining a presence of an object further comprises:

determining the object reflection distance is less than a first defined value; and

controlling a function of an apparatus dependent on determining the object reflection distance.

13. The method as claimed in claim 12, wherein controlling a function of an apparatus comprises at least one of:

controlling a speaker output level; and

waking the apparatus from standby.

14. The method as claimed in claim 11, wherein determining at least one impulse response model comprises determining at least two distinguishable signal impulse models, and wherein determining a presence of an object from the at least one impulse model comprises:

determining an object reflection delay value for each impulse model;

determining an object location based on the object reflection delay value for each impulse model; and

determining a motion of the object based on determining object locations.

15. The method as claimed in claim 11, wherein determining the at least one impulse response model comprises:

transforming the at least one audio signal into a sparse representation domain; and

sparse sensing the at least one audio signal in the sparse representation domain to determine the impulse response model.

16. The method as claimed in claim 15, wherein transforming the at least one audio signal into the sparse representation domain comprises at least one of:

cross-correlating the at least one audio signal against a reference signal; and

framing the at least one audio signal before cross-correlating.

17. The method as claimed in claim 15, wherein sparse sensing comprises at least one of:

discrete Fourier transforming the cross-correlated at least one audio signal;

organizing the discrete Fourier transform products into a Toeplitz form;

determining the annihilating filter roots associated with the Toeplitz form discrete Fourier transform products; and

determining the impulse response model pulse times and amplitudes based on the annihilating filter root values.

18. The method as claimed in claim 17, further comprising:

denoising the Toeplitz form discrete Fourier transform products before determining the annihilating filter roots.