A Model Identification Method for Tuning of PID Controller in a Smith Predictor Structure

In this paper, a model identification method is presented for tuning of PID parameters in Smith predictor structure based on internal model control. The purposed method fits stability boundary locus (SBL) of a plant model with SBL of a FOPDT (First Order Plus Dead Time) or a SOPDT (Second Order Plus Dead Time) model to determine the controller parameters. Two examples are employed to illustrate the applicability and simplicity of the purposed method in both tuning of controller parameters and identification of model parameters for an integer order plant and a fractional order plant.