Tethered UAV Payload Oscillation Damping During Winch Operations

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Unmanned aerial vehicles (UAVs) face challenges in efficiently damping oscillations of payloads coupled to a tethered winch system, which can lead to instability during payload delivery and retrieval operations.

Innovation Solution

The implementation of a control system that switches to forward flight mode to induce drag on the payload, reducing flight stabilization along certain dimensions, thereby dissipating energy and damping oscillations, and a payload coupling apparatus with a solid-state design that includes no moving parts for secure and reliable payload handling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the UAV uses traditional flight stabilization methods to dampen payload oscillations, then the payload stability is improved, but the system complexity and energy consumption increase

Engineering Contradiction:
Improvepayload stabilityVSAvoidsystem complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent converts the harmful oscillations of the payload into beneficial drag forces by moving the UAV forward. The payload oscillations create increased aerodynamic drag during forward flight, which naturally dampens the oscillations without requiring additional stabilization systems. This transforms a problematic phenomenon into a useful damping mechanism.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The system uses the UAV's own forward motion to generate drag forces that dampen payload oscillations. The payload itself, through its oscillatory movement, creates the drag force needed for stabilization. This self-service mechanism eliminates the need for external or additional active stabilization systems.

Inventive Principle:
Principle #25Self-service

2Stability of the object's composition

If the UAV reduces flight stabilization to dampen oscillations through energy dissipation, then the oscillation damping is improved, but the payload stability deteriorates

Engineering Contradiction:
Improveoscillation dampingVSAvoidpayload stability
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The system dynamically adjusts the UAV's flight mode between hover and forward flight based on payload oscillation conditions. During tether deployment and retrieval, the UAV hovers to maintain payload stability. When oscillations occur, the UAV transitions to forward flight to dampen oscillations through drag, then returns to hover to restore stability. This dynamic switching allows the system to achieve both oscillation damping and payload stability.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If the winch system includes moving parts for payload handling, then the operational flexibility is improved, but the reliability and maintenance requirements worsen

Engineering Contradiction:
Improveoperational flexibilityVSAvoidsystem reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent replaces traditional mechanical moving parts in the winch system with a solid-state spool design. The spool is rotated by a motor to wind and unwound to pay out the tether, eliminating complex mechanical components such as gears, belts, and clutches. This substitution maintains operational flexibility for payload deployment and retrieval while significantly improving reliability by removing parts that can wear or fail.

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

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 effectively damps payload oscillations, ensuring stable and reliable delivery and retrieval operations without the complexity and failure risks associated with moving parts, enhancing the reliability and efficiency of UAV payload management.

Implementation Method 1

the UAV's control system may dampen the oscillations by causing the UAV to switch to a forward flight mode in which movement of the UAV results in drag on the payload, thereby damping the oscillations due to the drag

Methodology Applied
Scientific EffectDrag: Drag

Implementation Method 2

the control system may cause the UAV to reduce an extent of flight stabilization along at least one dimension, thereby resulting in damping of the detected oscillations due to energy dissipation during movement of the UAV along the at least one dimension

Methodology Applied
Scientific EffectEnergy dissipation: Viscous Damping

Data Source

PatentEP3509948B1System for damping oscillations of a payload
Publication Date: 2021.11.03 WING AVIATION LLC
  • EP3509948B1 patent drawingFigure 1A
  • EP3509948B1 patent drawingFigure 1B~1C
  • EP3509948B1 patent drawingFigure 1D

AI summary

Described herein are methods and systems to dampen oscillations of a payload coupled to a tether of a winch system arranged on an unmanned aerial vehicle (UAV). For example, the UAV's control system may dampen the oscillations by causing the UAV to switch to a forward flight mode in which movement of the UAV results in drag on the payload, thereby damping the oscillations. In another example, the control system may cause the UAV to reduce an extent flight stabilization along at least one dimension, thereby resulting in damping of the detected oscillations due to energy dissipation during movement of the UAV along the dimension. In this way, the control system could select and carry out one or more such techniques, and could do so during retraction and/or deployment of the tether.