Applied Process Control

8Stability and Quality of Control

8.1 Introduction

Control theory has until recently been taught in a way that did not distinguish much between the fields of application, whether those be missiles, aircraft, power systems or chemical processes. The advent of the digital computer has however opened up a vast range of new applications, which have perceptibly moved the emphasis away from the types of things that the classical analysis methods handled. This is particularly the case in the processing industries where the control engineer has a new focus on advanced process control (APC), model predictive control (MPC) and real time optimisation (RTO). Of course, issues of loop stability and controller performance are still important, but in the ...