SYSTEMS, APPARATUS, AND METHODS FOR DRONE AUDIO NOISE REDUCTION

• US 20190043465A1
• Filed: 11/08/2017
• Published: 02/07/2019
• Est. Priority Date: 11/08/2017
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Cordourier Maruri, Hector, Huang, Jonathan, Lopez Meyer, Paulo, De La Guardia Gonzalez, Rafael, Gomez Gutierrez, David, Aldana Lopez, Rodrigo, Campos Macias, Leobardo, Parra Vilchis, Jose, Camacho Perez, Jose, Zamora Esquivel, Julio
• Granted Patent: US 10,290,293 B2
• Time in Patent Office: Days
• CPC Class Codes: G10K 11/175 using interference effects; Masking sound
• CPC Class Codes: G10K 2210/1281 Aircraft, e.g. spacecraft, airplane or helicopter
• CPC Class Codes: G10L 2021/02085 Periodic noise
• CPC Class Codes: G10L 2021/02165 Two microphones, one receiving mainly the noise signal and the other one mainly the speech signal
• CPC Class Codes: G10L 21/0208 Noise filtering
• CPC Class Codes: H04R 1/1083 Reduction of ambient noise active noise reduction per se G10K11/175; protective devices for the ear, e.g. providing acoustic protection A61F11/06
• CPC Class Codes: H04R 2227/001 Adaptation of signal processing in PA systems in dependence of presence of noise
• CPC Class Codes: H04R 2410/01 Noise reduction using microphones having different directional characteristics
• CPC Class Codes: H04R 2410/05 Noise reduction with a separate noise microphone
• CPC Class Codes: H04R 2410/07 Mechanical or electrical reduction of wind noise generated by wind passing a microphone
• CPC Class Codes: H04R 3/00 Circuits for transducers , loudspeakers or microphones

Abstract

Methods, systems, and apparatus for audio noise reduction from a drone are disclosed. An example apparatus includes a first sensor to gather acoustic data and a second sensor to gather rotational motion data of a rotor. The example apparatus also includes an analyzer to match the rotational motion data to a filter and filter the acoustic data using the filter. The analyzer also is to generate an audio signal based on the filtered acoustic data.

Claims

1. An apparatus to reduce audio noise from a drone, the apparatus comprising:

a first sensor to gather acoustic data;

a second sensor to gather rotational motion data of a rotor; and

an analyzer to;

match the rotational motion data to a filter;

filter the acoustic data using the filter; and

generate an audio signal based on the filtered acoustic data.

2. The apparatus of claim 1, wherein the first sensor is an omnidirectional microphone.

3. The apparatus of claim 1, wherein the analyzer is to filter the acoustic data during the rotational motion of the rotor.

4. The apparatus of claim 1, wherein the filter is a first filter and the analyzer is to match the rotational motion data to the first filter by:

identifying a second filter of a rotational motion value greater than the rotational motion data;

identifying a third filter of a rotational motion value lower than the rotational motion data; and

using a combination of the second filter and the third filter as the first filter.

5. The apparatus of claim 1, wherein the rotational motion data is first rotational motion data, the filter is a first filter, and the rotor is a first rotor,

wherein the second sensor or a third sensor is to gather second rotational motion data of a second rotor, and the analyzer is to further:

match the second rotational motion data to a second filter; and

filter the acoustic with the second filter.

6. The apparatus of claim 1, wherein the rotational motion data is first rotational motion data gathered at a first time, the filter is a first filter, and the audio signal is a first audio signal at the first time,

wherein the second sensor is to gather second rotational motion data of the rotor at a second time, the second rotational motion data having a value different than the first rotational motion data, and the analyzer is to further:

match the second rotational motion data to a second filter, the second filter different than the first filter;

filter the acoustic data with the second filter; and

generate a second audio signal at the second time based on the filtering of the acoustic data with the second filter.

