confidential coherent machine vision lasers 3d triangulation – key success parameters

CONFIDENTIAL

Coherent Machine Vision Lasers

3D Triangulation – Key Success parameters

Superior Reliability & Performance COMPANY CONFIDENTIAL P. 2

Agenda

• Coherent Overview

• 3D Triangulation Overview

• Properties of Structured Light

• Key Success Parameters

• Uniformity Highlight


19%

19%

14%

48%

48%

21%

24%

7%

• Founded in 1966

• TTM Sales $788.4 Million

• TTM Orders $799.3 Million

• 2,328 Employees

• Sales 24% U.S. and 76% International

• Approximately 387 Patents, 114 Pending

Provider of Photonics Solutions - Primarily Lasers for Commercial and Scientific Research Applications

____________________Note: Photonics is the Merger of Lasers, Optics and ElectronicsSource: Company management as of 6/30/12

Materials Processing

Microelectronics

OEM Components& Instrumentation

Scientific Research& Gov. Programs

Revenue MixTTM

Revenue MixTTM

Europe

United States

R.O.W.

Asia Pacific

Geographic Sales Distribution TTM

Geographic Sales Distribution TTM

Coherent – The Photonics Company


Diversified Product and Applications

Core MarketsCore Markets

FPD, API, Semi, Solar Marking, Engraving,

Cutting and WeldingDiagnostic &

Therapeutic Medical, Defense and Display

Ultrafast

1 2 to 4 1 1

OLED, Smartphones, Tablets

High PowerMaterials Processing

Laser Eye Care Attosecond Physics

PrimaryApplication FocusPrimaryApplication Focus

Growth vs Market Growth vs Market

Growth Opportunities Growth Opportunities

Scientific Research & Government Programs

OEM ComponentsInstrumentation

Materials ProcessingMicroelectronics

SAM Position SAM Position


3D Machine Vision

• In today’s world of expanding 3D vision systems, the camera and laser are equal partners in the accuracy, stability and repeatability of the measurements made and used by the applications.

• The requirements on the laser for power, pointing and electrical stability are far above a typical illumination system requirements.

• Having a source which produces very high power density, very thin measurement cross sections with a uniform return that does not mask the profile of the object is critical to success in these demanding applications.


Structured Light Applications

• Weld Seam• Glue Bead• Gasket seals• Soldier Paste• BGA• Wood Primary and Secondary

processing• Food portioning/sorting• Packaging• Tire – Wall and Tread• Wheel alignment• Alignment guidance• Bottle

• PCBA post assembly• Rail car• Rail track• Road / Tunnel• Rail Brakes• Contour measurement• Steel / Extrusion• 3D Reconstruction• Bin Picking• Non Contact Surface

Profile


3D Triangulation

• Projecting a narrow band of light onto a three-dimensionally shaped surface produces a line of illumination that appears distorted from other perspectives than that of the projector, and can be used for an exact geometric reconstruction of the surface shape.


- Which Triangulation Setup?

- Which 3D Camera?

- Which Line Laser?

- Which Objective Lens?

??

?

3D Triangulation


Essential Information Needed: The Basic Parameters of the Application

-Object Size (Width, Height and Length)

- Required Scan Accuracy in X-, Y- and Z-Dimension

- Scan Speed

- Type of Application

- Type of Material

X

Y

ZW

L

H

mm/s

3D Triangulation


Which Triangulation Setup?

-Standard Setup

-Sheet-Of-Light Plane vertical to the scan direction Y

-All points of a height profile have the same Y-coordinate

-dz=dx/sin(α)

