Intelligent Simulation Modeling of a Flexible Manufacturing System with Automated Guided Vehicles

Although simulation is a very flexible and cost effective problem solving technique, it has been traditionally limited to building models which are merely descriptive of the system under study. Relatively new approaches combine improvement heuristics and artificial intelligence with simulation to provide prescriptive power in simulation modeling. This study demonstrates the synergy obtained by bringing together the "learning automata theory" and simulation analysis. Intelligent objects are embedded in the simulation model of a Flexible Manufacturing System (FMS), in which Automated Guided Vehicles (AGVs) serve as the material handling system between four unique workcenters. The objective of the study is to find satisfactory AGV routing patterns along available paths to minimize the mean time spent by different kinds of parts in the system. System parameters such as different part routing and processing time requirements, arrivals distribution, number of palettes, available paths between workcenters, number and speed of AGVs can be defined by the user. The network of learning automata acts as the decision maker driving the simulation, and the FMS model acts as the training environment for the automata network; providing realistic, yet cost-effective and risk-free feedback. Object oriented design and implementation of the simulation model with a process oriented world view, graphical animation and visually interactive simulation (using GUI objects such as windows, menus, dialog boxes; mouse sensitive dynamic automaton trace charts and dynamic graphical statistical monitoring) are other issues dealt with in the study

Land as a Renewable Resource: Integrating Climate, Energy, and Profitability Goals using an Agent-Based NetLogo Model

The objectives of this study center over the course of the beef production life cycle as a management strategy to optimize the financial and natural resource endowment on farms at the county level based on the data available. Although the application is to West Virginia, implications can be derived for other areas with similar resource endowments. The beef farms located in adjacent locations within a county are identified as suppliers of inputs to the farm of interest (or contracting farm) in order to provide the basic foundation for agglomeration economies.;Both an intertemporal component and a spatial component are involved since clustering systems are enhanced when key players are interconnected over space. This is accomplished by using an optimal control framework as the basis of a NetLogo agent-based model (ABM) that explicitly includes a spatial component. This model is intended to provide a foundation for developing agglomeration economies in which other locations are able to supply resources to given locations - or to serve as input markets - by taking advantage of the spatially integrated nature of the agriculture industry. The spatial component provides the basis for regional economic development through clustering among the agricultural and other sectors since they might share locally produced inputs/outputs in the supply chain, thereby enhancing both scope economies and agglomeration economies. Thus, the integration of environmentally friendly technologies that enhance diversified products for the area such as renewable energy as well as digested manure along with high quality beef products and carbon offsets would create new markets which expand market channels and spur economic development, of interest to policy makers at all levels. As a result, farmers would be able not only to produce essential inputs for their own farms but, given appropriate incentives, would also supply them to adjacent farms boosting the local economy. Furthermore, a comparison with conventional, confined animal feeding operations (CAFOs), is briefly provided for perspective as well as the basis for environmental improvement through PBB techniques. Our intention is to replicate a diversified PBB industry and its interaction with surrounding communities in order to identify the optimized paths of the farmer and society in an intertemporal setting. The design of policy instruments is based on the results from the ABM wherein maximizing farm-level profitability that is able to bring benefits to society in which clustering among locations contributes in intensifying the benefits from the adoption of sustainable best management practices (BMPs). Thus, the explicit recognition and use of multifunctional land attributes enables us to address bio-fuel production and climate-related issues such as carbon offsets as well as to expand adoption of sustainable BMPs across space and time. In order to determine policy instruments, we ran our ABM with the absence of carbon prices and cost-share programs as well as different carbon prices and cost-share percentages under different clustering systems along a planning horizon of 15 years. We also compared the profitability between a diversified entrepreneur with a specialized business as an approach to identify the financial motivation to establish our proposed business concept. Results indicate that in order to observe environmental and social benefits as well as economic development in Appalachia through the introduction of a diversified PBB industry, a combination of cost-share policies and carbon prices must be considered. Our results imply that for an average grass-fed beef enterprise with 93 acres of pastureland (as is typical of Appalachia) as the primary resource surrounded by nearby cow/calf farms within an approximate 20 mile radius, will need to rely on a minimum of {dollar}13 per ton CO2e reduced along with a cost share program willing to share the risk of no less than half of the capital investment associated with an anaerobic digester within a clustering system of up to two participants to successfully diversify its business bringing environmental and economic development to the region. Alternatively, a policy combination of 50 percent cost share with a {dollar}26 carbon price not only will enhance environmental improvement but also profitability under unexpected as well as certain weather conditions. We also found that more renewable energy can be generated when more farms join a regional cluster, implying a synergistic effect through clustering. We estimate results under both deterministic and stochastic situations. The latter relate primarily to weather uncertainty and animal death loss, since those are the variables for which data is available. (Abstract shortened by UMI.)

