PID dead-time predictor design for industrial DCS systems using Smith rule

A dead-time is usually associated with input and output of the industrial control systems, especially water and wastewater treatment systems. This dead-time is not a fixed time during process function, therefore, a conventional PID controller which is related to this dead-time can not be designed by the conventional methods. An adaptive scheme is designed to control an industrial water and wastewater treatment plant by using Smith adaptive rule. Stability of the proposed adaptive system is proved and the simulation results show the quality performance of the adaptive PID controller.