02. automated 3d ct industrial developments & trends (cairnhill).pdf
TRANSCRIPT
AUTOMATED 3D CT:
INDUSTRIAL
DEVELOPMENTS
AND TRENDS
By S H Lim, Cairnhill Metrology
World Metrology Day, 18 May 2012, NMC, Singapore
V = 0.5 µm, 50kV, 480µA, Mode 3, 4h
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
Outline
Introduction / Brief History
I. XCT Market & Applications
II. XCT Enabling Technologies
III. Industrial Trends and Further Work Areas
Acknowledgement
2
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
Introduction
• ‘Tomography’ comes from the Greek ‘tomos’, which means ‘slice’ –
images are taken through the volume of the object; and ‘graphein’ ,
which means ‘to write’ or record the image.
• In this presentation, “XR” = X-Ray (usually 2D); “XCT” = X-Ray
Computer Tomography, the 3D view from X-ray images. (CT and CAT,
Computer Aided Tomography, are interchangeable terms.)
• For Metrology class XCT, perhaps the term “Metro-XCT” or “MXCT”?
3
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Automated 3D CT Industrial Development & Trends
Wilhelm Conrad Röntgen (1845–1923), discovered electromagnetic X-radiation
on 8 Nov 1895, which won him the first Nobel Prize in Physics in 1901.
Johann Radon (1887–1956), formulated the integral transform of a function over a
straight line, the inverse transform and the transform in three-dimensions in 1917.
Godfrey Hounsfield (1919–2004) constructed a computer that could take input
from X-rays at various angles to create an image of an object in “slices”. His
prototype head scanner was successfully applied on 1 Oct 1971 on a cerebral cyst
patient in London. In 1975, he built a whole-body scanner.
Allan McLeod Cormack (1924-1998), developed the theoretical underpinnings of
CT scanning. In 1979, Hounsfield and Cormack shared the Nobel Prize for
Physiology or Medicine, for their independent contributions to XCT.
4
Milestones in History
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Discovery
of X-rays
W.C. Röntgen
Würzburg 1895
“Ueber eine neue
Art von Strahlen.”
(“On a new kind of
rays.”)
“... dass durch die schwarze Cartonhülse,
..., ein Agens hindurchgeht, das im Stande
ist, lebhafte Fluorescenz zu erzeugen...”
(“... that through the black cartoon casing,
..., an agent is permeating, which is able to
produce vivacious fluorescence”)
Principles of X-ray Inspection
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
What Are X-rays
X-rays are electro-magnetic radiation with wavelengths in the range of
0.01nm to 10nm (hard: 0.1 – 0.01nm; soft: 10 – 0.1nm). X-rays are
emitted by electrons outside the nucleas; Gamma rays by the nucleas.
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
Über die Bestimmung von Funktionen längs gewisser Mannigfaltigkeiten
Berichte der mathematisch-physikalischen Kl. Sächsischen Gesellschaft
der Wissenschaften 59, Leipzig 1917, S. 262
dxdyRyxyxf
Rg
)sincos(),(
)(
The Radon transform is
the set of projections for all
7
Johann Radon’s Integral Transform
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
G.N. Hounsfield
A.M. Cormack
EMI, London
8
First Tomography System
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Automated 3D CT Industrial Development & Trends
Outline
Introduction & Brief History
I. XCT Market & Applications
II. XCT (Metrology) Enabling Technologies
III. Industrial Trends and Further Work Areas
Acknowledgement
9
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
• Since 1971, Medical Imaging XCT complements X-ray; in turn
complemented by Nuclear-Magnetic Resonance Imaging.
• From 80’s, XCT Failure Analysis, Materials Analysis and Defects
Inspection in Aerospace, Automotive and Electronics.
• From 90’s, Online XR for Food Safety in production
• From 2006, Metrology XCT - for complex product design, early
first-article inspection (plastic injection molding), functional
analysis, 3D defects inspections and reverse engineering.
