laser versus white light scanning for email

8/3/2019 Laser Versus White Light Scanning for Email

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Laser Triangulation Technology

compared to Structured (White) Light


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Laser Triangulation AngleCamera & Lens

Camera & Lens

Laser Diode

Projector

Laser TraceCross Section of Patch

The angle used for the laser triangulation actually allows for capture of data on

edges and vertical walls. The standoff on white light systems means the angle is low,combined with smoothing and sharpening the edge results can be of low quality.

No points are captured

on the vertical wall.


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Top View

Cross section

Laser TriangulationVery good at capturing information on

edges. All data is captured in one

coordinate system so no patch stitching is

required. Camera is filtered for narrow band

of light so will work in most ambient light

conditions.

White Light vs. Laser Triangulation


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Top View

Cross section

White LightVery fast at capturing information on planer surfaces but not very good with

edges. Edge definition can be further distorted by automatic smoothing and edge

sharpening algorithms. Will either require lots of setup time on part for multiple

shots or require photogrammetry system. Scan patches are in different coordinate

systems and need to be stitched back together. Ambient lighting conditions can

effect performance of this type system by distorting transitions of white to black

White Light vs. Laser Triangulation


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Problems with patch Stitching

Part shot from

3 directionsTwo more shots will be

needed to tie the part

together.

Patches have no

relationship to each other

and no overlap to work

with.

With 5 shots the X andZ can be locked in.

The hoped for results

X

Y

Z

The results are a best fit with

nothing locking in Y axis. To do

this correctly you will need to

use targets and or

photogrammetry. Potato

chipping and error build-up are

problems with this technology.


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Hardware Scanworks V5 + Infinite Arm

Time 4 days

Customer Nanjing Automobile(group) corporation

Software Geomagic Studio

Alignment Steel balls glued on the car body first.

Steel balls used to align different scan passes.

Accuracy (less than)< 0.5mm(scan all minibuss surface error)

Strengths Unbeatable scanning speed

Flexible to scan underneath and inside the vehicle

No need for developer spray or powder

Can accurately measure very dark surfaces

Unconstrained by ambient conditions


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Inner Drivers Cabin

NOT POSSIBLE WITH WHITE LIGHT SCANNER

POSSIBLE WITH LASER SCANNER


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Complete Inside Surface




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Complete Assembly of Inside and Outside surface with drivers cabin




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Case Study: Car Scan


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Case Study: Car Scan


Time 4 hours

Customer Changan Auto

Software Geomagic Studio

Alignment Steel balls glued on the car body first.

Steel balls used to align different scan passes.

Accuracy (less than)< 0.3mm(scan all car surface error)

Strengths Unbeatable scanning speedFlexible to scan underneath and inside the vehicle





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Complete Outside Surface

POSSIBLE WITH WHITE LIGHT SCANNER



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Inner Drivers Cabin


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Case Study:


Time 3 day evaluation exercise

Customer Maruti Suzuki

Software PolyWorks V11

Alignment Used Principal Location Points/Features from CAD

For free-form parts, best fit alignment with 1/1 sub-sampling

Accuracy (less than)< 0.1mm

Strengths Unbeatable scanning speedUnbeatable edge and feature scanning


No need for markers/targets



Portable: Most parts scanned on shop floor


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Rear Closure Panel Inner

CAD data aligned with SCAN data


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Sharp Clear Edges and Distinct Features


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MarutiC

omponentParts


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laser versus white light scanning for email

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