Open-loop controller: Difference between revisions

Revision as of 18:09, 21 May 2021

Revision as of 09:16, 29 October 2022

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{{Short description|Control system whose input is independent of output}}

{{Other uses of|Open-loop}}

{{more footnotes|date=January 2015}}

In [[control theory]], an '''open-loop controller''', also called a '''non-feedback controller''', theis a [[control actionsystem]] fromin which the controllercontrol action is independent of the "process output", which is the [[process variable]] that is being controlled.<ref name="auto">"Feedback and control systems" - JJ Di Steffano, AR Stubberud, IJ Williams. Schaums outline series, McGraw-Hill 1967</ref> It does not use [[feedback]] to determine if its output has achieved the desired goal of the input command or process "set point".

There are many open-[[Control loop|loop]] controls, such as on/off switching of valves, machinery, lights, motors or heaters, where the control result is known to be approximately sufficient under normal conditions without the need for feedback. The advantage of using open-loop control in these cases is the reduction in component count and complexity. However, an open-loop system cannot correct any errors that it makes or correct for outside disturbances, and cannot engage in [[machine learning]], unlike a [[closed-loop control system]].

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