Robosphere 2004, Nov. 9-10 Eyewitness Account (Part 2)

I should mention that as a condition for being allowed to
attend the Robosphere workshop for free, I was supposed to
volunteer my time to help with the proceedings. I spent the
early part of lunch getting briefed on my responsibilities.
My job title for the first day was Miscellaneous. I was
essentially supposed to sit near the entrance hall and take
care of anything that didn't fall under the category of
registration, audio/visual, or video recording. I think the
only thing I did was to ask someone if they needed anything.
They said "no".

So after briefing, I went to get some lunch. I think the
first person I met was Greg
Hornby. He was a former student of Jordan Pollack at
Brandeis University and now working at NASA Ames research
center. I didn't know this at the time, but I did ask him a
little about his work. He mentioned that his work was on
evolutionary algorithms. I wasn't particularly interested
at the time because I've heard that word thrown about so
often that I just considered it a dead-end buzzword. I came
to appreciate it later in the workshop.

His work is essentially in evolutionary algorithms for
computer-automated design. The way this works is that you
give the computer a bunch of parameters, a task, and a
simulation environment. The computer then proceeds to make
up a robot design and test it in the simulation environment.
If it does well, it tries to improve on that design. If it
does poorly, it discards those changes and tries another
route. What's interesting is that this is done in an
analogous way to natural selection in the process of
evolution. Many populations of different robots with
different designs are tested in a simulation environment.
The poor performers are terminated and the good performers
are allowed to continue existing. In addition, the good
performers are allowed to "mate" and create hybrid designs
that try to combine the best features of both performers.

I think I talked more about this here
in my Oct. 22 entry last year. This is a very interesting
approach to robot design that is starting to show that it
has more and more useful applications.

Someone else I met at lunch was Greg
Chirikjian and one of his students, Kiju Lee, from John
Hopkins University. His work involves self-replicating
robots. I saw him once at a robotics conference in New
Orleans, but didn't have a chance to talk to him.

The idea of self-replicating robots is that you send a small
colony of robots to some place like the Moon or Mars. Once
there, they utilize the resources that they find in the soil
or regolith, synthesize this into parts, and make copies of
themselves. This essentially allows the robots to multiply
completely on their own and saves you lots of time and money
in shipping extra robots and parts to these
extra-terrestrial environments.

This may sound cool or scary, but it's a really really
difficult problem. This idea has been around for quite a
while, but not taken very seriously because the technology
just isn't there. Chirikjian has shown several
demonstrations of an actual self-replicating robot making a
copy of itself in an autonomous manner. Albeit, the robot
is made out of legos and there are only four parts to be
assembled to make an extra robot copy. Nevertheless, the
feat is amazing to anyone has actually tried to do something
like this. Go ahead and try to do it yourself. You'll be
surprised how hard it is to make a robot that can build and
assemble an exact copy of itself-- even a simplified assembly.

After lunch, it was time to head back into the conference
hall and assume my post as Miscellaneous man.

The first speaker was Ashley Stroupe from NASA JPL in
Pasadena, California. She's one of the staffers on the Mars
Rover projects, so she immediately has a superstar presence.
Not that people are asking her for her autograph, but
people are interested in her work like in the normal humdrum
way of academics.

But this talk was not about the Mars rovers. This talk was
about autonomous construction robots. More specifically,
"Sustainable Cooperative Robotic Technologies for Human and
Robotic Outpost Infrastructure Construction and
Maintenance". Their work essentially consisted of two
rover-like robots, with manipulator arms, and operating in a
sandbox. There task was to go to two sides of a beam, pick
up the beam in a synchronized manner, turn around and carry
it to the construction site, and set the beam down aligned
on top of another beam. This was done in a completely
autonomous manner with no human intervention. This was the
culmination of about 9 months worth of work.

I was deeply impressed. I've had experience trying to get
mobile robots to interact and manipulate objects in precise
way and realized all the difficulties. It's particularly
difficult for mobile robots since you don't have a fixed
reference frame to work with. The robot has to be adaptive
and able to perceive the object well enough to know where it
is and understand how it affects the object. Their only
sensors in this feat were a camera and some force-torque
sensors on the arms to keep the robots synchronized while
carrying the beam. Some fiducial markers were placed on the
beams and the cameras were used to detect them so the robots
could more easily position themselves and the beams.

So currently the project at NASA is in very preliminary
stages and its not clear whether it will continue to be
funded, but this project seems to align very well with
NASA's new space objectives outline by President Bush a year
ago which include robotic and manned missions to the Moon
and Mars.

More later.

Jacob Everist