7. The apparatus of claim 1, wherein the analyzer is to identify ground-based activity based on the audio signal.

8. The apparatus of claim 1, further including a controller to set the rotor to a first calibration rotational motion, wherein the first sensor is to gather first preliminary acoustic data when the rotor is set at the first calibration rotational motion, and the analyzer is to establish a first reference filter based on the first preliminary acoustic data and match the first calibration rotational motion to the first reference filter,

wherein the controller is to set the rotor to a second calibration rotational motion, the first sensor is to gather second preliminary acoustic data when the rotor is set at the second calibration rotational motion, and the analyzer is to establish a second reference filter based on the second preliminary acoustic data and match the second calibration rotational motion to the second reference filter, and

wherein the analyzer matches the rotational motion data to a filter by:

determining which of the first calibration rotational motion or the second calibration rotational motion is closer in value to the rotational motion data;

selecting between the first reference filter and the second reference filter associated with the first calibration rotational motion or the second calibration rotational motion that is closer is in value to the rotational motion data; and

using the selected first reference filter or second reference filter as the filter.

9. The apparatus of claim 8, wherein the analyzer is to establish the first reference filter by:

converting the first preliminary acoustic data into the frequency domain;

determining an average amplitude of the frequency spectrum; and

performing spectral subtraction based on the average amplitude of the frequency spectrum.

10. The apparatus of claim 8, wherein the analyzer is to establish the first reference filter based on a signal-to-noise ratio gain.

11. A method of reducing audio noise from a drone, the method comprising:

establishing, by executing an instruction with a processor, a filter for rotational motion data gathered from a rotor;

filtering, by executing an instruction with a process, acoustic data gathered from the drone using the filter; and

generating, by executing an instruction with a process, an audio signal based on the filtered acoustic data.

12. The method of claim 11, wherein the filter is a first filter and matching the rotational motion data to the first filter includes:

identifying a second filter of a rotational motion value greater than the rotational motion data;

identifying a third filter of a rotational motion value lower than the rotational motion data; and

using a combination of the second filter and the third filter as the first filter.

13. The method of claim 11, wherein the rotational motion data is first rotational motion data, the filter is a first filter, and the rotor is a first rotor, the method further including:

establishing a second filter for second rotational motion data gathered from a second rotor; and

filtering the acoustic with the second filter.

14. The method of claim 11, wherein the rotational motion data is first rotational motion data gathered at a first time, the filter is a first filter, and the audio signal is a first audio signal at the first time, the method further including:

establishing a second filter for second rotational motion data gathered from the rotor at a second time, the second rotational motion data having a value different than the first rotational motion data, the second filter different than the first filter;

filtering the acoustic data with the second filter; and

generating a second audio signal at the second time based on the filtering of the acoustic data with the second filter.

15. The method of claim 11, further including:

setting the rotor to a first calibration rotational motion;

gathering first preliminary acoustic data when the rotor is set at the first calibration rotational motion;

establishing a first reference filter based on the first preliminary acoustic data;

matching the first calibration rotational motion to the first reference filter;

setting the rotor to a second calibration rotational motion;

gathering second preliminary acoustic data when the rotor is set at the second calibration rotational motion;

establishing a second reference filter based on the second preliminary acoustic data; and

matching the second calibration rotational motion to the second reference filter, wherein matching the rotational motion data to a filter includes;

determining which of the first calibration rotational motion or the second calibration rotational motion is closer in value to the rotational motion data;

selecting between the first reference filter and the second reference filter associated with the first calibration rotational motion or the second calibration rotational motion that is closer is in value to the rotational motion data; and

using the selected first reference filter or second reference filter as the filter.

16. The method of claim 15, wherein establishing the first reference filter includes:

converting the first preliminary acoustic data into the frequency domain;

determining an average amplitude of the frequency spectrum; and

performing spectral subtraction based on the average amplitude of the frequency spectrum.

