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Carl,<br>
<br>
You know old people repeat themselves ;) <br>
<br>
The SR04 robot can do line-following of the simpler variety. It is
set up so the line width doesn't matter (as long as it is not wider
than the robot) and the sensors are "shown" what the line looks like
and what the background looks like before it sets off. That way it
can run with any convenient lines that might be found, i.e., stripes
in a parking lot, safety lines in a shop, tar lines in the asphalt,
lines on a basketball or tennis court, etc. When DPRG held its
meetings at the Science Place in Fair Park, there were inlaid lines
of the solar system orbits in the floor of the lobby. You no doubt
remember the video I shared of SR04 following the ecliptic around
the room at the Science Place as an example.<br>
<br>
So I guess I have a bias towards behaviors that are not tuned to a
specialized environment. Now if one rotated the challenge course
up on it's edge and made it 3D, the robot would then be
perimeter-following --- itself a challenge up from simple
wall-following --- rather than line-following. There are lots of
environments where that turns out to be really useful.<br>
<br>
You may remember the video I shared of nBot following the perimeter
of a complex environment in the basement of the Heroy building at
SMU as an example. <br>
<br>
A more significant example is the video of jBot using conditional
wall-following to escape from dead-end cul de sacs while navigating
the TI campus in Denton, available on jBot's webpage.<br>
<br>
Of course if the challenge-level line following solutions turn out
to be applicable in some nifty way when the robot runs in the real
world away from the contest course, then I clearly will have been
wrong!! <br>
<br>
On that note, I'd encourage you as you get physical to think about
what is required to run on less-than-optimal non-contest surfaces
(wheel size and traction, torque, ground clearance, etc), and build
that in from the beginning. Just my $.02.<br>
<br>
The work that you and Ron are doing is first rate and very much food
for thought --- obviously! At this point I haven't been able to do
any roboting at all for about a year, so I'm content to let you guys
push the envelope while I just yell from the sidelines. <br>
<br>
onward!<br>
dpa<br>
<br>
<br>
<br>
<br>
<div class="moz-cite-prefix">On 12/10/2017 12:51 PM, Carl Ott wrote:<br>
</div>
<blockquote
cite="mid:CA+XqQZQKWyQ=h7sCuGoFpU3H3TTXzSKLNqGF68y+QG7XHw_PnQ@mail.gmail.com"
type="cite">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<div dir="ltr">David,
<div><br>
</div>
<div>you've shared those videos before - fun for speed even if
the line is rather boring :)...</div>
<div><br>
</div>
<div>you mentioned no plans to field a robot - why not?</div>
<div><br>
</div>
<div>e.g. You could field the first line-following bipedal
walking robot in the club, and give Ron and I a 'run' for the
money...</div>
<div><br>
</div>
<div>Carl</div>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Sun, Dec 10, 2017 at 11:51 AM, David
Anderson <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:davida@smu.edu" target="_blank">davida@smu.edu</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div text="#000000" bgcolor="#FFFFFF"> I did see Ron's robot
demo, and interesting contrast between his approach and
Carl's, though Carl's is admittedly a simulation at this
point. <br>
<br>
Carl says that this year he is going to "get physical" so
I was about to post a link to Olivia Newton-John's "Let's
Get Physical" as a theme song. But then I went back and
read the lyrics, and all the thinly and not-so-thinly
veiled innuendo from 1980's disco seem oddly discordant in
today's cultural environment ("I've been patient, I've
been good. Trying to keep my hands on the table"). <br>
<br>
So instead I offer the following, in keeping with the
line-following theme and the observation that all robot
contests eventually devolve into races. Even if the
requirements are, say, that only line-following WALKING
robots are allowed:<br>
<br>
<a moz-do-not-send="true"
class="m_8354197153887660578moz-txt-link-rfc2396E"
href="https://www.youtube.com/watch?v=4XiRxNkZleY"
target="_blank"><https://www.youtube.com/<wbr>watch?v=4XiRxNkZleY></a><br>
<a moz-do-not-send="true"
class="m_8354197153887660578moz-txt-link-freetext"
href="https://www.youtube.com/watch?v=4XiRxNkZleY"
target="_blank">https://www.youtube.com/watch?<wbr>v=4XiRxNkZleY</a><br>
<br>
cheers!<br>
dpa<br>
<br>
<br>
<br>
<div class="m_8354197153887660578moz-cite-prefix">On
12/10/2017 11:32 AM, Doug Paradis wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">David,
<div> From watching actual robots run the stain
elements, I know that it very possible for the robot
to follow the outside edge of the stain and recover
