A NEW METHOD OF TUNING THREE TERM CONTROLLERS FOR DEAD-TIME PROCESSES WITH A NEGATIVE/POSITIVE ZERO

The use of the Pseudo-Derivative Feedback (PDF) structure in the control of stable or unstable dead-time processes with a negative or a positive zero is investigated. A simple direct synthesis method for tuning the PDF controller is presented. Moreover, a modification of the proposed method, which ensures its applicability in the case of large overshoot response processes with dead time, is also presented. The PDF control structure and the proposed tuning method ensure smooth closed-loop response to set-point changes, fast regulatory control and sufficient robustness against parametric uncertainty. Simulation results show that, in most cases, the proposed method is as efficient as the best of the most recent PID controller tuning methods for dead-time processes with negative/positive zeros, while its simplicity in deriving the controller settings is a plus point over existing PID controller tuning formulae.