Open-loop controller: Difference between revisions

Revision as of 07:40, 16 October 2016

Revision as of 04:28, 17 October 2016

Line 1:

{{Multiple issues|

{{nomore footnotes|date=January 2015}}

[[File:Remote manipulators 003.jpg|thumb|upright|[[Remote manipulator]] arms for working with radioactive materials – an open-loop mechanism, controlled by hand controls]]

{{refimprove|date=December 2011}}

}}

[[File:Remote manipulators 003.jpg|thumb|upright|[[Remote manipulator]] arms for working with radioactive materials – an open-loop mechanism, controlled by hand controls]]

An '''open-loop controller''', also called a '''non-feedback controller''', is a type of [[Controller (control theory)|controller]] that computes its input into a system using only the current [[state (controls)|state]] and its [[mathematical model|model]] of the system.

A characteristic of the open-loop controller is that it does not use [[feedback]] to determine if its output has achieved the desired goal of the input. This means that the system does not observe the output of the processes that it is controlling. Consequently, a true open-loop system can not engage in [[machine learning]] and also cannot correct any errors that it could make. It also may not compensate for disturbances in the system.

==Open-loop and closed-loop (feedback) control==

Fundamentally, there are two types of control loop; open loop control, and closed loop (feedback) control.

Line 18 ⟶ 22:

Likewise; "A ''Feedback Control System'' is a system which tends to maintain a prescribed relationship of one system variable to another by comparing functions of these variables and using the difference as a means of control.'"<ref>{{cite book|title= The Origins of Feedback Control|last=Mayr|first= Otto|year= 1969|publisher =The Colonial Press, Inc.|___location= Clinton, MA USA|isbn= |pages=}}</ref>

The advanced type of automation that revolutionized manufacturing, aircraft, communications and other industries, is feedback control, which is usually ''continuous'' and involves taking measurements using a [[sensor]] and making calculated adjustments to keep the measured variable within a set range. <ref name="Bennett 1993"/> The theoretical basis of closed loop automation is [[control theory]].

== Examples ==

Line 40 ⟶ 44:

==References==

{{Reflist}}

* Kuo, Benjamin C. (1991). ''Automatic Control Systems'' (6th ed.). New Jersey: Prentice Hall. ISBN 0-13-051046-7.

* Ziny Flikop (2004). "Bounded-Input Bounded-Predefined-Control Bounded-Output" (http://arXiv.org/pdf/cs/0411015)