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8 comments
Anonymous Poster #1

Feedback and Feedforward Control

06/12/2011 9:53 AM

Please any one explain that what is the feedback, negative feedback and feedforward control?

and what is the difference between feedback and feedforward control?

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#1

Re: Feedback and feedforward control

06/12/2011 10:31 AM

Can no one do anything for themselves anymore?

Controller (control theory) - Wikipedia, the free encyclopedia

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#5
In reply to #1

Re: Feedback and feedforward control

06/13/2011 2:32 AM

I hadn't thought to look up the article, though years in refinery control testing and calibration left me interested. Pneumatic force balance instruments were still common 40 years ago, having replaced mercury based iron float instruments in the early '50s. As I get it, the earliest artificial feedback control system was James Watt's flyball governor, which made practical the steam expansion engine.

Wikipedia is surprisingly thorough and lucid.

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#2

Re: Feedback and feedforward control

06/12/2011 10:58 AM

So you want the basics in control theory of systems. Well your question is so fundamental that I think that this may be a homework problem. So I will give you only basic answers.

First, my answer here is a form of feedback. You asked a question and I gave you feedback on your question. Now I ask you a question, does my answer at all control you, your question or your ability to achieve your goal? (Whatever your goal maybe.) Your answer will tell you if this feedback is a feedback control. Now if you just continue (start) to think on your own by realizing the meaning of each word and how each word modifies the meaning of the whole sentence, you should be able to answer your own questions. Now my mild return that you should do your own thinking is itself a specific type of feedback from your input. Do you think this feedback helps your initial question of having us do your work (positive) or not having us do your work (negative)? Now don't get confused over the question of which approach works better for you, the question determining the polarity of the feedback is does the output response support or cancel the input. (OK, I tricked myself there. I tried but failed to obfuscate the answer for one of your questions.)

So that just leaves the question between feedback and feedforward control. Well if you now understand the path of feedback and forward is an antonym of backward, what do you think feedforward control is?

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#3
In reply to #2

Re: Feedback and feedforward control

06/12/2011 11:36 AM

GA. Lewis Carroll would be proud!

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#4

Re: Feedback and Feedforward Control

06/13/2011 12:53 AM

Many will give you reply as "Basic Homework question". So next time you will control yourself from asking such basic questions. This is the feedback control system.

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#6
In reply to #4

Re: Feedback and Feedforward Control

06/13/2011 5:06 PM

So are you stating that the members also know as Lyn and RedFred are actually feedback control elements? Are they active or passive? Do we need to be careful that they don't give us an inductive kick? And the most important question is, "Will they let the band pass?"

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#7
In reply to #6

Re: Feedback and Feedforward Control

06/13/2011 5:13 PM

I'll let most bands pass. I may wince when they go out of tune but I'll let them pass. For the record, I don't consider somebody gargling or growling into a microphone while somebody else plays canned music a band.

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#8
In reply to #4

Re: Feedback and Feedforward Control

06/14/2011 4:27 AM

GA to you and also to the two members of the feedback system .

Now what is feedforward system ? The OP's computer blocks CR4 site from opening ? Or do the CR4 moderators get an sms alert and block the OP?

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