Tethered UAV Buoyancy and Wind Power for Long Endurance

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Solution Overview

Problem

Current UAV systems for C4ISR functions face limitations in payload capacity, mission duration, and operational costs due to significant resource requirements, with conventional fixed and rotary wing UAVs needing substantial human involvement and fuel-dependent blimps or tethered airships having limited flight durations and recovery challenges.

Innovation Solution

A tethered unmanned aerial vehicle (TUAV) with a fuselage, rigid wings, and buoyancy cells containing lighter-than-air gas, integrated wind-powered generators, and a lifting gas replenishment system, allowing for long-duration flights and autonomous operation without onboard fuel, with control surfaces for flight control and a tether attachment structure for secure anchoring.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If conventional fixed or rotary wing UAVs are used, then payload capacity and mobility are improved, but mission duration is limited due to fuel constraints and substantial resource requirements

Engineering Contradiction:
Improvemission durationVSAvoidresource requirements
Core Design Contradiction:
Duration of action of moving objectVSQuantity of substance

Solution Approach 1:

The TUAV uses an onboard wind-powered generator to generate electrical power autonomously from wind energy, eliminating the need for external fuel supply and reducing ground support resources. The system serves itself by converting environmental wind energy into electrical power for onboard equipment.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces the conventional mechanical fuel-based propulsion system with a wind-powered electrical generation system. Instead of using combustion engines requiring fuel, the TUAV uses aerodynamic lift from wings combined with wind-driven generators to produce electricity, substituting mechanical chemical energy conversion with aerodynamic and electromagnetic energy conversion.

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

2Duration of action of moving object

If blimps or tethered airships are used, then flight duration can be extended, but recovery becomes difficult if the tether is broken and fuel requirements limit duration

Engineering Contradiction:
Improveflight durationVSAvoidrecovery capability
Core Design Contradiction:
Duration of action of moving objectVSReliability

Solution Approach 1:

The TUAV incorporates autonomous flight control capabilities and onboard navigation systems that enable it to return to its launch site automatically if the tether is broken. The vehicle can independently navigate, position itself, and execute recovery procedures without requiring external assistance, thereby improving reliability.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent employs a hybrid buoyancy system using lighter-than-air gas in buoyancy cells to provide lift, changing the physical state of the propulsion system from purely mechanical (fixed-wing) to aerostatic-aerodynamic hybrid. This allows extended flight duration without fuel consumption for lift generation, while the controlled buoyancy adjustment enables precise position control and safe recovery.

Inventive Principle:
Principle #35Parameter changes

3Duration of action of moving object

If tethered airships with diesel generators are used, then extended flight duration is achieved, but fuel consumption limits the duration and increases operational cost

Engineering Contradiction:
Improveflight durationVSAvoidfuel consumption
Core Design Contradiction:
Duration of action of moving objectVSUse of energy by moving object

Solution Approach 1:

The patent replaces the diesel generator-based mechanical power system with a wind-powered aerodynamic generation system. The TUAV uses wings to generate lift and reduce the need for active propulsion, while wind-driven generators convert kinetic energy directly into electrical power, eliminating fuel consumption entirely.

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

Solution Approach 2:

The invention extracts and utilizes wind energy from the environment as a free energy source, removing the dependency on carried fuel. By harnessing the kinetic energy of moving air through the wind-powered generator, the system obtains unlimited operational duration constrained only by environmental conditions rather than fuel capacity.

Inventive Principle:
Principle #2Taking out (Extraction)

4Adaptability or versatility

If conventional UAVs are used, then operational flexibility is maintained, but significant personnel and facility resources are required increasing cost

Engineering Contradiction:
Improveoperational flexibilityVSAvoidpersonnel and facility resources
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The TUAV incorporates autonomous flight control, self-positioning, and automated recovery capabilities that eliminate the need for substantial human involvement in daily operations. The vehicle independently manages navigation, maintains position using buoyancy control and flight surfaces, and executes recovery procedures, thereby reducing personnel requirements while maintaining operational flexibility.

Inventive Principle:
Principle #25Self-service

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 long-duration, cost-effective, and autonomous flight with reduced human intervention, maintaining positional control and generating electrical power for extended periods, overcoming limitations of conventional UAVs and blimps by utilizing wind energy and gas replenishment for buoyancy.

Implementation Method 1

at least one buoyancy cell disposed within the fuselage and configured for containing a lighter than air gas. The one or more buoyancy cells can contain a predetermined volume of lighter than air gas sufficient to provide positive buoyancy for the TUAV when the TUAV is disposed in air

Methodology Applied
Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Implementation Method 2

At least one wind-powered generator is integrated with the TUAV and configured to generate electric power in response to the flow of air across the least one wing when the TUAV is aloft

Methodology Applied
Scientific EffectWind power generation: Wind Power

Implementation Method 3

The wing is comprised of an airfoil shaped body capable of producing lift in response to a flow of air across a major wing surface

Methodology Applied
Scientific EffectAerodynamic lift: Aerofoil

Data Source

PatentEP3287358B1Tethered unmanned aerial vehicle
Publication Date: 2020.08.26 HARRIS CORP
  • EP3287358B1 patent drawingFigure 1
  • EP3287358B1 patent drawingFigure 2~3
  • EP3287358B1 patent drawingFigure 4~5

AI summary

Tethered unmanned aerial vehicle (TUAV) includes at least one wing (104) fixed to a fuselage (102). The wing is comprised of an airfoil shaped body capable of producing lift in response to a flow of air across a major wing surface, and can include at least one flight control surface (202), such as an aileron. One or more buoyancy cell (302) is disposed within the fuselage (102) for containing a lighter than air gas to provide positive buoyancy for the TUAV when the TUAV is disposed in air. A tether attachment structure facilitates attachment of the TUAV to a tether which is secured to an attachment point (109) for securing the TUAV to the ground when aloft. A wind-powered generator is integrated with the TUAV and configured to generate electric power in response to the flow of air across the least one wing when the TUAV is aloft.