Conceptual modeling architecture and implementation of object-oriented simulation for automated guided vehicle (AGV) systems

Traditional simulation languages and simulators do not fully support the need to design, modify, and extend simulation models of manufacturing systems, especially, material handling systems. Since AGV systems, one type of automated material handling systems, require complicated control logic, flexible job routings, and frequent layout modifications and extensions to correspond to production requirements, the time consumption and efforts to achieve the above tasks in traditional paradigms are significant. However, such difficulties can be overcome by the use of object-oriented simulation. This research develops an object-oriented modeling architecture for the simulation of AGV (automated guided vehicle) systems by extending Beaumariage's object-oriented modeling environment (1990) which is originally designed for the simulation of job shop type manufacturing systems. For this extension, several classes required to comprise an AGV system are created into the original environment which include AGV, limited size queue, control point, track segment, machine cell, AGV system control classes, and so on. This architecture provides a flexible environment that enables the modeling of traditional and tandem AGV system layouts. A best-first search approach, one artificial intelligence search algorithm, is employed to direct AGVs to determine the shortest path from all possible travel paths. The computerized modeling system with this conceptual architecture is easy to use, especially compared with traditional simulation tools. In addition, the extended object-oriented architecture used for the simulation of AGV systems is program independent and may be implemented in any object-oriented language. The prototype system implemented as a portion of this research is performed in Smalltalk/V. Two case examples are presented for verification and validation

An object-oriented analysis technique for developing object-oriented simulations in Silk.

Simulation is very popular as an analysis tool for complex systems. A new paradigm shift towards object oriented simulations is hoping to make simulations even more powerful and accessible. However, in order for those not familiar with object oriented techniques to join this shift, methods must be developed for them to build object oriented simulations, until they acquire an understanding of this programming paradigm. This is an attempt to develop a procedure for just such novice model builders. This thesis begins with some background on object oriented paradigm concepts. It then provides an overview of several different object oriented analysis techniques and attempts to define the common steps of these approaches. Several different commercial object-oriented simulation software are described, with an in depth description of the software selected, Silk, a java based simulation software. The general object oriented analysis approach is then adapted for simulation purposes, resulting in a proposed object oriented analysis technique for developing simulations, and an example is given. Object oriented analysis techniques such as use-case modeling and noun extraction are used to identify potential objects in a discrete manufacturing system to be simulated. These objects are then mapped to existing object classes in the Silk software for final model building.Dept. of Industrial and Manufacturing Systems Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2003 .Z36. Source: Masters Abstracts International, Volume: 42-03, page: 1031. Adviser: R. S. Lashkari. Thesis (M.A.Sc.)--University of Windsor (Canada), 2003

Search-based system architecture development using a holistic modeling approach

This dissertation presents an innovative approach to system architecting where search algorithms are used to explore design trade space for good architecture alternatives. Such an approach is achieved by integrating certain model construction, alternative generation, simulation, and assessment processes into a coherent and automated framework. This framework is facilitated by a holistic modeling approach that combines the capabilities of Object Process Methodology (OPM), Colored Petri Net (CPN), and feature model. The resultant holistic model can not only capture the structural, behavioral, and dynamic aspects of a system, allowing simulation and strong analysis methods to be applied, it can also specify the architectural design space. Both object-oriented analysis and design (OOA/D) and domain engineering were exploited to capture design variables and their domains and define architecture generation operations. A fully realized framework (with genetic algorithms as the search algorithm) was developed. Both the proposed framework and its suggested implementation, including the proposed holistic modeling approach and architecture alternative generation operations, are generic. They are targeted at systems that can be specified using object-oriented or process-oriented paradigm. The broad applicability of the proposed approach is demonstrated on two examples. One is the configuration of reconfigurable manufacturing systems (RMSs) under multi-objective optimization and the other is the architecture design of a manned lunar landing system for the Apollo program. The test results show that the proposed approach can cover a huge number of architecture alternatives and support the assessment of several performance measures. A set of quality results was obtained after running the optimization algorithm following the proposed framework --Abstract, page iii

Enterprise modeling for CIM information systems architectures: An object-oriented approach

