Object-oriented Petri Nets Research Articles

Object Petri Nets Based Monitoring for the Aircraft Assembly System in MES

Monitoring design is one of basic problems during the development of manufacturing execution systems. In this paper we study the monitoring problems for the Aircraft assembly system in manufacturing execution system environment according to the computer integrated manufacturing system architecture of the Aircraft Company in China. We show that the problem of designing monitoring system for manual assembly system is reducible to modeling and synthesizing problem of monitoring system based on Object Petri Nets. Next the problem of implementing the monitoring system results in designing of structure and functions of the monitoring system. In particular, an efficient rapid prototype schema for implementation is presented. An application is demonstrated how to deal with object Petri nets based monitoring for the aircraft vertical fin assembling.

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

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.

Modeling Method of Automotive Body CAN/LIN Nets Application Protocol Based on Object-oriented Colored Petri Net

Recently automotive nets are adopted to solve increasing problems in automotive electronic systems.Technologies of automotive local area network from CAN and LIN can solve the problems of the increasing of wire bunch weight and lack in module installation space.However,the multilayer automotive nets software becomes more and more complex,and the development expense is difficult to predict and to keep in check.In this paper,the modeling method of hierarchical automotive nets and the substitution operation based on object-oriented colored Petri net(OOCPN) are proposed.The OOCPN model which analyzes the software structure and validates the collision mechanism of CAN/LIN bus can speed the automobile system development.First,the subsystems are divided and modeled by object-oriented Petri net(OOPN).According to the sets of message sharing relations,the message ports among them are set and the communication gate transitions are defined.Second,the OOPN model is substituted step by step until the inner objects in the automotive body control modules(BCM) are indivisible and colored by colored Petri net(CPN).And the color subsets mark the node messages for the collision mechanism.Third,the OOCPN model of the automotive body CAN/LIN nets is assembled,which keeps the message sets and the system can be expanded.The proposed model is used to analyze features of information sharing among the objects,and it is also used to describe each subsystem real-time behavior of processing messages and implemental device controllers operating,and puts forward a reasonable software framework for the automotive body control subsystem.The research can help to design the communication model in the automotive body system effectively and provide a convenient and rapid way for developing the logical hierarchy software.

Dynamic Simulation of the Equipment Repair Support System based on the OPN Model

It is more difficult that mathematical method analyzes the Object-oriented Petri Net (OPN) model of equipment repair support system which is enormous and complicated, the thread and concrete operation method to apply CPN- Tools simulation software in simulating and analyzing its OPN model was put forward. According to the thread of simulating and concrete operation method, it was successful to construct the Colored Petri Net (CPN) model of the example OPN model of equipment repair support system and verify its dynamic performance with CPN-Tools. Then, it concludes that the method of simulation analysis for the OPN model is rational and effective.

Based Aspect-oriented Petri Nets in Software Engineering

Aspect Oriented (Aspect-Oriented, referred to as AO) as a new programming technology is increasingly cause for concern. This article describes a number of experts to study the current object-oriented Petri Nets (OO PN) adding aspect-oriented thinking, combined with software design and development cycle, given the aspect-oriented OO PN in software engineering methods and steps. Shows the method of using AO PN government office system software design and development of application examples, and gives some object class, the log section and the application form. As the plane of isolation, reducing the coupling, the use of AO PN ways in different applications will use a combination of each section, allowing code reusability enhancement. OOPN itself can process the software system design and development of effective control to ensure that the software system reliability and standardization.

Simulation and Optimization of Job Shop Scheduling for Dry Transformers Based on eM-Plant

The model of job shop scheduling to fabricate dry transformers is constructed by Object-oriented Petri Net (OPN) in this paper, the essential attributes and ways of all object classes are defined to judge if there is a deadlock in the system. The overall OPN model of job shop scheduling is built according to relations of event actions in the manufacturing system. Product processes in the job shop is simulated by eM-Plant software to reconstruct and optimize the manufacturing system at last.

