Page 274 - Concise Encyclopedia of Robotics

Real Time
A robot that operates in this fashion is analogous to a human or animal
that exhibits reflex actions when certain stimuli occur.
The principal asset of the reactive paradigm is high speed.Just as human
or animal reflexes occur faster than behaviors that involve conscious thought
(deliberation), robots using the reactive paradigm can respond to changes
in their environment almost instantly. However, there are drawbacks to
this approach. The simple sense/act approach can sometimes result in
cycling back and forth between two conditions, without making any
progress toward the intended goal. This can be considered the robotic
equivalent of human disorientation or panic. Compare HIERARCHICAL PARADIGM
and HYBRID DELIBERATIVE/REACTIVE PARADIGM.
REAL TIME
In communications or data processing, operation done “live” is called
real-time operation. The term applies especially to computers. Real-time
data exchange allows a computer and the operator to converse.
Real-time operation is convenient for storing and verifying data within
a short time.This is the case,for example,when making airline reservations,
checking a credit card, or making a bank transaction. However, real-time
operation is not always necessary. It is a waste of expensive computer
time to write a long program at an active terminal. Long programs are
best written off-line, tested in real time (on-line), and debugged off-line.
In a fleet of insect robots all under the control of a single computer,
real-time operation can be obtained for all the robots simultaneously.One
method of achieving this is time sharing. The controller pays attention
to each robot for a small increment of time, constantly rotating among
the robots at a high rate of speed. Compare TIME SHIFTING.
RECTANGULAR COORDINATE GEOMETRY
See CARTESIAN COORDINATE GEOMETRY.
RECURSION
Recursion is a logical process in which one or more tasks are set aside while
the main argument is being made. Recursion is common in computer
programs, where it can take the form of nested loops. Recursion is also
useful in proving mathematical and legal propositions. It is a powerful
tool in artificial intelligence (AI).
Keep final goal in mind
Recursion can be intricate, and is one of the most advanced forms of
human reasoning. For recursion to work, the overall direction of progress
is toward the final goal. Sidetracking might seem to have nothing to do

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