Curved-Track NDI Scanning for High-Rate Fuselage Inspection

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Solution Overview

Problem

Existing non-destructive inspection (NDI) systems for barrel-shaped fuselage sections in aircraft manufacturing are inefficient, costly, and struggle to maintain high production rates, particularly in inspecting composite materials and internal stiffeners.

Innovation Solution

A method and apparatus using a curved track system with NDI sensor units mounted on a carriage that travels along linear and curved rails, combined with motion capture or encoder tracking, to perform high-speed, three-dimensional scanning of both the outer mold line and internal stiffeners of fuselage sections, enabling concurrent external and internal scanning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple-axis robotic systems with encoded rails and end effectors are used to move ultrasonic transducer arrays over the fuselage section, then inspection precision is improved, but system cost and complexity increase significantly

Engineering Contradiction:
Improveinspection precisionVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The inspection system is divided into separate functional modules: a robotic crawler for navigation, ultrasonic transducer arrays for inspection, and a control system. The crawler moves along the fuselage surface independently while the transducer arrays are positioned and oriented as needed, separating the navigation function from the inspection function to reduce overall system complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A compliant end effector acts as an intermediary between the rigid robotic crawler and the fuselage surface. This compliant mechanism accommodates surface variations and positioning errors without requiring high-precision encoding rails, simplifying the guidance system while maintaining inspection precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If traditional NDI systems inspect the outer mold line of fuselage sections, then external surface inspection is achieved, but inspection speed is insufficient to maintain high production rates

Engineering Contradiction:
Improveexternal surface inspection capabilityVSAvoidinspection speed
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The system combines external and internal inspection capabilities into a single integrated platform. The robotic crawler can inspect the outer mold line, then transition to the interior to inspect stiffeners and internal structures, eliminating the need for separate inspection processes and doubling productivity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The inspection process is made continuous by enabling the robotic crawler to move seamlessly from external to internal inspection without interruption. The system maintains inspection activity throughout the entire process, eliminating idle time between external and internal inspection operations.

Inventive Principle:
Principle #20Continuity of useful action

3Reliability

If the fuselage section is rolled in a rotating tool frame for internal stiffener inspection, then gravity-related inspection issues are resolved, but the system becomes large and expensive

Engineering Contradiction:
Improveinternal stiffener inspection reliabilityVSAvoidsystem size and cost
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Instead of rotating the fuselage section in a large tool frame, the approach is inverted: the robotic crawler moves along the interior surface while the fuselage remains stationary. This eliminates the need for large rotating equipment and complex tool frames, reducing system size and cost while maintaining inspection reliability.

Inventive Principle:
Principle #13The other way round (Inversion)

4Productivity

If high-speed scanning of both external and internal surfaces is performed, then productivity increases to meet production schedules, but measurement precision may be compromised

Engineering Contradiction:
Improveinspection throughputVSAvoidflaw detection accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The system uses dynamic positioning with real-time feedback control to maintain measurement precision during high-speed scanning. The robotic crawler incorporates sensors and control algorithms that continuously adjust its position and orientation to compensate for motion variations, ensuring accurate flaw detection even at high inspection speeds.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2952890B1Automated scanning method for non-destructive inspection of curved cylinder-like workpieces
Publication Date: 2025.07.02 THE BOEING CO
  • EP2952890B1 patent drawingFigure 1
  • EP2952890B1 patent drawingFigure 2
  • EP2952890B1 patent drawingFigure 3

AI summary

Systems and methods for high-speed non-destructive inspection of a half- or full-barrel-shaped workpiece, such as a barrel-shaped section of an aircraft fuselage. Such workpieces can be scanned externally using a mobile (e.g., translating) arch gantry system comprising a translatable arch frame disposed outside the fuselage section, a carriage that can travel along a curved track carried by the arch frame, a radially inward-extending telescopic arm having a proximal end fixedly coupled to the carriage, and an NDI sensor unit coupled to a distal end of the telescoping arm. The stiffeners of the fuselage sections can be scanned using a mobile scanner platform disposed inside the fuselage section, which platform comprises a radially outward-extending telescopic arm rotatably coupled to a mobile (e.g., holonomic or linear motion) platform and an NDI sensor unit coupled to a distal end of the telescoping arm. The scan data is matched with position data acquired using any one of a plurality of tracking systems to enable the display of NDI features/flaws on a three-dimensional representation of the workpiece.