EPTA Autorotation Backup Power for eVTOL Emergency Landing
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Solution Overview
Problem
Traditional helicopters and emerging eVTOL models lack reliable emergency landing systems, particularly during power failures, with multi-rotors facing challenges if one propeller fails and tiltrotors lacking proven mechanisms for safe landings, especially during the tilting phase.
Innovation Solution
An electric propeller torque arm (EPTA) system with a redundant power supply and autorotation mechanism, including a high-energy emergency motor and battery, combined with a jettisonable battery pack and a multi-redundant autonomous landing system using LiDAR and computer vision, ensures controlled descent and safe landing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional helicopters rely solely on inertial autorotation during power failure, then the system complexity is reduced, but the reliability of emergency landing is insufficient
Solution Approach 1:
The patent applies beforehand cushioning by incorporating a backup emergency motor and battery system that activates automatically during power failure. This pre-prepared emergency power source cushions the impact of main power loss, ensuring the rotor can maintain rotation and enable safe autorotation landing, thus improving emergency landing reliability without requiring complete system simplification.
Solution Approach 2:
The patent utilizes parameter changes by switching from the main power system to an emergency power system with different operational parameters. The emergency motor operates with adjusted power output and duration parameters specifically optimized for autorotation maintenance, allowing the system to adapt to failure conditions while managing overall complexity through parameter optimization rather than structural complexity.
2Speed
If the battery pack is retained during emergency descent, then the power supply duration is extended, but the descent rate increases
Solution Approach 1:
The patent applies segmentation by dividing the power supply system into two distinct segments: the main battery pack and a separate emergency battery. The emergency battery provides targeted, short-duration power specifically for rotor speed maintenance during critical descent phases, while the main battery can be jettisoned to reduce weight and descent rate. This segmentation allows optimized power duration without compromising descent rate control.
Solution Approach 2:
The patent implements preliminary action by pre-positioning the emergency battery and emergency motor system ready for immediate activation upon main power failure. This preliminary preparation ensures that rotor speed maintenance power is available exactly when needed during the transition to autorotation, without requiring the main battery pack to remain attached, thus achieving both extended critical power duration and reduced descent rate.
3Adaptability or versatility
If multi-rotors are used for vertical take-off and landing, then the adaptability is improved, but the reliability during propeller failure is reduced
Solution Approach 1:
The patent applies taking out by extracting the tail rotor system from the overall propulsion architecture. By using a single main rotor with vertical take-off and landing capability, the system eliminates multiple propellers and their associated failure modes. The extracted simplified configuration maintains adaptability for vertical operations while improving reliability by removing the vulnerability of multiple propeller systems to partial failure.
4Adaptability or versatility
If tiltrotors are used to combine vertical lift and speed, then the adaptability is improved, but the reliability during tilting phase failure is reduced
Solution Approach 1:
The patent applies inversion by reversing the conventional approach: instead of tilting propellers to achieve vertical lift and forward speed, the system uses a fixed horizontal rotor that provides vertical lift through rotation, with forward speed achieved through aerodynamic lift during flight. This inverted configuration eliminates the mechanically complex and failure-prone tilting mechanism, maintaining adaptability for both vertical and horizontal flight while significantly improving reliability during the transition phase.
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
Enables controlled autorotation and safe landings with reduced descent rates, surpassing traditional helicopters by maintaining rotor speed and utilizing real-time feedback for a smooth touchdown.
Implementation Method 1
a high-energy, short-duration emergency motor drive system is activated. This emergency system includes a high-energy, high-current emergency battery and a dedicated emergency motor
Implementation Method 2
the lift generated by the rotor blades allows the helicopter to descend gently, akin to the way a maple seed drifts to the ground
Implementation Method 3
When the driving torque equals the resisting torque, the net torque is zero, and the rotor maintains continuous rotation due to its existing inertia
Data Source
AI summary
Flight safety of electric vertical take-off and landing (eVTOL) aircrafts is a matter of life and death, crucial to their future regulatory and market acceptance as the next generation of aerial vehicles. Only those aircraft equipped with a safe emergency landing system will be selected for human use, but the current eVTOL models lack reliable emergency landing systems. The first inventor, who already holds patents for an eVTOL helicopter with an electric propeller torque arm (EPTA) driving the main rotor—featuring high efficiency, structural simplification, zero emissions, and low noise—successfully completed test flights and then invented the safest, most innovative autorotation landing system. This system significantly enhances and optimizes the traditional helicopter's inherent autorotation landing capability, ensuring a critical safety measure for eVTOLs during power system failures. Thus, this invention of the safety landing system will help make the safest vertical take-off and landing aircraft eligible for market acceptance.