# US 12,767,324 B2 · Rotor units having asymmetric rotor blades > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,767,324 B2 - Document ID: US12767324B2 - Status: Granted - Kind: B2 - Application number: 17/347,549 - Filed: 2021-06-14 - Published: 2021-10-07 - Granted: 2026-10-20 - Earliest claimed: 2016-12-30 - Assignees: Wing Aviation LLC - Applicants: Wing Aviation LLC - Inventors: Giulia Pantalone; Adam Woodworth - Web page: https://patentgrep.com/patent/US12767324B2 ## CPC - B64C 27/467: Aerodynamic features - B64C 27/463: {Blade tips} - B64U 30/29: Constructional aspects of rotors or rotor supports; Arrangements thereof - B64C 27/32: Rotors - B64C 2230/14: achieving noise reductions - B64U 10/14: with four distinct rotor axes, e.g. quadcopters - B64U 40/10: for adjusting control surfaces or rotors - B64U 2101/30: for imaging, photography or videography - B64U 2101/67: the UAVs comprising tethers for lowering the goods - B64U 2201/104: using satellite radio beacon positioning systems, e.g. GPS - B64C: AEROPLANES; HELICOPTERS - B64U: UNMANNED AERIAL VEHICLES [UAV]; EQUIPMENT THEREFOR ## Abstract An aerial vehicle is provided including rotor units connected to the aerial vehicle, and a control system configured to operate at least one of the rotor units. The rotor unit includes rotor blades, wherein each rotor blade includes a surface area, and wherein an asymmetric parameter is defined, at least in part, by the relationship between the surface areas of the rotor blades. The value of the asymmetric parameter is selected such that the operation of the rotor unit: (i) moves the rotor blades such that each rotor blade produces a respective vortex and (ii) the respective vortices cause the rotor unit to produce a sound output having an energy distribution defined, at least in part, by a set of frequencies, wherein the set of frequencies includes a fundamental frequency, one or more harmonic frequencies, and one or more non-harmonic frequencies having a respective strength greater than a threshold strength. ## Claims ### Claim 1 An aerial vehicle comprising: a plurality of rotor units connected to the aerial vehicle, wherein the plurality of rotor units is configured to provide thrust to the aerial vehicle, and wherein at least one rotor unit of the plurality of rotor units comprises: two or more rotor blades, wherein each rotor blade of the two or more rotor blades comprises a surface area, and wherein an asymmetric parameter is defined, at least in part, by the relationship between the surface areas of the two or more rotor blades; a control system configured to operate the at least one rotor unit, wherein the value of the asymmetric parameter is such that the operation of the at least one rotor unit: (i) moves the two or more rotor blades such that each rotor blade produces a respective vortex and (ii) the respective vortices produced by the two or more rotor blades cause the rotor unit to produce a sound output having an energy distribution defined, at least in part, by a set of frequencies, wherein the set of frequencies comprises a fundamental frequency, one or more harmonic frequencies of the fundamental frequency, and one or more non-harmonic frequencies of the fundamental frequency, each frequency of the set of frequencies having a respective strength greater than a threshold strength of 5 db(A). ### Claim 2 (depends on 1) The aerial vehicle of claim 1, wherein the aerial vehicle further comprises a second plurality of rotor units connected to the aerial vehicle, and wherein the second plurality of rotor units is configured to provide lift to the aerial vehicle. ### Claim 3 (depends on 2) The aerial vehicle of claim 2, wherein at least one rotor unit of the second plurality of rotor units comprises two or more rotor blades, and wherein each rotor blade of the two or more rotor blades of the at least one rotor unit of the second plurality of rotor units comprises the same dimensions. ### Claim 4 An aerial vehicle comprising: a first plurality of rotor units connected to the aerial vehicle, wherein the first plurality of rotor units is configured to provide forward thrust to the aerial vehicle, and wherein at least one rotor unit of the first plurality of rotor units comprises: two or more rotor blades, wherein each rotor blade of the two or more rotor blades comprises a surface area, and wherein an asymmetric parameter is defined, at least in part, by the relationship between the surface areas of the two or more rotor blades; a control system configured to operate the at least one rotor unit, wherein the value of the asymmetric parameter is such that the operation of the at least one rotor unit: (i) moves the two or more rotor blades such that each rotor blade produces a respective vortex and (ii) the respective vortices produced by the two or more rotor blades cause the rotor unit to produce a sound output having an energy distribution defined, at least in part, by a set of frequencies, wherein the set of frequencies comprises a fundamental frequency, one or more harmonic frequencies of the fundamental frequency, and one or more non-harmonic frequencies of the fundamental frequency, each frequency of the set of frequencies having a respective strength greater than a threshold strength of 5 dB (A); and a second plurality of rotor units connected to the aerial vehicle, wherein the second plurality of rotor units is configured to provide lift to the aerial vehicle. ### Claim 5 (depends on 4) The aerial vehicle of claim 4, wherein the one or more harmonic frequencies of the fundamental frequency comprise five harmonic frequencies of the fundamental frequency, and wherein the one or more non-harmonic frequencies of the fundamental frequency comprise three-non harmonic frequencies of the fundamental frequency. ### Claim 6 (depends