Page 60 - Designing Sociable Robots

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Designing Sociable Robots 41

Competent behavior in a complex world Any convincing robotic creature must ad-
dress similar behavioral issues as living, breathing creatures. The robot must exhibit robust,
flexible, and appropriate behavior in a complex dynamic environment to maintain its “well-
being.” This often entails having the robot apply its limited resources (finite number of
sensors, actuators and limbs, energy, etc.) to perform various tasks. Given a specific task,
the robot should exhibit a reasonable amount of persistence. It should work to accomplish
a goal, but not at the risk of ignoring other important tasks if the current task is taking
too long. Frequently the robot must address multiple goals at the same time. Sometimes
these goals are not at cross-purposes and can be satisfied concurrently. Sometimes these
goals conflict, and the robot must figure out how to allocate its resources to address both
adequately. Which goals the robot pursues, and how it does so, depends both on external
influences (from the environment) as well as on internal influences (from the creature’s
motivations, perceptions, and so forth).

Believable behavior Operating well in a complex dynamic environment, however, does
not ensure convincing, life-like behavior. For Kismet, it is critical that the caregiver perceive
the robot as an intentional creature that responds in meaningful ways to her attempts at
communication. As previously discussed in chapter 3, the scaffolding the human provides
through these interactions is based upon this assumption. Hence, the SNS must address
a variety of issues to promote the illusion of a socially aware robotic creature. Blumberg
(1996) provides such a list, slightly modified as shown here: convey intentionality, promote
empathy, be expressive, and allow variability.
These are the high-level design issues of the overall human-robot system. The system
encompasses the robot, its environment, the human, and the nature of interactions between
them. The human brings a complex set of well-established social machinery to the inter-
action. My aim is not a matter of re-engineering the human side of the equation. Instead, I
want to engineer for the human side of the equation—to design Kismet’s synthetic nervous
system to support what comes naturally to people.
If Kismet is designed in a clever manner, people will intuitively engage in appropriate
interactions with the robot. This can be accomplished in a variety of ways, such as phys-
ically designing the robot to establish the correct set of social expectations for humans,
or having Kismet send social cues to humans that they intuitively use to fine-tune their
performance.
The following sections present a high-level overview of the SNS. It encompasses the
robot’s perceptual, motor, attention, motivation, and behavior systems. Eventually, it should
include learning mechanisms so that the robot becomes better adapted to its environment
over time.