Hybrid adaptive Petri nets: a conceptual framework for partial fluidization of Petri nets

1970 ◽  
pp. 50
Author(s):  
E. Fraca ◽  
J. Júlvez ◽  
M. Silva
Keyword(s):  
Petri Nets ◽  
Petri Net ◽  
Dynamic Systems ◽  
Discrete Event Systems ◽  
Discrete Event ◽  
Modeling And Analysis ◽  
Analysis Techniques ◽  
High Transition ◽  
Large Systems ◽  
Event Dynamic

Petri nets (PNs) constitute a well known family of formalisms for the modeling and analysis ofDiscrete Event Dynamic Systems (DEDS). As most formalisms for discrete event systems, PNssuffer from the state explosion problem, which renders enumerative analysis techniquesunfeasible for large systems. A technique to overcome the problem is to relax integralitycontraints of the discrete PN model, leading to continuous PN. This relaxation highly reducesthe complexity of analysis techniques but may not preserve important properties of theoriginal PN system such as deadlock‐freeness, liveness, reversibility, etc. This work focuses onHybrid Adaptive Petri nets (HAPNs), a Petri net based formalism in which the firing oftransitions is partially relaxed. The transitions of a HAPN can behave in two different modes:continuous mode for high transition workload, and discrete in other case. This way, a HAPN isable to adapt its behaviour to the net workload, it offers the possibility to represent morefaithfully the discrete model and use efficient analysis techniques by behaving as continuouswhen the load is high. Reachability space and the deadlock‐freeness property of hybridadaptive nets is studied in this work.

scholarly journals Supervisors of Petri Nets

2019 ◽  
Vol 27 (45) ◽  
pp. 33-41
Author(s):  
Jana Flochová ◽  
Tomáš Lojan
Keyword(s):  
Petri Nets ◽  
Communication Networks ◽  
Supervisory Control ◽  
Manufacturing Systems ◽  
Discrete Event Systems ◽  
Discrete Event ◽  
Modeling And Analysis ◽  
Industrial Systems ◽  
Software Application ◽  
Event Systems

Abstract The design and operation of modern industrial systems require modeling and analysis in order to select the optimal design alternative and operational policy. Discrete event system models are encountered in a variety of fields, for example computers, communication networks, manufacturing systems, sensors or actuators, faults diagnosis, robotics and traffic. The paper describes principles and methods of supervisory control of discrete event systems initiated by Ramadge and Wonham. Three supervisory control methods based on the Petri net models are introduced, and the key features of the Petri tool software application for the supervisory control of discrete event systems modeled by Petri nets are highlighted.

Fault Detection, Isolation and Characterisation for Discrete Event Systems Based on Petri Nets Models

2010 ◽  
pp. 387-416
Author(s):  
Dimitri Lefebvre ◽  
Edouard Leclercq ◽  
Souleiman Ould El Mehdi
Keyword(s):  
Petri Nets ◽  
Petri Net ◽  
Discrete Event Systems ◽  
Discrete Event ◽  
Practical Interest ◽  
Transportation Systems ◽  
Intermittent Faults ◽  
Event Systems ◽  
Stochastic Time

Petri net models are used to detect and isolate faults in case of discrete event systems as manufacturing, robotic, communication and transportation systems. This chapter addresses two problems. The first one is the structure designs and parameters identification of the Petri net models according to the observation and analysis of the sequences of events that are collected. Deterministic and stochastic time Petri nets are concerned. The proposed method is based on a statistical analysis of data and has a practical interest as long as sequences of events are already saved by supervision systems. The second problem concerns the use of the resulting Petri net models to detect, isolate and characterize faults in discrete event systems. This contribution includes the characterization of intermittent faults. This issue is important because faults are often progressive from intermittent to definitive and early faults detection and isolation improve productivity and save money and resources.

scholarly journals Equivalent and Efficient Optimization Models for an Industrial Discrete Event System with Alternative Structural Configurations

Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Juan-Ignacio Latorre-Biel ◽  
Emilio Jiménez-Macías ◽  
Mercedes Pérez de la Parte
Keyword(s):  
Petri Nets ◽  
Petri Net ◽  
Discrete Event Systems ◽  
Discrete Event ◽  
Discrete Event System ◽  
Optimization Techniques ◽  
Event System ◽  
Event Systems ◽  
Structural Configurations ◽  
Computational Resources

