Aircraft Reference System Using Laser Targets for Dimensional Measurement

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Solution Overview

Problem

Aircraft manufacturers face challenges in achieving precise and repeatable measurements of aircraft dimensions due to changes caused by attached components and fuel levels, which affect wing alignment and symmetry, and existing methods are limited by accessibility and reliability of measurement points.

Innovation Solution

A system utilizing two measurement devices placed near aircraft doors, with reflective devices inside, to establish a measurement baseline by projecting laser lights and calculating distances, allowing for precise determination of wing and fuselage dimensions, and enabling continuous monitoring of shape and positioning changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional alignment point drawings and golden rivets are used for measurements, then measurement points are accessible and easy to locate, but measurement precision and reliability deteriorate due to changes in aircraft shape and size from attached components and fuel level variations

Engineering Contradiction:
Improvemeasurement precisionVSAvoidreliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent introduces laser targets as intermediary measurement markers that are permanently attached to the aircraft structure at critical locations. These targets serve as stable reference points that remain fixed relative to the aircraft's structural framework, rather than relying on surface features that change with fuel level or attached components. The laser tracking devices measure distances to these intermediary targets, providing reliable and precise measurements that are independent of temporary configuration changes.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces traditional mechanical measurement systems (golden rivets, alignment drawings, surface contact measurements) with optical measurement systems. Laser tracking devices emit laser beams that measure distances to reflective targets using time-of-flight or phase-shift methods. This substitution eliminates the need for physical contact with the aircraft surface and provides non-contact, high-precision measurements that are not affected by surface geometry changes.

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

2Ease of manufacture

If gyroscopes or predictive shim processes with surface contact measurements are used, then measurement processes are established, but measurement accessibility worsens because many measurement points become covered and inaccessible once the aircraft enters service

Engineering Contradiction:
Improveease of manufactureVSAvoidease of operation
Core Design Contradiction:
Ease of manufactureVSEase of operation

Solution Approach 1:

The patent establishes laser target positions and measurement baselines during the manufacturing phase, before the aircraft enters service. Permanent laser targets are attached to the aircraft structure at locations that remain accessible throughout the aircraft's operational life. This preliminary setup creates a enduring measurement reference system that can be used repeatedly for quality verification, maintenance, and rework without requiring access to temporary manufacturing fixtures or covered surfaces.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If multiple measurement devices and reflective devices are deployed inside and outside the aircraft, then measurement precision and baseline accuracy improve, but device complexity increases

Engineering Contradiction:
Improvemeasurement precisionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent employs laser tracking devices that can perform multiple functions: establishing measurement baselines between targets, measuring distances to various aircraft features, and verifying both manufacturing quality and in-service conditions. The same optical measurement system serves both manufacturing and maintenance phases, eliminating the need for separate measurement systems. The reflective targets serve as universal reference points for all measurement activities.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 system provides a reliable and repeatable method for measuring aircraft dimensions, improving wing symmetry and alignment, reducing the need for adjustments, and enabling more accurate maintenance and performance optimization.

Implementation Method 1

projecting laser lights and calculating distances

Methodology Applied
Scientific EffectLaser: Laser

Implementation Method 2

first plurality of reflective devices inside the aircraft proximate the first door. The first plurality of reflective devices is in a first optical path with the first measurement device

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP2944918B1Aircraft enhanced reference system and method
Publication Date: 2017.05.10 THE BOEING CO
  • EP2944918B1 patent drawingFigure 1
  • EP2944918B1 patent drawingFigure 2
  • EP2944918B1 patent drawingFigure 3~4

AI summary

A method including placing first and second measurement devices proximate first and second aircraft doors, respectively, and determining a first position of the second measurement device relative to a second position of the first measurement device. The method includes placing first and second pluralities of reflective devices inside the aircraft proximate the first and second doors, respectively. The method includes measuring first and second distances from the first and second measurement devices to the first and second pluralities of reflective devices, respectively, and measuring second distances from the second measurement device to the second plurality of reflective devices. Based on a determined position of the second measurement device and further based on the first distances and second distances, third distances are determined between each of the first and second pluralities of reflective devices. The third distances provide a measurement baseline for points on a fuselage and wings.