Robotics Reference
In-Depth Information
they were human. The robots had to find their way to the registration
booth in the Shaw Convention Center and register for the conference,
whereupon they were given a map of the convention center. Each robot
then had to find its way to a specified hall within the building in time to
present a technical lecture about itself. Winner of the 2002 contest was
a robot called GRACE,
14
developed by a consortium of more than 20
researchers from five different institutions: Carnegie Mellon University,
the U.S. Naval Reaserch Laboratory, Northwestern University, Metrica,
Inc. and Swarthmore College. Clearly a robot would need to demon-
strate several different AI technologies in order to meet the challenge
successfully, and the integration of all these technologies is a significant
task in itself.
GRACE is based on a commercially available mobile robot
15
incor-
porating touch sensors, infrared sensors and a laser-based range-finder, all
of which allow GRACE to navigate its way around its environment. To
give GRACE a face the robot was connected to a flat-panel LCD screen
that displays its computer-animated facial expressions.
GRACE's first task when it was brought to the entrance of the con-
ference center was to find the registration area by asking people the way.
GRACE's software includes a commercially available speech recognition
package,
16
a text-to-speech software package,
17
and it could also follow
directions given by people pointing the way.
GRACE employs the “goal
→
sub-goal” approach to problem-solving
described in Chapter 6.
18
For its first goal, finding the registration desk,
GRACE created sub-goals, intermediate points on the route, on the basis
of its various interactions with other delegates and with the conference
staff, in order to determine its route. Whenever all of its currently avail-
able directions had been executed, GRACE concluded that either it has
arrived at its destination, which it could determine by asking someone
or by seeing an appropriate sign such as “Registration Desk”, or that
additional information was required to reach the current sub-goal, in
which case the robot would once again ask for directions. If no hu-
man was within sight when it needed fresh directions, the robot per-
formed a random walkabout until its laser scanner latched onto a hu-
14
Graduate Robot Attending Conference.
15
The Real World Interface (RWI) B21 robot from iRobot Corporation.
16
IBM's ViaVoice system.
17
Edinburgh University's “Festival” package.
18
See the section “Problem Solving” in Chapter 6.
