A Closed-Loop Diagnostic Method for Evaluating PI Controller Parameter Migration Across Architectures

Transferring the parameters of PI controllers used in industrial automation between different control architectures is often unavoidable, particularly in cases of hardware replacement, firmware updates, or architectural migration. While in practice the direct transfer of algorithms and parameters is expected to preserve controller performance, empirical evidence suggests that the control quality may significantly degrade in the new architecture. This article presents a methodology based on an empirical dataset, employing a closed-loop, process- and sensor-independent diagnostic procedure to assess the feasibility of parameter migration. The proposed “2-test” method applies two types of measurements (P-only and I-only), focusing exclusively on the behavior of the controller unit. Based on metrics derived from the measurement results, the differences between the old and new architectures can be objectively evaluated. The findings indicate that PI parameter migration does not guarantee the preservation of original control performance in most cases; however, the presented method supports preliminary decision-making and may help avoid retuning.