Collapsible Lift Propellers for UAVs
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Solution Overview
Problem
Unmanned aerial vehicles (UAVs) face challenges in efficiently managing lift during take-off and landing, requiring excess lift capacity while minimizing electrical power consumption and avoiding drag and stability issues during transit operations.
Innovation Solution
The development of collapsible lift propellers with a pivotably mounted radial extension that biases into a transverse position when not in use, utilizing a torsion spring and airflow to align with the direction of travel, reducing power consumption and enhancing stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If lift propellers are operated continuously to maintain excess lift capacity, then lift availability is improved, but electrical power consumption increases
Solution Approach 1:
The propeller blade is designed with a collapsible extension that can dynamically change its configuration between extended and collapsed states. This dynamic structural change allows the propeller to adapt its lift-generating surface area based on operational requirements, enabling the system to maintain reliability when needed while reducing energy consumption when excess lift is not required
2Use of energy by moving object
If lift propellers are shut down to reduce power consumption, then electrical power consumption is reduced, but drag and stability issues worsen
Solution Approach 1:
The collapsible extension automatically transitions between extended and collapsed configurations based on the rotational state of the propeller. During transit when the propeller is not rotating, the extension collapses to minimize drag and maintain stability. When the propeller rotates for lift generation, the extension extends to provide the necessary lift surface area
Solution Approach 2:
The propeller blade's extension automatically changes configuration based on the propeller's operational state without requiring external control systems. The structural design itself provides the mechanism for adapting to different operational modes, eliminating the need for additional actuators or control mechanisms
3Object-generated harmful factors
If propeller extension is collapsed to reduce drag during transit, then drag is reduced, but lift capacity is worsened
Solution Approach 1:
The propeller blade incorporates an extension that can dynamically adjust its configuration. When collapsed, the extension minimizes the blade's surface area to reduce drag during transit operations. When extended, the same structure increases the lift-generating surface area to provide maximum lift capacity during takeoff and landing operations
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 allows for efficient management of lift capacity, reducing power consumption and drag, while maintaining stability during transit and operation, by dynamically adjusting the propeller orientation based on operational needs.
Implementation Method 1
a biasing element, e.g., a torsion spring, for biasing the radial extension into the second position or orientation
Implementation Method 2
When the lift propeller is spinning under power at an angular velocity consistent with normal operations of an aerial vehicle to which the lift propeller is mounted, the biasing force provided by the biasing element is overcome by airflow over the propeller
Data Source
AI summary
Aerial vehicles may be equipped with collapsible lift propellers and thrust propellers. The collapsible lift propellers may include retractable tips that may pivot or rotate from a first orientation substantially co-aligned with a main body of the collapsible lift propellers during ordinary operations and a second orientation substantially transverse to the main body of the collapsible lift propellers when rotation of the collapsible lift propellers is stopped. The collapsible lift propellers may further include biasing elements, e.g., springs for biasing the retractable tips into the second orientation, and mechanical stops for inhibiting the pivoting or rotation of the retractable tips beyond the first orientation.