Fiber Optic Slat Flap Control Lever for Stable Position Sensing

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Solution Overview

Problem

Current slat/flap control systems in airplanes deteriorate over time due to airgap changes, necessitating a more reliable and longer-lasting control system.

Innovation Solution

A system utilizing an optical fiber to control slat and flap positions by applying an external force to cause a phase shift, determined by a cam's radius at different circumferential locations, with a processor adjusting positions based on this shift.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a magnet position control system with airgap transformer is used, then slat and flap positions can be controlled, but the system effectiveness deteriorates over time due to airgap changes

Engineering Contradiction:
Improvecontrol system effectivenessVSAvoidsystem longevity
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent replaces the magnetic field-based transformer control system with an optical fiber-based control system. The optical system uses light transmission through fiber optics to detect slat and flap positions, eliminating the airgap transformer that degrades over time. This substitution of mechanical/electromagnetic components with optical components resolves the reliability issue caused by airgap changes.

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

Solution Approach 2:

The patent changes the detection parameter from magnetic field coupling (transformer) to optical phase shift. By measuring the phase shift of light traveling through the optical fiber that changes with slat/flap positions, the system achieves more stable and reliable position detection without the degradation issues of magnetic systems.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If optical fiber with external force application is used, then phase shift detection provides precise position control, but device complexity increases

Engineering Contradiction:
Improveposition detection precisionVSAvoidcontrol system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces an optical fiber as an intermediary element that physically connects the slat/flap mechanism to the detection system. The fiber acts as a mediator that translates mechanical position changes into optical phase shifts, providing precise measurement while maintaining a relatively simple overall system architecture.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The optical fiber creates an optical copy or representation of the mechanical position state through phase modulation. Instead of directly measuring mechanical dimensions, the system uses light phase as an analogous representation of position, enabling precise indirect measurement.

Inventive Principle:
Principle #26Copying

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

Provides a reliable and durable control of slat and flap positions using optical phase shift detection, enhancing system longevity and precision.

Implementation Method 1

passing a light having an input optical phase through an optical fiber, applying an external force to the optical fiber to cause the light exiting the optical fiber to have output optical phase, determining a phase shift between the input optical phase and the output optical phase

Methodology Applied
Scientific EffectOptical phase shift: Photoelasticity

Data Source

PatentEP4371875B1Fiber optic slat flap system and control lever
Publication Date: 2025.08.20 HAMILTON SUNDSTRAND CORP
  • EP4371875B1 patent drawingFigure 1
  • EP4371875B1 patent drawingFigure 2
  • EP4371875B1 patent drawingFigure 3

AI summary

A control system performs a method of controlling a wing of an airplane. The control system includes an optical fiber (112, 114), a bending device (410) and a processor (210). The optical fiber is configured to receive light having an input optical phase. The bending device applies an external force on the optical fiber. The external force causes the light exiting the optical fiber to have an output optical phase. a processor determines a phase shift between the input optical phase and the output optical phase and controls the wing based on the phase shift.