10
I. XCT Market & Applications
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
• Process Pressures
• Yields Enhancements, Defects Reduction & Increased Throughput
• Environmental Drivers
• Major accidents and recall; Fear of Litigation
• Design & Functional Innovation Pressures
• Increasing Miniaturization
• Innovative Computer Aided Designs (for performance and features)
• Metrology at the Limits of Physics
Result: Early Metrology and Analysis - from Lab to Real-Time
11
XCT Market Applications: Process Drivers
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Automated 3D CT Industrial Development & Trends
Ham caught in seal
From L: Edge Mask, Clip Mask, Can Edge Mask and Deoxidizer Mask
L: Chipped biscuit R: Chipped sausage
12
Food XR Contaminant Detection
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Automated 3D CT Industrial Development & Trends
Product Presence confirmed by Density
Smart Multi-lane Production Line removes contaminants from each lane
Bulk Products Divided into 16 lanes for contaminant removal
13
Food XR Contaminant Detection
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Automated 3D CT Industrial Development & Trends
•2D applications • PCBAs
• Power electronics, solar & hybrid technology
• Multilayer circuit boards
• Semiconductors & Electronics
• 3D Computed Tomography applications • Turbine & Blades
• 3D Metrology
• Material Sciences
• Biomedical
• Geology & Exploration
14
Electronics, Turbines, Material Science, Metrology, etc
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
15 Micro-Metrology Seminar, 12 April 2012
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Automated 3D CT Industrial Development & Trends
v|tome|x CT 2D ndt
systems 2D microfocus
systems Nanofocus 2D + 3D Systems
X-ray Tubes
• 3D Metrology
• Casting
• Composites
• Turbineblades
• Material
sciences
• Castings
• Electronic
assemblies
• Sensors
• OEM
• Scientific
research
• PCBA
• Multilayer
• Power
electronics
• Sensors
• Semicon-
ductors
• Sensors
• 3D Metrology
• Biomedical
• Material
sciences
• Geology
16
GE Phoenix | X-ray Products & Applications
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
1. Knowledge from Medical Imaging CT
2. 3D Visualisation Software
3. X-Ray Detector and Beam
4. Calibration with Tactile / Calibration Objects
5. CMM Mechanical Stability and Abbé Principles
17
II. XCT Enabling Technologies
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Automated 3D CT Industrial Development & Trends
2D-CT or
Fan Beam CT
18
XCT Principle of Operation
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Automated 3D CT Industrial Development & Trends
Acquisition Reconstruction Surface-
extraction Analysis
• CT-System:
Source (power, focal spot size, …)
Stability (granite basis, …)
• Environment:
Temperature, vibrations, …
• User:
choice of parameters , measurement
strategy, …
• Interaction between
X-rays (Energy, spectral range, …)
Sample (material, geometry, …)
Detector (dynamic range, noise level …)
• Used algorithms
Beam hardening correction (BHC)
exact surface extraction
Process chain Factors influencing the
measurement results
Image contrast & Resolution
19
XCT System Elements
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Automated 3D CT Industrial Development & Trends
20
Example of XCT Internal Set-up
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Automated 3D CT Industrial Development & Trends
1. Techniques from Medical Imaging CT
2. 3D Visualisation Software
3. X-Ray Detector and Beam
4. Calibration with Tactile / Calibration Objects
5. CMM Mechanical Stability and Abbé Principles
21
II. XCT Enabling Technologies
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
• Powerful Enabler! Volume rendering (a sub-specialty of 3D Computer
Graphics) research at Heidelberg University; resulted in Volume Graphics
GmbH founded in 1997 with core VGL® voxel (VGStudio) technology
• Voxel (volumetric pixel) = a volume element representing a value on a grid in
3D space. (Pixel reps 2D data). A volume/voxel data set = 3D array of voxels
• Polygonal meshes represent the surfaces of 3D objects. Voxels represent
the surfaces and the entire internal geometries of the objects in fine details.
• Uses Windows 7 Workstations. Exports to Polyworks, Calypso, PC-DMIS
• Other 3D Visualisation Software also on market
(view movie clip)
22
3D Visualisation Software
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Automated 3D CT Industrial Development & Trends
