If you study control theory you will encounter so-calledÌýblock diagrams, which are schematic representations of control systems and help one to understand how they work. Below is the block diagram for a cruise control system.
VinÌýÌýis
the
desired
speed,
set
by
the
driver.
VoutÌýÌýis
the
actual
speed
on
the
speedometer.
The
pale
blue
device
calculates
the
error:Ìýe
=ÌýVinÌý-Ìý³ÕoutÌýÌý
°Õ³ó±ðÌýprocessorÌýrepresents
the
engine
and
braking
system.
Action of theÌýcontroller:
- ¾±´ÚÌýeÌý> 0, then accelerate
- ¾±´ÚÌýeÌý< 0, then decelerate