Influence of the Selection of Reaction Curve’s Representative Points on the Accuracy of the Identified Fractional-Order Model

In this paper, a general procedure for identifying fractional first-order plus dead-time (FFOPDT) model is presented. This based on fitting three arbitrary points the process reaction curve, where information obtained from simple open-loop test. A simplification of identification also considered, only symmetrically located curve are selected. The proposed symmetrical has been applied to following sets representative points: (5–50–95%), (10–50–90%), (15–50–85%), (20–50–80%), (25–50–75%), and (30–50–70%). Analytical expressions corresponding FFOPDT parameters these have obtained. order show effectiveness applicability fractional-order models get insight into influence selection set accuracy identified model, some numerical examples proposed. gives good results in comparison with other integer- methods. Finally, conclusions final remarks offered context.