Often overlooked pitfalls of straightforward implementation of textbook controller tuning methods

Abstract

AbstractVarious approaches to the PID controller tuning account for a substantial part of the undergraduate control engineering curricula. At the most general level, these approaches can be divided into two groups. Model based methods use some kind of mathematical model of the controlled plant while the experimental methods rely on a simple experiment that is performed with the plant. The students usually understand that obtaining a sufficiently accurate mathematical model of the plant is not easy and may involve many complex issues. On the other hand, the experimental methods may be regarded as an easy to follow recipe that can be directly applied according to the textbook to obtain the desired tuning. This paper shows the common pitfalls that can arise when these methods are applied in their idealized textbook form. The main focus is on how these pitfalls can be demonstrated using experiments with two laboratory plants of different complexity.