Magnetic Flap Misalignment Detection System

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Solution Overview

Problem

Existing systems for detecting misalignment of aircraft flaps are unreliable, prone to false failures, and require replacement of components, leading to untimely aircraft immobilizations and increased structural stress due to lack of precise misalignment detection.

Innovation Solution

A detection system using magnetic sensors and a neodymium-iron-boron magnet to measure misalignment between adjacent flaps, with a three-sensor configuration providing improved accuracy and robustness, allowing for precise alert thresholds and automatic temperature compensation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a metal fuse and spring mechanism is used to detect misalignment, then misalignment detection is achieved, but the system reliability deteriorates due to false failures and numerous component replacements

Engineering Contradiction:
Improvemisalignment detectionVSAvoidsystem reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces the mechanical fuse-spring detection system with a magnetic field-based sensing system. Hall effect sensors detect the position of a magnet mounted on the flap, eliminating mechanical contact components that are prone to failure. This substitution of mechanical systems with electromagnetic sensing resolves the reliability issue while maintaining detection precision.

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

Solution Approach 2:

The patent uses a magnetic field representation of the physical position rather than direct mechanical contact. The magnet creates a magnetic field that serves as a copy or representation of the flap's position, which is then detected by non-contact Hall effect sensors. This copying approach eliminates wear and false failures associated with mechanical contact.

Inventive Principle:
Principle #26Copying

2Device complexity

If the detection system uses a binary signal output, then simple alert triggering is achieved, but progressive measurement of misalignment is lost

Engineering Contradiction:
Improvesignal processing simplicityVSAvoidprogressive misalignment measurement
Core Design Contradiction:
Device complexityVSLoss of information

Solution Approach 1:

The patent provides more information than the minimum required by implementing a detection system that outputs continuous positional data rather than just binary alert signals. The Hall effect sensors provide progressive measurement of misalignment throughout the entire range of motion, enabling both simple alert triggering and detailed progressive measurement simultaneously.

Inventive Principle:
Principle #16Partial or excessive action

3Measurement precision

If the detection device is mounted astride two flaps with a metal plate fuse, then misalignment detection is achieved, but the device size increases reducing compactness

Engineering Contradiction:
Improvemisalignment detectionVSAvoiddetection device volume
Core Design Contradiction:
Measurement precisionVSVolume of moving object

Solution Approach 1:

The patent extracts the detection function from a large mechanical structure and concentrates it in a compact magnetic sensing assembly. The magnet and Hall effect sensors can be mounted directly on the flap surface, eliminating the need for a large metal plate fuse structure that spanned across both flaps. This extraction principle reduces the detection device volume while maintaining detection capability.

Inventive Principle:
Principle #2Taking out (Extraction)

4Strength

If no misalignment detection system is installed, then structural dimensioning can account for over-stresses, but the structure mass increases

Engineering Contradiction:
Improvestructural strengthVSAvoidstructure mass
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The patent implements preliminary detection of misalignment conditions before they lead to damaging over-stresses. By detecting misalignment early through the magnetic sensing system, the control system can take preventive action (such as stopping flap actuation) before excessive forces develop. This preliminary action eliminates the need to design for worst-case over-stress scenarios, reducing structural mass while maintaining safety.

Inventive Principle:
Principle #10Preliminary action

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 effectively detects misalignment, reduces structural stress, and enables predictive maintenance by providing a proportional measurement of misalignment, thus preventing over-stressing and allowing for timely corrective actions.

Implementation Method 1

A magnet in the form of a neodymium-iron-boron magnet is mounted on the outer rib of the adjacent airfoil. Two magnetic sensors, arranged at equal distance from the magnet when the flaps are in the retracted position and along the axis of actuation of the flaps, are mounted on the outer rib of the flap.

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

A detection system using magnetic sensors and a neodymium-iron-boron magnet to measure misalignment between adjacent flaps

Methodology Applied
Scientific EffectHall effect: Hall Effect

Data Source

PatentEP2392510B1Skew detection system for aircraft lifting surfaces
Publication Date: 2013.11.06 SONACA SA
  • EP2392510B1 patent drawingFigure 1~2
  • EP2392510B1 patent drawingFigure 3~5
  • EP2392510B1 patent drawingFigure 6~8

AI summary

The invention relates to a system for detecting misalignment of adjacent flaps of load-bearing surfaces, the two adjacent flaps being actuated to be moved simultaneously from a retracted position to an extended position. The detection system comprises first means disposed on one of the two adjacent flaps and second means disposed on the other of the two adjacent flaps. The first and second means are arranged opposite each other and cooperate to trigger an alarm upon a predetermined misalignment of the two adjacent flaps. The first means comprise a magnet (30), and the second means comprise magnetic sensors (31, 32, 33), each delivering an electrical signal, representative of its relative position with respect to the magnet, to electronic processing means that provide an alarm signal when the predetermined misalignment is reached.