Latent Nestling Method: A new fault diagnosis methodology for complex systems

The context of our work is the complex systems simulation. Complex systems modelling and simulation require to take into account the interactions between the different components. For instance, an airport ground traffic simulation requires to model the planes with the pilots, the control tower, the

The travelling salesman problem, which can be solved with various methods, is a traditional and typical problem in artificial intelligence (AI). As an evolution of Petri nets, colored Petri nets (CPN) can be dedicated to modeling and analysis of different systems as a new attempt. The paper shows the brief description of the given problem and CPN, we detail the implementation of the CPN model of the problem and analyze the simulation result. This CPN example shows the potentiality of CPN application in AI.

MPLS addresses large networks; it is difficult to achieve a realistic model in the short term. This is why we plan to simulate different approaches. Our study is thus concretized by the development of models able to bring solutions to the problems of evaluation of the performances and improvement of the quality of the services of the networks MPLS. This paper presents the modeling of MPLS routers by colored Petri nets. Petri networks represent a mathematical tool, health in the field of modeling and verification systems; in addition to their analytical strength it provides a simple graphical representation which helps the modeling of complex systems.

Coloured Petri Nets (CPNs) is a language for the modelling and validation of systems in which concurrency, communication, and synchronisation play a major role. Coloured Petri Nets is a discrete-ev...

Petri Nets provide a graphical notation for modeling systems and performing analysis. Colored Petri Nets (CPNs) combine the strengths of ordinary Petri Nets with a high level programming language, making them more suitable for modeling large systems. A CPN model is an executable representation of a system that can be analyzed through simulation. CPN models are built using CPN Tools, a graphical software tool and interface used to create, edit, simulate, and analyze models. This tutorial is meant to introduce the reader to the vocabulary and constructs of CPNs and illustrate the use of CPN Tools in creating and simulating models by means of a familiar, simple example. In particular, we show how to create a CPN model of the call center example presented by White and Ingalls in their tutorial Introduction to Simulation.

This paper proposes a method based on chaotic spread spectrum sequence for synchronous online diagnosis of intermittent faults for complex and cable. networks, such as the aircraft power system. The novelties of the proposed method include: 1) since chaotic spread spectrum signals are sensitive to initial values, the number of chaotic sequences are not limited and the proposed method is not limited by the number of cables under monitoring; 2) with the self-correlation characteristic and cross-correlation characteristic of chaotic sequence, the proposed method can be extended to online diagnosis of multiple cable intermittent faults; and 3) the signal source impedance amplification method is proposed for intermittent arc faults of multiple cables, which improves the reflection coefficient and increases the accuracy of online detection and location of intermittent arc faults. A series of simulations and experiments on multiple cables with different intermittent fault modes are conducted to verify the effectiveness of the proposed approaches.

In this work, the analysis of behavioural and structural features of automated systems has been investigated by using coloured Petri Nets (CPNs). CPN is one of the best modelling methods of the automated system. Many features of Petri Nets can be searched by reachability tree and invariants. They also show the features of CPN. Reachability tree shows the markings which can be reached by the net. With P invariants we can determine the correctness of the net. In this work, an algorithm to calculate reachability tree of automated systems is developed. P invariants of CPN is analysed and Martinez-Silva algorithm is applied to CPNs. Time performances of these methods are also determined.

With the aim of solving the problems of the Petri nets to the place/transition nets automatic conversion and realization of Petri nets parallel control and running, the algorithm is proposed to transform Color Petri net systems transform into P/T nets. The algebraic model of colored Petri nets and P/T nets, and its intrinsic mechanism is analyzed, the process and theory verification of the colored Petri nets into P/T nets are given. The colored Petri nets into P/T network algorithm is proposed, through the network model of formal, colored Petri nets correlation matrix pretreatment. Experimental results show that it is an effective method to solve Color Petri Net systems transform into P/T nets, lay the foundation for various senior Petri nets system transformation into P/T nets and achieve the parallelism and simulation of running.

PurposeA major factor to the success of flexible manufacturing systems (FMSs) is their ability to transport work pieces between different workstations. FMS have now become more advanced and material‐handling systems have become progressively more sophisticated, it is not exceptional to have automated steering of tools to workstations as well. Such system design will improve the tool‐handling capability and the system productivity while holding tool cost to a minimum. Tool cost could represent as much as 25 percent of the operating cost. The purpose of this paper is to propose a new colored Petri net (CPN)‐based approach to the design and development of a tool sharing control system that is intended to help use of the proper and minimal number of tools for a manufacturing system.Design/methodology/approachA new black token timed PN model is first developed, to reduce the complexity of the graphical representation a new CPN model is developed. The new CPN model also allows to find the optimal sequence. The optimal sequence has no effect on the work in process (WIP) but it influences the number of tools used in the system. The main input to the PN model for a manufacturing system is the process plan. Next, all the invariants and total number of possible elementary circuits are determined using the Integrated Net Analyzer (INA) software. Output from the INA software is exported to the Excel spreadsheet. The Excel spreadsheet can be designed to calculate the total number of tokens, processing time, cycle time, etc. of each elementary circuit. Subsequently, the constraints used in Lingo will be created according to critical circuit rules. Finally, linear programming (LP) technique is used to optimize the WIP and tool inventory. Lingo software is used for the LP, the constraints from the Excel sheet will be the input data to the Lingo program, and based on those constraints the Lingo will provide the optimal values for the desired parameters. The output from Lingo will be used to recalculate the cycle time of each elementary circuit in the Excel sheet. The system is then analyzed before and after the implementation of the CPN model.FindingsA new CPN model based on tool‐sharing philosophy for an FMS with N part types and M stations is proposed.Originality/valueThe paper presents a new CPN‐based approach to the design and development of a tool sharing control system, that is, intended to help use of the proper and minimal number of tools for a manufacturing system. The new CPN model also allows to find the optimal sequence. The idea is new and pure and has not been presented before using the methodology adopted in this paper.

