Tuning of PID controller for higher order system

Abstract

PID controllers have been widely used in process control industries because of its implementational and tuning advantages. It is mainly used because of its relatively simple structure and robust performance. It seems conceptually very easy to achieve multiple objectives such as short transients and high stability, but tedious in practice. The speed of the response of the system is inversely proportional to the time constant of the dominant pole of the plant. Thus, it is advisable to design such a plant which has pole very near to the origin. Better responses can be found in different systems with different dynamics, like those with low order or high order, monotonic or oscillatory responses and large dead time or small dead time. Tuning of PID controllers for first order plus dead time is very simple and common in practice. Many methods have been found out which can generate the algorithm for first order plus dead time model, but first order plus dead time model is unable to generate peaks for monotonic processes.