Uses and applications of artificial intelligence in manufacturing

The purpose of the THESIS is to provide engineers and personnels with a overview of the concepts that underline Artificial Intelligence and Expert Systems. Artificial Intelligence is concerned with the developments of theories and techniques required to provide a computational engine with the abilities to perceive, think and act, in an intelligent manner in a complex environment. Expert system is branch of Artificial Intelligence where the methods of reasoning emulate those of human experts. Artificial Intelligence derives it\u27s power from its ability to represent complex forms of knowledge, some of it common sense, heuristic and symbolic, and the ability to apply the knowledge in searching for solutions. The Thesis will review : The components of an intelligent system, The basics of knowledge representation, Search based problem solving methods, Expert system technologies, Uses and applications of AI in various manufacturing areas like Design, Process Planning, Production Management, Energy Management, Quality Assurance, Manufacturing Simulation, Robotics, Machine Vision etc. Prime objectives of the Thesis are to understand the basic concepts underlying Artificial Intelligence and be able to identify where the technology may be applied in the field of Manufacturing Engineering

Regenerative life support system research

Sections on modeling, experimental activities during the grant period, and topics under consideration for the future are contained. The sessions contain discussions of: four concurrent modeling approaches that were being integrated near the end of the period (knowledge-based modeling support infrastructure and data base management, object-oriented steady state simulations for three concepts, steady state mass-balance engineering tradeoff studies, and object-oriented time-step, quasidynamic simulations of generic concepts); interdisciplinary research activities, beginning with a discussion of RECON lab development and use, and followed with discussions of waste processing research, algae studies and subsystem modeling, low pressure growth testing of plants, subsystem modeling of plants, control of plant growth using lighting and CO2 supply as variables, search for and development of lunar soil simulants, preliminary design parameters for a lunar base life support system, and research considerations for food processing in space; and appendix materials, including a discussion of the CELSS Conference, detailed analytical equations for mass-balance modeling, plant modeling equations, and parametric data on existing life support systems for use in modeling

Introduction to Production: Philosophies, Flow, and Analysis

Production is a fundamental societal and economic activity. Production has to do with the transformation of raw materials into useful objects and includes the knowledge to complete the transformation effectively. Thus, production is a board topic ranging from philosophies about how to approach production such as lean and quick response manufacturing, how to organize production facilities, how to analyze production operations, how to control the flow of materials during production, the devices used to move materials within a facility, and strategies for coordinating multiple production facilities. An integrated introduction to production is presented in a set of learning modules. In significant part, these learning modules are based on over 20 years of interactions with the professional production community in the West Michigan region where Grand Rapids and Holland are the principal cities. This community consists almost exclusively of small and medium size companies engaged primarily in high mix, low volume manufacturing. Students in the Bachelor of Science in Engineering and Master of Science in Engineering programs at Grand Valley State University often work in production for these companies. Thus, interactions are facilitated particularly though master’s degree capstone projects, several of which are referenced in the learning modules. The learning modules are well-grounded in established production concepts. Emphasis is placed on proven procedures such as systematic layout planning, factory physics, various production flow control techniques such as kanban and POLCA, and discrete event simulation. Professional practice is a focus of the learning modules. Material from processional groups such as the Lean Enterprise Institute and the Material Handling Institute (MHI) is integrated. The opportunity to read and discuss professional publications presenting production improvement projects is provided. Students are referred to professional videos and web sites throughout the learning modules. All materials provided are referenced are open access and free of charge. When downloading the main file, it is important to also download and use the Main File Support as it contains supplemental materials.https://scholarworks.gvsu.edu/books/1022/thumbnail.jp

Development of a Computer-Integrated Manufacturing Simulation Model: A Hybrid Systems Approach.

