Aircraft Panel Tuned Mass Dampers for Adaptive Cabin Noise Control

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Solution Overview

Problem

Existing noise control systems for aircraft cabins face challenges in being adjustable, energy-efficient, and lightweight, as active systems consume high energy and passive systems are inflexible due to fixed frequency responses, while current semi-active systems require large and heavy components.

Innovation Solution

A semi-active noise control system comprising a layer with conductive tracks, tuned mass dampers, and sensors, where the eigenfrequency of the dampers is adjusted based on control signals to match noise frequencies, allowing for flexible noise damping with low energy consumption and reduced weight by using miniaturized components and eliminating heavy harnesses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If active noise control systems are used with microphones and loudspeakers, then noise cancellation capability is improved, but energy consumption increases and weight increases

Engineering Contradiction:
Improvenoise cancellation capabilityVSAvoidenergy consumption
Core Design Contradiction:
Object-affected harmful factorsVSUse of energy by moving object

Solution Approach 1:

The patent replaces active acoustic noise control (using microphones and loudspeakers) with a semi-active mechanical vibration control system using tuned mass dampers. The tuned mass dampers passively absorb vibrations at specific frequencies through mechanical resonance, eliminating the need for high-power loudspeakers and continuous energy consumption while maintaining noise cancellation effectiveness.

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

Solution Approach 2:

The patent extracts and removes the heavy and energy-consuming active components (microphones, loudspeakers, and their connecting harnesses) from the system, retaining only the essential vibration absorption function through tuned mass dampers. This extraction eliminates unnecessary energy consumption while preserving the core noise cancellation capability.

Inventive Principle:
Principle #2Taking out (Extraction)

2Use of energy by moving object

If passive noise control systems with tuned mass dampers are used, then energy consumption is reduced, but adaptability to changing noise frequencies deteriorates

Engineering Contradiction:
Improveenergy consumptionVSAvoidadaptability to noise frequencies
Core Design Contradiction:
Use of energy by moving objectVSAdaptability or versatility

Solution Approach 1:

The patent introduces adjustable stiffness elements into the tuned mass dampers, allowing the eigenfrequency to be dynamically tuned to match different noise frequencies. This dynamic adjustment capability enables the passive system to adapt to changing noise environments without requiring active components, maintaining low energy consumption while improving frequency adaptability.

Inventive Principle:
Principle #15Dynamics

3Object-affected harmful factors

If large actuators and sensors are distributed in aircraft cabin, then noise cancellation coverage is improved, but weight increases and installation effort increases

Engineering Contradiction:
Improvenoise cancellation coverageVSAvoidsystem weight
Core Design Contradiction:
Object-affected harmful factorsVSWeight of moving object

Solution Approach 1:

The patent replaces heavy active actuators (loudspeakers) and sensors with lightweight passive tuned mass dampers that can be directly integrated into the aircraft structure. This substitution dramatically reduces system weight while maintaining noise cancellation coverage through the distributed placement of multiple small dampers.

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

Solution Approach 2:

The patent merges the tuned mass dampers with the aircraft's existing structural panels, eliminating the need for separate heavy components and extensive harness connections. The dampers are integrated directly into the panel structure, reducing both weight and installation effort while maintaining effective noise cancellation coverage.

Inventive Principle:
Principle #5Merging (Combining)

4Device complexity

If purely passive tuned mass dampers are used, then system complexity is reduced, but adjustability to different frequencies deteriorates

Engineering Contradiction:
Improvesystem complexityVSAvoidfrequency adjustability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent enables frequency adjustability by providing mechanisms to change the stiffness parameter of the tuned mass dampers. Through adjustable stiffness elements, the eigenfrequency of each damper can be tuned to match different noise frequencies, adding adaptability to the simple passive system without significantly increasing complexity.

Inventive Principle:
Principle #35Parameter changes

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 system provides flexible noise damping with low energy consumption and easy maintenance by adjusting the eigenfrequencies of tuned mass dampers to match noise profiles, reducing weight and installation effort, while maintaining effective noise reduction across varying noise environments.

Implementation Method 1

vibrations of the fuselage of the aircraft and of interior components lead to disturbing noise within the cabin

Methodology Applied
Scientific EffectVibration: Vibration

Implementation Method 2

If the eigenfrequency of the tuned mass damper matches the frequency of the noise component to be attenuated, the vibration of the tuned mass damper is in resonance

Methodology Applied
Scientific EffectResonance: Resonance

Implementation Method 3

spring-mass systems that are attached to the vibrating component/structure and that comprise an eigenfrequency

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4300484A1Semi-active noise control system for an aircraft
Publication Date: 2024.01.03 AIRBUS OPERATIONS GMBH
  • EP4300484A1 patent drawingFigure 1
  • EP4300484A1 patent drawingFigure 2
  • EP4300484A1 patent drawingFigure 3

AI summary

A semi-active noise control system (100) comprising a layer (110) that is configured to be part of an interior panel of an aircraft (200) is disclosed. The layer (110) comprises a plurality of conductive tracks (111), a driver arrangement (112), a plurality of tuned mass dampers (113), and a plurality of sensors (114). Each of the plurality of tuned mass dampers (113) comprises an eigenfrequency that depends on a control signal applied to the tuned mass damper (113) and is connected to the driver arrangement (112) via at least one of the plurality of conductive tracks (111) and configured to receive control signals from the driver arrangement (112). Each of the plurality of sensors (114) is connected to the driver arrangement (112) via at least one of the plurality of conductive tracks (111) and is configured to sense vibrations and/or acoustic sounds and send measurement signals (115) to the driver arrangement (112). The driver arrangement (112) is configured to analyze the measurement signals (115) and to generate and send control signals (116) to the tuned mass dampers (113) such that the eigenfrequency of the tuned mass dampers (113) is matched with the frequency of the vibrations and/or acoustic sounds sensed by the sensors (114).