SYSTEMS, METHODS, APPARATUS, AND COMPUTER-READABLE MEDIA FOR SOURCE LOCALIZATION USING AUDIBLE SOUND AND ULTRASOUND

• US 20120224456A1
• Filed: 08/04/2011
• Published: 09/06/2012
• Est. Priority Date: 03/03/2011
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Visser, Erik, Momeyer, Brian
• Granted Patent: US 9,354,310 B2
• Time in Patent Office: Days
• US Class Current: 367/127
• CPC Class Codes: G01S 15/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S15/46
• CPC Class Codes: G01S 15/86 Combinations of sonar systems with lidar systems; Combinations of sonar systems with systems not using wave reflection
• CPC Class Codes: G01S 15/876 Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector G01S15/872 takes precedence
• CPC Class Codes: G01S 2013/468 by Triangulation, i.e. two antennas or two sensors determine separately the bearing, direction or angle to a target, whereby with the knowledge of the baseline length, the position data of the target is determined
• CPC Class Codes: G01S 2015/465 by Trilateration, i.e. two transducers determine separately the distance to a target, whereby with the knowledge of the baseline length, i.e. the distance between the transducers, the position data of the target is determined
• CPC Class Codes: G01S 3/8006 Multi-channel systems specially adapted for direction-finding, i.e. having a single aerial system capable of giving simultaneous indications of the directions of different signals
• CPC Class Codes: G01S 7/521 Constructional features

Abstract

A method of signal processing includes calculating a range based on information from a reflected ultrasonic signal. Based on the calculated range, one among a plurality of direction-of-arrival (DOA) estimation operations is selected. The method also includes performing the selected operation to calculate an estimated direction of arrival (DOA) of an audio-frequency component of a multichannel signal. Examples of DOA estimation operations include operations based on phase differences between channels of the multichannel signal and operations based on a difference in gain between signals that are based on channels of the multichannel signal.

Claims

1. A method of signal processing, said method comprising:

based on information from a first reflection of a first ultrasonic signal, estimating a first range of a sound-emitting object;

based on the estimated first range, selecting one among a plurality of direction-of arrival estimation operations; and

performing the selected direction-of-arrival estimation operation to calculate, based on information from an audio-frequency component of a multichannel signal, an estimate of a direction of arrival of the audio-frequency component.

2. The method according to claim 1, wherein a first channel of the multichannel signal is based on a signal produced by a first detector and a second channel of the multichannel signal is based on a signal produced by a second detector.

3. The method according to claim 2, wherein said estimating the first range includes calculating a time of flight of the first ultrasonic signal to the first detector, and wherein said information from the first reflection of the first ultrasonic signal includes said calculated time of flight of the first ultrasonic signal to the first detector.

4. The method according to claim 1, wherein said estimating the first range includes calculating a time of flight of the first ultrasonic signal to a first detector, and wherein said information from the first reflection of the first ultrasonic signal includes said calculated time of flight of the first ultrasonic signal to the first detector, and

wherein said estimating the first range includes calculating a time of flight of the first ultrasonic signal to a second detector, and wherein said information from the first reflection of the first ultrasonic signal includes said calculated time of flight of the first ultrasonic signal to the second detector.

5. The method according to claim 4, wherein the audio-frequency component of the multichannel signal is based on signals produced by the first and second detectors.

6. The method according to claim 4, wherein said method comprises, based on the calculated times of flight of the first ultrasonic signal to the first and second detectors, calculating a second estimate of a direction of arrival of the audio-frequency component.

7. The method according to claim 6, wherein said method comprises combining the calculated estimate of a direction of arrival and the calculated second estimate according to a relative weighting to obtain a combined estimate of a direction of arrival,

wherein the relative weighting is based on a level of the audio-frequency component.

8. The method according to claim 7, wherein the relative weighting is based on a difference between the calculated estimate of a direction of arrival and the calculated second estimate.

9. The method according to claim 7, wherein said method includes calculating a time of flight of a second ultrasonic signal to the first detector, and

wherein the relative weighting is based on a difference between the times of flight of the first and second ultrasonic signals to the first detector.

10. The method according to claim 2, wherein said method comprises:

based on information from a second reflection of the first ultrasonic signal, estimating a second range;

based on information from a first reflection of a second ultrasonic signal that is emitted after the first ultrasonic signal, estimating a third range;

based on information from a second reflection of the second ultrasonic signal, estimating a fourth range;

based on a relation between (A) a difference between the first and third ranges and (B) a difference between the second and fourth ranges, selecting one among the third and fourth ranges;

based on the selected range, performing a second selection of one among the plurality of direction-of-arrival estimation operations; and

performing the direction-of-arrival estimation operation selected by the second selection to calculate, based on information from the audio-frequency component, a second estimate of the direction of arrival of the audio-frequency component.

