A direct digital PID tuning rule for SOPDT systems

This paper presents a PID tuning rule based on easily obtainable process data, for second order under-damped systems with time delays (SOPDT). The aim of the PID tuning rule is to give the exact settings in order to obtain the fastest response from the closed loop system without overshoot. Contrary to other well known tuning rules, the proposed tuning rule is obtained using direct digital control considering the sampling effect in implementation. To show the efficiency of the proposed method experiments are done over a “fan and plate” system and the results are compared to other well known PID tuning rules like Ziegler-Nichols and IMC.