Page 315 - Introduction to AI Robotics

298
8
Multi-agents

Figure 8.1 Georgia Tech’s winning robot team for the 1994 AAAI Mobile Robot
Competition, Pick Up the Trash event. (Photograph courtesy of Tucker Balch and
AAAI.)

miniature helicopter. This combination permits the team to send a human
observer a comprehensive view of a particular site, such as a hostage situa-
tion.
A special case of a cooperative, heterogeneous team of robots has been
dubbed marsupial robots. The motivation for marsupial robots stemmed from
concerns about deploying micro-rovers for applications such as Urban Search
and Rescue. Micro-rovers often have limited battery power, which they
can’t afford to spend just traveling to a site. Likewise, micro-rovers may
not be able carry much on-board processing power and need to have an-
other, more computationally powerful workstation do proxy (remote) pro-
cessing. A marsupial team consists of a large robot which carries one or
more smaller robots to the task site, much like a kangaroo mother carries
a joey in her pouch. Like a joey, the daughter robot is better protected in
the pouch and can conserve energy or be recharged during transport. The
mother can protect a delicate mechanism or sensor from collisions while it
navigates through an irregular void. The mother can also carry a payload
of batteries to recharge (feed) the daughter. It can serve as a proxy worksta-
tion, moving to maintain communications. The mother is likely to be a larger
robot, while the daughter might be a micro-rover with sensors very close to
the ground. The mother will have a better viewpoint and sensors, so in some
circumstances it can communicate advice to the smaller daughter to help it
cope with a “mouse’s eye” view of the world. A teleoperator can also control