11. The method according to claim 2, wherein said method comprises:

calculating a time of flight of a second ultrasonic signal to the first detector and a time of flight of the second ultrasonic signal to the second detector;

detecting that (A) a difference between the time of flight of the first ultrasonic signal to the first detector and the time of flight of the second ultrasonic signal to the first detector does not exceed a second threshold value and (B) the second time of flight of the second ultrasonic signal differs from the second time of flight of the first ultrasonic signal; and

in response to said detecting, updating the estimated first range based on the second time of flight of the second ultrasonic signal.

12. The method according to claim 1, wherein said method includes:

based on the estimate of the direction of arrival of the audio-frequency component, selecting a portion of an image as a focus window; and

based on the estimated first range of the sound-emitting object and on information from the focus window, performing a camera focus operation.

13. The method according to claim 1, wherein at least one among said plurality of direction-of-arrival estimation operations includes calculating the estimate based on a difference in gain between channels of the audio-frequency component.

14. The method according to claim 1, wherein at least one among said plurality of direction-of-arrival estimation operations includes calculating the estimate based on a difference in gain between channels of a beam generated from the audio-frequency component.

15. The method according to claim 1, wherein at least one among said plurality of direction-of-arrival estimation operations includes calculating the estimate based on a difference in gain between beams generated from the audio-frequency component.

16. The method according to claim 1, wherein at least one among said plurality of direction-of-arrival estimation operations includes calculating the estimate based on a difference in phase between channels of the audio-frequency component.

17. The method according to claim 1, wherein said selecting one among a plurality of direction-of-arrival estimation operations comprises:

comparing the estimated first range to a threshold value;

if the estimated first range is less than the threshold value, selecting a first one among the plurality of direction-of-arrival estimation operations; and

if the estimated first range is greater than the threshold value, selecting a second one among the plurality of direction-of-arrival estimation operations.

18. The method according to claim 1, wherein the audio-frequency component includes sound emitted by the sound-emitting object.

19. An apparatus for signal processing, said apparatus comprising:

means for estimating a first range of a sound-emitting object, based on information from a first reflection of a first ultrasonic signal;

means for selecting one among a plurality of direction-of-arrival estimation operations, based on the estimated first range; and

means for performing the selected direction-of-arrival estimation operation to calculate, based on information from an audio-frequency component of a multichannel signal, an estimate of a direction of arrival of the audio-frequency component.

20. The apparatus according to claim 19, wherein a first channel of the multichannel signal is based on a signal produced by a first detector and a second channel of the multichannel signal is based on a signal produced by a second detector.

21. The apparatus according to claim 20, wherein said means for estimating the first range includes means for calculating a time of flight of the first ultrasonic signal to the first detector, and wherein said information from the first reflection of the first ultrasonic signal includes said calculated time of flight of the first ultrasonic signal to the first detector.

22. The apparatus according to claim 19, wherein said means for estimating the first range includes means for calculating a time of flight of the first ultrasonic signal to a first detector, and wherein said information from the first reflection of the first ultrasonic signal includes said calculated time of flight of the first ultrasonic signal to the first detector, and

wherein said means for estimating the first range includes means for calculating a time of flight of the first ultrasonic signal to a second detector, and wherein said information from the first reflection of the first ultrasonic signal includes said calculated time of flight of the first ultrasonic signal to the second detector.

23. The apparatus according to claim 22, wherein the audio-frequency component of the multichannel signal is based on signals produced by the first and second detectors.

24. The apparatus according to claim 22, wherein said apparatus comprises means for calculating a second estimate of a direction of arrival of the audio-frequency component, based on the calculated times of flight of the first ultrasonic signal to the first and second detectors.

25. The apparatus according to claim 24, wherein said apparatus comprises means for combining the calculated estimate of a direction of arrival and the calculated second estimate according to a relative weighting to obtain a combined estimate of a direction of arrival,

wherein the relative weighting is based on a level of the audio-frequency component.

26. The apparatus according to claim 25, wherein the relative weighting is based on a difference between the calculated estimate of a direction of arrival and the calculated second estimate.

27. The apparatus according to claim 25, wherein said apparatus includes means for calculating a time of flight of a second ultrasonic signal to the first detector, and

wherein the relative weighting is based on a difference between the times of flight of the first and second ultrasonic signals to the first detector.

