Method for compensating for interfering noises in a hands-free apparatus in a motor vehicle, and hands-free apparatus

Patent metadata

Field	Value
Publication number	US-10636404-B2
Application number	US-201816044796-A
Country	US
Kind code	B2
Filing date	Jul 25, 2018
Priority date	Jul 27, 2017
Publication date	Apr 28, 2020
Grant date	Apr 28, 2020

Abstract

The invention relates to a method for compensating for interfering noises in a hands-free apparatus in a motor vehicle as well as a hands-free apparatus in a motor vehicle, comprising at least one microphone, at least one loudspeaker, a control device with at least one adaptive filter as well as a transmitting and receiving apparatus, wherein a pre-filter is arranged before the adaptive filter or predetermined filter coefficients (w[n]) are saved in the adaptive filter, wherein the filter coefficients (w[n]) minimize a vehicle-specific acoustic error signal of the vehicle interior.

First claim

What is claimed is:

1. A method for compensating for interfering signals in a hands-free apparatus in a motor vehicle, using at least one microphone, at least one loudspeaker, a control device with at least one adaptive filter, as well as a transmitting and receiving apparatus, comprising the following method steps, conducted during an initial calibration routine, wherein during the initial calibration routine a motor vehicle interior is without a person:
a) outputting a known acoustic test signal via the at least one loudspeaker,
b) determining filter coefficients (w[n]) of the adaptive filter in order to minimize an acoustic error signal, the error signal representing an acoustic influence of an interior of the motor vehicle, and
c) saving the filter coefficients (w[n]) determined in the method step b) in a pre-filter of the adaptive filter or in the adaptive filter itself;
d) further adapting the filter coefficients (w[n]) when operating the motor vehicle with at least one person being present in the motor vehicle interior.

2. The method of claim 1 , wherein the initial calibration routine is conducted prior to use of the hands-free apparatus.

3. The method of claim 1 , wherein the known acoustic test signal is a noise signal.

4. The method of claim 1 , wherein the known acoustic test signal comprises white noise.

5. The method of claim 1 , wherein the initial calibration routine is triggered manually or automatically at the end of the line after the final assembly of the motor vehicle.

6. The method of claim 5 , wherein the initial calibration routine is performed with windows and doors of the motor vehicle closed.

7. A hands-free apparatus in a motor vehicle, comprising at least one microphone, at least one loudspeaker, a control device with at least one adaptive filter comprising filter coefficients, as well as a transmitting and receiving apparatus, wherein a pre-filter comprising pre-filter coefficients is arranged before the adaptive filter or predetermined filter coefficients (w[n]) are saved in the adaptive filter, wherein at least some of the pre-filter coefficients or the predetermined filter coefficients (w[n]) are obtained during an initial calibration routine of an interior of the motor vehicle, wherein the motor vehicle is without a person during the initial calibration routine, and wherein the pre-filter coefficients or the predetermined filter coefficients (w[n]) minimize a vehicle-specific acoustic error signal of the interior and wherein the control device is configured to further adapt the filter coefficients (w[n]) of the adaptive filter when operating the motor vehicle with at least one person being present in the motor vehicle.

8. The hands-free apparatus according to claim 7 , wherein the control device comprises a signal generator that is designed to output a known acoustic test signal via the at least one loudspeaker at least during the initial calibration routine.

9. The hands-free apparatus according to claim 7 , wherein the adaptive filter comprises an algorithm according to a gradient search method.

10. The hands-free apparatus according to claim 7 , wherein the control device has a noise suppression unit that is arranged between the adaptive filter and the transmitting and receiving apparatus, which noise suppression unit is configured to attenuate one or more of driving noises and wind noises.

11. The hands-free apparatus according claim 7 , wherein a receiving pre-processing unit is arranged between the transmitting and receiving apparatus and the at least one loudspeaker, wherein the receiving pre-processing unit is configured to generate a reference audio signal for a transmitting pre-processing unit.

12. The hands-free apparatus according to claim 7 , wherein the control device is configured such that the size of the residual error can be specified.

13. The hands-free apparatus according to claim 7 , wherein the control unit is designed such that the number of filter coefficients of the adaptive filter can be specified.

14. The hands-free apparatus according to claim 7 , wherein the control device is configured such that the last respectively valid filter coefficients w[n] are saved in the adaptive filter and maintain their validity.

15. The hands-free apparatus according to claim 8 , wherein the adaptive filter comprises an algorithm according to a gradient search method.

16. The hands-free apparatus according to claim 8 , wherein the control device has a noise suppression unit that is arranged between the adaptive filter and the transmitting and receiving apparatus, which noise suppression unit is configured to attenuate one or more of driving noises and wind noises.

17. The hands-free apparatus according to claim 9 , wherein the control device has a noise suppression unit that is arranged between the adaptive filter and the transmitting and receiving apparatus, which noise suppression unit is configured to attenuate one or more of driving noises and wind noises.

18. The hands-free apparatus according claim 8 , wherein a receiving pre-processing unit is arranged between the transmitting and receiving apparatus and the at least one loudspeaker, wherein the receiving pre-processing unit is configured to generate a reference audio signal for a transmitting pre-processing unit.

19. The hands-free apparatus according claim 9 , wherein a receiving pre-processing unit is arranged between the transmitting and receiving apparatus and the at least one loudspeaker, wherein the receiving pre-processing unit is configured to generate a reference audio signal for a transmitting pre-processing unit.

20. The hands-free apparatus of claim 7 , wherein the initial calibration routine is conducted prior to use of the hands-free apparatus.

21. A hands-free apparatus in a motor vehicle, comprising at least one microphone, at least one loudspeaker, a control device with a pre-filter comprising pre-filter coefficients, wherein the pre-filter receives an output signal of the microphone, at least one adaptive filter comprising filter coefficients, wherein the adaptive filter receives an output signal of the pre-filter, and a transmitting and receiving apparatus receiving an output signal of the adaptive filter, wherein at least some of the pre-filter coefficients are obtained during an initial calibration routine of a motor vehicle interior, wherein the motor vehicle interior is without a person during the initial calibration routine, and wherein the pre-filter coefficients minimize a vehicle-specific acoustic error signal of the interior and wherein the control device is configured to further adapt the filter coefficients (w[n]) of the adaptive filter when operating the motor vehicle with at least one person being present in the motor vehicle.

Assignees

• Volkswagen Ag
• Volkswagen Atiengesellschaft

Inventors

• Bork Simon

Classifications

• G10L2021/02082

  the noise being echo, reverberation of the speech · CPC title

• H04M9/082

  using echo cancellers (echo cancellers per se H04B3/23) · CPC title

• G10L21/0208 Primary

  Noise filtering · CPC title

• G10K11/178 Primary

  by electro-acoustically regenerating the original acoustic waves in anti-phase · CPC title

• H04M9/08

  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 title