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John,<br>
<br>
But I think you _are_ making your point. That's why I suggested it
might be useful to examine the traffic cones in the UV spectrum.
Maybe the plastic itself has a unique signature, irrespective of the
color. Or maybe not. Would also need a UV sensitive sensor or
camera, which might not be trivial, though the astronomers seem to
do it all the time. Someone needs to investigate...<br>
<br>
My first pass at finding the cones a few years ago just used the
robot's sonar to attempt to identify the proper shape, like SR04
does in the can collecting contest. In that contest, the SR04 robot
does not care what color the cans are. I actually thought it was a
bit of a cheat when the club decided to paint them all orange in
order to facilitate a certain type of sensor. They aren't "soda
cans" any more; they are fluorescent orange cylinders. <br>
<br>
In a previous enlightenment SR04 was able to locate the cans with
it's sonar, and then sort them according to color (Coke, Sprite,
Root Beer, Orange Soda) using a bi-color LED and CDS cell on the
ends of the grippers. All wasted effort with the "modified" cans.
:)<br>
<br>
But the cones turned out to be devilishly hard to identify with the
sonar unless you were already looking directly at it. The shape
tends to send the sonar reflections off in different directions
otherwise. As with lots of robot techniques, things that look good
on paper or around the water cooler often don't work in a practical
application.<br>
<br>
Now the Mars rovers had a tiny mass spectrometer on the end of the
robot arm. There's a nifty solution! Except for the cost, which
is shall we say above my pay grade. And that also requires that the
sample be pre-located and have close proximity. Not so useful for
our applications. Still, a boy can dream.<br>
<br>
onward!<br>
dpa<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
<div class="moz-cite-prefix">On 12/06/2016 12:20 AM, David Anderson
wrote:<br>
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<blockquote cite="mid:584658A4.6030205@smu.edu" type="cite">
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Flame cultivator. Awesome. I googled "cotton farm flame
cultivator" and came up with this:<br>
<br>
<a moz-do-not-send="true" class="moz-txt-link-freetext"
href="https://flameengineering.com/pages/agricultural-flaming-guide">https://flameengineering.com/pages/agricultural-flaming-guide</a><br>
<br>
Invented by one Price McLemore in 1938. Clever. I want to see
one in action!<br>
<br>
cheers<br>
dpa<br>
<br>
<br>
<div class="moz-cite-prefix">On 12/05/2016 11:28 PM, John Swindle
wrote:<br>
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<blockquote
cite="mid:158d29b186b-6637-9c9e@webprd-m17.mail.aol.com"
type="cite"> <font face="Arial, Helvetica, sans-serif" size="2"
color="black">
<div>Dave,<br>
<br>
Great stuff. Thanks for setting me straight on the
already-uniqueness of the orange cones.<br>
<br>
But I'm still not making my point (largely because I'm still
slowly formulating it). At the same time, I get your point,
which is: Go and do it! But vision-related stuff is just not
interesting for me to pursue.<br>
<br>
More of my point: It's not to look for, say, an orange cone,
but to look for, say, a plastic thing or a rubber thing or a
wood (or non-wood) thing. Unique in the arena and likely
unique in a large unconstrained space.<br>
<br>
My interest in this is to build a robot that weeds the yard.
I suspect that it is insufficient to look at leaf shapes,
and I suspect that different plants have other signatures
that will be easier to detect, as with the Earth sciences
satellites that see what kind of trees are in a forest.<br>
<br>
When I saw a root heater weed killer for sale (basically a
soldering iron on a stick), I got interested in having a
gadget wander about the yard, selectively cooking the roots
of undesired plants. A vinegar spray works also, but the
root heater is more precise. (A flame cultivator is more
dramatic though. We had those on the cotton farm.)<br>
<br>
You say we often build stuff that is purpose-built to win an
arbitrary contest. In this case, I am looking for something
that serves as a sensor for something beyond color and
shape differences. It would be great if it involved sound!
Talk to the weeds.<br>
<br>
I thought we developed sight for visible light because
that's what gets through the atmosphere. Water has a big
impact on the atmosphere as well.<br>
<br>
And so a UV sensor would be OK for a robot because it would
either be designed to not get burned up by UV, or we
wouldn't care that the sensor only lasted a few years. We
try to anthropomorphize things too much, building our own
limitations into our creations.<br>
<br>
Good stuff. Back to slowly formulating now.<br>
<br>
John Swindle<br>
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<br>
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