23
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
1. Medical Imaging CT Techniques
2. 3D Visualisation Software
3. X-Ray Detector and Beam
4. Calibration with Tactile / Calibration Objects
5. CMM Mechanical Stability and Abbé Principles
24
II. XCT Enabling Technologies
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
1. Image Acquisition/Contrast-Resolution/Spot Size
2. Data Reconstruction
3. Beam Artefact (Noise)
4. Accelerated Acquisition & Reconstruction Speed
5. Comparison with Synchrotron!
25
X-Ray Detector and Beam
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
Limits to High Contrast & Resolution:
• Smallest Voxel Size (FPD Detector Resolution)
• Focal Spot Size (Micro Focus / Nano Focus Tube)
• Mechanical Accuracy
• Software Algorithms (Interacts with above)
26
Image Acquisition
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
CT slice of carbonate sample at 2 μm Voxel size
• CsI Scintillator High Spatial and Contrast Resolution
• Efficient low-noise electronics outstanding dynamic S/N ratio 10000:1
• Active temperature stabilization - optimal long term stability and linearity
Image from GE DXR Detector Image from common FPD
GE DXR Flat Panel Detector: Image Format: 1024 x 1024
or 2048 x 2048 pixel, 200µm pitch; 3092 x 2400 pixel, 100µm pitch
(Nanotom). 65,536 grey scale.
27
Image Acquisition - Detector Resolution
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
Swichable Tubes: Example 180 kV nanofocus®and
240 kV microfocus tube in one compact CT system
28
Image Acquisition – XR Tube Spot Size
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
Current
Leading
Technology Microfocus and
high-power
Nanofocus
tubes
29
Image Acquisition – XR Tube Spot Size
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
The 4 images show the resolution using the different
modes of the high-power nanofocus tube. While the 1.5µm
line pairs in Mode0 is weakly visible, it is clearly resolved
in Mode3. The focus changed from 2.5µm to < 1µm
Leading in
Technology high-power
nanofocus tube
Mode0 Mode1 Mode2 Mode3
30
Image Acquisition – Final Resolution
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
Resolution at each mode
i.e.. smallest resolvable structures:
Mode 0: F ~ 2,5 µm ( P < 3 W )
Mode 1: F ~ 2,0 µm ( P = 2 W )
Mode 2: F ~ 1,0 µm ( P = 1 W )
Mode 3: F ~ 0,8 µm ( P = 0,8 W )
Approx values for the focal spot size as resolution limits.
31
Image Acquisition – Final Resolution
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
System
Three contributions
from apparatus:
• voxel size V
• focal spot size F
• mechanics
U=(M-1)F
V=P/M
The focal spot size is the ultimate limit of resolution!
32
Image Acquisition – Final Resolution
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
Detector pixel size P<< U F limits resolution
Detector pixel P >> U P, i.e.V limits resolution
Hence the precondition for a final resolution A: -
• Voxel size (= pixel size / M) < A
• Focal spot size F < A
• Sample rotation is feasible at desired magnification M
33
Image Acquisition – Final Resolution (A)
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
• Voxel size 1.2 µm !!
Miniature
Chess rook
(made by means of
Laser-Stereo-
Lithography)
Nominal actual
comparison
Laser Zentrum
Hannover/D
34
Image Acquisition: Nominal Actual Comparison
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
AlMg5Si7 Alloy: Material Research, University & Industrial Metallography Labs
35
Image Acquisition – Nanotom m Performance
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
1. Image Acquisition / Contrast & Resolution / Spot Size
2. Data Reconstruction
3. Beam Artefact (Noise)
4. Accelerated Acquisition & Reconstruction Speed
5. Comparison with Synchrotron!
36
X-Ray Detector and Beam
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
Where does the 3D information come from?
X-ray images show the different attenuation of beams after crossing different
object areas
xI
I
eII x
0
0
ln
),;,,( phEZzyx
37
Data Reconstruction
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
How to extract the 3D information?
Projections contain information on material distribution in the sample
Radon (simplified): starting out from an unlimited number of 2D projections of
an 3D object one can reconstruct completely this 3D object
Result (ideally):
dsZzyxI
I),,,(ln
0
),,,( Zzyx
38
Data Reconstruction
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
4 x 4 pixels
The projections provide information of position and density of the
object features.
39
Data Reconstruction
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
It can be shown:
ryxfyxfb
1),(),(
fb is equal to f, but blurred with 1/r
Solution: Filter projections with prior to backprojection
FRcwhereRcRgRg )(),()()('
40
Data Reconstruction
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
Example: Glow Plug
projection inversion log + filter back-projection
dsZzyxI
I),,,(ln
0
0I
I ),,,( Zzyx
41
Data Reconstruction (Real Algorithm)