Sheet-Of-Light Plane

X

Y

Z

Scan direction

Scan direction

α

3D Triangulation


Example Calculation

November 25, 2008

10° 20° 30° 40° 50° 60° 70° 80°

MAX 1214.74064878811

616.739990659401

421.875 328.160494728368

275.359350093528

243.569644814373

224.474998881638

214.191550944649

TRSH 607.370324394055

308.369995329701

210.9375 164.080247364184

137.679675046764

121.784822407187

112.237499440819

107.095775472325

COG 303.685162197028

154.18499766485

105.46875 82.0401236820921

68.8398375233819

60.8924112035934

56.1187497204094

53.5478877361623

100

300

500

700

900

1100

1300

dZ vs Tringulation angle -Standard500mm WD 30 FA 1280 Pixel

dZ re

solu

tion

in u

m


Example Calculation

10° 20° 30° 40° 50° 60° 70° 80°

MAX 359.923155196477

182.737775010193

125 97.2327391787758

81.5879555832674

72.1687836487032

66.5111107797445

63.4641632428591

TRSH 179.961577598239

91.3688875050965

62.5 48.6163695893879

40.7939777916337

36.0843918243516

33.2555553898723

31.7320816214295

COG 89.9807887991193

45.6844437525482

31.25 24.3081847946939

20.3969888958169

18.0421959121758

16.6277776949361

15.8660408107148

25

75

125

175

225

275

325

375

dZ vs Tringulation angle -Standard150mm WD 30 FA 1280 Pixel

dZ re

solu

tion

in u

m


Alternative Triangulation Setups: Reverse Geometry

-Advantage: Increased height resolution dz=dx/tan(α)

-Drawback: Points of a height profile have different Y-

coordinate

-Suitable For Plane Objects

Scan direction

X

YZ Sheet-Of-Light Plane

Scan direction

α

3D Triangulation


Alternative Triangulation Setups: Specular Geometry

-Advantage: Highly increased height resolution

dz=dx*cos(β)/sin(α+β)

-Advantage/Drawback: Increased image intensity due to direct

reflexion

-Drawback: Points of a height profile have different Y-coordinate

-Suitable For Plane ObjectsScan direction


X

YZ

Scan direction

α β

3D Triangulation


-Advantage: Reduction of direct light reflexions

-Drawback: Reduced height resolution dz=dx*cos(β)/sin(α-β)

Scan direction


X

YZ

Alternative Triangulation Setups: Look-Away Geometry

Scan direction

α

β

3D Triangulation


Triangulation Angle α

Occlusion: Edge Height * tan(α)

Triangulation Angle

The bigger the triangulation angle:- the higher the Z-Resolution- the bigger the occlusion

3D Triangulation

Example:5mm tall objectα = 40 degreesOcclusion (Ω) is 4.2mm

Ω


Z-Range

Z-RangeFOV

(nominal)

FOV & Z-Range

Trapezoidal shape is due to lens view angle

3D Triangulation


Key Success Parameters

• Uniformity• Poor uniformity in the reflected wave front can results in reduced accuracy and

limitation on measurement resolution

• Pointing Stability• Temperature dependent pointing effects the accuracy of the calibration and system

accuracy

• Straightness• A curved or bowed line limits the measurement window of the item being measured

• Bore-sight• Poor Bore sight increases the installation time and risk of system mis-alignment

• Power Stability• Directly effects the measurement sensitivity for any thresholding or low contrast

measurements


Properties of Structured Light

• Uniformity

• Straightness

• Line Width

• Depth of Field

• Divergence

• Field dependent focus (“Bowtie”)



80% Clip Point

RI floor

IMin

IMax IAvg

Uniformity Straightness



WDD

02w

D

MWDw

2

0

42

WD = working distanceM2 = M squared of diodeD = Diameter of beam on collimator

Beam Size Depth of Field



θWDWDθ

Divergence Field dependent focus


Uniformity Highlight

• Side by side comparison of competitors line and StingRay line• A – 50mW 660nm (Competitor)• B – 35mW 660nm (StingRay)

• Uniformity variations can be interpreted as features by the software

• Poor management of power density in the line, effect is need for more power to get the same SNR = Higher cost, Higher Safety classification

A

BB


Uniformity Highlight

Line A Plot Line B Plot

A

confidential coherent machine vision lasers 3d triangulation – key success parameters

Documents

d camera

d machine vision

d triangulationprojecting

d vision systems

line laser

basic parameters

merger of lasers

scan accuracy