CALIBRATION METHOD AND SYSTEM

• US 20150181360A1
• Filed: 03/03/2014
• Published: 06/25/2015
• Est. Priority Date: 12/22/2012
• Status: Active Grant

• Current Assignee: Ecole polytechnique fãdãrale de lausanne epfl (Schweizerische Eidgenossenschaft)
• Original Assignee: Ecole polytechnique fãdãrale de lausanne epfl (Schweizerische Eidgenossenschaft)
• Inventors: DOKMANIC, Ivan, VETTERLI, Martin, DAUDET, Laurent
• Granted Patent: US 9,949,050 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01B 5/00 Measuring arrangements characterised by the use of mechanical techniques
• CPC Class Codes: G01C 15/00 Surveying instruments or accessories not provided for in groups G01C1/00 - G01C13/00
• CPC Class Codes: G01H 7/00 Measuring reverberation time ; room acoustic measurements
• CPC Class Codes: G01S 15/06 Systems determining the position data of a target
• CPC Class Codes: G01S 15/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S15/46
• CPC Class Codes: G01S 15/46 Indirect determination of position data
• 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 17/06 Systems determining position data of a target
• 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 7/539 using analysis of echo signal for target characterisation; Target signature; Target cross-section
• CPC Class Codes: G01S 7/54 with receivers spaced apart
• CPC Class Codes: H04R 1/08 Mouthpieces; Microphones; Attachments therefor
• CPC Class Codes: H04R 29/005 Microphone arrays
• CPC Class Codes: H04S 7/305 Electronic adaptation of stereophonic audio signals to reverberation of the listening space H04S7/301 takes precedence

Abstract

The present invention concerns a method for calibrating an array of receivers (r_i), each receiver being configured for receiving a signal transmitted by at least one transmitter (s_i), and echoes of the transmitted signal as reflected by one or more reflective surfaces (w), said method comprising the following steps:

• • sorting said echoes, by assigning each echo to a reflective surface or to a combination of reflective surfaces (w)
  • calibrating said array of receivers (r_i) based on said sorting.

Claims

1. A method for calibrating an array of receivers, each receiver being configured for receiving a signal transmitted by at least one transmitter, and echoes of the transmitted signal as reflected by one or more reflective surfaces, said method comprising the following steps:

sorting said echoes, by assigning each echo to one reflective surface or to a combination of reflective surfaces

calibrating said array of receivers based on said sorting.

2. The method of the previous claim, wherein said sorting comprising

selecting a set of echoes from the echoes as received by the receiver

assigning each echo of the set to one reflective surface or to a combination of reflective surfaces.

3. The method of the previous claim, wherein said calibrating comprising

selecting a calibration module among a number of calibration modules

running said calibration module for all the echoes'"'"' assignments

calculating for each running a fit parameter

selecting an echoes'"'"' assignment on the basis of said fit parameter.

4. The method of the previous claim, comprising

selecting the echoes'"'"' assignment which minimizes said fit parameter.

5. The method of the claim 1, wherein said calibrating an array of receivers meaning determining the position of at least one receiver, and wherein the location and/or the orientation of the reflective surfaces is known.

6. The method of claim 3, wherein said calibrating comprising

determining the location of the transmitter(s) based on the selected echoes'"'"' assignment.

7. The method of claim 3, wherein said calibrating comprising

determining the location and/or orientation of the reflective surface(s) based on the selected echoes'"'"' assignment.

8. The method of the previous claim, the array of receivers comprising at least M_min+1 receivers, wherein M_min is the minimum number of receivers required by the calibration module, the method comprising

selecting a sub-array of receivers from said array of receivers, said sub-array comprising a number of receivers less that the number of receivers of said array of receivers

calibrating said array of receivers based on the signals and echoes received only by said sub-array of receivers.

9. The method of the previous claim, wherein said selecting is based on the knowledge of which receivers of the array of receivers are dose in space.

10. The method of claim 1, said transmitter being a loudspeaker, said array of receivers being an array of microphones, said signal being an acoustic signal.

11. The method of claim 10, said reflective surface being a wall of a room.

12. The method of claim 1, said transmitter being a mobile device, each of said receiver being a mobile device.

13. The method of claim 1, said transmitter being a light source, said array of receivers being an array of light sensitive devices as a photo diodes or cameras, said signal being a light signal.

14. The method of claim 13, said reflective surface being a mirror.

15. A system for calibrating an array of receivers, comprising:

at least one transmitter for sending a signal;

said array of receivers for receiving the transmitted signal and the echoes of the transmitted signals as reflected by one or more reflective surfaces;

a first computing module for sorting said echoes by assigning each of said echoes to one reflective surface or to a combination of reflective surfaces;

a second computing module for calibrating said array of receivers based on said sorting.

16. The system of claim 15, the first and second computing modules being the same module.

17. The system of claim 15, said array of receivers being an array of microphones, said transmitter being a loudspeaker.

18. The system of the previous claim, said reflective surface being a wall of a room.

19. The system of claim 15, said transmitter being a mobile device, each of said receiver being a mobile device.

20. The system of claim 15, said array of receivers being an array of light sensitive devices as a photo diodes or cameras, said transmitter being a light source.

21. The system of the previous claim, said reflective surface being a mirror.

22. A computer program product, comprising:

a tangible computer usable medium including computer usable program code for calibrating an array of receivers, said receiver of the array being configured for receiving a signal transmitted by a transmitter, and echoes of the transmitted signal as reflected by one or more reflective surfaces, the computer usable program code being used for

sorting said echoes, by assigning each of said echoes to one reflective surface or to a combination of reflective surfaces;

calibrating said array of receivers based on said sorting.

23. A method for calibrating an array of transmitters, comprising the following steps:

receiving by a receiver a signal transmitted by at least one transmitter, and echoes of the transmitted signal as reflected by one or more reflective surfaces,

sorting said echoes, by assigning each echo to one reflective surface or to a combination of reflective surfaces

calibrating said array of transmitters based on said sorting.

24. A system for calibrating an array of transmitters, comprising:

said array of transmitters;

a receiver for receiving the signals transmitted by said array of transmitters, and the echoes of the transmitted signals as reflected by one or more reflective surfaces;

a first computing module for sorting said echoes by assigning each of said echoes to one reflective surface or to a combination of reflective surfaces;

a second computing module for calibrating said array of transmitters based on said sorting.

25. A computer program product, comprising:

a tangible computer usable medium including computer usable program code for calibrating an array of transmitter, said array of transmitter being configured for transmitting signals to a receiver, said receiver being configured for receiving a signal transmitted by said array of transmitters, and echoes of the transmitted signals as reflected by one or more reflective surfaces, the computer usable program code being used for

sorting said echoes, by assigning each of said echoes to one reflective surface or to a combination of reflective surfaces;

calibrating said array of transmitters based on said sorting.