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
1. Image Acquisition / Contrast & Resolution / Spot Size
2. Data Reconstruction
3. Beam Artefact (Noise)
4. Accelerated Acquisition & Reconstruction Speed
5. Comparison with Synchrotron!
42
X-Ray Detector and Beam
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
• Beam Drift – thermal effects on tube
• Ring Artefacts – deviating detector pixel cause ring structures
randomized detector shift
• Feldkamp Artefacts – surfaces parallel to beam cannot be
properly reconstructed (algorithm) tilting the sample
• Cone Beam Artefacts (geometry) keep away from edge
• Beam Hardening (poly-energetic beam) correction
algorithms
• Partial Volume Artefacts & Other Systemic Errors
43
Beam Artefacts (Noise)
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
Rules of thumb:
Absorption
increases
with Density
Beam Hardening
Density
Increases with
Atomic Number
Periodic Table of Elements
44
Beam Artefacts Vis-à-vis Atomic Density
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
Energy Range for X-ray NDT application: 30-450kV
Material Thickness (mm)
W
ire
IQ
I (%
) Curves based on
Fe – steel
density ~7,85 g/cm3
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
Example: Aluminum Die Cast
The longer the way through the material the
harder the radiation becomes.
46
Beam Hardening
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Automated 3D CT Industrial Development & Trends
130 kV Tungsten
Target
Shift of the mean energy, absorption of soft photons.
47
Beam Hardening
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
Influence of beam hardening on the extracted surface
(a) Surface without reduction
of beam hardening artefacts
(b) Surface with advanced
beam hardening correction
CT Volume data of
sphere plate
• Beam hardening correction significantly improves data quality
48
Beam Hardening – Correction Techniques (I)
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
Influence of beam hardening on the extracted surface
(a) surface without reduction
of beam hardening artefacts
(b) Surface with advanced
beam hardening correction
• Does this influence the measurement ?
49
Beam Hardening – Correction Techniques (I)
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
Influence of beam hardening on distance measurements
Strong reduction of sphere distance error E due to advanced BHC algorithm
Without BHC With Advanced BHC technique
-0.004
-0.003
-0.002
-0.001
0.000
0.001
0.002
0.003
0.004
0 5 10 15 20
Sphere distance [mm]
Length
measurm
ent E
rror
E ,
[m
m].
-0.004
-0.003
-0.002
-0.001
0.000
0.001
0.002
0.003
0.004
0.0 5.0 10.0 15.0 20.0
Sphere distance [mm]
Length
measure
ment err
or
E,
[mm
].
50
Beam Hardening – Correction Techniques (I)
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
Influence of surface extraction algorithm on probing error size for sphere plate
• probing error size PS: ISO PS8 µm, phoenix|x-ray PS4 µm
-10
-8
-6
-4
-2
0 0 2 4 6 8 10 12 14 16
PS
[µ
m]
ISO
phoenix|x-ray
51
Beam Hardening – Correction Techniques (II)
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
1. Image Acquisition / Contrast & Resolution / Spot Size
2. Data Reconstruction
3. Beam Artefact (Noise)
4. Accelerated Speed for Acquisition & Reconstruction
5. Comparison with Synchrotron!
52
X-Ray Detector and Beam
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
The ESRF synchrotron is a cyclic particle accelerator (electrons emitted by an electron
gun are accelerated in Linac and transmitted to a circular Booster synchrotron, to reach
an energy level of 6 GeV (billion electron-volts), to be injected into a large storage ring,
844m in circumference, to circulate in a vacuum environment at a constant energy for
many hours. The guiding magnetic field (bending the particles into a closed path) is time-
dependent, synchronized to a particle beam of increasing kinetic energy. Bending, beam
focusing and acceleration can be separated into different components.
European Synchrotron Radiation Facility,
Grenoble, France
53
Synchrotron (Super Microscope)
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
V = 0.5 µm, 50kV, 480µA, Mode 3, 3h
50 µm
ESRF Radiation based CT Prior state-of-the-art nanotom m
3) Stainless steel: Material Research, University & Industrial Metallography Labs
54
nanotom m Comparison with Synchrotron
Improved sharpness (+40%), increased SNR (+100%), increased contrast range and fewer artefacts due to reduced tube & detector drifts (position & correction) and high contrast detector
Rings are artefact noise
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
With previous state-of-the art CT, it was only possible to see the steel and air inclusions!
Nanotom m shows the air and steel as well as high absorbing and low absorbing inclusions!