17. A drone, comprising:

a rotor;

a motor to rotate the rotor;

means for gathering acoustic data;

means for gathering revolutions per minute (rotational motion) data of a rotor; and

means for processing the acoustic data and the rotational motion data by;

matching the rotational motion data to a filter;

filtering the acoustic data using the filter; and

generating an audio signal based on the filtered acoustic data.

18. The drone of claim 17, wherein the filter is a first filter and the means for processing is to match the rotational motion data to the first filter by:

identifying a second filter of a rotational motion value greater than the rotational motion data;

identifying a third filter of a rotational motion value lower than the rotational motion data; and

using a combination of the second filter and the third filter as the first filter.

19. The drone of claim 17, wherein the rotational motion data is first rotational motion data, the filter is a first filter, and the rotor is a first rotor,

wherein the means for gathering rotational motion data is to gather second rotational motion data of a second rotor, and the means for processing is to:

match the second rotational motion data to a second filter; and

filter the acoustic with the second filter.

20. The drone of claim 17, wherein the rotational motion data is first rotational motion data gathered at a first time, the filter is a first filter, and the audio signal is a first audio signal at the first time,

wherein the means for gathering rotational motion data is to gather second rotational motion data of the rotor at a second time, the second rotational motion data having a value different than the first rotational motion data, and the means for processing is to further:

match the second rotational motion data to a second filter, the second filter different than the first filter;

filter the acoustic data with the second filter; and

generate a second audio signal at the second time based on the filtering of the acoustic data with the second filter.

21. The drone of claim 17, further including means for controlling the motor that is to:

set the rotor to a first calibration rotational motion, wherein the means for gathering acoustic data is to gather first preliminary acoustic data when the rotor is set at the first calibration rotational motion, and the means for processing is to establish a first reference filter based on the first preliminary acoustic data and match the first calibration rotational motion to the first reference filter; and

set the rotor to a second calibration rotational motion, wherein the means for gathering acoustic data is to gather second preliminary acoustic data when the rotor is set at the second calibration rotational motion, and the means for processing is to establish a second reference filter based on the second preliminary acoustic data and match the second calibration rotational motion to the second reference filter, and

wherein the means for processing matches the rotational motion data to a filter by;

determining which of the first calibration rotational motion or the second calibration rotational motion is closer in value to the rotational motion data;

selecting between the first reference filter and the second reference filter associated with the first calibration rotational motion or the second calibration rotational motion that is closer is in value to the rotational motion data; and

using the selected first reference filter or second reference filter as the filter.

22. A non-transitory computer readable storage medium comprising computer readable instructions that, when executed, cause one or more processors to at least:

match rotational motion data gathered from a rotor to a filter;

filter acoustic data gathered from the drone using the filter; and

generate an audio signal based on the filtered acoustic data.

23. The storage medium as defined in claim 22, wherein the filter is a first filter and the computer readable instructions, when executed, further cause the processor match the rotational motion data to the first filter by:

identifying a second filter of a rotational motion value greater than the rotational motion data;

identifying a third filter of a rotational motion value lower than the rotational motion data; and

using a combination of the second filter and the third filter as the first filter.

24. The storage medium as defined in claim 22, wherein the rotational motion data is first rotational motion data, the filter is a first filter, and the rotor is a first rotor, and the computer readable instructions, when executed, further cause the processor to:

match second rotational motion data gathered from a second rotor to a second filter; and

filter the acoustic with the second filter.

25. The storage medium as defined in claim 22, wherein the rotational motion data is first rotational motion data gathered at a first time, the filter is a first filter, and the audio signal is a first audio signal at the first time, and the computer readable instructions, when executed, further cause the processor to:

match second rotational motion data gathered from the rotor at a second time to a second filter, the second rotational motion data having a value different than the first rotational motion data, the second filter different than the first filter;

filter the acoustic data with the second filter; and

generate a second audio signal at the second time based on the filtering of the acoustic data with the second filter.