Adaptive PID Control

Conventional PID controllers are used commonly in industry. However, under various circumstances, such as changing process conditions, the PID loop does not necessarily perform in an `optimal´ manner, and retuning may then be required. This paper presents a reformulation of the adaptive pole-placement controller such that subject to some conditions and restrictions, it has the structure of a digital PID controller. Various properties of this adaptive PID controller are described and illustrated by simulation examples.