3) Stainless steel: Material Research, University & Industrial Metallography Labs
ESRF Radiation based CT nanotom m
CLOSEST to synchrotron CT
55
nanotom m Comparison with Synchrotron
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
1. Medical Imaging CT Techniques
2. 3D Visualisation Software
3. X-Ray Detector and Beam
4. Calibration with Tactile / Calibration Objects
5. CMM Mechanical Stability and Abbé Principles
56
II. XCT Enabling Technologies
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
Characteristic Values
• Probing Error Form PF = Rmax – Rmin
scattering of the surface points around the regression sphere (noise)
• Probing Error Size PS = Dm – Dr (Deviation measured from reference diameter)
surface position
• Size Measurement Error E = Lm – Lr (Deviation between measured and reference length)
measurement precision over long distances
• German guideline VDI 2630 – determination of char. values for CT (in progress)
regression sphere Rmin
Rmax PF
Da
57
Calibration with Tactile / Calibration Objects
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
Reference objects
• Traceability to national material standards through calibration
• Arrangement of spheres like above (ruby-balls on CF-stick sphere plate)
• Calibrated “sphere plate” with 16 sphere shaped calottes designed and
calibration by German National PTB.
Material: Zerodur® (near zero coefficient of thermal expansion)
Uncertainties: Positional = 1.5µm; Form = 2 µm
58
XCT Calibration Artefacts
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
• Correction of the voxel size by comparing
measured with nominal value (Ball-stick)
• FOD will be set temporarily to a new value
(until restart of datos|x)
• Log file of changes is written
• Function is password-protected
• Warning is give if nom-act difference is
above 1%
date time Voxact Vox Nom FOD dFOD FDD Act User
11/25/08 16:09:36 39.997 39.984 225 -0.073 500 Brunke
11/26/08 13:50:38 7.8772 7.8598 59.999 -0.133 300 Brunke
11/26/08 16:59:01 4.107 4.1009 29.999 -0.045 300 Brunke
11/27/08 11:32:57 4.1461 4.1009 17.999 -0.196 299.999 Brunke
11/27/08 13:47:52 4.1022 4.1009 18 -0.006 299.999 Brunke
11/27/08 17:07:48 1.8555 1.8525 9 -0.015 300 Brunke
11/28/08 11:41:38 1.9087 1.8525 7.499 -0.221 250 Brunke
59
Easy Cal XCT Calibration Application
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Automated 3D CT Industrial Development & Trends
University of Padova CT Tetrahedron and Pan Flute Gauge Zeiss Calibration Ref Sphere
PTB Calotte Cube QFM Cylinder
60
On-going Work on XCT Calibration Objects
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
1. Medical Imaging CT Techniques
2. 3D Visualisation Software
3. X-Ray Detector and Beam
4. Calibration with Tactile / Calibration Objects
5. CMM Mechanical Stability and Abbé Principles
61
II. XCT Enabling Technologies
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
• Mechanically sturdy construction; granite base,...
• Linear/Axial Alignments and Precision Rotary
Table. Abbé errors minimized / compensated.
• Volumetric Calibration with Traceable Cal Objects
• Environmental factors: temperature, humidity,
vibration. Good air conditioning critical for XCT.
• Comparison with Reference Laboratory CMM!
62
CMM Mechanical Stability and Abbé Principles
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
• Mechanically sturdy construction; granite base,...
• Linear/Axial Alignments and Precision Rotary
Table. Abbé errors minimized / compensated.
• Volumetric Calibration with Traceable Cal Objects
• Environmental factors: temperature, humidity,
vibration. Good air conditioning critical for XCT.
• Comparison with Reference Laboratory CMM!
63
CMM Mechanical Stability and Abbé Principles
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
Test object: Aluminum casting, appr. 90x90x150 mm3
250 µm Voxelsize, BHC, optimized surface extraction
Distance of two cylinder holes, 25 measurements, tolerance 0.1 mm
CAD Nominal value: 45.015 mm
• Mean measured value: 45.015mm
• = 0.002 mm
• cg = 1.41, cgk = 1.34*
45,011 45,013 45,014 45,016 45,016
45,011 45,015 45,018 45,018 45,012
45,013 45,015 45,015 45,016 45,015
45,012 45,017 45,017 45,017 45,018
45,012 45,018 45,015 45,013 45,017
*Messprozessfähigkeit nach Bosch Heft 10
„Fähigkeit von Mess- und Prüfprozessen“
64
v|tome|x l450 Repeatability (Mechanical Accuracy)
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
• Mechanically sturdy construction; granite base,...
• Linear/Axial Alignments and Precision Rotary Table.
