Attributes of the Hybrid Paradigm

Attributes of the Hybrid Paradigm

The organization of a Hybrid Deliberative/Reactive system can be described
as: PLAN, then SENSE-ACT. It is shown in Fig. 7.1. The PLAN box includes
all deliberation and global world modeling, not just task or path planning.
The robot would first plan how to accomplish a mission (using a global world
model) or a task, then instantiate or turn on a set of behaviors (SENSE-ACT)
to execute the plan (or a portion of the plan). The behaviors would execute
until the plan was completed, then the planner would generate a new set of
behaviors, and so on.
The idea of PLAN, then SENSE-ACT evolved from two assumptions of
the Hybrid Paradigm. First, planning covers a long time horizon and requires
global knowledge, so it should be decoupled from real-time execution

The organization of sensing in the Hybrid architecture is more complex.
Sensing is truly hybrid, as seen in Fig. 7.2. In the behaviors, sensing remains
as it was for the Reactive Paradigm: local and behavior specific. But planning
and deliberation requires global world models. Therefore, planning
functions have access to a global world model. The model is constructed by
processes independent of the behavior-specific sensing. However, both the
perceptual schemas for the behaviors and the model making processes can
share the same sensors. Furthermore, the model making processes can share
the percepts created by the perceptual schemas for behaviors (eavesdrop) or
it can have sensors which are dedicated to providing observations which are
useful for world modeling but aren’t used for any active behaviors.
The organization of the SENSE, PLAN, ACT primitives in the Hybrid ParaREACTOR
digmis conceptually divided into a reactive (or reactor) portion and a deliberDELIBERATOR
ation (or deliberator) portion. Although many architectures will have discrete