Monsieur Can Kutlu YUKSEL
Sciences et Technologies de l’information et de la
Communication (STIC)
Soutiendra publiquement ses travaux de thèse intitulés
“Time-Delay Compensation and Periodic Control”
dirigés par Monsieur Silviu NICULESCU et Tomas VYHLIDAL
Soutenance prévue le mardi 08 avril 2025 à 10h00
Lieu : FME CTU, Technicka 4, Praha 6, CZ, room Nr. A1-305h
Composition Jury:
Abstract: There are various scenarios where one demands a system to operate in a periodic manner and, therefore, a lasting need to have a controller that can meet this demand. Arguably, the most common approach to construct these controllers is the Repetitive Control design paradigm. Nevertheless, if the considered systems suffer from time-delays and/or particular types of periodic signals, then the guidelines from the repetitive control paradigm may be too strict and far-fetched to follow. The thesis seeks alternative ways of constructing the controller in the Internal Model Control framework and studies the structures resembling that of the repetitive control but with different free-variables to conveniently carry over the main ideas for periodic control to time-delay systems. The proposed IMC controller structure consists of a delay-free inverse of the model approximating the system, low-pass filters to ensure the properness of the controller, and time-delays to shape the frequency response of the overall closed-loop. The first design proposition utilizes third-order filters and lumped delays to achieve the periodic regulation of systems approximated by first-order models with time-delay. The motivation behind this is to meet the demand for flexibility and convenience in industrial applications. The second design approach considers a filter constructed based on the zeros and poles desired for the closed-loop sensitivity. A notable advantage of this approach, in contrast to the first one, is that high-order systems with delays can be additionally addressed analytically. The last design considers a distributed delay closely resembling the structures used for high-order repetitive controllers. Nevertheless, a notable difference is that the lumped delay components within the distributed delay are not necessarily related to the period of the targeted signal. The use of the distributed delay makes the controller vary linearly with respect to its parameters, which, as a consequence, favors an optimization-based design approach. Finally, a preliminary theory based on Youla-Kučera parametrization is presented as a future direction for the research. This theory reveals that repetitive controllers and IMC-based controllers can be viewed as a particular realization of the Youla-Kučera parametrization. Moreover, this parameter shows that the proposed design methods for periodic control can be extended to unstable infinite-dimensional time-delay systems.