28. The apparatus according to claim 20, wherein said apparatus comprises:

means for estimating a second range based on information from a second reflection of the first ultrasonic signal;

means for estimating a third range based on information from a first reflection of a second ultrasonic signal that is emitted after the first ultrasonic signal;

means for estimating a fourth range based on information from a second reflection of the second ultrasonic signal;

means for selecting one among the third and fourth ranges based on a relation between (A) a difference between the first and third ranges and (B) a difference between the second and fourth ranges;

means for performing a second selection of one among the plurality of direction-of arrival estimation operations, based on the selected range; and

means for performing the direction-of-arrival estimation operation selected by the second selection to calculate, based on information from the audio-frequency component, a second estimate of the direction of arrival of the audio-frequency component.

29. The apparatus according to claim 20, wherein said apparatus comprises:

means for calculating a time of flight of a second ultrasonic signal to the first detector and a time of flight of the second ultrasonic signal to the second detector;

means for detecting that (A) a difference between the time of flight of the first ultrasonic signal to the first detector and the time of flight of the second ultrasonic signal to the first detector does not exceed a second threshold value and (B) the second time of flight of the second ultrasonic signal differs from the second time of flight of the first ultrasonic signal; and

means for updating the estimated first range, in response to said detecting, based on the second time of flight of the second ultrasonic signal.

30. The apparatus according to claim 19, wherein at least one among said plurality of direction-of-arrival estimation operations includes calculating the estimate based on a difference in gain between channels of the audio-frequency component.

31. The apparatus according to claim 19, wherein at least one among said plurality of direction-of-arrival estimation operations includes calculating the estimate based on a difference in gain between channels of a beam generated from the audio-frequency component.

32. The apparatus according to claim 19, wherein at least one among said plurality of direction-of-arrival estimation operations includes calculating the estimate based on a difference in gain between beams generated from the audio-frequency component.

33. The apparatus according to claim 19, wherein at least one among said plurality of direction-of-arrival estimation operations includes calculating the estimate based on a difference in phase between channels of the audio-frequency component.

34. The apparatus according to claim 19, wherein said means for selecting one among a plurality of direction-of-arrival estimation operations comprises:

means for comparing the estimated first range to a threshold value;

means for selecting a first one among the plurality of direction-of-arrival estimation operations, if the estimated first range is less than the threshold value; and

means for selecting a second one among the plurality of direction-of-arrival estimation operations, if the estimated first range is greater than the threshold value.

35. The apparatus according to claim 19, wherein the audio-frequency component includes sound emitted by the sound-emitting object.

36. An apparatus for signal processing, said apparatus comprising:

a range estimator configured to estimate a first range of a sound-emitting object, based on information from a first reflection of a first ultrasonic signal;

a comparator configured to select one among a plurality of direction-of-arrival estimation operations, based on the estimated first range; and

a direction calculator configured to perform the selected direction-of-arrival estimation operation to calculate, based on information from an audio-frequency component of a multichannel signal, an estimate of a direction of arrival of the audio-frequency component.

37. The apparatus according to claim 36, wherein a first channel of the multichannel signal is based on a signal produced by a first detector and a second channel of the multichannel signal is based on a signal produced by a second detector.

38. The apparatus according to claim 37, wherein said range estimator is configured to calculate a time of flight of the first ultrasonic signal to the first detector, and wherein said information from the first reflection of the first ultrasonic signal includes said calculated time of flight of the first ultrasonic signal to the first detector.

39. The apparatus according to claim 36, wherein said range estimator is configured to calculate a time of flight of the first ultrasonic signal to a first detector, and wherein said information from the first reflection of the first ultrasonic signal includes said calculated time of flight of the first ultrasonic signal to the first detector, and

wherein said range estimator is configured to calculate a time of flight of the first ultrasonic signal to a second detector, and wherein said information from the first reflection of the first ultrasonic signal includes said calculated time of flight of the first ultrasonic signal to the second detector.

40. The apparatus according to claim 39, wherein the audio-frequency component of the multichannel signal is based on signals produced by the first and second detectors.

41. The apparatus according to claim 39, wherein said apparatus comprises a second direction calculator configured to calculate a second estimate of a direction of arrival of the audio-frequency component, based on the calculated times of flight of the first ultrasonic signal to the first and second detectors.

42. The apparatus according to claim 41, wherein said apparatus comprises a combiner configured to combine the calculated estimate of a direction of arrival and the calculated second estimate according to a relative weighting to obtain a combined estimate of a direction of arrival,

wherein the relative weighting is based on a level of the audio-frequency component.

