Controllers-tune them right

Abstract

Basic controllers which apply to process control are reviewed. Common types of controllers discussed are two-position, proportional, integral, derivative, proportional plus integral, proportional plus derivative and proportional plus integral plus derivative. The author presents a simple method for adjusting the controller when it is installed on a system, making use of the online manual-tuning procedure. Having shown that the controller settings can be obtained in the field, it will be possible for the engineer/operator to tune the controller for certain applications and thus determine the controller parameters even before the process reaction curve is built.<>