Robustness analysis of controller designed for first, second and third order delayed process model

Disturbances and uncertainties in the system create a barrier to the healthier performance of the process industries. The large effects can be observed in the fundamental time response characteristics i.e. transient and steady state characteristics of the system. Hence, the need of robust controller arises, application of which makes system ineffective to the invasion of uncertainties in the process territory. In this paper a first order system with delay is considered and SOPDT and TOPDT models are derived from FOPDT process model using Skogestad's half rule. PID controller is designed for all the three process models using numerous tuning methods and system set point tracking is analyzed. Further robustness subject is studied for all the designed controllers.