A List of Responders
Virtual Manufacturing Background Project
Thomas_De_Fazio@qmlink.draper.com
Abstract of Current Work: Exploratory research into a design-specific approach to Design For Assembly (DFA) in the Concurrent Engineering (CE) environment: The research addresses DFA for dense and complicated mechanical assemblies, for which it is felt that current DFA methods are inadequate. Currently, DFA comprises generic checklists, is based on experience with a wide range of products, and is effective if a product functional design engineer has substantial design, material, and process freedoms. Our recent successful product-specific DFA efforts in industry have addressed concurrent engineering of automotive power-transmission units and other dense, complicated mechanical assemblies, with both tight design constraints and dimensional tolerances. These efforts resulted in successful paradigms that would not be suggested by current DFA guidance, and some that would run counter to, or even violate current DFA guidance. Objectives of the research are to explore this realm in a systematic way, and to develop more rational bases for collaboration of product design engineers concerned with function, and production engineers c! oncerned with assembly, in the realm of concurrent engineering of dense, complicated, or tightly specified and constrained mechanical assemblies. The research uses the logic of Assembly Sequence Analysis (ASA) as structure, tool, and a basis for measure of results. The use of ASA differentiates our work from current DFA means. ASA is a design-specific logical means of relating product design geometry to assembly choices. Both design geometry and assembly choices offer new metrics and support conventional ones: parts-count, assembly-line topology, count of non-productive assembly tasks, for example. To date ASA has been used in one direction; from product design to assembly choice. Part of the work is to explore possibilities of using ASA in the other direction; to flag awkward assembly constraints, and to suggest areas for design reconsideration. Among the implied research questions are: How may one use ASA to look back from assembly sequence to design geometry? What useful information may move from assembly consideration to product design? What are means for postponing imposition of assembly constraints during preliminary design? Our current and recent work seems relevant to your categories 1, 3, 4, 6, 7, 8(?), 10, 12. That is, our work seems, more or less, to read on the descriptions of the above-cited categories. List of relevant references: T. L. De Fazio, & D. E. Whitney, "Simplified Generation of All Assembly Sequences," IEEE Jnl. Robotics & Automation, Vol. RA-3, No. 6, pp. 640-658, Dec. 1987. D. F. Baldwin & al., "An Integrated Computer Aid for Generating & Evaluating Assembly Sequences for Mechanical Products," IEEE Jnl. Robotics & Automation, Vol. 7, No. 1, 78-94, Feb. 1991. T. L. De Fazio & D. E. Whitney, "Computer Aids for Finding and Evaluating Assembly Sequences: What is now Done, and what are Some Gaps in Current Application," Invited Paper, Workshop S1, 1992 IEEE Int'l Conf. on Robotics & Automation, Nice, France, May 1992. T. L. De Fazio & al., "A Prototype of Feature-Based Design for Assembly," Trans. ASME, J. of Mechanical Design, Vol. 115, No. 4, Dec. 1993. D. E. Whitney, & al., "Problems and Issues in Design and Manufacture of Complex Electro-Mechanical Systems," Final Report for ARPA Contract No. N00030-91-G-0110, Jan. 1994. J. L. Nevins & D. E. Whitney, Ed's, & T. L. De Fazio, & al., "Concurrent Design of Products and Processes: A Strategy for the Next Generation in Manufacturing." McGraw-Hill, New York, 1989. T. E. Abell & al., "Computer Aids for Finding, Representing, Choosing Amongst, and Evaluating the Assembly Sequences of Mechanical Products," (Ch. 15) in "Computer-aided Mechanical Assembly Planning," L. S. Homem de Mello & S. Lee, Editors. Kluwer Academic Publishers, June 1991.
A List of Responders
Virtual Manufacturing Background Project
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