Abbé errors minimized / compensated.
• Volumetric Calibration with Traceable Cal Objects
• Environmental factors: temperature, humidity,
vibration. Good air conditioning critical for XCT.
• Comparison with Reference Laboratory CMM!
65
CMM Mechanical Stability and Abbé Principles
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
phoenix v|tome|x L CT system
GE Sensing & Inspection
Al Cylinderhead model by
ACTech GmbH
v|tome|x L Vs Reference Class CMM
66
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Automated 3D CT Industrial Development & Trends
Leitz PMM 12106 in certified measurement room
MPE (E) = 0.8 + L/400 µm
Measurement of 40 features (distances, diameters,
angles, GD&T)
Calibrated and certified
67
Step 1: Measurement by Reference CMM
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Automated 3D CT Industrial Development & Trends
Leitz Ref CMM
?
CT system
Compare Results between Ref CMM and XCT
68
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Automated 3D CT Industrial Development & Trends
Distances
Feature tactile DKD value CT value Dev CT-tactile
1. Z09A-Z09B-A 64,9993 65,0041 0,005
2. Z09A-Z10A-A 20,0094 20,0056 -0,004
3. Z09B-Z10A-A 68,0055 68,0088 0,003
4. Z13A-Z13B-A 88,4336 88,4332 0,000
5. Z10A-Z13B-A 100,6552 100,6476 -0,008
XCT Vs Reference CMM Measurements
69
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Automated 3D CT Industrial Development & Trends
Diameters
Feauture tactile DKD
value CT value Dev CT-tactile
1. Z09A-DM 3,5963 3,5956 -0,001
2. Z09B-DM 3,5974 3,5952 -0,002
3. Z10A-DM 3,5962 3,5959 0,000
4. Z10B-DM 3,5949 3,5930 -0,002
5. Z13A-DM 6,0153 6,0194 0,004
6. Z13B-DM 6,0162 6,0197 0,003
7. Z14-DM 7,0033 7,0083 0,005
XCT Vs Reference CMM Measurements
70
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Automated 3D CT Industrial Development & Trends
*Made of aircraft aluminium. Data courtesy
of Continental AG, Frankfurt/D, Chassis &
Safety Dept.
71
XCT Measurement of a Valve Block*
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
real Al part
• STL measure data
• alignment
• variance analysis
Measurement Report
Measurement Report
?
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Verification of XCT Dimensional Metrology
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
Hexagon/Leitz PMM 866
MPE (E): 0.8 µm + L/400c(L in mm)
herheit für die Prüfaufgabe: 5 µm
Measurement of 30 features (distances,
diameters, angles..) in 2 hours
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Step 1: Measurements by Reference CMM
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
GE/phoenix|x-ray v|tome|x L 450
Probing error size (PS): 2 + L/90 µm (L in mm)
Complete scan of the part in 30 min
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Step 2: Measurement by High-Resolution XCT
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
Name Merkmal Einstellungen Soll Ist Tol+ Tol- Test Abw. Ist KMM Abw. CT-KMM
Ref Q Durchmesser 28,000 28,034 0,06 0,01 i.O. 0,035 28,034 0,000
Ref P Durchmesser 7,000 7,055 0,1 0 i.O. 0,055 7,054 0,001
Motorsteckerbohrung Durchmesser 10,000 10,037 0,06 0 i.O. 0,037 10,035 0,002
CT measurement: 28.0349
CMM measurement 28.0344
Diff. CT-CMM: 0.0005
Step 3: Report Creation & Results Comparison
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World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
feature nom.
meas.
CT diff. CT meas. CMM
diff.
CT-CMM
Zyl 1175_1 11,750 11,780 0,030 11,776 0,004
Zyl 1175_2 11,750 11,775 0,025 11,775 0,000
Zyl 1175_3 11,750 11,781 0,031 11,776 0,005
Zyl 1175_4 11,750 11,773 0,023 11,776 -0,003
Zyl 1175_5 11,750 11,783 0,033 11,776 0,007
Zyl 1175_6 11,750 11,778 0,028 11,775 0,003
Zyl 1175_7 11,750 11,782 0,032 11,779 0,003
Zyl 1175_8 11,750 11,779 0,029 11,775 0,004
Zyl 1175_9 11,750 11,785 0,035 11,779 0,006
Zyl 1175_10 11,750 11,783 0,033 11,777 0,006
Zyl_EUV_1 10,750 10,760 0,010 10,766 -0,006
Zyl_EUV_2 10,750 10,761 0,011 10,767 -0,006
Zyl 1175_1 11,750 11,780 0,030 11,776 0,004
Zyl 1175_2 11,750 11,775 0,025 11,775 0,000
Step 3: Report Creation & Results Comparison
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World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
feature type nominal meas. CT meas. CMM
Diff.
