National Instruments NI myRIO, Essentials Manual

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CHAPTER 14. COMPONENT PLACEMENT INSPECTOR 105
with Add Array Elements that indicates the number of defects found for
a given component color.
T
IP
: Use the “Quick Drop” shortcut (Ctrl + space bar) to look up
and place a LabVIEW element by name. See Appendix C on page 139
for more LabVIEW tips.
14.2 Development Tips
Representative Images
• Create a mock-up of a printed circuit board with properly-placed compo-
nents similar to that pictured in Figure 14.1 on page 101. Use several of
each color and size of brick.
•
Set up the camera on a table-top camera copy stand and adjust the field
of view to accommodate a single board. Allow for the board to be tilted
and translated somewhat. Adjust the camera mode to obtain reasonably
high resolution and the camera attributes to obtain good contrast without
over or underexposure.
NOTE : Ensure that the camera’s physical setup remains undisturbed
throughout this project! The conditions under which you define the
color matching ROIs must be identical to the way that your finished
vision application collects images of the board.
•
Collect one image to serve as the basis of your color matching ROIs. Align
the board with the pixel array to the best of your ability.
• Collect additional images of the defect-free board with varying amounts
of translation and rotation. Use these images during vision script develop-
ment to verify that your script detects zero defects even when the board
orientation changes.
• Collect multiple views of each product label defect category, including
missing bricks, swapped bricks, etc.
•
If you plan to use the “image flip” option in the Machine Vision App
template you will want to collect all of your images so that they appear
in the same orientation when you develop your script. Consider one of
these two options:
– Run either the Machine Vision App project or one of your exist-
ing projects with the “image flip” option enabled, adjust the camera