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7.12 End Notes
Exercise 7.11 [Advanced Reading]
Read more about the Saphira architecture in “The Saphira Architecture for Autono-
mous Mobile Robots” by Kurt Konolige and Karen Myers in Artificial Intelligence and
Mobile Robots. 77 They describe the system built for a demonstration for the TV special,
Scientific American Frontiers. Summarize the behaviors and agents used. How would
the same tasks be accomplished using AuRA, SFX, 3T, or TCA?

7.12 End Notes

For the roboticist’s bookshelf.
Behavior-Based Robotics by Ron Arkin 10 is the most complete work on AI robotics.
It has a comprehensive list of influential robot architectures, and explores in detail
many of the issues only lightly touched upon in this book. Well worth reading and
using as a reference.

About Saphira and Pioneer robots.
So why did RWI/ActivMedia choose the Saphira architecture for their Pioneer line?
Because the Pioneer robot is based on a robot designed by a class taught at Stanford
by Kurt Konolige, one of the architects of Saphira.

Foam-henge and the importance of architectures.
One criticism that applies to many of the Hybrid architectures is that they have
moved away from subsumption or vector summation to more open-ended meth-
ods such as voting, rule-based arbitration, fuzzy logic, etc. There are definitely cases
where there is a single best action to take. For example, consider what happened at a
1995 demonstration of the UGV Demo II program. The demonstration took place at
the Martin Marietta (now Lockheed Martin) facility near Denver, Colorado. The Mar-
tin team was responsible for integrating various research contracts into a form usable
by the HMMWV and for hosting demos. To help with the demo, they had several
very large foam boulders created for the demo by a California special effects com-
pany. That way, the team could arrange the boulders in challenging positions to test
the Demo II vehicles (versus trying to move real boulders). The boulders eventually
became nicknamed “Foam-henge” as a play on Stonehenge.
The demonstration involving Foam-henge started with the audience standing at
the rise of a canyon. Foam-henge was placed in the middle of the predicted path for
an autonomous HMMWV. This was intended to be a test of its ability to detect and
respond to unmodeled obstacles. The audience watched as a HMMWV navigating
slowly, but autonomously, out of the canyon. The vehicle approached Foam-henge,
then stopped, clearly detecting the boulder nearest it. Still stopped, the front wheels
of the robot turned hard to the right. The wheels then turned hard to the left. Just as
quickly, the wheels returned to the straight position, and the HMMWV accelerated