Fundamentals of Machine Vision

Part 1 in a Series:

General Overview

© 2014, Pete Kepf, All Rights Reserved

Pete Kepf, CVP

www.kepf.me

Pete Kepf, CVPwww.kepf.me

Overview

Technical

Lighting

Lenses

Software Tools

Business

Hardware/ Deliverable Comparison

Risk Assessment

Vendor Selection


Machine Vision is the use of a computer to acquire visual information and/or extract image information for purposes of data storage or automatic decision making.


Top Five Industrial Users*

1. Semiconductors

2. Wood

3. Electronics

4. Transportation

5. Pharma/ Medical Device

* Source Automated Imaging Association


Motion/ Robot Guidance

Defect/ Flaw Detection

Inspection/ Grading/ Sorting

Identification/ Verification

Data Acquisition

Measurement/ Gauging


Motion

Flaw

Identification

Sort

Data Acquisition

Measurement


Vision Components

Lens

Camera

Processor

Input/ Output

Peripherals

Lighting

Frame/ Enclosure

Controls/ Software

Part Handling/ Reject/ Sorter


Components

Cameras, Frame Grabbers, Computers, Boards,

Peripherals

Lens, Lighting, Sensors, Framing, Valves, Motion

Solutions

Value Added Distributors, Systems Integrators, Machine Builders


1. Find a Trusted Source (Vendor, AIA, Search)

2. Define the Requirements

3. Research the Technology

4. Refine the Requirements

5. Professionally evaluate the requirements

6. Obtain Budget/ Price/ Performance Data

7. Perform Risk Assessment

8. Select Vendor


Lighting Light Sources and Frequencies

Lighting Sources and Angles

Lenses Common Types of Machine Vision Lenses

Security/ vs. Machine Vision Lenses

Cameras GigE

USB

Software Tools Image Processing

Image Pre-processing


Line Light

Back Light

Diffuse/ Work Envelope Light

Diffuse Dome Light

Pattern Projector

Front (Spot) Light

Axial Light

Ring Light

Off Axis Ring Light


Useful for:

• Line Scan• Linear Parts• Structured

Light


Useful for:

• Gauging• Measurement


Useful for:

• Robot Work Cells

• Top Light Assembly

• Reflective Parts


Useful for:

• Highly Reflective Parts


Useful for:

• Structured Light

• Height Derivation


Useful for:

• Small Parts• Structured Light


Useful for:

• Highly Reflective Parts

• Surface Defects


Useful for:

• General-purpose


Useful for:

• Surface Defects• Reflective Parts


(Previous: Halogen- Fluorescent- Xenon;

Now: LED)

Source: www.thermalcamerarentals.com

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0CAYQjB0&url=http://www.thermalcamerarentals.com/how-do-infrared-thermal-imaging-cameras-work.html&ei=XZRCVMKKI5GAygTfhIGABA&bvm=bv.77648437,d.aWw&psig=AFQjCNHglS1whv65BoQQh8gIVOcE97y7nQ&ust=1413735615111561


Types of Lenses

Terms:

Working Distance (WD): Distance from the end of the lens to the part to be inspected.

Field of View (FOV): Image area that contains the area of the part to be inspected.


Function

Macro

Telecentric

Large-format (“Line Scan”)

Size

C-Mount

CS-Mount

F-Mount


Useful for:

• WD: 73-527mm• Low Distortion• Vibration

Resistance• Sensor Size: ½”.

2/3”


Vibration ResistantLow Distortion


Useful for:

• WD: 40-340mm• Extremely Low

Distortion• Sensor Size: ½”.

2/3”


• Ideal for Coaxial lighting• Eliminate Perspective Error• Accurate 3D Measurement


Today’s sensors (4-9 Megapixels) are often 1”


CS Mount: 12.5mm flange back distance

C-Mount: 17.526mm flange back distance

Thread size identical

Can use C-mount lens on CS camera with 5mm extension

Can NOT use CS lens on C-mount camera

F-Mount used when: Sensor size > 4/3”

Additional spece required between lens flange and image sensor


Hardware/ Deliverable Comparison

“Sensor”, “System”, “Smart Camera”

“Turn-key”, “Assisted Installation”

Risk Assessment

Problem Definition

Solution Verification

Vendor Selection

Knowledge Base

Resources

Engineering

Fundamentals of Machine Vision