Automated Vision System for Composite Ply Boundary Inspection

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Solution Overview

Problem

Current optical laser template (OLT) methods for inspecting ply boundaries and orientations in composite structures are time-consuming and inefficient, especially for large structures like aircraft fuselage barrels, limiting production rates and requiring extensive labor and multiple OLTs due to angle of incidence issues.

Innovation Solution

A system combining a vision system with laser tracker measurement devices and encoders to map and compare the actual placement of carbon fiber on a cure mandrel against nominal data in real-time, enabling automated inspection and correction during the fiber placement process, reducing the need for manual rework and increasing production efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If optical laser template (OLT) inspection is used for ply boundary inspection, then measurement precision is maintained, but productivity is significantly reduced due to 30-90 minutes inspection time per ply

Engineering Contradiction:
Improveply boundary inspection accuracyVSAvoidproduction rate
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent replaces the manual mechanical OLT inspection process with an automated vision system that uses cameras and image processing algorithms to detect ply boundaries and orientations. The system captures images of the composite structure, processes them through software algorithms, and automatically determines ply placement accuracy, eliminating the need for manual inspection while maintaining measurement precision.

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

Solution Approach 2:

The patent introduces an automated vision system as an intermediary between the fiber placement machine and the inspection process. This system includes cameras positioned to view the composite structure, image processing software that analyzes the captured images, and a computer that coordinates the inspection process, thereby automating the previously manual OLT inspection workflow.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If multiple OLTs are used to cover full fuselage circumference, then measurement precision is maintained, but device complexity increases

Engineering Contradiction:
Improvefull fuselage inspection accuracyVSAvoidnumber of OLTs and metrology systems
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent employs a single multi-functional vision system that can inspect the entire fuselage circumference by capturing images at multiple angles and positions. The system uses a single camera or limited number of cameras that can be repositioned or rotated to view different sections of the fuselage, eliminating the need for multiple separate OLT units while maintaining comprehensive inspection coverage.

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

Solution Approach 2:

The patent transitions from the limited two-dimensional projection approach of OLT to three-dimensional imaging capabilities. The vision system captures images from multiple angles and positions around the fuselage, using spatial dimensionality to achieve complete coverage without requiring multiple separate inspection devices.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Adaptability or versatility

If OLT projection is used on enlarged surfaces, then inspection capability is maintained, but measurement precision deteriorates due to angle of incidence limitations

Engineering Contradiction:
Improvecapability to inspect modified structuresVSAvoidprojection accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent replaces the laser projection-based OLT system with a vision system that captures images of the actual ply placement on the composite structure. This approach eliminates the angle of incidence problems inherent in laser projection, as the vision system can capture images from optimal angles and use image processing to accurately determine ply boundaries and orientations regardless of surface geometry.

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

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 solution significantly reduces inspection time, improves production rate capabilities, and allows for accurate ply placement on larger structures without relaxing tolerances, providing traceability and continuous quality improvement through real-time data feedback.

Implementation Method 1

A vision system, including one or more cameras, is mounted to the head of the automated fiber placement machine so that the vision system has a field of view of the composite tows after they have been compacted

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 2

A laser tracking system is used to measure a position and an orientation of the AFP head, and the vision system mounted thereon, relative to the mandrel

Methodology Applied
Scientific EffectLaser time of flight: Time of Flight

Data Source

PatentEP2188115B1Methods and systems for automated ply boundary and orientation inspection
Publication Date: 2015.04.15 THE BOEING CO
  • EP2188115B1 patent drawingFigure 1
  • EP2188115B1 patent drawingFigure 2
  • EP2188115B1 patent drawingFigure 3

AI summary

A method and a system for determining the positional laydown accuracy of an automated lamination machine so during fabrication of a multiple layered part is described. The method includes measuring a position of a placement head (54) of the lamination machine (50) in a coordinate system, determining a location of a ply edge with respect to the placement head, transforming the location of the ply edge into the coordinate system, based on the measured head position, transforming the location of the ply edge from the coordinate system into a second coordinate system that is associated with the part being fabricated, and comparing actual ply edge location in the second coordinate system to an expected ply edge location defined in the second coordinate system, the second coordinate system associated with the part being fabricated, to determine the laydown accuracy of the machine.