Adjustable Propeller Blades for UAV Noise Reduction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Unmanned aerial vehicles (UAVs) generate noise due to propeller rotation, which can be disturbing to humans and animals, and existing solutions do not effectively address the need for noise reduction without compromising lifting force or efficiency.

Innovation Solution

The UAV system features adjustable propeller blades that can change position, shape, and configuration during flight, allowing for the generation of anti-sounds to interfere with and reduce the noise produced by the propellers, using sensors and machine learning to optimize sound profiles based on operational conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If propeller rotation speed is increased to improve lifting force, then lifting force is improved, but noise generation increases

Engineering Contradiction:
Improvelifting forceVSAvoidnoise
Core Design Contradiction:
ForceVSObject-generated harmful factors

Solution Approach 1:

The patent implements adjustable propeller blade configurations that can dynamically change during flight. The system includes mechanisms to alter blade pitch, blade area, and blade shape in real-time, allowing the propeller to optimize between lifting performance and noise reduction based on operational requirements

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes physical parameters of the propeller blades including pitch angle, blade area, and blade shape. These parameter changes allow the propeller to operate at different characteristics - high lift configurations when needed and low noise configurations when operating near humans or animals

Inventive Principle:
Principle #35Parameter changes

2Force

If propeller blade area is increased to improve lifting force, then lifting force is improved, but noise generation increases

Engineering Contradiction:
Improvelifting forceVSAvoidnoise
Core Design Contradiction:
ForceVSObject-generated harmful factors

Solution Approach 1:

The patent implements adjustable propeller blade configurations that can dynamically change during flight. The system includes mechanisms to alter blade pitch, blade area, and blade shape in real-time, allowing the propeller to optimize between lifting performance and noise reduction based on operational requirements

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The propeller blade is divided into multiple adjustable segments or sections that can be independently controlled. This segmentation allows different parts of the blade to be optimized for different functions - some sections for lift generation and others for noise reduction, or allows dynamic reconfiguration of the effective blade area

Inventive Principle:
Principle #1Segmentation

3Force

If propeller blade pitch is increased to improve lifting force, then lifting force is improved, but noise generation increases

Engineering Contradiction:
Improvelifting forceVSAvoidnoise
Core Design Contradiction:
ForceVSObject-generated harmful factors

Solution Approach 1:

The patent implements adjustable propeller blade configurations that can dynamically change during flight. The system includes mechanisms to alter blade pitch, blade area, and blade shape in real-time, allowing the propeller to optimize between lifting performance and noise reduction based on operational requirements

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes physical parameters of the propeller blades including pitch angle, blade area, and blade shape. These parameter changes allow the propeller to operate at different characteristics - high lift configurations when needed and low noise configurations when operating near humans or animals

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach effectively reduces noise pollution from UAVs while maintaining or optimizing lifting force and efficiency, allowing for quieter operation without significant power consumption increases.

Implementation Method 1

sound generated by a first propeller of the coaxially aligned propellers causes interference with sound generated by a second propeller of the coaxially aligned propellers

Methodology Applied
Scientific EffectSound wave interference: Interference

Data Source

PatentEP3433168B1Coaxially aligned propellers of an aerial vehicle
Publication Date: 2020.08.19 AMAZON TECH INC
  • EP3433168B1 patent drawingFigure 1
  • EP3433168B1 patent drawingFigure 2~3
  • EP3433168B1 patent drawingFigure 4~5

AI summary

Sounds are generated by an aerial vehicle during operation. For example, the motors and propellers of an aerial vehicle generate sounds during operation. Disclosed are systems, methods, and apparatus for actively adjusting the position and/or configuration of one or more propeller blades of a propulsion mechanism to generate different sounds and/or lifting forces from the propulsion mechanism. A propulsion apparatus, comprising a motor (206), a propeller having a propeller blade (204) and a propeller adjustment controller configured to enable movement of the propeller such that the propeller blade (204) is extendable away from the motor (206) or retractable toward the motor (206). A method for adjusting a propulsion mechanism, comprising: determining a lifting force to be generated by the propulsion mechanism; determining a sound limit to be produced by the propulsion mechanism; selecting a combination of a revolutions per minute ("RPM") of a motor of the propulsion mechanism, a first position of a first propeller of the propulsion mechanism that will generate a first lifting force when rotated by the motor at the RPM, a second position of a second propeller of the propulsion mechanism that will generate a second lifting force when rotated by the motor at the RPM and a third position of a third propeller of the propulsion mechanism that will generate a third lifting force when rotated by the motor at the RPM such that a combination of the first lifting force, the second lifting force, and the third lifting force will generate the lifting force and produce a sound below the sound limit; causing, while the motor is rotating: the first propeller to move to the first position; the second propeller to move to the second position; and the third propeller to move to the third position.