eVTOL Propeller Speed Control for Dutch-Roll Suppression
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Solution Overview
Problem
eVTOL aircraft experience Dutch-roll oscillations due to turbulence, which can impact safety and comfort, and existing control surfaces are not effective as they add weight and complexity, making them undesirable for eVTOL designs.
Innovation Solution
An active turbulence suppression (ATS) system that uses a controller to receive roll angle data and query a database for propeller speed profiles to activate lift propellers and counteract external forces, thereby stabilizing the aircraft without the need for additional control surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If control surfaces are added to counteract Dutch-roll oscillations, then aircraft stability is improved, but device complexity and weight increase
Solution Approach 1:
The patent replaces traditional mechanical control surfaces with an active turbulence suppression system that uses sensor data and computational algorithms to control existing propellers. The controller receives sensor data characterizing aircraft motion and generates control signals to adjust propeller speeds, substituting mechanical control surfaces with an electronic control system that uses existing propulsion components.
Solution Approach 2:
The patent makes existing propellers serve dual functions: their primary propulsion role and their secondary role as control surfaces for turbulence suppression. By modulating propeller speeds based on sensor feedback, the same propellers that provide thrust also generate corrective forces to counteract Dutch-roll oscillations, eliminating the need for dedicated control surfaces.
2Stability of the object's composition
If control surfaces are added to counteract Dutch-roll oscillations, then aircraft stability is improved, but weight increases
Solution Approach 1:
The patent replaces the physical weight of control surfaces with an electronic control system that manipulates the speed of existing propellers. Instead of adding heavy mechanical components to generate corrective aerodynamic forces, the system uses sensors and controllers to modulate the rotation speed of propellers that already exist, achieving stability without additional structural weight.
Solution Approach 2:
The patent enables the existing propulsion system to serve its own dual purpose. The propellers that provide thrust also provide the control authority needed for turbulence suppression, eliminating the need for separate control surfaces and their associated weight. The system uses the aircraft's own propulsion components to counteract disturbances.
3Device complexity
If active turbulence suppression system is implemented, then device complexity is reduced, but control precision requirements increase
Solution Approach 1:
The patent implements a feedback control system where sensors continuously measure aircraft motion parameters including roll angle, and the controller uses this feedback to adjust propeller speeds in real-time. The system receives sensor data characterizing instantaneous roll angle and other motion parameters, then generates control signals to counteract detected deviations from desired flight conditions.
Solution Approach 2:
The patent replaces complex mechanical control surface actuation systems with an electronic control system that uses sensor feedback to modulate propeller speeds. This substitution reduces mechanical complexity while requiring precise sensor measurements and sophisticated control algorithms to achieve the desired stability enhancement.
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
The ATS system effectively mitigates Dutch-roll oscillations by activating propellers to generate counteracting forces, improving safety and reducing weight and complexity in eVTOL aircraft designs.
Implementation Method 1
causing the at least one lift propeller of the VTOL aircraft to rotate at the respective propeller speed to generate a force to counteract the external force
Data Source
AI summary
A system can include a controller that can generate a query request in response to an instantaneous roll angle of a vertical take off and landing (VTOL) aircraft being equal to or greater than a roll angle threshold. The instantaneous roll angle being equal to or greater than the roll angle threshold can indicate that the VTOL aircraft has deviated or is about to deviate from a current stable aircraft state. A database can provide propeller control data identifying a propeller speed profile for at least one propeller of the VTOL aircraft in response to the query request. The database can store different propeller speed profiles for at least some propellers of the VTOL aircraft for respective roll angles. The controller can cause the at least one propeller of the VTOL aircraft to rotate at the propeller speed to return the VTOL aircraft to the stable aircraft state.