11 research outputs found
NASA Tech Briefs, July 1993
Topics include: Data Acquisition and Analysis: Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences
The implementation of CAD/CAM systems in the metalworking industries
This thesis reports on a case survey of 15 UK metalworking companies and their experience of
implementing an integrating technology - CAD/CAM. The thesis places this process of
implementation in the organisational context of these companies by examining the ways in which
the engineering/manufacturing interface is coordinated. This interface is important, because it is
also critical to the effective implementation of such techniques as total quality management and
simultaneous engineering.
In order to develop an incisive analysis of these companies, a contingency approach to
organisational analysis is developed around the idea of flows of information and materials and
their interaction with the structure of the organisation in a process of structuration. This analysis
is placed in the strategic context of the organisations' relationships to their environment through
the notion of a production strategy. Models of the process of implementation are then reviewed,
and a recursive model of implementation as organisational changing is developed which
emphasises the processes of organisational learning.
The management of the engineering design process has been little examined, in comparison to the
management of manufacturing, and research and development. This thesis develops an analysis
of the management of the entire production process from the conception of the product right
through to its delivery to the customer in these 15 firms. It then goes on to examine the recent
organisational changes in the engineering and manufacturing functions before examining the
implementation process in detail. Finally, the basis of organisational integration from both a
technological and organisational perspective is analysed, which provides the basis for some more
general propositions on the development of production management over the next decade
The Federal Conference on Intelligent Processing Equipment
Research and development projects involving intelligent processing equipment within the following U.S. agencies are addressed: Department of Agriculture, Department of Commerce, Department of Energy, Department of Defense, Environmental Protection Agency, Federal Emergency Management Agency, NASA, National Institutes of Health, and the National Science Foundation
NASA Tech Briefs, April 1993
Topics include: Optoelectronics; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences
NASA Tech Briefs, February 1993
Topics include: Communication Technology; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences
NASA Tech Briefs, May 1997
Topics covered include: Advanced Composites, Plastics and Metals; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences; Life Sciences; Books and Reports
Structured grid generation for gas turbine combustion systems
Commercial pressures to reduce time-scales encourage innovation in the design and
analysis cycle of gas turbine combustion systems. The migration of Computational
Fluid Dynamics (CFD) from the purview of the specialist into a routine analysis tool is
crucial to achieve these reductions and forms the focus of this research. Two significant
challenges were identified: reducing the time-scale for creating and solving a CFD prediction
and reducing the level of expertise required to perform a prediction.
The commercial pressure for the rapid production of CFD predictions, coupled with the
desire to reduce the risk associated with adopting a new technology led, following a
review of available techniques, to the identification of structured grids as the current
optimum methodology.
It was decided that the task of geometry definition would be entirely performed within
commercial Computer Aided Design (CAD) systems. A critical success factor for this
research was the adoption of solid models for the geometry representation. Solids
ensure consistency, and accuracy, whilst eliminating the need for the designer to undertake
difficult, and time consuming, geometry repair operations. The versatility of parametric
CAD systems were investigated on the complex geometry of a combustion system and found to be useful in reducing the overhead in altering the geometry for a
CFD prediction. Accurate and robust transfer between CAD and CFD systems was
achieved by the use of direct translators.
Restricting the geometry definition to solid models allowed a novel two stage grid generator
to be developed. In stage one an initial algebraic grid is created. This reduces
user interaction to a minimum, by the employment of a series of logical rules based on
the solid model to fill in any missing grid boundary condition data. In stage two the
quality of the grid is improved by redistributing nodes using elliptical partial differential
equations. A unique approach of improving grid quality by simultaneously smoothing
both internal and surface grids was implemented. The smoothing operation was
responsible for quality, and therefore reduced the level of grid generation expertise
required.
The successful validation of this research was demonstrated using several test cases
including a CFD prediction of a complete combustion system
Advancement in robot programming with specific reference to graphical methods
This research study is concerned with the derivation of advanced robot
programming methods. The methods include the use of proprietary
simulation modelling and design software tools for the off-line
programming of industrial robots. The study has involved the generation
of integration software to facilitate the co-operative operation of these
software tools.
The three major researcli'themes7of "ease of usage", calibration and the
integration of product design data have been followed to advance robot
programming. The "ease of usage" is concerned with enhancements in the
man-machine interface for robo t simulation systems in terms of computer
assisted solid modelling and computer assisted task generation.
Robot simulation models represent an idealised situation, and any off-line
robot programs generated from'them may contain'discrepancies which could
seriously effect thq programs' performance; Calibration techniques have
therefore been investigated as 'a method of overcoming discrepancies
between the simulation model and the real world.
At the present time, most computer aided design systems operate as
isolated islands of computer technology, whereas their product databases
should be used to support decision making processes and ultimately
facilitate the generation of machine programs. Thus the integration of
product design data has been studied as an important step towards truly
computer integrated manufacturing.
The functionality of the three areas of study have been generalised and
form the basis for recommended enhancements to future robot programming
systems
Specification-driven design
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Civil Engineering, 1990.Includes bibliographical references (leaves 144-151).by Nayel Salah el-Schafei.Ph.D