Charles R. McLean

A Proposed Hierarchical Control Model for Automated Manufacturing Systems

Abstract The Automated Manufacturing Research Facility is being constructed at the National Bureau of Standards. This small, integrated, flexible manufacturing system will serve as a research test bed to aid in the identification, design, and testing of standards for the automated factory of the future. This paper describes the five layer hierarchical production control model proposed to manage these factories. Included is a discussion of the philosophy behind this model, the functional requirements of each layer within the model, a brief description of the data services needed to support this approach, and an overview of the techniques used to implement existing subsystems.

THE VIRTUAL MANUFACTURING CELL

Abstract A virtual manufacturing cell is being developed at the National Bureau of Standards as part of the control software for the Automated Manufacturing Research Facility (AMRF) project. The traditional group technology (GT) cell has evolved from the need to maintain the flexibility to manufacture a family of parts while gaining some of the efficiency associated with a single process flow line. GT cells are normally defined by a fixed physical grouping of machining workstations that produce a particular class of parts. A shop based upon virtual manufacturing cells provides greater flexibility than existing GT shop configurations by time sharing machining workstations. Virtual GT cells are not identifiable as fixed physical groupings of machinery, but as data files and processes in a control computer. Functions performed by these processes include analysis, reporting, routing, scheduling, dispatching, and monitoring. At a higher level, the shop control system schedules cell activation and allocates workstations and other resources to these cells. Workstations are at all times under the control of either a particular virtual cell or a pool cell composed of idle workstations.

The IMS MISSION architecture for distributed manufacturing simulation

This paper presents an overview of a neutral reference architecture for integrating distributed manufacturing simulation systems with each other, with other manufacturing software applications, and with manufacturing data repositories. Other manufacturing software applications include, but are not limited to systems used to: design products; specify processes; engineer manufacturing systems; and manage production. The architecture identifies the software building blocks and interfaces that will facilitate the integration of distributed simulation systems and enable the integration of those systems with other manufacturing software applications. The architecture is being developed as part of the international Intelligent Manufacturing Systems (IMS) MISSION project.

Disassembly of products

With incoming recycling regulations, resource conservation needs and an increased awareness of the state of the environment by both the consumer and the producer, a fundamental reappraisal of the traditional manufacturing paradigm has been emerging. The manufacturers are under tremendous pressure to dispose of products in an environmentally responsible manner. To this end many companies are establishing disassembly plants and developing product designs which specifically facilitate disassembly. Once disassembled, the items can be reused, recycled or discarded. This paper provides an overview of the research in the area of disassembly of products.

The expanding role of simulation in future manufacturing

Simulation technology holds tremendous promise for reducing costs, improving quality, and shortening the time-to-market for manufactured goods. Unfortunately, this technology still remains largely underutilized by industry today. This paper suggests benefits to industry resulting from the widespread, pervasive implementation of manufacturing simulation technology. Potential simulation impact areas are closely intertwined with strategic manufacturing. Yet, a number of factors currently inhibit the deployment of simulation technology in industry today. The development of new simulation interface standards could help increase the deployment of simulation technology. Interface standards could improve the accessibility of this technology by helping to reduce the expenses associated with acquisition and deployment, minimize model development time and costs, and provide new types of simulation functionality that are not available today.

Integrated simulation and gaming architecture for incident management training

The simulation-based training systems that are available or under development today for incident management are typically focused on macro level sequence of events. A few systems targeted at individual responders are under development using a gaming environment. Separate uses of such systems provide disparate experiences to decision makers and individual responders. There is a need to provide common training experiences to these groups for better effectiveness. This paper presents a novel approach integrating gaming and simulation systems for training of decision makers and responders on the same scenarios preparing them to work together as a team. An integrated systems architecture is proposed for this purpose. Major modules in gaming and simulation subsystems are defined and interaction mechanisms established. Research and standards issues for implementation of the proposed architecture are discussed.

An architecture for a generic data-driven machine shop simulator

Standard interfaces could help reduce the costs associated with simulation model construction and data exchange between simulation and other software applications - and thus make simulation technology more affordable and accessible to a wide range of potential industrial users. Currently, small machine shops do not typically use simulation technology because of various difficulties and obstacles associated with model development and data translation. This paper provides an overview of work currently underway at the National Institute of Standards and Technology (NIST) to develop a software architecture, standard data interfaces, and a prototype generic machine shop simulator that can be readily reconfigured for use by a large number of small machine shops. It also reviews prior work in this area and describes future work.

Input data management methodology for discrete event simulation

Input Data Management (IDM) is a time consuming and costly process for Discrete Event Simulation (DES) projects. In this paper, a methodology for IDM in DES projects is described. The approach is to use a methodology to identify and collect data, then use an IDM software to extract and process the data. The IDM software will structure and present the data in Core Manufacturing Simulation Data (CMSD) format, which is aimed to be a standard data format for any DES software. The IDM methodology was previously developed and tested by Chalmers University of Technology in a case study in the automotive industry. This paper presents a second test implementation in a project at the National Institute of Standards and Technology (NIST) in collaboration with an aerospace industry partner.

Virtual reality simulation of a mechanical assembly production line

This paper presents our work on the application of virtual reality simulation to the design of a production line for a mechanically-assembled product. The development of this simulation was undertaken as a part of the Manufacturing Simulation and Visualization Program at the National Institute of Standards and Technology in Gaithersburg, MD. The major research problem is the partitioning and analysis of the assembly operation of the prototype product into different tasks and allocation of these tasks to different assembly workstations. Issues such as cycle times, material handling and assembly line balancing complicate the problem. This paper demonstrates the difficulties of using simulation modeling for concurrent graphical simulation of assembly operations and discrete event analysis of a production process in the same model. It also points out the need to speed up the modeling process and reduce the level of effort required in the construction of a simulation model.

Flexible manufacturing systems for mass customisation manufacturing

This paper presents innovative approaches in realising and exercising mass customisation in theoretical and practical applications. Strategies of generalised production line platform and modularisation are explored to support dynamic reconfigurations of mass customisation. NISTs XML-based Shop Data information integration specification is utilised to derive a data driven reconfigurable mass customisation modelling methodology. A simulation model of a Boeing aircraft major component assembly line is created and driven by a batch control file, which is generated from the XML-based Shop Data specification.