scholarly journals Controller Synthesis of Time Petri Nets Using Stopwatch

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Parisa Heidari ◽  
Hanifa Boucheneb
Keyword(s):  
Complex Systems ◽  
Petri Nets ◽  
Petri Net ◽  
Controller Synthesis ◽  
Preemptive Scheduling ◽  
Time Petri Nets ◽  
Shared Resources ◽  
Time Petri Net ◽  
Ordinary Time ◽  
The Given

Scheduling is often a difficult task specially in complex systems. Few tools are targeted at both modeling and scheduling of the systems. In controller synthesis, a scheduler is seen as a controller to manage shared resources and timing requirements of a system. This paper proposes a time Petri net-based approach for controller synthesis and finding a scheduler using stopwatch. The solution suggested here is particularly interesting for preemptive scheduling purposes. This paper deals with time Petri nets with controllable and uncontrollable transitions and assumes that a controllable transition can be suspended and retrieved when necessary. In fact, the paper supposes that every controllable transition can be associated with stopwatch. With this hypothesis, the objective is to model a system by time Petri nets and calculate subintervals where the system violates the given property. Then, the controller associates the corresponding controllable transitions with stopwatch to suspend them in their bad subintervals. The interesting advantage of this solution is that this approach synthesizes an ordinary time Petri net model before adding stopwatch. Therefore, complicated computations and overapproximations required during controller synthesis of time Petri nets associated with stopwatch are avoided.

scholarly journals Description of membrane systems with time Petri nets: promoters/inhibitors, membrane dissolution, and priorities

2020 ◽  
Vol 2 (4) ◽  
pp. 341-354
Author(s):  
Péter Battyányi ◽  
György Vaszil
Keyword(s):  
Petri Nets ◽  
Petri Net ◽  
Time Petri Nets ◽  
Membrane Systems ◽  
Time Petri Net ◽  
Priority Relation ◽  
Complex Cases

AbstractWe continue the investigations of the connection between membrane systems and time Petri nets by extending the examined class of systems from simple symbol-object membrane systems to more complex cases: rules with promoters/inhibitors, membrane dissolution, and priority relation on the rules. By constructing the simulating time Petri net, we retain one of the main characteristics of the Petri net model; namely, the firings of the transitions can take place in any order, and there is no need to introduce maximal parallelism in the Petri net semantics. Instead, we substantially exploit the gain in computational strength obtained by the introduction of the timing feature for Petri nets.

scholarly journals Dépliage des réseaux de Petri temporels à modèle sous-jacent non sauf

2011 ◽  
Vol Volume 14 - 2011 - Special... ◽  
Author(s):  
M. Sogbohossou ◽  
D. Delfieu
Keyword(s):  
Petri Nets ◽  
Petri Net ◽  
The State ◽  
Time Petri Nets ◽  
Real Time System ◽  
Time Petri Net ◽  
Finite Set ◽  
International Audience ◽  
Hard Real Time ◽  
Temporal Specifications

International audience For the formal verification of the concurrent or communicating dynamic systems modeled with Petri nets, the method of the unfolding is used to cope with the well-known problem of the state explosion. An extension of the method to the non safe time Petri nets is presented. The obtained unfolding is simply a prefix of that from the underlying ordinary Petri net to the time Petri net. For a certain class of time Petri nets, a finite prefix capturing the state space and the timed language ensues from the calculation of a finite set of finite processes with valid timings. The quantitative temporal constraints associated with these processes can serve to validate more effectively the temporal specifications of a hard real-time system. Pour la vérification formelle des systèmes dynamiques concurrents ou coopérants modélisés à l’aide des réseaux de Petri, la méthode du dépliage est utilisée pour endiguer le phénomène bien connu de l’explosion combinatoire. Une extension de la méthode aux réseaux de Petri temporels à modèle sous-jacent non sauf est présentée. Le dépliage obtenu est simplement un préfixe de celui du réseau de Petri ordinaire sous-jacent au réseau temporel. Pour une certaine classe de réseaux temporels, un préfixe fini capturant l’espace d’état et le langage temporisé découle du calcul d’un ensemble fini de processus finis réalisables. Les contraintes temporelles quantitatives associées à ces processus peuvent servir à valider plus efficacement les spécifications temporelles d’un système temps réel dur.

scholarly journals State space computation and analysis of Time Petri Nets

2006 ◽  
Vol 6 (3) ◽  
pp. 301-320 ◽  
Author(s):  
GUILLAUME GARDEY ◽  
OLIVIER H. ROUX ◽  
OLIVIER F. ROUX
Keyword(s):  
Petri Nets ◽  
State Space ◽  
Petri Net ◽  
Timed Automata ◽  
Reactive Systems ◽  
Time Petri Nets ◽  
Classical State ◽  
Time Petri Net ◽  
Reduction Methods ◽  
Timed Automaton

The theory of Petri Nets provides a general framework to specify the behaviors of real-time reactive systems and Time Petri Nets were introduced to take also temporal specifications into account. We present in this paper a forward zone-based algorithm to compute the state space of a bounded Time Petri Net: the method is different and more efficient than the classical State Class Graph. We prove the algorithm to be exact with respect to the reachability problem. Furthermore, we propose a translation of the computed state space into a Timed Automaton, proved to be timed bisimilar to the original Time Petri Net. As the method produce a single Timed Automaton, syntactical clocks reduction methods (DAWS and YOVINE for instance) may be applied to produce an automaton with fewer clocks. Then, our method allows to model-check T-TPN by the use of efficient Timed Automata tools.

scholarly journals ε-TPN: definition of a Time Petri Net formalism simulating the behaviour of the timed grafcets

2019 ◽  
Vol Volume 31 - 2019 - CARI 2018 ◽  
Author(s):  
Médésu Sogbohossou ◽  
Medesu Sogbohossou ◽  
Antoine Vianou ◽  
Nabil Gmati ◽  
Eric Badouel ◽  
...  
Keyword(s):  
Petri Nets ◽  
Control Systems ◽  
Timed Automata ◽  
Operational Semantics ◽  
Formal Modeling ◽  
Time Petri Nets ◽  
Time Petri Net ◽  
Finite State ◽  
Definition Of ◽  
Finite State Space

To allow a formal verification of timed GRAFCET models, many authors proposed to translate them into formal and well-reputed languages such as timed automata or Time Petri nets (TPN). Thus, the work presented in [Sogbohossou, Vianou, Formal modeling of grafcets with Time Petri nets, IEEE Transactions on Control Systems Technology, 23(5)(2015)] concerns the TPN formalism: the resulting TPN of the translation, called here ε-TPN, integrates some infinitesimal delays (ε) to simulate the synchronous semantics of the grafcet. The first goal of this paper is to specify a formal operational semantics for an ε-TPN to amend the previous one: especially, priority is introduced here between two defined categories of the ε-TPN transitions, in order to respect strictly the synchronous hypothesis. The second goal is to provide how to build the finite state space abstraction resulting from the new definitions. Afin de permettre la vérification formelle des grafcets temporisés, plusieurs auteurs ont proposé de les traduire dans des langages formels de réputation tels que les automates temporisés et les réseaux de Petri temporels (TPN). Ainsi, les travaux présentés dans [Sogbohossou, Vianou, Formal modeling of grafcets with Time Petri nets, IEEE Transactions on Control Systems Technology, 23(5)(2015)] concernent le formalisme des TPN: le réseau résultant de la traduction, dénommé ici ε-TPN, intègre des délais infinitésimaux (ε) pour simuler la sémantique synchrone du grafcet. Le premier objectif de cet article est de définir la sémantique opérationnelle d'un ε-TPN afin d'améliorer l'ancienne définition: spécifiquement, une priorité est introduite ici entre deux catégories de transitions définies pour ces réseaux, dans l'optique de respecter rigoureusement l'hypothèse synchrone. Le second but est de fournir une méthode de calcul de l'espace d'état fini qui découle des nouvelles définitions.

scholarly journals On Modeling and Simulation of Resource Allocation Policies in Cloud Computing Using Colored Petri Nets

2020 ◽  
Vol 10 (16) ◽  
pp. 5644 ◽  
Author(s):  
Stavros Souravlas ◽  
Stefanos Katsavounis ◽  
Sofia Anastasiadou
Keyword(s):  
Resource Allocation ◽  
Petri Nets ◽  
Petri Net ◽  
Object Oriented ◽  
Colored Petri Nets ◽  
Allocation Scheme ◽  
Shared Resources ◽  
Basic Characteristics ◽  
Resource Allocation Scheme ◽  
Maximum Utilization

The Petri net (PN) formalism is a suitable tool for modeling parallel systems due to its basic characteristics, such as synchronization. The extension of PN, the Colored Petri Nets (CPN) allows the incorporation of more details of the real system into the model (for example, contention for shared resources). The CPNs have been widely used in a variety of fields to produce suitable models. One of their biggest strengths is that their overall philosophy is quite similar to the philosophy of the object-oriented paradigm. In this regard, the CPN models can be used to implement simulators in a rather straightforward way. In this paper, the CPN framework is employed to implement a new resource allocation simulator, which is used to verify the performance of our previous work, where we proposed a fair resource allocation scheme with flow control and maximum utilization of the system’s resources.

scholarly journals Comparison and Evaluation of Deadlock Prevention Methods for Different Size Automated Manufacturing Systems

