In the framework of Indutry 4.0 the plants in the manufacturing industry are becoming significantly more flexible and characterized by variable topology. Such systems can be described by discrete-event systems (for instance, automata, petri-nets) conveniently. Faults in actuators, sensors or plant components lead to a reduction of the overall system performance. With the help of fault tolerant control it is possible to ensure that the system continues its operation and the impact of faults is automatically compensated. In order to improve the plant availability, new methods are being developed for the fault tolerant control of discrete-event systems.

Publications:

• R. Fritz, P. Zhang. Detection and Localization of Stealthy Cyber Attacks in Cyber-Physical Discrete Event Systems. IEEE Transactions on Automatic Control, 2023, DOI: 10.1109/TAC.2023.3253462.
• M. Jia, A. Köhler, R. Fritz, P. Zhang. Monte-Carlo tree search with neural networks for Petri nets. Proceedings of the 2022 American Control Conference (ACC), 2022.
• Köhler, P. Zhang. State estimation in discrete event Systems modeled by signal interpreted Petri nets. IEEE Control Systems Letters, Vol. 6, pp. 2078-2083, 2021
• A. Köhler, P. Zhang, R. Fritz. Specification governor for fault tolerant control of large-scale manufacturing systems. European Journal of Control, Vol. 62, pp. 198-205, 2021.
• R. Fritz and P. Zhang. Fault-tolerant tracking control of petri nets. Automatisierungstechnik, Vol. 6, No. 1, pp. 30-40, 2018.
• A. Köhler, P. Zhang. Fault diagnosis in discrete event systems modeled by signal interpreted Petri nets. Proceedings of the 22nd IFAC World Congress (IFAC), Yokohama, Japan, 2023.
• A. Köhler, P. Zhang. Pareto modeling of discrete manufacturing systems by signal interpreted Petri nets. Proceedings of the 2023 American Control Conference (ACC), San Diego, USA, 2023.
• A. Köhler, R. Fritz, P. Zhang. Approach to design distributed logic controllers for large-scale manufacturing systems. Proceedings of the 2021 American Control Conference (ACC), pp. 495-500, 2021.
• R. Fritz, N. Krebs, P. Zhang. A Monte-Carlo Tree Search based Tracking Control Approach for Timed Petri Nets. Proceedings of the 21^st IFAC World Congress (IFAC), pp. 2125-2130, Berlin, Germany, 2020.
• R. Fritz, M. Fauser, P. Zhang. Controller encryption for discrete event systems. Proceedings of the 2019 American Control Conference (ACC), pp. 5633-5638, Philadelphia, USA, 2019.
• R. Fritz, P. Schwarz, P. Zhang. Modeling of Cyber Attacks and a Time Guard Detection for ICS Based on Discrete Event Systems. Proceedings of the 2019 European Control Conference (ECC), pp. 4368-4373, Naples, Italy, 2019.
• R. Fritz, J. Napitupulu, P. Zhang. Tracking control for Petri nets based on Monte-Carlo Tree Search. Proceedings of the 2019 European Control Conference (ECC), pp. 4180-4185, Naples, Italy, 2019.
• R. Fritz, P. Zhang. Modeling and detection of cyber attacks on discrete event systems. Proceedings of the 14th Workshop on Discrete Event Systems (WODES), pp. 296-301, Sorrento Coast, Italy, 2018.
• R. Fritz, P. Zhang. Tracking control for petri nets with forbidden states. Proceedings of the 2018 European Control Conference (ECC), pp. 1888-1893, Limassol, Cyprus, 2018.
• R. Fritz, P. Zhang. Overview of fault-tolerant control methods for discrete event systems. Proceedings of the 10th IFAC Symposium on Fault Detection, Supervision and Safety for Technical Processes (SAFEPROCESS), Warsaw, Poland, 2018.
• R. Fritz, P. Zhang. Detektion von Angriffen auf Cyber-Physische Fertigungssysteme. Proceedings of the 2018 Automation, pp. 69-80, Baden-Baden, Germany, 2018.

Master Thesis:

• J. Trieb. Entwicklung eines Digitalen Zwillings für einen Fertigungsprozess. 2023.
• P. Marijan. Investigation of Opacity in SIPNs and Its Application to a Laboratory Plant. 2021.
• N. Krebs. Ablaufplanung in Multi-Batch Prozessen basierend auf Monte-Carlo Tree Search von Petri-Netzen. 2020.
• P. Schwarz. Cyber-Angriffe und deren Detektion in ereignisdiskreten Systemen. 2018.
• T. Laubscher. Entwurf und Analyse einer Cloud-basierten Steuerung einer Fertigungslinie. 2016.
• R. Fritz: Online Rekonfiguration von flexiblen Fertigungssystemen basierend auf ganzzahliger linearer Programmierung / online Reconfiguration of flexible manufacturing systems based on Integer linear programming. 2016.
• J. D. Fernández: Online Control Reconfiguration of Flexible Manufacturing Plants based on Petri Net Models. 2014.

Bachlor Thesis:

• M. Fauser. Steuerungsverschlüsselung für ereignisdiskrete Systeme. 2018.
• P. Marijan. Modellierung eines Hafens basierend auf ereignisdiskreten Systemen. 2018.
• T. Laubscher. Steuerung einer Fertigungslinie mit Hilfe von MatLab/Stateflow. 2015.
• C. Hakizimana. Application of Model Checking to Logic Control Systems - A Comparison Study. Studienarbeit, 2014.