Detect missing electronic part on PCBs, what is the best solution ?

[tonnybui.vn]

Hi all,

    I have the project using camera and check the parts on electronic board, If part is missing, we will draw the rectangle for this position.

   I think 2 ways for this project : 

   ------------------

        Idea 1: Take 1 electronic board picture from camera and compare with same picture. ( using golden template.)

           => However, we can not draw the rectangle for part by part on elect. board.

           => Can not make the library for part kind on board.

        Idea 2 : Will using the CWIMAQvision  colorlearn by adding the rectangle and colorlearn for rectangle area.

           After that we save data of sample to .TXT file. 

           When we load new picture for checking, we will compare the rectangle area color with our data in attached file.

          If it's different => It's missing part or ..

        Idea 3 ......

  --------------

   Everybody pls help me to advice the best solution with your experience.

   If posible, pls give me your example for this.

   Thanks so much for your reading.

  Tonnybui

[0utlaw]

Hello Tonnbui,

These whitepaper might be a good place to start:

Image Analysis and Processing

http://www.ni.com/white-paper/3470/en

Using Edge Detection in Machine Vision Gauging Applications: How to Inspect for missing components 

http://www.ni.com/white-paper/4536/en#toc6

As long as the images you are looking at are of the same size and orientation, establishing a known "good" line map or rake is probably the least processing-intensive and most robust way to check PCBs with a known layout.  Figuring out which part is missing would only require knowing which parts are in which locations on the board.

As for template or pattern matching, these examples might also be worth looking at:

Pattern Matching Example

http://zone.ni.com/devzone/cda/epd/p/id/5594

Color Pattern Matching Example

http://zone.ni.com/devzone/cda/epd/p/id/5548

Hope that helps!

Regards,

[tonnybui.vn]

Hello 0utlaw,

   Thanks for your help.

   I already study the CWIMAQvision with Colorclearn and Matchingcolorpattern .

   I make the VB6 data same as attached picture.

   However, After I clicked the Colorclearn Button, the colorspectrum will display data of rectanguler area.

   but I can not use the data of colorspectrum to compare with new image for same rectangle area.

  Can you help me for the example VBcode  to load 1 rectange (with input name of this rectangle).

   We learn color for this rectangle area. After that we will compare with new picture (take from camera) with same rectangle area to detect the missing ( compare color) for part in this rectangle.

  Pls support your example code vb.

  Thanks

[0utlaw]

Hello Tonnybui,

The IMAQ shipping examples that are typically located in the National Instruments/Vision/Examples directory are probably the best place to start looking.  This may vary slightly based on the release- what version of the Vision Development Module are you using?

Additionally, you may want to take a look at the following:

Tutorial: IMAQ Pattern Matching Examples

http://zone.ni.com/devzone/cda/epd/p/id/1105 

and if you're unable to locate the shipping examples, the following KnowledgeBase article describes how to access them:

KnowledgeBase 5S7DFQEN: How Do I Install C, C++, Visual Basic DotNet Examples for Vision Development Module and Vision Builder AI?

http://digital.ni.com/public.nsf/allkb/692DAC7C72E2D4BF8625796000709509?OpenDocument 

Regards,