2015 ◽  
Vol 2015 ◽  
pp. 1-19 ◽  
Author(s):  
Emad Abouel Nasr ◽  
Abdulaziz M. El-Tamimi ◽  
Abdulrahman Al-Ahmari ◽  
Husam Kaid
Keyword(s):  
Petri Nets ◽  
Iterative Methods ◽  
Petri Net ◽  
Manufacturing Systems ◽  
Deadlock Prevention ◽  
Automated Manufacturing ◽  
Shared Resources ◽  
Automated Manufacturing Systems ◽  
High Resource ◽  
Model And Simulation

In automated manufacturing systems (AMSs), deadlocks problems can arise due to limited shared resources. Petri nets are an effective tool to prevent deadlocks in AMSs. In this paper, a simulation based on existing deadlock prevention policies and different Petri net models are considered to explore whether a permissive liveness-enforcing Petri net supervisor can provide better time performance. The work of simulation is implemented as follows. (1) Assign the time to the controlled Petri net models, which leads to timed Petri nets. (2) Build the Petri net model using MATLAB software. (3) Run and simulate the model, and simulation results are analyzed to determine which existing policies are suitable for different systems. Siphons and iterative methods are used for deadlocks prevention. Finally, the computational results show that the selected deadlock policies may not imply high resource utilization and plant productivity, which have been shown theoretically in previous publications. However, for all selected AMSs, the iterative methods always lead to structurally and computationally complex liveness-enforcing net supervisors compared to the siphons methods. Moreover, they can provide better behavioral permissiveness than siphons methods for small systems. For large systems, a strict minimal siphon method leads to better behavioral permissiveness than the other methods.

Schedule Optimization of Time Petri Nets Based on Ant Colony Systems

2012 ◽  
Vol 263-266 ◽  
pp. 1733-1739
Author(s):  
Xian Ming Liu ◽  
Li Pan ◽  
Hong Zheng
Keyword(s):  
Petri Net ◽  
Heuristic Search ◽  
Ant Colony ◽  
Time Petri Nets ◽  
Modeling And Analysis ◽  
Schedule Optimization ◽  
Artificial Ants ◽  
Time Petri Net ◽  
Ant Colony Systems ◽  
Update Rules

This paper presents a time Petri net model with the optimizing mechanism based on ant colony systems that addresses the problem of schedule optimization. The choice rules and pheromone update rules of artificial ants are embedded into the evolution rules of a time Petri net, so the modeling and scheduling analysis of real systems can be integrated into the same model. Compared with the approaches based on the heuristic search and genetic algorithms, our method efficiently unifies the modeling and analysis of schedule problems based on a time Petri net.

Optimal enforcement of liveness for decentralized systems of flexible manufacturing systems using Petri nets

2020 ◽  
Vol 42 (12) ◽  
pp. 2206-2220
Author(s):  
Muhammad Bashir
Keyword(s):  
Computational Complexity ◽  
Petri Nets ◽  
Petri Net ◽  
Supervisory Control ◽  
Flexible Manufacturing ◽  
Flexible Manufacturing Systems ◽  
Manufacturing Systems ◽  
Common Elements ◽  
Decentralized Controllers ◽  
The Given

The decentralized supervisory structure has drawn much attention in recent years. Many studies are reported in the paradigm of automata while few can be found in the Petri net model. This paper proposes a new method for decentralized supervisory control using the Petri net paradigm. Two efficient Algorithms are developed in the proposed method. Algorithm 1 is used to compute decentralized working zones from the given LS3PR Petri net model for flexible manufacturing systems. Algorithm 2 is used to compute the decentralized controllers that enforced liveness to the decentralized working zones. The sequential assembling is used to reconnect and controlled the working zones via decentralized controllers. The decentralized controller is added to the decentralized working zones that have common elements, that is, common transitions. The proposed method has the following advantages: (i) it can be applied to a complex Petri net model for flexible manufacturing systems, (ii) the proposed methods has less computational complexity when compared with the previous methods, (iii) the proposed method can obtain a minimal number of decentralized controllers that enforce liveness of the uncontrolled Petri net model. Experimental examples are presented to explore the applicability of the proposed methods.

scholarly journals Applying global time Petri net analysis on the embedded software context

2011 ◽  
Vol 22 (6) ◽  
pp. 610-619 ◽  
Author(s):  
Leticia Mara Peres ◽  
Luis Allan Künzle ◽  
Eduardo Todt
Keyword(s):  
Petri Net ◽  
Schedulability Analysis ◽  
Embedded Software ◽  
Earliest Deadline First ◽  
Time Petri Nets ◽  
Time Petri Net ◽  
Global Time ◽  
Earliest Deadline ◽  
Class Graph ◽  
Time Type

This paper presents an application of Global Time technique (GTT) which is an approach to construct class graphs of Time Petri nets based on relative and global time. Besides the constructing of GTT class graph we propose a schedulability analysis of quantitative time type for fixed priority policies and Earliest Deadline First (EDF). We propose that analysis of scenarios, or behavior itineraries duration of a system, can be done using this approach.

Sign in / Sign up

Export Citation Format

Share Document