Computer Integrated Manufacturing (CIM) information systems have become extremely important to the global competitiveness of most manufacturing firms. And although much has been written about CIM development and implementation many problems still plague practitioners. For example, lack of integration, islands of automation, sub-optimization of resources, and the inability to migrate to future technology are a few types of problems. Further, few methodologies have been developed that systematically address these issues. In this paper, we outline an Object-Oriented approach to modeling manufacturing enterprises. The approach offers a procedure and techniques for defining CIM information systems architectures which could serve as blueprints for CIM development and implementation in manufacturing enterprises.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31672/1/0000608.pd

Flexible cooperation in non-standard application environments

The integration of preexisting systems into a single, heterogeneous, distributed non-standard application system in domains like office automation or computer-integrated manufacturing are regarded as cooperating systems. They are characterized through teamwork, distribution and the handling of complex data structures (e.g. multimedia data). Object-oriented database systems, providing for complex object management, represent one approach in support of such applications. They concentrate, however, on data modeling aspects and use more or less conventional transaction concepts, based on a global execution control. Hence, they only partially fulfill application requirements as they do not adequately cope with the autonomy that is often inherent to the system's components. As a consequence, we suggest S-transactions as an appropriate means for describing the cooperation of system components in terms of transactions and beyond. In this paper we outline the modeling of conventional transactions (flat or nested as well as distributed and design transactions) in terms of STDL, the S-transaction definition language. Beyond that we point out how to specify SAGAs and similar concepts. Finally we discuss the specification of non-linear but maybe acyclic or even cyclic cooperation structuresPrepared for: Naval Ocean Systems Center and funded by the Naval Postgraduate School.http://archive.org/details/flexiblecooperat00holtO&MN, Direct FundingNAApproved for public release; distribution is unlimited

Review of research in feature-based design

Research in feature-based design is reviewed. Feature-based design is regarded as a key factor towards CAD/CAPP integration from a process planning point of view. From a design point of view, feature-based design offers possibilities for supporting the design process better than current CAD systems do. The evolution of feature definitions is briefly discussed. Features and their role in the design process and as representatives of design-objects and design-object knowledge are discussed. The main research issues related to feature-based design are outlined. These are: feature representation, features and tolerances, feature validation, multiple viewpoints towards features, features and standardization, and features and languages. An overview of some academic feature-based design systems is provided. Future research issues in feature-based design are outlined. The conclusion is that feature-based design is still in its infancy, and that more research is needed for a better support of the design process and better integration with manufacturing, although major advances have already been made

Digitally interpreting traditional folk crafts

The cultural heritage preservation requires that objects persist throughout time to continue to communicate an intended meaning. The necessity of computer-based preservation and interpretation of traditional folk crafts is validated by the decreasing number of masters, fading technologies, and crafts losing economic ground. We present a long-term applied research project on the development of a mathematical basis, software tools, and technology for application of desktop or personal fabrication using compact, cheap, and environmentally friendly fabrication devices, including '3D printers', in traditional crafts. We illustrate the properties of this new modeling and fabrication system using several case studies involving the digital capture of traditional objects and craft patterns, which we also reuse in modern designs. The test application areas for the development are traditional crafts from different cultural backgrounds, namely Japanese lacquer ware and Norwegian carvings. Our project includes modeling existing artifacts, Web presentations of the models, automation of the models fabrication, and the experimental manufacturing of new designs and forms

Cloud-based manufacturing-as-a-service environment for customized products

This paper describes the paradigm of cloud-based services which are used to envisage a new generation of configurable manufacturing systems. Unlike previous approaches to mass customization (that simply reprogram individual machines to produce specific shapes) the system reported here is intended to enable the customized production of technologically complex products by dynamically configuring a manufacturing supply chain. In order to realize such a system, the resources (i.e. production capabilities) have to be designed to support collaboration throughout the whole production network, including their adaption to customer-specific production. The flexible service composition as well as the appropriate IT services required for its realization show many analogies with common cloud computing approaches. For this reason, this paper describes the motivation and challenges that are related to cloud-based manufacturing and illustrates emerging technologies supporting this vision byestablishing an appropriate Manufacturing-as-a-Service environment based on manufacturing service descriptions