Simulation Modeling Based on the Object-Oriented for Camshaft Production Line

With the production system of modern manufactures complexity increasing, it is very difficult to establish a practical model to satisfy the current trend by means of traditional methods and theories of modeling. According to IDEF0 modeling method, this paper presents a functional model of the production line object model framework. Based on this, an object-oriented abstraction mechanism is considered to solve the camshaft production line complexity practical situation and an object-oriented Petri nets (OPNs) modeling is proposed. Simulation models are established by using Witness 2008 simulation software based on camshaft production line to analyze the layout and bottleneck of production line, to check the design programs, and to optimize configuration and layout of the production line furthermore. The manufacturing capacity of the line is also discussed in this paper. Finally the corresponding solutions to avoid the existing bottleneck of the line are also discussed in detail.

Modeling of reconfigurable manufacturing systems based on colored timed object-oriented Petri nets

To cope with the rapid change in manufacturing market requirements, reconfigurable manufacturing systems (RMSs) with the feature of reconfigurability, have to be developed. A model that describes the reconfiguring process of a manufacturing system is developed by applying colored timed object-oriented Petri nets. Based on the main difference between configurations of RMSs and flexible manufacturing systems (FMSs), a modular hierarchical structure of RMS is developed. By the object-oriented method, all the object classes in the RMS model are identified. A macro-place is used to model the aggregation of many processes and a macro-transition is used to link all the related macro-places. Macro-places and macro-transitions are connected with arcs to form a Petri net named a macro-level Petri net so that the control logic of RMS is represented. The macro-level Petri net is refined by hierarchical steps, each step describing these macro-places by more detailed sub macro-places until all the macro-places cannot be divided. Then the characteristics of material flow and time constraints in RMS are modeled by applying colored tokens and associated time-delay attributes. This model integrates object-oriented methods, stepwise refinement ideas and Petri nets together. The RMS activities can be encapsulated and modularized by the proposed method, so that RMS can be easily constructed and investigated by the system developers.

Applied Research on FMS with UML-OOPN Integration Modeling Method

Base on the characteristic of the system, a model of FMS (Flexible Manufacturing System) is carried on in this paper by combining with the merit of OOPN (Object-Oriented Petri Nets) and UML (Unified Modeling Language). The static structure of FMS is described with UML, but for the dynamic characteristics of the system we complete with object-oriented petri nets, and then the system Petri net model was transform into the UML state diagrams and sequence diagrams according to the corresponding mapping and the transformation rule, thus we obtain a integrity model of the system while improving the reliability of the model.

Seven at one stroke: LTL model checking for high-level specifications in B, Z, CSP, and more

The size of formal models is steadily increasing and there is a demand from industrial users to be able to use expressive temporal query languages for validating and exploring high-level formal specifications. We present an extension of LTL, which is well adapted for validating B, Z and CSP specifications. We present a generic, flexible LTL model checker, implemented inside the PROB tool, that can be applied to a multitude of formalisms such as B, Z, CSP, B||CSP, as well as Object Petri nets, compensating CSP, and dSL. Our algorithm can deal with deadlock states, partially explored state spaces, past operators, and can be combined with existing symmetry reduction techniques of PROB. We establish correctness of our algorithm in general, as well as combined with symmetry reduction. Finally, we present various applications and empirical results of our tool, showing that it can be applied successfully in practice.

An integrated object-oriented approach for design and analysis of an agile manufacturing control system

The agile manufacturing paradigm has emerged as an important concept in the development of manufacturing systems. The control software, developed based on the object-oriented technology, leads to reusability, reconfigurability, and scalability; and the agility of a manufacturing control system can be achieved. In this research, an efficient and systematic methodology for developing an object-oriented agile manufacturing control system is proposed. The proposed development process is divided into four stages: functional analysis, static structural analysis, behavior analysis and verification, and system implementation. The Integration Definition for Function Modeling (IDEF0), Object-Oriented Petri Net (OPN), and Unified Modeling Language (UML) are integrated into the corresponding stages based on their characteristics. In order to develop the system rapidly and efficiently, the transformation rules between the IDEF0 and OPN, and between the OPN and sequence diagram are conducted. In addition, the attributes and operations for each object are also defined directly from the OPN model. The result of the integrated IDEF0/OPN/UML systematically leads to object-oriented control software design for manufacturing systems. Finally, an assembly and packaging system is given to illustrate how the integrated object-oriented approach is implemented for developing the manufacturing control system.

