Modeling and Reduction of Drone Propulsion System Noise

• US 20180005643A1
• Filed: 01/20/2016
• Published: 01/04/2018
• Est. Priority Date: 01/20/2015
• Status: Active Grant

• Current Assignee: Dolby Laboratories Licensing Corporation (Dolby Laboratories Incorporated)
• Original Assignee: Dolby Laboratories Licensing Corporation (Dolby Laboratories Incorporated)
• Inventors: TSINGOS, Nicolas R.
• Granted Patent: US 10,522,166 B2
• Time in Patent Office: Days
• CPC Class Codes: B64C 2220/00 Active noise reduction systems
• CPC Class Codes: B64C 39/024 of the remote controlled vehicle type, i.e. RPV
• CPC Class Codes: B64U 10/13 Flying platforms
• CPC Class Codes: B64U 50/19 using electrically powered motors
• CPC Class Codes: G01H 3/00 Measuring characteristics of vibrations by using a detector in a fluid G01H7/00, G01H9/00, G01H11/00 take precedence
• CPC Class Codes: G10K 11/175 using interference effects; Masking sound
• CPC Class Codes: G10L 2021/02085 Periodic noise
• CPC Class Codes: G10L 2021/02166 Microphone arrays; Beamforming
• CPC Class Codes: G10L 21/0208 Noise filtering
• CPC Class Codes: G10L 21/0216 characterised by the method used for estimating noise
• CPC Class Codes: G10L 21/0232 Processing in the frequency domain

Abstract

In some embodiments, a method, apparatus and computer program for reducing noise from an audio signal captured by a drone (e.g., canceling the noise signature of a drone from the audio signal) using a model of noise emitted by the drone'"'"'s propulsion system set, where the propulsion system set includes one or more propulsion systems, each of the propulsion systems including an electric motor, and wherein the noise reduction is performed in response to voltage data indicative of instantaneous voltage supplied to each electric motor of the propulsion system set. In some other embodiments, a method, apparatus and computer program for generating a noise model by determining the noise signature of at least one drone based upon a database of noise signals corresponding to at least one propulsion system and canceling the noise signature of the drone in an audio signal based upon the noise model.

Claims

1. A method, comprising steps of:

generating a noise model, including by determining the noise signature of at least one drone having a propulsion system set, as a function of voltage supplied to the propulsion system set, based upon a database of noise signals corresponding to at least one propulsion system and at least one microphone; and

canceling the noise signature of the drone in an audio signal based upon the noise model.

2. The method of claim 1, wherein the step of generating a noise model comprises steps of:

recording a database of noise signals, each of the noise signals representing noise emitted by at least one electric motor and at least one propeller coupled to the electric motor while a voltage is supplied to the electric motor, wherein the noise signals corresponding to each said electric motor include noise signals representing noise emitted while each voltage (V) of a set of voltages is supplied to the electric motor, said set of voltages extending across a voltage range; and

generating a parametric model of the noise as a function of V.

3. The method of claim 1, further comprising the step of:

microphone array beamforming and wind noise reduction.

4. The method of claim 1, wherein the noise cancellation occurs on board the drone resulting in a clean microphone feed being transmitted to a remote location for further processing.

5. The method of claim 1, wherein the noise cancellation occurs at a remote location using voltage information transmitted from the drone to the remote location.

6. The method of claim 5, wherein one channel transmitted from the drone is designated a dirty microphone feed channel and another channel transmitted from the drone is designated to include a multiplexed digital signal for each of a voltage feed related to each drone propulsion system.

7. The method of claim 5, wherein the remote location aggregates data in order to cancel noise from a plurality of drones.

8. The method of claim 5, wherein information is transmitted back from the drones to the remote location in a wireless synchronized procedure.

9. The method of claim 8, wherein the wireless synchronized procedure is repeated for multiple paths and a time alignment scheme is implemented including by estimating relative positions of the plurality of drones using a camera-based tracking system or global positioning satellite tracking system.

10. The method of claim 9, wherein the drone or plurality of drones are reconfigured dynamically based on motion tracking and tracked using reflecting targets.

11. The method of claim 8, wherein a flexible surround microphone array is created.

12. The method of claim 8, wherein camera and actor aware dialog recording is employed to combine a camera'"'"'s pan/zoom/field of view information with drone tracking to optimize recording a position outside of a camera view frustum for recording dialog on movie, television or multimedia sets.

13. The method of claim 1, wherein each propulsion system of the propulsion system set comprises at least one electric motor and at least one propeller.

14. A computer program product comprising a computer-readable medium which is a non-transitory medium, and on which is stored instructions for performing the method of claim 13.

15. An apparatus, comprising:

at least one processor; and

at least one memory which is a non-transitory medium, and on which is stored a computer program,

in which the at least one memory with the computer program is configured with the at least one processor to cause the apparatus to at least;

generate a noise model by determining the noise signature of at least one drone based upon a database of noise signals corresponding to at least one propulsion system and at least one microphone; and

cancel the noise signature of the drone in an audio signal based upon the noise model.

16. The apparatus of claim 15, wherein the propulsion system comprises at least one electric motor and at least one propeller.

17. An apparatus for use in at least one user equipment, comprising:

circuitry adapted to cause the apparatus to at least;

generate a noise model by determining the noise signature of at least one drone based upon a database of noise signals corresponding to at least one propulsion system and at least one microphone; and

cancel the noise signature of the drone in an audio signal based upon the noise model.

18. The apparatus of claim 17, wherein the propulsion system comprises at least one electric motor and at least one propeller.

19. A method for performing noise reduction on audio captured by a drone having a propulsion system set and a microphone set, the propulsion system set including at least one propulsion system, each said propulsion system including an electric motor, and the microphone set including at least one microphone, said method including steps of:

(a) providing voltage data indicative of instantaneous voltage supplied to each electric motor of the propulsion system set; and

(b) in response to the voltage data, using modeled noise to perform noise reduction on an audio signal captured by the microphone set of the drone, where the modeled noise is determined by a model of noise emitted by the propulsion system set as a function of instantaneous voltage supplied to said each motor of the propulsion system set.

20. The method of claim 19, wherein step (a) of providing voltage data indicative of instantaneous voltage supplied to each electric motor of the propulsion system set further includes steps of:

receiving at a processing system at least one signal indicative of the voltage data; and

parsing the at least one signal to identify said voltage data.

21-41. -41 (canceled)