The key to the successful factory of the future will be the effective coordination of managerial functions and production operations. The research presented in this dissertation addresses this coordination issue, especially in terms of understanding the impact and possibilities which exist in an information-rich environment. Such an environment is often referred to in the literature as being a computer-integrated manufacturing (CIM) environment. An interactive simulation modeling program, MOSES (Manufacturing Organization Simulation and Evaluation System), was developed for the purpose of describing, analyzing, and understanding such manufacturing. MOSES is a copyrighted computer program, a menu-driven, interactive, simulation modeling tool. MOSES users are able to define the manufacturing environment to be simulated by keying in data values (e.g., products, bills of material, and production rates) which describe the organization. MOSES then uses these data values to build the manufacturing simulation model. That is, once the manufacturing parameters have been defined, MOSES can simulate the manufacturing organization (from orders through distribution) without the user having to write any computer code or having to understand the principles of simulation modeling. MOSES users are then able to interact with the manufacturing organization as managers in the dynamic simulation environment. This interactive capability allows MOSES users to test various manufacturing scenarios, watch the model\u27s progress from the perspectives of different organizational functions (e.g., from marketing or from production), override model-generated decisions (e.g., by changing the demand forecast), and view the results. The MOSES approach to simulation modeling differs from traditional approaches. In short, MOSES uses both mathematic and logical modeling principles, employs traditional simulation modeling techniques but in combination with database technology, and includes the user as an integral component in the simulation process

Existing and Required Modeling Capabilities for Evaluating ATM Systems and Concepts

ATM systems throughout the world are entering a period of major transition and change. The combination of important technological developments and of the globalization of the air transportation industry has necessitated a reexamination of some of the fundamental premises of existing Air Traffic Management (ATM) concepts. New ATM concepts have to be examined, concepts that may place more emphasis on: strategic traffic management; planning and control; partial decentralization of decision-making; and added reliance on the aircraft to carry out strategic ATM plans, with ground controllers confined primarily to a monitoring and supervisory role. 'Free Flight' is a case in point. In order to study, evaluate and validate such new concepts, the ATM community will have to rely heavily on models and computer-based tools/utilities, covering a wide range of issues and metrics related to safety, capacity and efficiency. The state of the art in such modeling support is adequate in some respects, but clearly deficient in others. It is the objective of this study to assist in: (1) assessing the strengths and weaknesses of existing fast-time models and tools for the study of ATM systems and concepts and (2) identifying and prioritizing the requirements for the development of additional modeling capabilities in the near future. A three-stage process has been followed to this purpose: 1. Through the analysis of two case studies involving future ATM system scenarios, as well as through expert assessment, modeling capabilities and supporting tools needed for testing and validating future ATM systems and concepts were identified and described. 2. Existing fast-time ATM models and support tools were reviewed and assessed with regard to the degree to which they offer the capabilities identified under Step 1. 3 . The findings of 1 and 2 were combined to draw conclusions about (1) the best capabilities currently existing, (2) the types of concept testing and validation that can be carried out reliably with such existing capabilities and (3) the currently unavailable modeling capabilities that should receive high priority for near-term research and development. It should be emphasized that the study is concerned only with the class of 'fast time' analytical and simulation models. 'Real time' models, that typically involve humans-in-the-loop, comprise another extensive class which is not addressed in this report. However, the relationship between some of the fast-time models reviewed and a few well-known real-time models is identified in several parts of this report and the potential benefits from the combined use of these two classes of models-a very important subject-are discussed in chapters 4 and 7

NASA Tech Briefs, August 1991

Topics: New Product Ideas; NASA TU Services; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences