PL
 |
EN
Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 10

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  discrete event system
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available remote Deadlock freeness supervisor for marked graph
100%
Sioud H. , Achour Z. , Sava A. , Rezg N.
|
2009
|
tom Vol. 57, nr 3
281-289
EN
This note presents a control synthesis approach for discrete event systems modeled by marked graphs with uncontrollable transitions. The forbidden behavior is specified by General Mutual Exclusion Constraints (GMEC). We prove that, even if the system to be controlled .s live, the closed loop control may generate deadlock situations. Using the structural proprieties of marked graph we defined the causes of deadlock situations, and we defined a formal method to avoid them.
2
Content available Event monitoring of parallel computations
100%
Gruzlikov A. , Kolesov N. , Tolmacheva M.
|
|
tom 25
|
nr 2
311-321
EN
The paper considers the monitoring of parallel computations for detection of abnormal events. It is assumed that computations are organized according to an event model, and monitoring is based on specific test sequences.
3
Content available Max-plus algebra as a tool to modelling and performance analysis of manufacturing systems
100%
Stańczyk J.
|
2018
|
tom Vol. 28, No. 3
77--97
EN
This contribution discusses the usefulness of (max, +) algebra as a mathematical framework for a class of manufacturing systems. This class can be described as dynamic and asynchronous, where the state transitions are initiated by events that occur at di screte instants of time. An event corresponds to the start or the end of an activity. Such systems are known as discrete event systems (DES). An overview of the concepts of modelling and analysis using the (max, +) algebra approach to DES has been given. Also, examples of manufacturing systems have been provided to illustrate the potential of this approach. The type of production process used, such as serial line, assembly line, etc., influences the modelling of different basic manufacturing systems. We have also presented the impact of the capacity of interoperable buffers. Based on an analytical model, effectiveness and performance indexes have been evaluated.
4
Content available Max-plus algebra as a tool to modelling and performance analysis of manufacturing systems
100%
STAŃCZYK J.
Operations Research and Decisions
|
2018
|
tom 28
|
nr 3
77-97
EN
This contribution discusses the usefulness of (max, +) algebra as a mathematical framework for a class of manufacturing systems. This class can be described as dynamic and asynchronous, where the state transitions are initiated by events that occur at di screte instants of time. An event corresponds to the start or the end of an activity. Such systems are known as discrete event systems (DES). An overview of the concepts of modelling and analysis using the (max, +) algebra approach to DES has been given. Also, examples of manufacturing systems have been provided to illustrate the potential of this approach. The type of production process used, such as serial line, assembly line, etc., influences the modelling of different basic manufacturing systems. We have also presented the impact of the capacity of interoperable buffers. Based on an analytical model, effectiveness and performance indexes have been evaluated.
5
Diagnosis-time assessment in discrete event systems using timed Petri nets
75%
Tabakow I.
Systems Science
|
2008
|
tom Vol. 34, no 3
17-23
EN
This paper describes a method of diagnosis-time assessment in discrete event systems. Any such system is modelled by a live, bounded, and reversible place-transition Petri net N. There are assumed some deterministically given delays associated with the transitions of N, and hence, N is assumed to be deterministic timed. Without loss of generality, the single place fault model is considered below and the corresponding diagnosis process is assumed to be sequential. The notions of D-partition of the set of places P of a given place-transition net N and net k-distinguishability are first introduced. Then, the corresponding net place invariants are computed. The system k-distinguishability measure is obtained in a unique way from the place-invariant matrix. For a large value of k, the system model is extended by using some set of additional places called test points and at the same time preserving the original net properties. In accordance with the above assumption of sequential fault diagnosis, the process of fault isolation is carried out step by step, where each step depends on the result of the diagnostic experiment at the previous step. Hence, the diagnosis-time assessment is realised by computing the absolute value of the time difference between the minimum cycle time of N and the worst-case fault-isolation time according to the diagnostic tree obtained. The complexity of the method proposed depends on the effectivity of the existing algorithms for computation of the P-cover, i.e., the set of P-invariants covering N. The approach proposed can be extended to higher level Petri nets, e.g., such as coloured ones. Several examples are given.
6
Content available On-the-fly diagnosability analysis of bounded and unbounded labeled Petri nets using verifier nets
63%
Li B. , Khlif-Bouassida M. , Toguéyni A.
International Journal of Applied Mathematics and Computer Science
|
2018
|
tom Vol. 28, no. 2
269--281
EN
This paper considers the problem of diagnosability analysis of discrete event systems modeled by labeled Petri nets (LPNs). We assume that the LPN can be bounded or unbounded with no deadlock after firing any fault transition. Our approach is novel and presents the on-the-fly diagnosability analysis using verifier nets. For a given LPN model, the verifier net and its reachability graph (for a bounded LPN) or coverability graph (for an unbounded LPN) are built on-the-fly and in parallel for diagnosability analysis. As soon as a diagnosability decision is established, the construction is stopped. This approach achieves a compromise between computation limitations due to efficiency and combinatorial explosion and it is useful to implement an engineering approach to the diagnosability analysis of complex systems.
7
Implementacja biblioteki modelowania układów zdarzeń dyskretnych opartej na języku CSL, z wykorzystaniem platformy .NET
63%
Wyciślik Ł. , Wiejak P.
|
|
tom Vol. 34, nr 2B
275--282
PL
Artykuł przedstawia bibliotekę służącą do modelowania układów zdarzeń dyskretnych według koncepcji wyboru działania, opartą na języku CSL. Cechą charakterystyczną rozwiązania jest zastosowanie platformy .NET oraz języka C#. Duża popularność tych technologii sprawia, że budowa modeli jest możliwa już przy minimalnym nakładzie związanym z zapoznaniem się z API samej biblioteki.
EN
The article presents the library used to discrete events systems modeling based on CSL language. The key point of this implementation is involving of .NET platform and C# language. Big popularity of these technologies makes that building of models is possible with minimal effort related to study of library API.
8
Content available A feasible schedule for parallel assembly tasks in flexible manufacturing systems
63%
Majdzik P.
|
2022
|
tom Vol. 32, no. 1
51--63
EN
The paper concerns the design of a framework for implementing fault-tolerant control of hybrid assembly systems that connect human operators and fully automated technical systems. The main difficulty in such systems is related to delays that result from objective factors influencing human operators’ work, e.g., fatigue, experience, etc. As the battery assembly system can be considered a firm real-time one, these delays are treated as faults. The presented approach guarantees real-time compensation of delays, and the fully automated part of the system is responsible for this compensation. The paper begins with a detailed description of a battery assembly system in which two cooperating parts can be distinguished: fully automatic and semi-automatic. The latter, nonderministic in nature, is the main focus of this paper. To describe and analyze the states of the battery assembly system, instead of the most commonly used simulation, the classic max-plus algebra with an extension allowing one to express non-deterministic human operators’ work is used. In order to synchronize tasks and schedule (according to the reference schedule) automated and human operators’ tasks, it is proposed to use a wireless IoT platform called KIS.ME. As a result, it allows a reference model of human performance to be defined using fuzzy logic. Having such a model, predictive delays tolerant planning is proposed. The final part of the paper presents the achieved results, which clearly indicate the potential benefits that can be obtained by combining the wireless KIS.ME architecture (allocated in the semi-automatic part of the system) with wired standard production networks.
9
Content available Dynamic control of a class of discrete event systems using a state reconstruction algorithm
63%
Martinelli F. , Nicosia S. , Valigi P.
Control and Cybernetics
|
2000
|
tom Vol. 29, no 1
275-294
EN
The problem of dynamic control of Discrete Event Dynamic Systems (DEDS) is addressed in this paper as a dynamic optimization problem : some resources must be allocated to the system in order to optimize a performance function which is assumed time-varying. The control scheme exploits a state reconstruction algorithm to compute an estimate of the performance for perturbed sample paths. The algorithm is based on the use of data extracted from the observation of the system and allows to accurately reconstruct its state behavior, for resource allocations different from the nominal one. The proposed control scheme is then used for dynamic allocation of buffer capacities in mamlfaeturing systems, such as Kanban systems. A parallel implementation of the whole algorithm is also mentioned.
10
Content available remote Study and analysis of discrete event-driven autonomous system with a case study for a robotics task
51%
Raj R. , Kos A.
Przegląd Elektrotechniczny
|
2023
|
tom R. 99, nr 9
50--56
EN
Highly probabilistic, potential, and dynamic domains are only relatively known to contribute classical techniques for complex system establishment impossible. Currently available technologies and strategies do not adequately address these novel needs. Thus, by enabling autonomous systems to adapt, decision-making and learning abilities, we can empower them with sufficient and appropriate expertise to recognize and address such issues. To address these requirements, discrete event-driven systems (DEDS) have been developed. This system can help the technologists of future autonomous systems by simulating the effect of auxiliary designs on the performance of the autonomous system. For modeling regular feedback of performance that is influenced by traditional techniques and depends on trust, the discrete event-driven method is most suited. This paper describes the DEDS system, the modeling of this system, and as well as the supervisory control system by explaining the supervisor, and partial supervisor. A comprehensive literature survey has been carried out in this article to explain the controllability, diagnosability, and observability potential of the DEDS system for various applications. Some of the major areas of applications such as healthcare, logistics, robotics, and banking sectors, have been discussed. Also, we have explained this system with the help of modeling a discrete event system for a queuing problem associated with robotics tasks as an example by the simulation with MATLAB 2022a. Lastly, the possible future research directions in the DEDS advancement have been provided.
PL
Wysoce probabilistyczne, potencjalne i dynamiczne domeny są znane z tego, że niemożliwe jest wniesienie klasycznych technik do tworzenia złożonych systemów. Obecnie dostępne technologie i strategie nie zaspokajają odpowiednio tych nowych potrzeb. Zatem, umożliwiając autonomicznym systemom adaptację, podejmowanie decyzji i zdolność uczenia się, możemy wyposażyć je w wystarczającą i odpowiednią wiedzę fachową, aby rozpoznawać i rozwiązywać takie problemy. Aby spełnić te wymagania, opracowano dyskretne systemy sterowane zdarzeniami (DEDS). System ten może pomóc technologom przyszłych systemów autonomicznych, symulując wpływ podsystemów pomocniczych na wydajność systemu autonomicznego. Do modelowania regularnych informacji zwrotnych na temat wyników, na które wpływają tradycyjne techniki i które zależą od zaufania, najbardziej odpowiednia jest metoda dyskretnych zdarzeń. W artykule opisano system DEDS, modelowanie tego systemu, a także system kontroli nadzorczej poprzez opisanie nadzorcy i kierownika częściowego. W tym artykule przeprowadzono obszerny przegląd literatury w celu wyjaśnienia sterowalności, diagnozowalności i potencjału obserwowalności systemu DEDS w różnych zastosowaniach. Omówiono niektóre z głównych obszarów zastosowań, takich jak sektor opieki zdrowotnej, logistyki, robotyki i bankowości. Wyjaśniliśmy również ten system za pomocą modelowania systemu zdarzeń dyskretnych dla problemu kolejkowania związanego z zadaniami robotyki na przykładzie symulacji z MATLAB 2022a. Na koniec przedstawiono możliwe przyszłe kierunki badań w zakresie rozwoju DEDS.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.