Security verification and performance analysis are both crucial aspects for designing effective and efficient authentication protocols. However, in most authentication protocol design practice, two independent models are often adopted for individual security verification and performance analysis, which could not guarantee that performance improvements taking no harm to its security functionalities. In this paper, a colored Petri nets (CPN) model based method is well utilized to integrate security verification and performance analysis for authentication protocols. The main idea is that the functional CPN model for an authentication protocol is constructed firstly for its security verification, and then performance related temporal constrains are added into above model to form a corresponding performance CPN model for simulation based performance evaluation towards that authentication protocol. Because such closely related CPN models are utilized where occurrence sequences existed in performance models are also behavior-equally existed in functional models, it is guaranteed that both models satisfy the security requirements for the authentication protocol. We present the security and performance joint analysis process of TRDP protocol, a representative example of authentication protocols, to illustrate the effectiveness of above CPN based integrated approach.

For avoiding false-alarm and diagnosing intermittent fault, based on the relationship analysis between intermittent fault and false-alarm, the intermittent fault diagnosis model of power system based on HMM (Hidden Markov Model)-SVM (Support Vector Machine) characteristics was constructed in this paper. By means of this model, the intermittent fault diagnosis procedure of power system based on HMM-SVM characteristics was built. Finally, the intermittent fault diagnosis simulation system of power system based on HMM-SVM characteristics was demonstrated and validated by QUEST software. The result showed that the proposed method was available, and can provided guidance for avoiding false-alarm and diagnosing intermittent fault, and support for stable performance in power system.

This paper describes model transformation for analyzing dynamic behavior of large-scale systems. The Unified Modeling Language (UML) based system model is transformed into the Colored Petri Nets (CPN) model, which is used for analyzing the scenarios of the use cases of a system and checking freedom of system deadlock at an early stage of software development. The CPN model that is executable is hierarchically structured on the basis of the functional decomposition of a large-scale system. The UML-based system model consisting of the use case model, class model and collaboration model is not executable so that the dynamic behavior of the system cannot be analyzed until implementation of the system. However, the UML-based system model has no hierarchical structure to be transformed into the hierarchical CPN model as well. The discrepancies of dynamic and structural views in the two models are resolved by transformation of the UML model into the layered, executable CPN model with three layers — the use case layer, object layer and operation layer. The model transformation is carried out using relationships among the use case model, class model, and collaboration model of the UML. With the executable CPN model transformed, the dynamic properties of the system are analyzed using the simulation technique, occurrence graph, and state space report provided by the Design/CPN tool. The approach in this paper is validated through two case studies — the gas station system and the distributed factory automation system.

Server consolidation for heterogeneous computer clusters using Colored Petri Nets and CPN Tools

Analysis of controlled technological systems using high level petri nets

The paper is a partial synthesis of the work that a team within the Faculty of Managerial and Technological Engineering has in the field of modeling and simulation of systems with Petri nets. The paper deals with three issues. The first part is Modeling and simulation of manufacturing systems with timed Petri nets. The first part presents the way in which the performances of some manufacturing systems are evaluated using timed Petri nets. The first example is a manufacturing system specific to the textile industry. The system has three production lines. In this case, the modeling with timed Petri nets allows the analysis of the operation of the flow lines and highlights the bottleneck. Another modeled manufacturing system is specific to a series production, more precisely it refers to the manufacture of gas cookers within a company from Oradea. The model with Petri nets also describes the supply sequences of the stocks of parts and subassemblies. The next modeled system is an automated manufacturing system for the packaging of detergents. The complexity of the Detergent Packing System and the high level of automation, require the use of efficient modeling and simulation methods to verify the validity of the solutions adopted. In this chapter is present the model of a robotic welding cell. The second part of the paper, the transition from timed Petri nets to hierarchical colored Petri nets, shows how Petri nets were developed for a robotic cell for metallographic analysis. The third part is dedicated to modeling with colored Petri nets timed with complex colors of the flexible manufacturing cell A007 within the Department of Industrial Engineering.