VTOL Flight Control Using Swash Plates and Differential Rotor Thrust

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Solution Overview

Problem

Current aircraft flight control systems for rotary fixed-wing aircraft lack efficiency in both vertical takeoff and landing capabilities and forward flight, requiring extensive runways and complex control surfaces that are prone to damage and maintenance issues.

Innovation Solution

A flight control method utilizing rotors with swash plates to generate asymmetric collective and cyclic control moments, allowing for vertical takeoff and transition to horizontal flight without traditional control surfaces, using differential rotor thrust and angular velocities to manage pitch, roll, and yaw.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional control surfaces (ailerons, elevators, rudders) are used for flight control, then the aircraft can achieve forward flight control, but the control surfaces are prone to damage and require extensive maintenance

Engineering Contradiction:
Improvecontrol surface durabilityVSAvoidmaintenance requirements
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The patent removes traditional control surfaces (ailerons, elevators, rudders) from the aircraft design and replaces them with a control system based on differential rotor thrust. This extraction eliminates the vulnerable moving parts that require maintenance while preserving flight control functionality through an alternative mechanism.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent substitutes the mechanical control surface system with an aerodynamic control system based on differential rotor thrust. Instead of using mechanical linkages and hinged surfaces, the control system uses variable thrust from multiple rotors to achieve pitch, roll, and yaw control, eliminating mechanical wear and damage risks.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If rotary fixed-wing aircraft use vertical takeoff capability, then runway requirements are eliminated, but flight control efficiency and forward flight performance deteriorate

Engineering Contradiction:
Improvevertical takeoff capabilityVSAvoidforward flight efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent employs dynamic control of multiple rotors that can independently adjust their thrust magnitude and direction. This dynamic capability allows the aircraft to transition smoothly between vertical takeoff configuration and horizontal forward flight configuration, optimizing performance for each flight phase without sacrificing either capability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The rotor system serves multiple functions: it provides vertical lift for takeoff and landing, generates forward thrust for horizontal flight, and enables attitude control through differential thrust. This multi-functionality eliminates the need for separate systems for vertical and horizontal flight operations.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Ease of operation

If asymmetric collective control is used between port and starboard rotors, then yaw moment and coordinated turns are achieved, but control system complexity increases

Engineering Contradiction:
Improvecoordinated turn capabilityVSAvoidcontrol system complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent combines multiple control functions (collective pitch control, cyclic pitch control, and yaw control) into a unified rotor control system. By integrating these functions into a single control architecture that manages all rotors simultaneously, the system achieves coordinated turns and yaw control without requiring separate mechanical control systems for each function.

Inventive Principle:
Principle #5Merging (Combining)

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 efficient vertical takeoff and landing, reduced maintenance needs, and enhanced reliability by eliminating the need for aerodynamic control surfaces, while maintaining efficient forward flight capabilities.

Implementation Method 1

generating thrust in a first port rotor driven by a first port electric motor on a first port wing and a first starboard rotor driven by a first starboard motor on a first starboard wing to induce vertical takeoff

Methodology Applied
Scientific EffectAerodynamic lift: Aerofoil

Implementation Method 2

A flight control method utilizing rotors with swash plates to generate asymmetric collective and cyclic control moments

Methodology Applied
Scientific EffectCyclic control: Swashplate

Implementation Method 3

generating asymmetric collective control between the first port rotor and the first starboard rotor to induce a yaw moment

Methodology Applied
Scientific EffectCollective control: Swashplate

Implementation Method 4

using differential rotor thrust and angular velocities to manage pitch, roll, and yaw

Methodology Applied
Scientific EffectDifferential thrust control:

Implementation Method 5

generating in a first port rotor a positive rotational moment in response to actuation of a first port swash plate, the first port rotor rotatably coupled to the first port wing, and generating in a first starboard rotor a negative rotational moment

Methodology Applied
Scientific EffectTorque: Torque

Data Source

PatentEP3653499B1Vertical takeoff and landing (VTOL) air vehicle
Publication Date: 2023.10.18 AEROVIRONMENT INC
  • EP3653499B1 patent drawingFigure 1
  • EP3653499B1 patent drawingFigure 2A~2C
  • EP3653499B1 patent drawingFigure 3A

AI summary

A flight control apparatus for fixed-wing aircraft includes a first port wing (115) and first starboard wing (120), a first port swash plate (145) coupled between a first port rotor 155) and first port electric motor (135), the first port electric motor (135) coupled to the first port wing (115), and a first starboard swash plate (150) coupled between a first starboard rotor (130) and first starboard electric motor (140), the first starboard electric motor (140) coupled to the first starboard wing (120).