Systems, apparatus, and methods for drone audio noise reduction

Patent metadata

Field	Value
Publication number	US-10290293-B2
Application number	US-201715806741-A
Country	US
Kind code	B2
Filing date	Nov 8, 2017
Priority date	Nov 8, 2017
Publication date	May 14, 2019
Grant date	May 14, 2019

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.

First claim

What is claimed is:

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:
identify a rotational motion value from the rotational motion data;
identify a first filter that matches a rotational motion value greater than the identified rotational motion value;
identify a second filter that matches a rotational motion value lower than the identified rotational motion value;
filter the acoustic data into filtered acoustic data with a combination of the first identified filter and the second identified filter as a matching 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 rotational motion data is first rotational motion data 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 third filter; and
filter the acoustic data into the filtered acoustic data with the matching filter and the third identified filter.

5. The apparatus of claim 1 , wherein the rotational motion data is first rotational motion data gathered at a first time 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:
identify a third filter that matches the second rotational motion data, the third identified filter different than the matching filter;
filter the acoustic data gathered at the second time into second filtered acoustic data using the third identified filter; and
generate a second audio signal based on the second filtered acoustic data.

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

7. The apparatus of claim 1 , further including a controller to:
set the rotor to a first calibration rotational motion, the first sensor to gather first preliminary acoustic data when the rotor is set at the first calibration rotational motion, and
set the rotor to a second calibration rotational motion, the first sensor to gather second preliminary acoustic data when the rotor is set at the second calibration rotational motion; and
the analyzer to:
establish a first reference filter based on the first preliminary acoustic data and correlate the first calibration rotational motion with the first reference filter,
establish a second reference filter based on the second preliminary acoustic data and correlate the second calibration rotational motion with the second reference filter,
determine which of the first calibration rotational motion or the second calibration rotational motion is closer in value to the rotational motion data;
select between the first reference filter associated with the first calibration rotational motion and the second reference filter associated with the second calibration rotational motion based on which of the first calibration rotational motion or the second calibration rotational motion is closer in value to the rotational motion data; and
use the selected first reference filter or the second reference filter to filter the acoustic data into the filtered acoustic data.

8. The apparatus of claim 7 , 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.

9. The apparatus of claim 7 , wherein the analyzer is to establish the first reference filter based on a signal-to-noise ratio gain.

10. A method of reducing audio noise from a drone, the method comprising:
identifying, by executing an instruction with a processor, a rotational motion value from rotational motion data gathered from a rotor;
identifying, by executing an instruction with the processor, a first filter that matches a rotational motion value greater than the identified rotational motion value;
identifying, by executing an instruction with the processor, a second filter that matches a rotational motion value lower than the identified rotational motion value;
using, by executing an instruction with the processor, a combination of the first identified filter and the identified second filter as a matching filter to filter acoustic data gathered from the drone into filtered acoustic data; and
generating, by executing an instruction with the processor, an audio signal based on the filtered acoustic data.

11. The method of claim 10 , wherein the rotational motion data is first rotational motion data and the rotor is a first rotor, the method further including:
establishing, by executing an instructions with the processor, a third filter for second rotational motion data gathered from a second rotor; and
filtering, by executing an instruction with a processor, the acoustic data into filtered acoustic data with the matching filter and the third identified filter.

12. The method of claim 10 , wherein the rotational motion data is first rotational motion data gathered at a first time and the audio signal is a first audio signal at the first time, the method further including:
establishing, by executing an instruction with the processor, a third 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 third identified filter different than the matching filter;
filtering, by executing an instruction with the processor, acoustic data gathered from the drone at the second time into second filtered acoustic data using the third established filter; and
generating, by executing an instruction with the processor, a second audio signal based on the second filtered acoustic data.

13. The method of claim 10 , further including:
setting, by executing an instruction with a processor, the rotor to a first calibration rotational motion;
gathering, by executing an instruction with the processor, first preliminary acoustic data when the rotor is set at the first calibration rotational motion;
establishing, by executing an instruction with the processor, a first reference filter based on the first preliminary acoustic data;
associating the first calibration rotational motion with the first reference filter;
setting, by executing an instruction with the processor, 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, by executing an instruction with the processor, a second reference filter based on the second preliminary acoustic data; and
associating the second calibration rotational motion with the second reference filter;
determining, by executing an instruction with the processor, which of the first calibration rotational motion or the second calibration rotational motion is closer in value to the rotational motion data;
selecting, by executing an instruction with the processor, between the first reference filter associate

Assignees

• Intel Corp

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

Classifications

• G10K2210/1281

  Aircraft, e.g. spacecraft, airplane or helicopter · CPC title

• G10K11/175 Primary

  using interference effects; Masking sound · CPC title

• H04R3/00

  Circuits for transducers (arrangements for producing a reverberation or echo sound G10K15/08; amplifiers H03F) · CPC title

• G10L2021/02085

  Periodic noise · CPC title

• G10L21/0208

  Noise filtering · CPC title