Generic Petri Nets Research Articles

Integration of JIT flexible manufacturing, assembly and disassembly system using Petri net approach

This paper presents a new generic Petri net (PN) model for design and performance evaluation of a flexible assembly system (FAS) and disassembly system (DAS) with dual kanban. The architectural design of the model is derived from a generic bill of materials (BOMs) in the FAS, a reverse BOM in the DAS and the process plan in the case of flexible manufacturing system (FMS). Integration of FMS, FAS and DAS by developing a new generic PN model with the pull system is introduced. Analysis and performance evaluation of the new model based on invariant analysis and linear programming are also introduced. The method will be illustrated by a small case study.

Petri-Net Models for Risk Analysis of Hazardous Liquid Loading Operations

A vigorous hazard assessment is almost mandatory for the safety and risk-free operation of any chemical plant. A systematic approach has been developed in this study to construct a generic Petri-net (PN) model for analyzing the liquid ammonia loading process. A set of sub-PNs were first built for all components in the system. Failure mechanisms were then developed and incorporated into these component models. On the basis of predefined hazardous conditions, the critical fault propagation scenarios were identified accordingly with simulation studies. It is observed from the simulation results that the proposed model can be effectively used for hazard identification in the sequential operations.

A software environment for flexible manufacturing system control software testing

The development of flexible manufacturing system (FMS) control software is a complex task in terms of both the hardware and the software. It is therefore an important task to provide testing facilities for FMS control software in the course of its development. This paper reports on the development of an FMS control software testing environment. The architecture of this testing environment is built to make the system open and intelligent. The openness is achieved to allow for the change in requirements, and the intelligence is meant to reduce manual work in software testing. A generic Petri net (GPN) model representing the behaviour of an FMS is introduced. A set of algorithms for detecting faults in the operation of an FMS control software program is proposed on the basis of the GPN model.

A generic Petri net model for flexible manufacturing systems and its use for FMS control software testing

Developing a flexible manufacturing system (FMS) controller is a complicated task both in the hardware development and software development. To test the control software prior to putting it into use is crucial for the development of a FMS controller. An intelligent testing environment for FMS controllers is under development, the aim of which is to reduce manual work in the testing. To reach this objective the automatic building of a behavioural model of the FMS is demanded. This paper proposes a generic Petri net (GPN) model and approach for the development of control software for FMSs. The principle of this approach is based on checking the control parts of FMSs with the help of temporal relationships between physical operations, and the specification of the FMS controller with GPN. The strategy of GPN modelling is then incorporated with more general problem solving strategies in artificial intelligence. A template is first defined for a GPN model, and then the model for FMS individuals is established in the form of instances of the template. The transitions of the GPN are represented with the proposed general expressions with two syntaxes, 'verb+ noun' and 'verb+ noun+ where', from which the GPN can be formulated. GPN makes it simple to express FMS controls, and procedural language can also be used for information processing. A case study for the testing of FMS controller software is provided to show effectiveness and cost saving over development with conventional methods in which only ordinary Petri net and procedural language are used.

A generic Petri nets based model for paper mills finishing processes : C. Valentin, P. Ladet, J. Ruiz, pp 435–440

A generic Petri nets based model for paper mills finishing processes : C. Valentin, P. Ladet, J. Ruiz, pp 435–440

A Generic Petri Nets Based Model for Paper Mills Finishing Processes

Abstract The aim of this paper is to present a methodology to design a generic Petri net based model for the class of paper mills finishing processes. This model is based on timed coloured Petri nets with decision solving procedures. This modeling tool is called by the generic term, high level Petri net. A special interest is given to represent the decision points of the system as conflicts in the net. The model is meant for simulation, to carry out qualitative analysis about the system. The purpose is to observe resource sharing and the consequences of different strategy choices on the production. Machine breakdowns, operation-machine allocation and times to change from one sort to another are taken into account. The basic concepts of the modeling tool and the methodology are first presented. Then, the characteristics of the class of processes are given. Finally, the generic model is explained.