LabVIEW
How can I reduce the effect from light in the vision system ?
Hi,
The first thing to do when making a vision system, is to make sure the
lightning is optimal.
This means you cannot use AC power supplies. You'll also have to make sure
that the lightning is directional if you want to see shadows, and diffuse if
you don't. In some cases, backlightning is good, in others you need colored
lights... It's a field of it's own. If you use one light, you will be able
to see circles of different lightning itensities (use a threshold to make
them visible).
If the error in the lightning is still not stable enough, you can normalize
the picture (if the light fluctuates over time), or subtract a calculated 2d
gradient from the original (if the itensity fluctuates in directions).
Most problems can be solved by choosing good light
ning. It will be expensive
if you need fancy diode array lightning, but it will still be cheaper then
solving it in software.
Regards,
Wiebe.
"Sophomore LV programmer" wrote in message
news:5065000000080000001A7E0000-1042324653000@exchange.ni.com...
> How can I reduce the effect from light in the vision system ? Now I
> encounter with the serious problem of repeatability of concentric
> measurement with vary in the range of 0.013-0.017 mm. but the
> specification is 0.025 max.Please help...
The first thing to do when making a vision system, is to make sure the
lightning is optimal.
This means you cannot use AC power supplies. You'll also have to make sure
that the lightning is directional if you want to see shadows, and diffuse if
you don't. In some cases, backlightning is good, in others you need colored
lights... It's a field of it's own. If you use one light, you will be able
to see circles of different lightning itensities (use a threshold to make
them visible).
If the error in the lightning is still not stable enough, you can normalize
the picture (if the light fluctuates over time), or subtract a calculated 2d
gradient from the original (if the itensity fluctuates in directions).
Most problems can be solved by choosing good light
ning. It will be expensive
if you need fancy diode array lightning, but it will still be cheaper then
solving it in software.
Regards,
Wiebe.
"Sophomore LV programmer"
news:5065000000080000001A7E0000-1042324653000@exchange.ni.com...
> How can I reduce the effect from light in the vision system ? Now I
> encounter with the serious problem of repeatability of concentric
> measurement with vary in the range of 0.013-0.017 mm. but the
> specification is 0.025 max.Please help...
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