Having defined the term "controlled system" it only remains to give definitions
of closed-loop control as contained in standards. First it is useful
to fully understand
Open-loop control
German standard DIN 19 226 defines open-loop control as a process
taking place in a system where by one or more variables in the form of
input variables exert influence on other variables in the form of output
variables by reason of the laws which characterize the system.
The distinguishing feature of open-loop control is the open nature of its
action, that is, the output variable does not have any influence on the
input variable.
Closed-loop control
DIN 19 226 defines closed-loop control as a process where the controlled
variable is continuously monitored and compared with the reference
variable. Depending on the result of this comparison, the input variable
for the system is influenced to adjust the output variable to the desired
value despite any disturbing influences. This feedback results in a
closed-loop action.
This theoretical definition can be clarified using the example of volumetric
flow control.
สมัครสมาชิก:
ส่งความคิดเห็น (Atom)
ไม่มีความคิดเห็น:
แสดงความคิดเห็น