3D Phase Measurement
Bringing 3D to RVI!
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Ed Hubben /
4/13/2015
3D PM Overview
3D Surface Scanning and Measurement System
Video Borescope Technology
Enables Internal 3D Examination of Equipment
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Ed Hubben /
4/13/2015
Measurement methods
Comparison
Stereo
Shadow
3D Phase
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Ed Hubben /
4/13/2015
Comparison Measurement
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Ed Hubben /
4/13/2015
Stereo Measurement Technology
Split view is difficult to use for general inspection
Accuracy and usability are very dependent on
surface conditions
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Ed Hubben /
4/13/2015
Shadow Measurement Technology
Fiber
Bundle
Slit
Aperture
Shadow
Imager
Shadow
Tip
Close
Z1
Far
Z2
X and Y should be on a perpendicular plane
Only know Z along the shadow line
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Ed Hubben /
4/13/2015
Phase Shifting
What if we had many shadows?
Fiber
Bundle
Slit
Aperture
Shadows
Imager
Shadow
Tip
Z1
Z2
And the shadows had structure?
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Ed Hubben /
4/13/2015
Phase Shifting
Typical Setup
Image 0
Object
Image 1
Image 2
Image 3
Camera
Projector
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Ed Hubben /
4/13/2015
Phase Shifting in the XLG3
LED
Arrays
Shadow
Pattern
Viewing
Optics
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Ed Hubben /
4/13/2015
Forward View Tip
Lens
Phase Gratings
Arc Lamp Illumination
Double Threads
Side View Tip
Phase Gratings
Lens
Arc Lamp Illumination
Double Threads
Optics Configuration
• Line patterns are projected using 3
LEDs on each side of viewing optics.
• Object distance at each point is
computed using pattern trajectories
(triangulation) known from calibration.
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GE Presenter and Event /
4/13/2015
Phase Images
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GE Presenter and Event /
4/13/2015
Phase Images
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GE Presenter and Event /
4/13/2015
Phase Images
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GE Presenter and Event /
4/13/2015
Image Capture and Analysis
1
2
3
4
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Ed Hubben /
4/13/2015
Types of 3D Measurement
Length
Multi-Segment Length
Area
Point to Line
Depth
Depth Profile
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Ed Hubben /
4/13/2015
Length and Multi-Segment Length
Crack in Turbine Guide Vane
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Ed Hubben /
4/13/2015
Area
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Ed Hubben /
4/13/2015
3D View of Area
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Ed Hubben /
4/13/2015
Point to Line
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Ed Hubben /
4/13/2015
Depth
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Ed Hubben /
4/13/2015
Depth Map
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Ed Hubben /
4/13/2015
Depth – Used for Blade Clearance
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Ed Hubben /
4/13/2015
Depth Profile
Illustrative example:
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Ed Hubben /
4/13/2015
Depth Profile
0.180” Slot
Should be in
same plane
Point furthest from
reference plane
Scale
No Data
Distance
Between
Cursors
Cross-Sectional
Area (only when
no red included)
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Ed Hubben /
4/13/2015
Depth Profile
Tear in Welded Blade Edge
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Ed Hubben /
4/13/2015
Point Cloud
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Ed Hubben /
4/13/2015
Point Cloud – x,y,z file
Compare worn
condition to new
geometry
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Ed Hubben /
4/13/2015
Application – Turbine Blade
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Ed Hubben /
4/13/2015
Application – Weld Inspection
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Ed Hubben /
4/13/2015
Weld in 3D
Not a flat plate!
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Ed Hubben /
4/13/2015