Conceptual Design for Assembly

This paper presents an approach to support computer-aided conceptual design of mechatronic assemblies in a collaborative, multi-user environment. We describe a system, Conceptual Understanding and Prototyping (CUP), that allows a team of design engineers, collaborating over the Internet, to develop a high-level structure-function-behavior (S-B-F) description of an assembly in a VRML-based virtual environment. Our goal is to enable users to navigate intricate product data management (PDM) and case-based design knowledge-bases, providing the ability to perform design at conceptual level and have intelligent CAD tools that can draw on details from large repositories of previously archived designs. This work furthers research efforts in computer support for collaborative design activities—drawing on work in Human-Computer Interaction (HCI) and Computer Supported Collaborative Work (CSCW). We envision CUP to be a network interface to next-generation of engineering PDM systems and CAD databases. We are deploying CUP as query interface to the National Design Repository (http://repos.mcs.drexel.edu). This will enable CAD users to interrogate large quantities of legacy data and identify artifacts with structural and functional similarities—allowing designers to perform case-based and variant design. 1Present Address: Center for Advanced Computing Research, Mailstop 15879, 1200 E. California Blvd. California Institute of Technology, Pasadena CA 91125 USA. Email: [email protected] 2Web: http://www.mcs.drexel.edu/ wregli; Email: [email protected]. INTRODUCTION It is conservatively estimated that more than 75% of engineering design activity is case-based design (27). An engineer or team of engineers, when posed with a new problem, synthesize solutions through a combination of analogical reasoning, experience, and search through design information archived in the corporate files and described in product and component catalogs. Over the past decade, 3D Solid Modeling has become a critical element of the product realization process—leading to successive generations of increasingly robust software tools for detailed design and engineering analysis. The goal of this research is to develop novel techniques and tools to support Conceptual Design. Conceptual Design is the initial phase of product development, when product development teams (consisting of design engineers, manufacturing engineers, marketing and management personnel) determine the essence of a new product. As has been often documented, and shown in Figure 1 (a), the design phase of the product realization process has a tremendous impact on the life-cycle cost of a product. However, as illustrated in Figure 1 (b), there are few tools to support 3D conceptual design. During Conceptual Design, teams of designers may begin to develop a new product by sketching its general shape on paper. This “back of the envelope” approach is key aspect of the creative thought process—once completed, one has a clearer idea of what is being created and can proceed to drafting or CAD activity. Previous research in areas such as conceptual design of graphical user interfaces (GUIs) (13; 18) and cased-based reasoning and case-based design (26; 25; 20; 10; 1) are relevant to our efforts. For example, much of the work in case-based reasoning has focused on developing symbolic representations for engineering knowledge about function and behavior, as well as algorithms for indexing, retrieving, and adapting design cases stored with these representations.