Variable Force-Torque Propellers for UAV Motor-Out Control

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Solution Overview

Problem

Current unmanned aerial vehicles (UAVs) face design tradeoffs between agility and energy efficiency, and lack the capability to maintain control in degraded operational states such as motor out situations, limiting their performance and safety.

Innovation Solution

The design incorporates a ring wing structure surrounding propulsion mechanisms that can reconfigure by modifying force-torque ratios of propellers through deployable flaps, protrusions, and blade sections to enhance controllability, allowing the UAV to transition between vertical takeoff and landing (VTOL) and horizontal flight orientations and maintain control in degraded states.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional fixed-configuration propellers are used, then the UAV structure is simple, but the controllability in degraded operational states is poor

Engineering Contradiction:
Improvecontrollability in degraded operational statesVSAvoidpropeller structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The propeller blade incorporates modifiable sections that can dynamically change configuration during flight. These sections can be extended, retracted, rotated, or expanded to alter the propeller's aerodynamic characteristics, enabling the UAV to maintain controllability in degraded states by adjusting propeller performance in real-time

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The propeller blade is divided into multiple independent sections, including modifiable blade sections that can be independently controlled. This segmentation allows specific portions of the blade to be adjusted without affecting the entire propeller, enabling fine-tuned control adjustments while maintaining overall structural integrity

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If variable force-torque ratios are implemented, then the controllability and safety in degraded states improve, but the device complexity increases

Engineering Contradiction:
Improveadaptability to degraded operational statesVSAvoidpropeller reconfiguration mechanism
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The propeller blade features localized modifiable sections with distinct aerodynamic properties that can be independently adjusted. These sections have different characteristics from the main blade body, allowing targeted modifications to specific areas of the propeller to achieve desired force-torque ratios without redesigning the entire blade

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The modifiable blade sections can change multiple aerodynamic parameters simultaneously, including area, orientation, and effective radius. By adjusting these parameters, the propeller can dynamically alter its force-torque ratio to adapt to various operational conditions, particularly degraded states where certain motors or propellers may be compromised

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 solution enables UAVs to efficiently operate in six degrees of freedom, improve controllability during motor out situations, and ensure safe landing by dynamically adjusting torque and lift, thereby enhancing both agility and energy efficiency.

Implementation Method 1

In example embodiments, the additional torque may be initiated, controlled, and/or modified by aerodynamic drag

Methodology Applied
Scientific EffectAerodynamic drag: Drag

Data Source

PatentEP3847098B1Aerial vehicle propellers having variable force-torque ratios
Publication Date: 2024.07.24 AMAZON TECH INC
  • EP3847098B1 patent drawingFigure 1
  • EP3847098B1 patent drawingFigure 2
  • EP3847098B1 patent drawingFigure 3

AI summary

Systems and methods to improve controllability of an aerial vehicle (100) responsive to degraded operational conditions are described. For example, one or more propeller blades (104) of an aerial vehicle may be modifiable between two or more configurations. The configurations may include a low torque configuration suitable for normal operational conditions, and a high torque configuration suitable for degraded operational conditions. Various aspects or portions of a propeller blade may be modified to increase torque generated by the propeller blade due t,) drag or air resistance. The additional generated torque may then be used as a source of additional torque to improve controllability of the aerial vehicle responsive to degraded operational conditions.