John G. Truxal
SUNY at Stony Brook
Feedback exists naturally in physiological, economic and social systems.
This monograph starts with familiar examples of feedback -- the body
temperature control system, the home heating system and the steering of
a car. Feedback is defined as a goal-seeking system in which the actual
output is measured and compared with the desired output. The difference
in the two values (or error) then forces the output to change toward a
The engineer has developed feedback as a central tool of system design.
With feedback, the engineer forces the system to behave in the desired
way, even if the system parts change their behavior radically.
Feedback is the essential elemcnt of automation. By automation we mean
machines replacing people in tasks requiring decisions. The author uses
simple examples to make these two terms, feedback and automation,
understandable to the lay reader.
The mathematics ranges from simple arithmetic to algebra.