CT-CMM
Zyl_1-Zyl_4 y Distance 23,500 23,468 23,473 -0,005
Zyl_1-Zyl_4 z Distance 30,000 30,009 30,007 0,002
Zyl_1-Zyl _10 y Distance 70,500 70,442 70,447 -0,005
Zyl_1-Zyl _10 z Distance 54,500 54,521 54,519 0,002
Zyl_4-Zyl_10 y Distance 47,000 46,974 46,974 0,000
Zyl_4-Zyl_10 z Distance 24,500 24,511 24,512 -0,001
Step 3: Report Creation & Results Comparison
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World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
Test objects: sphere sticks with 40, 4 and 2mm sphere-to-sphere distance
PS = 0.0015 mm + L/3000 (L in mm) (Probing Error Size per VDI/VDE 2630!)
nanotom
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Characteristic Values
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
Test objects: sphere sticks with 40 mm,4 mm and 2 mm sphere-to-sphere distance (+/-
4K tube temperature after 2 h Warm-up time)
• Sphere distance error < 1 µm!!
• Repositioning accuracy of linear axes < 2 µm
Nominal sphere distance 39,9844 4,1009 1,8525
Voxelsize [mm] 0,06 0,006 0,003
Allowed tolerance [mm] 0,025 0,015 0,02
Sigma [mm] 0,0006 0,0004 0,0005
cg 1,35 1,35 1,3400
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Repeatability
nanotom
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
Rotation axis v|tome|x:
• Radial = +/- 2 µm
• Axial = +/- 2.5 µm
Rotation axis nanotom:
• Radial = +/- 0.05 µm
• Axial = +/- 0.05 µm
v|tome|x
nanotom
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v|tome|x & nanotom Axial / Radial Accuracy
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
Outline
Introduction & Brief History
I. XCT Market Applications
II. XCT Enabling Technologies
III. Industrial Trends and Further Work Areas
Acknowledgement
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World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
• XCT advances mean new applications beyond failure / defects
analysis. 3D internal, structural and dimensional metrology for
iterative functional design-analysis now possible!
• XCT set to become a pillar of competitive manufacturing!
• Strong take up and vibrant competition will improve ROI.
• Future trends include In-Line XCT for production!
• More work on international standards and calibration artefacts.
• Safety in XCT use must not be overlooked.
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III. Industrial Trends and Further Work Areas
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
• ISO 15708-1 [29] Non-destructive testing - Radiation methods – Computed
tomography – Part1: Principles
• ISO 15708-2 [112] Non-destructive testing – Radiation methods – Computed
tomography – Part 2: Examination practices
• ISO/TC 213 WG10 [113] Geometrical product specifications (GPS) – Acceptance
and reverification tests for coordinate measuring machines (CMM) – Computed
tomography
• ASTM E 1695 [114] Standard test method for measurement of computed
tomography (CT) system performance
• ASTM E 1441 [115] Standard guide for computed tomography (CT) imaging
• ASTM E 1570 [116] Standard practice for computed tomographic (CT)
examination
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Existing XCT-Related International Standards
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
Inspection System
Automatic defect analysis and -classification
Inspection volume up to 500mm x 1000mm L
Scan- and inspection times 5-10mm/s
Spatial resolution 300µm
Designed for 24/7 operation in foundries
Belt or Palette conveying systems
Interfaces to adjacent process steps
Core competence and world wide service from GE
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Future: GE Inline-CT System Concept
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
Acquisition Inlet Data Transfer
Identification
Outlet Data
Transfer
• Conveying thru principle
• X-ray shielding housing
• Dust proofed
• Simple Installation
• Air conditioning
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Future: GE Inline-CT System concept
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
2D NDT Fast 3D NDT Inline CT 3D-ADR NDT Inline-Metrology
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GE Roadmap
(view second movie clip)
World Metrology Day, 18 May 2012
Automated 3D CT Industrial Development & Trends
THANK YOU!!
Visit us at www.cairnhill.com
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