Graphical Robust PID Tuning of TITO Processes

In this paper, PID controller for Decentralized TITO process is tuned using graphical approach. Ideal decoupler is used to decouple TITO system and then each decoupled system is approximated to FOPDT model. The Graphical method uses boundaries determined by the loci of stability and frequency domain characteristics such as Gain, and Phase margin etc. common region of these loci gives the values of the PID controller coefficients. The results are validated using MATLAB and the simulated results are presented for Coupled tank system.