The dynamics of process control

摘要

HOW best does a process controller go about controlling the controlled variable at or very near set point at all times? At any given time, if the current set point and variable are the same and are changing at the same rate, then the controller is providing the correct output. If the two are not the same at a given time or if they are changing at different rates, then the controller needs to adjust its output so as to bring the variable to and maintain it at set point.