Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8651
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Conference Object Citation - Scopus: 12Computation of Supervisors for Fault-Recovery and Repair for Discrete Event Systems(IFAC Secretariat, 2014) Sülek, A.N.; Schmidt, K.W.In this paper, we study the fault-recovery and repair of discrete event systems (DES). To this end, we first develop a new method for the fault-recovery of DES. In particular, we compute a fault-recovery supervisor that follows the specified nominal system behavior until a fault-occurrence, that continues its operation according to a degraded specification after a fault and that finally converges to a desired behavior after fault. We next show that our method is also applicable to system repair and we propose an iterative procedure that determines a supervisor for an arbitrary number of fault occurrences and system repairs. We demonstrate our method with a manufacturing system example. © 2021 Elsevier B.V., All rights reserved.Conference Object Citation - Scopus: 11Computation of Supervisors for Reconfigurable Machine Tools(IFAC Secretariat, 2012) Schmidt, K.W.The rapid reconfiguration of manufacturing systems is an important issue in today's manufacturing technology in order to adjust the production to varying product demands and types. In this paper, we study the control of reconfigurable machine tools (RMTs) with the aim of fast reconfiguration and an easy controller implementation. We first formulate a particular reconfiguration problem for RMTs in a discrete event system setting, and then provide necessary and sufficient conditions for its solution. Moreover, we propose an algorithm for the construction of a reconfiguration supervisor as the composition of one supervisor for each separate RMT configuration and one supervisor that performs the transition between configurations. The reconfiguration supervisor can be computed in polynomial time, and allows configuration changes within a bounded delay. In addition, our method facilitates the addition of a new configuration during system operation.Conference Object Citation - Scopus: 8Computation of Fault-Tolerant Supervisors for Discrete Event Systems(IFAC Secretariat, 2013) Sülek, A.N.; Schmidt, K.W.Fault-tolerance addresses the problem of operating a system even in case of faults. In this paper, we study fault-tolerance in the supervisory control framework for discrete event systems (DES). We consider DES, where certain events might no longer be possible in case a fault happens. In this setting, we first identify necessary and suficient conditions for the existence of a supervisor that realizes a given behavioral specification both in the non-faulty and in the faulty case. We further show that it is possible to determine a supremal fault-tolerant sublanguage in case the existence condition is violated. Finally, we propose an algorithm for the computation of this sublanguage and prove its correctness. Different from existing work, our fault-tolerant supervisor allows fault occurrences and system repairs at any time. The concepts and results developed in this paper are illustrated by a manufacturing system example. © 2013 IFAC.Conference Object Citation - Scopus: 5Abstraction-Based Supervisory Control for Recon-Gurable Manufacturing Systems(IFAC Secretariat, 2013) Khalid, H.M.; Kirik, M.S.; Schmidt, K.W.Reconfiguration control for discrete event systems (DES) is concerned with the realization of different system configurations by modification of the supervisory control loop. In this paper, we study the reconfiguration supervisor design for reconfigurable manufacturing systems (RMS) that comprise multiple components. We construct a modular supervisor for each configuration and system component in order to realize each active configuration and to quickly change between configurations. Different from the existing literature that is focused on monolithic design, our method is abstraction-based, and, hence applicable to large-scale DES. © 2013 IFAC.