It's been pointed out that I have committed the sin of using undefined jargon. For the record, PID stands for Proportional Integral Derivative. PID is a ubiquitous type of feedback controller, mostly thanks to being conceptually quite simple. The input is an error signal (or a measurement and setpoint signal) of some process under control. The PID controller applies 3 types of feedback: P - proportional, in which the control output is proportional to the error signal. I - integral, in which the control output is proportion to the time-integral of the error signal. D - derivative, in which the control output is proportional to the time-derivative of the error signal. These three terms are added together to produce the control output. By the right selection ("tuning") of the 3 gain values, stable feedback control of a wide variety of processes is possible.

on 2009-05-22 23:32

on 2009-05-22 23:38

Aviv Keshet wrote: > I - integral, in which the control output is proportion to the time-integral of > the error signal. > D - derivative, in which the control output is proportional to the > time-derivative of the error signal. > > These three terms are added together to produce the control output. By the right > selection ("tuning") of the 3 gain values, stable feedback control of a wide > variety of processes is possible. > > > We'll be using a couple of PID control systems for our big dish. -- Marcus L. Principal Investigator, Shirleys Bay Radio Astronomy Consortium http://www.sbrac.org