Date: Sat, 11 Mar 2006 23:06:12 -0600 (CST)
Subject: science place
X-UID: 147

There are too many images so I uploaded them to the website instead of
sending them as email attachments.

http://golem5.org/robot1/images/img2771.jpg
http://golem5.org/robot1/images/img2773.jpg
http://golem5.org/robot1/images/img2778.jpg
http://golem5.org/robot1/images/img2782.jpg
http://golem5.org/robot1/images/img2785.jpg
http://golem5.org/robot1/images/img2790.jpg

It took much longer than expected to get the robot assembled and checked
out. I woke up at midnight and worked until about 7:30 am, slept for an
hour, and then continued until around 11:00 am. The DPRG meeting started
at noon so I arrived at just about the correct time.

Well, the robot didn't make it any farther than about 25 feet. The right
wheel came loose. The blue Loc-tite was not enough. Eventually, the left
wheel also came loose.

There is a good solution to this problem in RC toys. They use a steel pin
that engages a slotted nut. This is kind of like a key. I'll have to do
something like this soon as adhesives will never hold up. Each drill motor
can put out something like 450 inch pounds of torque. That's like hanging
a 37 pound weight on a one foot arm.

The bungie cord pulling the front wheels into position is not very stable.
As soon as a wheel toes in, the tendency is to snowplow. I didn't see this
before as I had always pulled or driven on hard packed surfaces. But on
grass, there is more resistance. The bungie will have to be replaced by a
cord, just like the front. Also, the tires need to be inflated. The rubber
tires are not stiff enough given the robot weight.

It was a good workout to carry the robot into the Science Place. The
Science Place (for those who do not reside in Texas) is similar to the San
Francisco Exploratorium except that there's no chaotic spirit of Frank
Oppenheimer behind everything. It's very refined, like a theme park. But
it's still one of the coolest things I've seen in Dallas. It's full of
happy children.

Children are fascinated by robots. They also seem to hold them in
reverence which I find impressive. It's like when I saw Chicken Run in a
theater full of children and they were absolutely silent, better than
adults. I think they were in awe.

Unfortunately, I don't have any photos of this process as I was in pain
while hauling the robot in and out of the building. The chunky military
style laptop case was slung over my back while I carried the robot. I
didn't have any energy left to pay much attention to what was going on
around me. I also hadn't had anything to eat since the previous day's
lunch.

This does tell me that in the proper social context, you can get away with
a lot. I think that a perfect R2D2 droid replica, one that really works
with a lot of AI inside, could be set loose inside the Science Place,
mobbed by children, and the adults would tolerate it for at least a little
while.

The DPRG meeting was interesting. You could definitely see different
personalities and skill sets in evidence. One guy had a very cool
simulation and visualization environment he had written. Most of the group
are hardware guys and at some level seemed less impressed than I was, I
think. Another guy had a presentation on optical mice sensors. It was
quite interesting. He gave the "O'Reilly" style presentation - exactly
what you need and want to know about how to hack mice to get the sensors
out of them and then subvert them for robotics uses. His final neat trick
was to take a $5 optical mouse, scotch tape a $1 loupe over the sensor,
and then use it as an optic flow camera. That's pretty slick (quite a
macho demonstration). After him, there were some indoor robots. My robot
came last.

I prefaced by asking people to interrupt if they had any questions. No one
did. I kind of rambled on about specifications and sort of the design
philosophy I'm currently on - modern control systems, Berkeley style three
camera solution, and how I'm going to use CORBA as the robot is becoming
so complicated that it is looking more like enterprise system software. I
have this feeling that the philosophy behind this robot is really heresy
to most. But it's so alien compared to other designs that no one says very
much.

This is the second time I've operated the robot outdoors. I learned a lot.
My guess is that I need to test as much as I can. It shortens the time
wasted on engineering that can not possibly work. I need shorter design,
test, analyze iterations. It's hard to do this as my natural personality
habit is to spend lots of time in design and analysis and little in
testing.

Also, I worked harder and got more done in about ten hours than I normally
would because of the pressure to get the system together for a demo. It
tells me that I can work harder and faster than I typically do if I can
remain focused.

For some reason, there was just too much floating around after the meeting
and demo so I went to the bookstore to decompress. The day disturbed me.

I saw a book about Paul McCready. His engineering philosophy was to say
that if you are not making mistakes, then you are not working fast enough.
He also said that if it works, it's beautiful. It was a philosophy
predicated on experimental verification. He was just very aggressive on
boutique projects. Another book had a detailed history of automatic cannon
design. It is interesting that modern Russian aircraft cannon have more
power in smaller and lighter packages than American designs. They are
clearly superior and well balanced for how they are used. American design
has moved rather more slowly. The explanation in the book is that it is
traditional in Russia to name a successful design after the engineers. The
US never does this. It's interesting how pragmatic the Russians are when
it comes to systems design.

The other thing I found out was that Jeri Ellsworth of retro Commodore 64
VLSI design fame (high school dropout ends up as famous self-taught VLSI
designer) had a software team of three or four guys. She did the hardware.
But there was a sizeable team around her for software. I'm thinking about
this as without that team, she could not have made the useful things of
beauty that she did. The feel-good popular media ignores the team and
portrays her as an army of one. She's mutant level strong but still must
work in a team to accomplish significant engineering objectives.