the line on the opposite side (my robot did this for
one). Following this path the robot would be
considered not following the line. Again after
watching multiple robots navigate the S curves, it
is easy to see if the robot is following the line
(I.e., swaying with the S curve) versus just cutting
across the center line (i.e., not following the
line). I agree that bigger robots, those with wheel
bases larger than the maximum radius of curve used
in the course (i.e., 6 inches), might not be as
responsive as the smaller robots. However, I still
believe that you can tell when they are not
following the line.</div>
<div><br>
</div>
<div> BTW, did you see Ron's robot demo on
Saturday? His robot was doing pretty well. I think
the course he was running had a S curve which he
handled without issue. The practice course didn't
have any stains, if I recall right.</div>
<div><br>
</div>
<div>Regards,</div>
<div>Doug P,</div>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Sun, Dec 10, 2017 at 10:49
AM, David Anderson <span dir="ltr"><<a
moz-do-not-send="true"
href="mailto:davida@smu.edu" target="_blank"><a class="moz-txt-link-abbreviated" href="mailto:davida@smu.edu">davida@smu.edu</a></a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div text="#000000" bgcolor="#FFFFFF"> Thanks
Doug,<br>
<br>
I'm not sure I follow your examples (pun
intended!). <br>
<br>
For the segmented S curves, the difference
between following the arc and following straight
line approximations of that arc are pretty
small, and likely to be indistinguishable from
Ron's robot's path, for example. Similarly,
each of the stains on the published "challenge"
course is on a straight line segment between the
entry point and exit point, so the paths would
be identical in both cases.<br>
<br>
For a robot with a base the size of the tiles,
I'm not sure there would be any difference at
all, unless the rules require that the "exact
center" of the robot must remain on the line, in
which case I don't see how either Carl's
approach or Ron's would qualify.<br>
<br>
This is just an intellectual exercise, I'm not
planning on fielding such a 'bot.<br>
<br>
cheers!<br>
dpa
<div>
<div class="m_8354197153887660578h5"><br>
<br>
<br>
<div
class="m_8354197153887660578m_-1585671555693740696moz-cite-prefix">On
12/10/2017 10:06 AM, Doug Paradis wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">David,
<div> Going from entry point to
exit point is not considered enough.
You have to follow the line. For
example, the segmented S curves, the
robot needs to follow the curve and
make an S type movement. Another
example is the stain elements, the
robot needs to follow the line across
the stain not follow the outside edge
of the stain. </div>
<div><br>
</div>
<div>Regards,</div>
<div>Doug P.</div>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Sun, Dec 10,
2017 at 1:11 AM, David Anderson <span
dir="ltr"><<a
moz-do-not-send="true"
class="m_8354197153887660578moz-txt-link-abbreviated"
href="mailto:davida@smu.edu"
target="_blank"><a class="moz-txt-link-abbreviated" href="mailto:davida@smu.edu">davida@smu.edu</a></a>></span>
wrote:<br>
<blockquote class="gmail_quote"
style="margin:0 0 0
.8ex;border-left:1px #ccc
solid;padding-left:1ex">
<div text="#000000"
bgcolor="#FFFFFF"> Great meeting
today. <br>
<br>
Doug, I have a question based on
Ron and Carl's presentations,
perhaps it has already been
answered, to wit:<br>
<br>
As I understand, the line
following course consists of an
assembly of square tiles, each of
which has an entry and exit point.<br>
<br>
Is it sufficient for the robot to
just identify the entry and exit
points, and drive directly from
one to the other?<br>
<br>
That is, it would not follow the
line per se, though with
sufficiently large robot the
differences would probably be
pretty negligible, but it would
follow the course.<br>
<br>
thanks,<br>
dpa
<div>
<div
class="m_8354197153887660578m_-1585671555693740696h5"><br>
<br>
<br>
<div
class="m_8354197153887660578m_-1585671555693740696m_-5699930273498463671moz-cite-prefix">On
12/09/2017 08:18 AM, Doug
Paradis wrote:<br>
</div>
</div>
</div>
<blockquote type="cite">
<div>
<div
class="m_8354197153887660578m_-1585671555693740696h5">
<div dir="ltr">John,
<div> Currently, the
intersecting lines are
always straight and all
intersections are 90
degrees. Curves lines at
an intersection would be
a possible addition to
further challenge
courses (interesting
idea). The link to the
course layout is at </div>
<div><a
moz-do-not-send="true"
href="https://www.dprg.org/wp-content/uploads/2017/11/DPRG-Roborama-2011b-Challenge-Level-LF-Course.pdf"
target="_blank"><a class="moz-txt-link-freetext" href="https://www.dprg.org/wp-conten">https://www.dprg.org/wp-conten</a><wbr>t/uploads/2017/11/DPRG-Roboram<wbr>a-2011b-Challenge-Level-LF-Cou<wbr>rse.pdf </a>