Performance Analysis of IEEE 802.11b Wireless Networks with Object Oriented Petri Nets

Communication protocols are often investigated using simulation. This paper presents a performance study of the distributed coordination function of 802.11 networks. Firstly, our study illustrates the different classes of Petri Nets used for modeling network protocols and their robustness in modeling based on formal methods. Next we propose a detailed 802.11b model based on Object-oriented Petri Nets that precises backoff procedure and time synchronization. Then, performance analyses are evaluated by simulation for a dense wireless network and compared with other measurements approaches. Our main goal is to propose a modular model that will enable to evaluate the impact of network performances on the performances of distributed discrete event systems.

Dynamic modeling and application research of embedded system software architecture

Applyingπ-calculus methods and combing the Object-oriented Petri Nets(OPN) and Time Petri Nets(TPN) of the Petri nets theories,embedded-systems software-architecture abstract model(ESAM)was established.And then,dynamic evolving,uniformity and deadlock of the ESAM model were researched.Last,the developed model was used to model and analyze the signal interlocking controller of railway station.

Modelling intelligent agents for autonomic computing in the PNagent framework

Petri nets have proven to be a valuable tool for modelling concurrent systems. As such, they should be suitable for modelling agent and multi-agent systems, as these are inherently concurrent. Nevertheless, there are not many systems that allow the modelling of the whole multi-agent system in Petri nets. The use of Petri nets is usually limited to subproblems such as the verification of interaction protocols. This paper describes the main concepts of PNagent – a tool for modelling Believe-Desire-Intention (BDI) agents using the formalism of Object-Oriented Petri Nets (OOPN). PNagent allows for developing, testing and running software agents in a consistent graphical environment. The framework is suitable for prototyping and experiments with both multi-agent applications and the particular agent architecture itself. At the same time, thanks to the formal nature of its underlying paradigm, it provides the means to verify an agent's properties. Thanks to its consistent environment and the high-level nature of the used formalism, the framework is also suitable for incorporating the ideas of autonomic computing.

Applying a semantic information Petri Net modeling method to AUV systems design

This paper informally introduces colored object-oriented Petri Nets(COOPN) with the application of the AUV system. According to the characteristic of the AUV system’s running environment, the object-oriented method is used in this paper not only to dispart system modules but also construct the refined running model of AUV system, then the colored Petri Net method is used to establish hierarchically detailed model in order to get the performance analyzing information of the system. After analyzing the model implementation, the errors of architecture designing and function realization can be found. If the errors can be modified on time, the experiment time in the pool can be reduced and the cost can be saved.

A Multi-View Software Process Model Based on Object Petri Nets

基于关注点分离原则,结合多视角软件过程建模与对象网之间的相似性,提出了一种基于对象网的多视角软件过程模型MOPN-SP-net,可以提高软件过程模型的可复用性(reusability).在使用MOPN-SP-net建模时,得到的多视角软件过程模型是一种多维网.直接分析这种多维网比较困难,为此,提供了一种从对象网到平面网的等价转换规则,且转换前后的模型在合理性准则上保持等价.根据这个转换规则,可以通过分析转换后平面网模型的合理性得知转换前的对象网的合理性.;According to the principle of Separation of Concerns, by investigating the similarity between multi-view software process modeling and object Petri nets, this paper proposes the MOPN-SP-net model which is a multi-view software process model based on object Petri nets and enhances the reusability of software process model. During process modeling, MOPN-SP-net is a multi-dimensional Petri net, which is difficult to analyze directly. So, this paper provides a translation rule from an object Petri net to an equivalent traditional flat Petri net. The translation preserves the soundness property. According to the translation rule, the soundness property of the MOPN-SP-net can be indirectly analyzed by its translated flat net.

