PID Tuning for Unstable Processes with Time Delay Based on Gain Margin

The paper discusses the control of an unstable first order time delay process by using the PID controller. A simple method of receiving proportional, integral, and differential gain of the parallel PID controller based on gain margin is presented in this paper. The results of the suggested method of projecting PID for the desired faster or slower close-loop system response are shown through simulation. The performances of the received close-loop system have been, via simulation, compared with the performances of the other received methods of projecting the PID controller both for the set-point response and for the disturbance response. The received values for IAE and ISE, settling and rise time, indicate that the suggested methods provide better results.