43. The apparatus according to claim 42, wherein the relative weighting is based on a difference between the calculated estimate of a direction of arrival and the calculated second estimate.

44. The apparatus according to claim 42, wherein said range estimator is configured to indicate a time of flight of a second ultrasonic signal to the first detector, and

wherein the relative weighting is based on a difference between the times of flight of the first and second ultrasonic signals to the first detector.

45. The apparatus according to claim 37, wherein said range estimator is configured to estimate:

a second range based on information from a second reflection of the first ultrasonic signal;

a third range based on information from a first reflection of a second ultrasonic signal that is emitted after the first ultrasonic signal; and

a fourth range based on information from a second reflection of the second ultrasonic signal, and

wherein said apparatus comprises;

a selector configured to select one among the third and fourth ranges based on a relation between (A) a difference between the first and third ranges and (B) a difference between the second and fourth ranges;

a second comparator configured to perform a second selection of one among the plurality of direction-of-arrival estimation operations, based on the selected range; and

a second direction calculator configured to perform the direction-of-arrival estimation operation selected by the second comparator to calculate, based on information from the audio-frequency component, a second estimate of the direction of arrival of the audio-frequency component.

46. The apparatus according to claim 37, wherein said range estimator is configured to calculate a time of flight of a second ultrasonic signal to the first detector and a time of flight of the second ultrasonic signal to the second detector;

and

wherein said apparatus comprises a second comparator configured to detect that (A) a difference between the time of flight of the first ultrasonic signal to the first detector and the time of flight of the second ultrasonic signal to the first detector does not exceed a second threshold value and (B) the second time of flight of the second ultrasonic signal differs from the second time of flight of the first ultrasonic signal, and

wherein said range estimator is configured to update the estimated first range, in response to said detecting, based on the second time of flight of the second ultrasonic signal.

47. The apparatus according to claim 36, wherein at least one among said plurality of direction-of-arrival estimation operations includes calculating the estimate based on a difference in gain between channels of the audio-frequency component.

48. The apparatus according to claim 36, wherein at least one among said plurality of direction-of-arrival estimation operations includes calculating the estimate based on a difference in gain between channels of a beam generated from the audio-frequency component.

49. The apparatus according to claim 36, wherein at least one among said plurality of direction-of-arrival estimation operations includes calculating the estimate based on a difference in gain between beams generated from the audio-frequency component.

50. The apparatus according to claim 36, wherein at least one among said plurality of direction-of-arrival estimation operations includes calculating the estimate based on a difference in phase between channels of the audio-frequency component.

51. The apparatus according to claim 36, wherein said comparator is configured to compare the estimated first range to a threshold value, to select a first one among the plurality of direction-of-arrival estimation operations if the estimated first range is less than the threshold value, and to select a second one among the plurality of direction-of-arrival estimation operations if the estimated first range is greater than the threshold value.

52. The apparatus according to claim 36, wherein the audio-frequency component includes sound emitted by the sound-emitting object.

53. A communications device including an apparatus according to claim 36.

54. A non-transitory computer-readable storage medium having tangible features that cause a machine reading the features to:

estimate a first range of a sound-emitting object, based on information from a first reflection of a first ultrasonic signal;

select one among a plurality of direction-of-arrival estimation operations, based on the estimated first range; and

perform the selected direction-of-arrival estimation operation to calculate, based on information from an audio-frequency component of a multichannel signal, an estimate of a direction of arrival of the audio-frequency component.

55. The medium according to claim 54, wherein at least one among said plurality of direction-of-arrival estimation operations includes calculating the estimate based on a difference in gain between channels of the audio-frequency component.

56. The medium according to claim 54, wherein at least one among said plurality of direction-of-arrival estimation operations includes calculating the estimate based on a difference in gain between channels of a beam generated from the audio-frequency component.

57. The medium according to claim 54, wherein at least one among said plurality of direction-of-arrival estimation operations includes calculating the estimate based on a difference in gain between beams generated from the audio-frequency component.

58. The medium according to claim 54, wherein at least one among said plurality of direction-of-arrival estimation operations includes calculating the estimate based on a difference in phase between channels of the audio-frequency component.

59. The medium according to claim 54, wherein said selecting one among a plurality of direction-of-arrival estimation operations comprises:

comparing the estimated first range to a threshold value;

if the estimated first range is less than the threshold value, selecting a first one among the plurality of direction-of-arrival estimation operations; and

if the estimated first range is greater than the threshold value, selecting a second one among the plurality of direction-of-arrival estimation operations.