on 4) The aerial vehicle of claim 4, wherein the one or more harmonic frequencies of the fundamental frequency comprise three harmonic frequencies of the fundamental frequency, and wherein the one or more non-harmonic frequencies of the fundamental frequency comprise three-non harmonic frequencies of the fundamental frequency. ### Claim 7 (depends on 4) The aerial vehicle of claim 4, wherein the fundamental frequency comprises the blade passing frequency of the at least one rotor unit of the first plurality of rotor units. ### Claim 8 (depends on 4) The aerial vehicle of claim 4, wherein the two or more rotor blades comprise: a first rotor blade comprising a first span, and a second rotor blade comprising a second span that is different than the first span, and wherein the asymmetric parameter is defined, at least in part, by the difference between the first span and the second span. ### Claim 9 (depends on 4) The aerial vehicle of claim 4, wherein the two or more rotor blades comprise: a first rotor blade comprising a first chord distribution, and a second rotor blade comprising a second chord distribution that is different than the first chord distribution, and wherein the asymmetric parameter is defined, at least in part, by the difference between the first chord distribution and the second chord distribution. ### Claim 10 (depends on 4) The aerial vehicle of claim 4, wherein the two or more rotor blades comprise: a first rotor blade comprising a first width at a specific distance from a root of the first rotor blade, and a second rotor blade comprising a second width at a corresponding specific distance from a root of the second rotor blade, wherein the second width is different than the first width, and wherein the asymmetric parameter is defined, at least in part, by the difference between the first width and the second width. ### Claim 11 (depends on 4) The aerial vehicle of claim 4, wherein the two or more rotor blades comprise: a first rotor blade, and a second rotor blade that is different than the first rotor blade, wherein the first rotor blade and the second rotor blade provide substantially the same forward thrust along an axis of rotation of the at least one rotor unit of the first plurality of rotor units. ### Claim 12 (depends on 4) The aerial vehicle of claim 4, wherein at least one rotor unit of the second plurality of rotor units comprises two or more rotor blades, and wherein each rotor blade of the two or more rotor blades of the at least one rotor unit of the second plurality of rotor units comprises the same dimensions. ### Claim 13 A method comprising: using a first plurality of rotor units to provide forward thrust to an aerial vehicle, wherein at least one rotor unit of the first plurality of rotor units comprises two or more rotor blades, wherein each rotor blade of the two or more rotor blades comprises a surface area, wherein an asymmetric parameter is defined, at least in part, by the relationship between the surface areas of the two or more rotor blades, and wherein the value of the asymmetric parameter is such that operation of the at least one rotor unit: (i) moves the two or more rotor blades such that each rotor blade produces a respective vortex and (ii) the respective vortices produced by the two or more rotor blades cause the rotor unit to produce a sound output having an energy distribution defined, at least in part, by a set of frequencies, wherein the set of frequencies comprises a fundamental frequency, one or more harmonic frequencies of the fundamental frequency, and one or more non-harmonic frequencies of the fundamental frequency, each frequency of the set of frequencies having a respective strength greater than a threshold strength of 5 dB (A); and using a second plurality of rotor units to provide lift to the aerial vehicle. ### Claim 14 (depends on 13) The method of claim 13, wherein the one or more harmonic frequencies of the fundamental frequency comprise five harmonic frequencies of the fundamental frequency, and wherein the one or more non-harmonic frequencies of the fundamental frequency comprise three non-harmonic frequencies of the fundamental frequency. ### Claim 15 (depends on 13) The method of claim 13, wherein the one or more harmonic frequencies of the fundamental frequency comprise three harmonic frequencies of the fundamental frequency, and wherein the one or more non-harmonic frequencies of the fundamental frequency comprise three-non harmonic frequencies of the fundamental frequency. ### Claim 16 (depends on 13) The method of claim 13, wherein the fundamental frequency comprises the blade passing frequency of the at least one rotor unit of the plurality of rotor units. ### Claim 17 (depends on 13) The method of claim 13, wherein the two or more rotor blades comprise: a first rotor blade comprising a first span, and a second rotor blade comprising a second span that is different than the first span, and wherein the asymmetric parameter is defined, at least in part, by the difference between the first span and the second span. ### Claim 18 (depends on 13) The method of claim 13, wherein the two or more rotor blades comprise: a first rotor blade comprising a first chord distribution, and a second rotor blade comprising a second chord distribution that is different than the first chord distribution, and wherein the asymmetric parameter is defined, at least in part, by the difference between the first chord distribution and the second chord distribution. ### Claim 19 (depends on 13) The method of claim 13, wherein at least one rotor unit of the second plurality of rotor units comprises two or more rotor blades, and wherein each rotor blade of the two or more rotor blades of the at least one rotor unit of the second plurality of rotor units comprises the same dimensions.