Estimation of a SOPDT process transfer function for PID tuning

The paper deals with the estimation of a Second-Order-Plus-Dead-Time (SOPDT) process transfer function for the tuning of a Proportional-Integral-Derivative (PID) controller. In particular, different methodologies for the estimation of the transfer function parameters based on the open-loop process step response are proposed and compared to an existing one that has been recently presented in the literature. A pole-zero cancellation strategy is then employed to tune the PID controller. Advantages and disadvantages of the different methods are then discussed by considering the obtained results and implementation issues.