Modeling production configuration using nested colored object-oriented Petri-nets with changeable structures

Configuring production processes based on process platforms has been well recognized as an effective means for companies to provide product variety while maintaining mass production efficiency. The production processes of product families involve diverse variations in manufacturing and assembly processes resulted from a large variety of component parts and assemblies. This paper develops a multilevel system of nested colored object-oriented Petri nets with changeable structures to model the configuration of production processes. To capture the semantics associated with production configuration decisions, some unique modeling mechanisms are employed, including colored Petri nets, object-oriented Petri nets, changeable Petri net structures, and net nesting. The modeling formalism comprises resource nets, manufacturing nets, assembly nets and process nets. The paper demonstrates how these net definitions are applied to the specification of production process variants at different levels of abstraction. Also reported is a case study in an electronics company. The system model is further analyzed with focus on conflict prevention and deadlock detection.

Performance modeling, real-time dispatching and simulation of wafer fabrication systems using timed extended object-oriented Petri nets

Semiconductor wafer fabrication system (SWFS) is the most complex and capital-intensive phase in the entire semiconductor manufacturing cycle. With characteristics of re-entrant processing routes, equipment uncertainty, product diversity and improving technologies, great challenges are presented in SWFS’s modeling, scheduling and simulation. To implement efficient production control, this paper provides a timed extended object-oriented Petri nets (TEOPNs) approach to performance modeling, real-timed dispatching and simulation of SWFSs. The TEOPNs models are constructed in a hierarchy to accord with the real-world SWFS’s organization, and a new type of signal place is added into the TEOPNs to respond the dynamic states of all processing facilities. A novel autonomy and coordination-based real-time dispatching mechanism (A&C-RDM) is developed in this paper, which executes under the support of the TEOPNs-based hybrid real-time dispatching control system (HRDCS). Owning to the ability of gathering dynamic real-time information of all production facilities and WIP products, the HRDCS can make adaptive dispatching decisions according to the local and global real-time processing status. Two sets of key elements of real-time dispatching, i.e. the state thresholds and dispatching rules, are defined in the HRDCS so that the A&C-RDM can integrate different types of dispatching rules. A set of simulation experiments prove the efficiency of the proposed modeling and dispatching algorithm. In summary, the proposed TEOPNs, HRDCS and A&C-RDM form the cornerstones of a real-time dispatching simulation prototype of SWFS, and the work described in this paper carries out an advanced integrated “modeling–dispatching–simulation” methodology.

Multiple-objective scheduling and real-time dispatching for the semiconductor manufacturing system

Implementing efficient scheduling and dispatching policies is a critical means to gain competitiveness for modern semiconductor manufacturing systems. In contemporary global market, a successful semiconductor manufacturer has to excel in multiple performance indices, consequently qualified scheduling approaches should provide efficient and holistic management of wafer products, information and manufacturing resources and make adaptive decisions based on real-time processing status to reach an overall optimized system performance. To cope with this challenge, a timed extended object-oriented Petri nets (EOPNs) based multiple-objective scheduling and real-time dispatching approach is proposed in this paper. Four performance objectives pursued by semiconductor manufacturers are integrated into a priority-ranking algorithm that serves as the initial scheduling guidance, and then all wafer lots will be dynamically dispatched by the hybrid real-time dispatching control system. A set of simulation experiments validate the proposed multiple-objective scheduling and real-time dispatching algorithm may achieve satisfactory performances.

On Reachability Analysis of Multi Agent Nets

Petri nets are known as a modeling language for concurrent and distributed systems. In recent years, various object-oriented Petri nets were proposed, and we are proposing a kind of object-oriented Petri nets, called multi agent nets (MANs). In this letter, we consider the reachability analysis of MANs. We propose an algorithm for generating an abstract state space of a multi agent net, and report results of computational experiments.