Chapter 6. PID Controller Tuning

In Chapter 5 we were given a process transfer function and a controller transfer function (P, PI, PID, etc.) and asked to find the closed-loop response (or stability). In this chapter we provide an overview of classical methods for tuning PID controllers. We also provide an introduction to model-based techniques, using the direct synthesis approach.

After studying this chapter, the reader should be able to do the following:

• Understand the different forms of a PID controller

• Tune PID controllers using the classical, Ziegler-Nichols, and Cohen-Coon methods

• Derive controllers based on a process model and desired closed-loop response

The major sections of this chapter are as follows:

6.1 Introduction

6.2 Closed-Loop Oscillation-Based Tuning

6.3 Tuning Rules for First-Order + Dead Time Processes

6.4 Direct Synthesis

6.5 Summary