On Equivalence between DD-CLUT and Suboptimal VRFT

Abstract

This work discusses two data-driven control methods: Virtual Reference Feedback Tuning (VRFT) and Data-Driven Closed-Loop Update Tuning (DD-CLUT). Although they are derived from different discussions, it is shown that DD-CLUT is a special case of VRFT. In particular, DD-CLUT is shown to be equivalent to the suboptimal VRFT. This result implies that suboptimal VRFT tunes the controller parameter so as to minimizes a weighted error between the updated closed-loop system and reference model.