Aircraft Fatigue Management via Virtual Load Sensor

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Solution Overview

Problem

Current fatigue management systems for aircraft components are limited by the need for direct load measurements and reliance on flight regime definitions, which can be inaccurate due to pilot variance and separation of high frequency and ground-air-ground loads, leading to conservative maintenance schedules and potential over-servicing of components not fully utilized.

Innovation Solution

A fatigue management system utilizing an on-board virtual load sensor that reconstructs continuous load history by correlating pilot input parameters with load data from classification flights, allowing for accurate fatigue life assessment without internal load sensors, and using neural networks to associate flight parameters with load classes for reliable fatigue consumption analysis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If direct load measurements are used, then measurement precision is improved, but device complexity increases due to installation of internal load sensors

Engineering Contradiction:
Improveload measurement accuracyVSAvoidsensor installation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent creates a virtual copy of the load sensor functionality through software correlation algorithms that map pilot inputs to load characteristics based on classification flight data, eliminating the need for physical sensors while maintaining measurement capability

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent introduces pilot input parameters as an intermediary variable that correlates with actual load conditions, allowing load assessment without direct measurement by serving as a proxy indicator of component stress

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If flight regime recognition is used, then ease of operation is improved, but measurement precision deteriorates due to pilot variance and inaccurate regime definitions

Engineering Contradiction:
Improvesystem operation simplicityVSAvoidload assessment accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent transforms the approach from categorical flight regime recognition to continuous parameter-based correlation, using specific pilot input values and their relationships to determine load characteristics, thereby eliminating the discrete classification inaccuracies

Inventive Principle:
Principle #35Parameter changes

3Reliability

If conservative maintenance schedules are used, then reliability is improved, but productivity deteriorates due to unnecessary servicing of components

Engineering Contradiction:
Improveoperational safetyVSAvoidmaintenance efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system enables each aircraft to self-assess its component fatigue status based on its own operational history and pilot inputs, allowing maintenance to be performed only when actually needed rather than following uniform conservative schedules

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent implements continuous feedback from pilot inputs and operational parameters to update fatigue consumption assessments in real-time, allowing dynamic adjustment of maintenance schedules based on actual component usage rather than static conservative intervals

Inventive Principle:
Principle #23Feedback

4Ease of manufacture

If separation of high frequency and ground-air-ground loads is used, then ease of manufacture is improved, but measurement precision deteriorates due to loss of continuous load history

Engineering Contradiction:
Improvedata processing simplicityVSAvoidload history accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent maintains continuous correlation between pilot inputs and load characteristics throughout the entire flight profile, preserving the continuous load history by continuously mapping operational parameters to fatigue consumption without breaking the data chain into separate frequency components

Inventive Principle:
Principle #20Continuity of useful action

Data Source

PatentEP2535692B1Fatigue management system
Publication Date: 2015.10.21 AIRBUS HELICOPTERS DEUT GMBH
  • EP2535692B1 patent drawingFigure 1
  • EP2535692B1 patent drawingFigure 2~3
  • EP2535692B1 patent drawingFigure 4

AI summary

The invention relates to a fatigue management system for determining the individual life of an aircraft, particularly the individual life of components of a helicopter, by means of an on board virtual load sensor and a method of operating a fatigue management system.