Browsing by Author "Schmidt, K.W."

Now showing 1 - 13 of 13

Citation - Scopus: 5
Abstraction-Based Supervisory Control for Recon-Gurable Manufacturing Systems
(IFAC Secretariat, 2013) Khalid, H.M.; Kirik, M.S.; Schmidt, K.W.; 271229; 06.08. Mekatronik Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
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.
Citation - Scopus: 8
Computation of Fault-Tolerant Supervisors for Discrete Event Systems
(IFAC Secretariat, 2013) Sülek, A.N.; Schmidt, K.W.; 17337; 06.08. Mekatronik Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
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.
Citation - Scopus: 12
Computation of Supervisors for Fault-Recovery and Repair for Discrete Event Systems
(IFAC Secretariat, 2014) Sülek, A.N.; Schmidt, K.W.; 06.08. Mekatronik Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
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.
Citation - Scopus: 2
Computation of Supervisors for Fault-Recovery and Repair for Discrete Event Systems
(Univelt Inc., 2014) Sülek, A.N.; Schmidt, K.W.; 17337; 107424; 06.08. Mekatronik Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
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. © IFAC.
Citation - Scopus: 11
Computation of Supervisors for Reconfigurable Machine Tools
(IFAC Secretariat, 2012) Schmidt, K.W.; 06.08. Mekatronik Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
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.
A Configurable Can Fd Controller: Architecture and Implementation
(Institute of Electrical and Electronics Engineers Inc., 2017) Afsin, M.E.; Schmidt, K.W.; Schmidt, E.G.; 06.08. Mekatronik Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
CAN FD is a new standard which provides fast data rate while preserving the compatibility with CAN (controller area network). In this paper, a Configurable IP core architecture (A-CAN) which is compatible with the CAN FD standard, is proposed. Different than existing CAN/CAN FD controllers, the numbers and sizes of transmit and receive buffers of A-CAN can be configured in run time. To this end, A-CAN enables the best use of single controller hardware for different applications and enables improving the real time communication performance. A-CAN communicates with the host device over SPI without any specific interface requirements. A-CAN is implemented on an FPGA Evaluation Board and its functionally is verified at a rate of 2 Mbps. © 2017 IEEE.
Citation - WoS: 1
Citation - Scopus: 1
A Fast and Optimal Static Segment Scheduling Method for Flexray V3.0
(Institute of Electrical and Electronics Engineers Inc., 2017) Cakmak, C.; Schmidt, E.G.; Schmidt, K.W.; 06.08. Mekatronik Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
We propose a novel and fast frame scheduling method for the Static Segment (SS) of the new in-vehicle network standard FlexRay v3.0 in this paper. The proposed methods assigns frames to the SS using the minimum number of time slots based on an Integer Linear Programming formulation. Different from the existing method in the literature, the proposed method computes optimal frame schedules within miliseconds. © 2017 IEEE.
The Implementation of Dynamic Distributed Real Time Industrial Communication Protocol (D 2rip)
(2012) Gözcü, A.K.; Turan, U.; Schmidt, E.G.; Schmidt, K.W.; 06.08. Mekatronik Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
Ethernet is a popular technology for industrial networking thanks to its low cost and high bandwidth. The current proposals to achieve real-time communication over Ethernet do not consider the determinism of the control applications resulting in inefficient use of bandwidth resources. We proposed a protocol stack architecture that works with standard Ethernet to address this problem. This paper describes the implementation of this architecture over Real-time Linux operating system and the first experiments to verify the operation. The implementation and performance of IEEE 1588 protocol which provides the required synchronization is also presented. © 2012 IEEE.
Citation - WoS: 1
Citation - Scopus: 1
A Lane Keeping System With a Weighted Preview Measurement
(Institute of Electrical and Electronics Engineers Inc., 2018) Saracoglu, K.; Ules, B.; Schmidt, K.W.; 06.08. Mekatronik Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
This paper proposes a new lane keeping system (LKS) based on a weighted preview measurement. The paper first identifies shortcomings of existing methods that use the sole measurement of lateral displacement error at a preview distance or at the center of gravity. Then, the novel idea of computing a weighted average of both measurements is proposed. The stability of the resulting LKS is analyzed and the improved performance of the resulting LKS is supported by simulation experiments. © 2018 IEEE.
Citation - Scopus: 1
A New Multi-Agent Decision Making Structure and Application To Model-Based Fault Diagnosis Problem
(Institute of Electrical and Electronics Engineers Inc., 2017) Leblebicioglu, M.K.; Zengin, Y.; Schmidt, K.W.; 06.08. Mekatronik Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
A new hierarchical multi-agent decision-making structure has been proposed. There are two phases of the structure. The first phase is the construction phase where the decision making structure consisting of switching and classification agents is built on the training data set generated by the system scenarios. In construction phase, switching and classification agents are trained and made ready for decision-making. In the decision phase, which is the second phase, the class of the new data sample is decided. This process is carried out by the transmission of the data sample to the correct classifier agent by the switching agents and the classification by the classifier agent. The proposed structure is applied to a complex fault identification problem and a successful result is obtained. The structure is also adaptable to other big data decision making problems. © 2017 IEEE.
Citation - Scopus: 2
An Optimization Model To Coordinate Scheduling and Controling in Projects: Case With Instantaneous Control Constraints
(National Technical University of Athens, 2014) Schmıdt, Klaus Werner; Hazir, Ö.; Schmidt, K.W.; Eryilmaz, U.; 17337; Mekatronik Mühendisliği; 06.08. Mekatronik Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
Today, many enterprises in different industries take part in various projects, and organizational performances depend more and more on project performances. In order to maximize performance, effective management of project functions is crucial. In this regard, we focus on scheduling and control functions and their relation. Characteristics of data sharing among them and possible integration strategies are theoretically investigated. A model base for a decision support framework that accounts for these interdependencies and supports managers is developed. To solve the formulated integrated project scheduling and control problem, a tabu search algorithm is combined with optimal control techniques. As a result, a project schedule as well as the means and timing of interventions are determined such that the project cost is minimized. The obtained results are supported by computational experiments. Integrated models and algorithms to be developed aim to fill an important theoretical gap in project management.
Supervisory Control for Failure Recovery in Discrete Event Systems
(2012) Schmidt, K.W.; 06.08. Mekatronik Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
Discrete event system models are used for systems with a discrete state space and event-driven state transitions such as communication systems and manufacturing systems. This paper proposes a polynomial-time algorithm for the construction of fault-tolerant supervisors for discrete event systems. Such supervisor ensures the desired system behavior as long as no faults occur, and realizes a redundant behavior in case of faults. © 2012 IEEE.
The Verification of a Novel Framework for Real-Time Shared Medium Communication Network Protocols
(2012) Kartal, Y.B.; Schmidt, E.G.; Schmidt, K.W.; 06.08. Mekatronik Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
The subject of this work is the real-time communication of the distributed industrial control applications over shared-medium Ethernet. We developed a framework for the real-time communication protocols over shared-medium Ethernet in our previous work. The framework is designed using the Timed Input/Output Automata formalism to serve the changing real-time communication needs of the embedded control applications. In this paper we present the modeling, simulation and formal verification process of the proposed framework using UPPAAL toolbox. © 2012 IEEE.