Overview of the Three Paradigms

Overview of the Three Paradigms

In order to set the stage for learning details, it may be helpful to begin with
a general overview of the robot paradigms. Fig. I.3 shows the differences
between the three paradigms in terms of the SENSE, PLAN, ACT primitives.
HIERARCHICAL The Hierarchical Paradigm is the oldest paradigm, and was prevalent from
PARADIGM 1967–1990. Under it, the robot operates in a top-down fashion, heavy on
planning (see Fig. I.3). This was based on an introspective view of how people
think. “I see a door, I decide to head toward it, and I plot a course around
the chairs.” (Unfortunately, as many cognitive psychologists now know, introspection
is not always a good way of getting an accurate assessment of
a thought process. We now suspect no one actually plans how they get out
of a room; they have default schemas or behaviors.) Under the Hierarchical
Paradigm, the robot senses the world, plans the next action, and then acts
(SENSE, PLAN, ACT). Then it senses the world, plans, acts. At each step,
the robot explicitly plans the next move. The other distinguishing feature of
the Hierarchical paradigm is that all the sensing data tends to be gathered
into one global world model, a single representation that the planner can use
and can be routed to the actions. Constructing generic global world models