If you have any
additional questions,
let me know. I would
love to see your work on
the tests that you are
developing.</div>
<div><br>
</div>
<div>Regards,</div>
<div>Doug P.</div>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On
Sat, Dec 9, 2017 at
12:36 AM, John Swindle <span
dir="ltr"><<a
moz-do-not-send="true"
class="m_8354197153887660578moz-txt-link-abbreviated"
href="mailto:swindle@compuserve.com"
target="_blank"><a class="moz-txt-link-abbreviated" href="mailto:swindle@compuserve.com">swindle@compuserve.com</a></a>></span>
wrote:<br>
<blockquote
class="gmail_quote"
style="margin:0 0 0
.8ex;border-left:1px
#ccc
solid;padding-left:1ex"><font
face="Arial,
Helvetica,
sans-serif" size="2"
color="black">Doug,
<div><br>
</div>
<div>I'd say the
crossing in your
drawing was about
either 30 degrees
or 150 degrees,
and since it could
come in on either
side, I'd have to
look for both. I
am not asking that
the rules state
which side the
angle is measured
from. My issue is
that I am
developing a
two-step test that
covers all the
conditions in the
Challenge, but in
the steps I need
to include
something that
rejects the
intersections. I
am OK with
rejecting any line
that is 70 degrees
to 110 degrees on
either side. If
the intersecting
line is straight,
the test is a bit
more robust. If
each side is 70 to
110 degrees (a
bent intersecting
line), my two-step
test might fail.</div>
<div><br>
</div>
<div>Doing it
"that's just
wrong" way,</div>
<div>John Swindle</div>
<div>
<div
class="m_8354197153887660578m_-1585671555693740696m_-5699930273498463671h5">
<div><br>
<br>
<div
style="font-family:arial,helvetica;font-size:10pt;color:black">-----Original
Message-----<br>
From: Doug
Paradis <<a
moz-do-not-send="true"
class="m_8354197153887660578moz-txt-link-abbreviated"
href="mailto:paradug@gmail.com" target="_blank"><a class="moz-txt-link-abbreviated" href="mailto:paradug@gmail.com">paradug@gmail.com</a></a>><br>
To: John
Swindle <<a
moz-do-not-send="true"
class="m_8354197153887660578moz-txt-link-abbreviated"
href="mailto:swindle@compuserve.com" target="_blank"><a class="moz-txt-link-abbreviated" href="mailto:swindle@compuserve.com">swindle@compuserve.com</a></a>><br>
Cc: DPRG <<a
moz-do-not-send="true"
class="m_8354197153887660578moz-txt-link-abbreviated"
href="mailto:dprglist@lists.dprg.org" target="_blank"><a class="moz-txt-link-abbreviated" href="mailto:dprglist@lists.dprg.org">dprglist@lists.dprg.org</a></a>><br>
Sent: Fri, Dec
8, 2017 11:52
pm<br>
Subject: Re:
LF
intersection
angle rule<br>
<br>
<div
id="m_8354197153887660578m_-1585671555693740696m_-5699930273498463671m_-2867064402782409486AOLMsgPart_2_81c7d011-0908-4c74-95cc-d249b881afbf">
<div
class="m_8354197153887660578m_-1585671555693740696m_-5699930273498463671m_-2867064402782409486aolReplacedBody">
<div dir="ltr">John,
<div> In
the challenge
course, all
the
intersections
are 90
degrees. The
rule was
written to
allow crossing
variations in
the future.
I'm thinking
that 70-90
degrees would
represent the
smallest angle
of the
intersection.
I not sure
that is right,
just the way I
would
interpret the
angle. </div>
<div>if you
saw an
intersection
that was like
this:</div>
<div>
| /</div>
<div>
| /</div>
<div>
/</div>
<div>
/ |</div>
<div>
/ |</div>
<div> /
|</div>
<div><br>
</div>
<div>What
angle would
you say the
intersection
was? </div>
<div><br>
</div>
<div>Regards,</div>
<div>Doug P.</div>
</div>
<div
class="m_8354197153887660578m_-1585671555693740696m_-5699930273498463671m_-2867064402782409486aolmail_gmail_extra"><br>
<div
class="m_8354197153887660578m_-1585671555693740696m_-5699930273498463671m_-2867064402782409486aolmail_gmail_quote">On
Fri, Dec 8,
2017 at 9:03
PM, John
Swindle <span
dir="ltr"><<a
moz-do-not-send="true"
class="m_8354197153887660578moz-txt-link-abbreviated"
href="mailto:swindle@compuserve.com" target="_blank"><a class="moz-txt-link-abbreviated" href="mailto:swindle@compuserve.com">swindle@compuserve.com</a></a>></span>
wrote:<br>
<blockquote
class="m_8354197153887660578m_-1585671555693740696m_-5699930273498463671m_-2867064402782409486aolmail_gmail_quote"
style="margin:0
0 0
.8ex;border-left:1px
#ccc
solid;padding-left:1ex"><font
face="Arial,
Helvetica,
sans-serif"
size="2"
color="black">
<div>
<div>Doug,</div>
<div> </div>
<div>The Line
Following
Challenge
rules say
"Intersections
may cross with
angles of 70 -
90 degrees."
Doesn't that
really mean 70
to 110
degrees? Is
the
intersecting
line straight,
or can it bend
at the
intersection?</div>
<div> </div>
<div>Thanks,</div>
<div>John
Swindle</div>
<div> </div>
<div
style="color:black;font-family:arial,helvetica;font-size:10pt"><br>
</div>
</div>
</font></blockquote>
</div>
<br>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</font></blockquote>
</div>
<br>
</div>
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