Discrete event systems in applications, such as industry and supply chain, may show a very complex behavior. For this reason, their design and operation may be carried out by the application of optimization techniques for decision making in order to obtain their highest performance. In a general approach, it is possible to implement these optimization techniques by means of the simulation of a Petri net model, which may require an intensive use of computational resources. One key factor in the computational cost of simulation-based optimization is the size of the model of the system; hence, it may be useful to apply techniques to reduce it. This paper analyzes the relationship between two Petri net formalisms, currently used in the design of discrete event systems, where it is usual to count on a set of alternative structural configurations. These formalisms are a particular type of parametric Petri nets, called compound Petri nets, and a set of alternative Petri nets. The development of equivalent models under these formalisms and the formal proof of this equivalence are the main topics of the paper. The basis for this formal approach is the graph of reachable markings, a powerful tool able to represent the behavior of a discrete event system and, hence, to show the equivalence between two different Petri net models. One immediate application of this equivalence is the substitution of a large model of a system by a more compact one, whose simulation may be less demanding in the use of computational resources.

scholarly journals Petri Net Based Modeling and Property Analysis of Distributed Discrete Event System

2019 ◽  
Vol 8 (12) ◽  
pp. 3887-3891
Keyword(s):  
Petri Net ◽  
Discrete Event Systems ◽  
Discrete Event ◽  
Discrete Event System ◽  
System Model ◽  
Communication Model ◽  
Computation Model ◽  
Science And Engineering ◽  
Modeling And Analysis ◽  
Event System

PetriNet is an imperative and handy language used for modeling and analysis of discrete event system (DES) i.e. a dynamic system that progress according to unexpected occurrence of events at probably unknown, asymmetrical interval of time. This concept provides an interface for analysis of behavioral and structural properties like liveness, boundedness and cover-ability tree of discrete event systems. These properties are not only necessary for proving the correctness of system model but also helpful in checking the deadlock conditions in a system. As a graph Petri Net is used for modeling and mathematically, it can be used for analysis of the system. In this paper, we have first modeled various DES like computation model and communication model using Petri Nets and then analyzed their properties using MATLAB. These DES models have applications in almost every domain of science and engineering.

scholarly journals Modelling and Control of Discrete Event Dynamic Systems

2000 ◽  
Vol 7 (26) ◽  
Author(s):  
Frantisek Capkovic
Keyword(s):  
Petri Nets ◽  
Dynamic Systems ◽  
Discrete Event ◽  
Analytical Models ◽  
Control Synthesis ◽  
Discrete Event Dynamic Systems ◽  
Oriented Graphs ◽  
Knowledge Based ◽  
Event Dynamic ◽  
And Control

Discrete event dynamic systems (DEDS) in general are <br />investigated as to their analytical models most suitable for control<br />purposes and as to the analytical methods of the control synthesis.<br /> The possibility of utilising both the selected kind of Petri nets<br />and the oriented graphs on this way is pointed out. Because many<br />times the control task specifications (like criteria, constraints, <br />special demands, etc.) are given only verbally or in another form of<br />non analytical terms, a suitable knowledge representation about<br />the specifications is needed. Special kinds of Petri nets (logical,<br />fuzzy) are suitable on this way too. Hence, the knowledge-based<br />control synthesis of DEDS can also be examined. The developed<br />graphical tools for model drawing and testing as well as for the<br />automated knowledge-based control synthesis are described and<br />illustratively presented.<br />Two approaches to modelling and control synthesis based on<br />oriented graphs are developed. They are suitable when the <br />system model is described by the special kind of Petri nets - state<br />machines. At the control synthesis the first of them is straightforward<br /> while the second one combines both the straight-lined model<br />dynamics development (starting from the given initial state <br />towards the prescribed terminal one) and the backtracking model<br />dynamics development.

Object-Oriented Petri Net Modeling and Analysis of China Railway Container Freight Yard Logistic System

2011 ◽  
Vol 467-469 ◽  
pp. 990-995
Author(s):  
Li Wang ◽  
Xiao Ning Zhu ◽  
Zheng Yu Xie
Keyword(s):  
Dynamic System ◽  
Petri Net ◽  
Discrete Event ◽  
Object Oriented ◽  
Operation Time ◽  
Modeling And Analysis ◽  
China Railway ◽  
Event Dynamic ◽  
Container Freight ◽  
High Coordination

The railway container freight yard logistic system is a typical discrete event dynamic system (DEDS) and has the feature of high randomness, low flexibility, uncertainty of operation time and high coordination demand of facilities. Object-oriented petri net (OPN) inherits the petri net (PN) advantages for efficiently describing the asynchronism, concurrency, distributivity, parallel DEDS and overcomes the disadvantages when faces complex discrete element dynamic system. We choose object-oriented petri net to model and analyze China railway container freight yard logistic system and get the object OPN model and communication relation net.

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