Thread: What is PID?
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Unread 25-05-2010, 16:34
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Re: What is PID?

(First, ignore the word "loop". It can mean two completely different things depending on context, neither of which is important to the basic concept of PID control.)

PID stands for the three words Proportional, Integral, and Derivative. Those are fancy ways of saying that the output depends on the input right now, on the accumulated input over time, and on how quickly the input is changing. It's a way to control something in order to cause a measured value to match a desired value. Changing the relative strength of the three parameters is called "tuning" the system, with the goal of reaching the target quickly with minimal overshoot and oscillation.

Most PID control algorithms start by computing an error value, which is just the difference between the target and the measured values.

With that simple description, you should be able to look at any number of detailed references and understand them better.
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