William C. Regli

Manufacturing feature recognition from solid models: a status report

The field of solid modeling has developed a variety of techniques for unambiguous representations of three-dimensional objects. Feature recognition is a sub-discipline of solid modeling that focuses on the design and implementation of algorithms for detecting manufacturing information from solid models produced by computer-aided design (CAD) systems. Examples of this manufacturing information include features such as holes, slots, pockets and other shapes that can be created on modern computer numerically controlled machining systems. Automated feature recognition has been an active research area in solid modeling for many years and is considered to be a critical component for integration of CAD and computer-aided manufacturing. The paper gives an overview of the state-of-the-art in feature recognition research. Rather than giving an exhaustive survey, we focus on the three of the major algorithmic approaches for feature recognition: graph-based algorithms, volumetric decomposition techniques, and hint-based geometric reasoning. For each approach, we present a detailed description of the algorithms being employed along with some assessments of the technology. We conclude by outlining important open research and development issues.

A Survey of Design Rationale Systems: Approaches, Representation, Capture and Retrieval

This paper provides a survey on recent research in the area of design rationale. The study of design rationale spans a number of diverse disciplines, touching on concepts from research communities in mechanical design, software engineering, artificial intelligence, civil engineering, computer-supported cooperative work, and human-factors and human-computer interaction research. We focus this survey on prototype design rationale systems for these application domains, and put forward several major criteria with which to describe and classify design rationale systems, including argumentation-based, descriptive, process-based approaches. Further, we attempt to abstract the place of systems and tools for design rationale capture and retrieval in the context of contemporary knowledge-based engineering and Computer-Aided Design (CAD) tools. This survey is structured around classes of fundamentally different approaches, their representation schema, their capture methods and retrieval techniques. A number of recent design rationale systems, including JANUS, COMET, ADD. REMAP, HOS, PHIDIAS, DRIVE and IBIS are analysed. We conclude with an assessment of current state-of-the-art and a discussion of critical open research issues.

The role of knowledge in next-generation product development systems

Information technology has played an increasingly important role in engineering productdevelopment. Its influence over the past decade has been accelerating and its impact inthe coming decade will undoubtedly be immense. This paper surveys several researchareas relating to knowledge representation, capture and retrieval, which will have agrowing influence on product development. Each of these areas could, on its own, providesufficient material for an entire survey paper. Unlike traditional survey papers, this paperdoes not attempt to provide a comprehensive review of a field of research from its incep-tion to the present. Rather, this paper aims to touch on a representative selection of recentdevelopments in these influential technical areas. The paper provides perspectives into thekinds of technologies that are emerging from rapidly expanding fields of research, anddiscusses challenges that must be overcome to enable transition of these technologies intoindustry practice to support the next generation of product development software tools.@DOI: 10.1115/1.1344238#

Managing digital libraries for computer-aided design

Abstract This paper describes our initial efforts to deploy a digital library to support computer-aided collaborative design. At present, this experimental testbed, The Engineering Design Knowledge Repository, is an effort to collect and archive public domain engineering data for use by researchers and engineering professionals. We envision this effort expanding to facilitate collaboration and process archival for distributed design and manufacturing teams. CAD knowledge-bases are vital to engineers, who search through vast amounts of corporate legacy data and navigate on-line catalogs to retrieve precisely the right components for assembly into new products. This research attempts to begin addressing the critical need for improved computational methods for reasoning about complex geometric and engineering information. In particular, we focus on archival and reuse of design and manufacturing data for mechatronic systems. This paper presents a description of the research problems, an overview of the initial architecture of the testbed and a description of some of our preliminary results on conceptual design and design retrieval.

Automated manufacturability analysis: a survey

In the market-place of the 21st century, there is no place for traditional ‘over-the-wall’ communications between design and manufacturing. In order to ‘design it right the very first time’, designers must ensure that their products are both functional and easy to manufacture. Software tools have had some successes in reducing the barriers between design and manufacturing. Manufacturability analysis systems are emerging as one such tool — enabling identification of potential manufacturing problems during the design phase and providing suggestions to designers on how to eliminate them.In this paper, we provide a survey of current state-of-the-art automated manufacturability analysis. We present the historical context in which this area has emerged and outline characteristics to compare and classify various systems. We describe the two dominant approaches to automated manufacturability analysis and overview representative systems based on their application domain. We describe support tools that enhance the effectiveness of manufacturability analysis systems. Finally, we attempt to expose some of the existing research challenges and future directions.

DAMLJessKB: a tool for reasoning with the Semantic Web

Fully realizing the Semantic Web vision will require practical tools. We believe that DAMLJessKB is one such tool. As more and more Web sites, network services, databases, and knowledge bases look to DAML as a de facto representation syntax, we hope that DAMLJessKB will become one in a suite of tools that let users truly leverage the shared semantics.

Machining feature-based comparisons of mechanical parts

Solid models are the critical data elements in modern computer-aided design (CAD) environments, describing the shape and form of manufactured artifacts. Their growing ubiquity has created new problems in how to effectively manage the many models that are now stored in the digital libraries of large design and manufacturing enterprises. Existing techniques from the engineering literature and from industrial practice, such as group technology, rely on human-supervised encoding and classification, while techniques from the multimedia database and computer graphics/vision communities often ignore the manufacturing attributes most significant in the classification of models. This paper presents our approach to the manufacturing similarly assessment of solid models of mechanical parts based on machining features. Our technical approach is three-fold: (1) perform machining feature extraction to map the solid model to a set of STEP AP 224 machining features; (2) construct a model dependency graph from the set of machining features; and (3) find the nearest neighbors to the query graph using an iterative improvement search across a database of other models. We also present empirical experiments to validate our approach using our testbed, the National Design Repository (). The contribution of this research is the first fully automated technique for machining feature-based comparisons of mechanical artifacts. We believe that this work can lead to radical changes in the way in which design data is managed in modern engineering enterprises.

Feature-based similarity assessment of solid models

This paper presents our initial efforts to develop a systematic approach for assessing the similarity of solid models based on how they will be manufactured. The goal of this work is to develop methods that, given a solid model representing the design of a new product, query a product information database (of solid models, associated manufacturing plans, and related attributes) and identify existing designs with manufacturing plans similar to some reasonable plan for the new design—or useful as a starting point for creation of a new plan for the new design. Our approach is based on the automatic generation (from CAD models) of graph structures that contain manufacturing information (in the form of manufacturing features). We are developing ways to measure similarity among these graph structures, so that given the graph structures corresponding to two different designs, we can tell how similar or different they are. The similarity measure will be used as a basis for indexing and retrieving similar designs from databases. An implementation of our approach is discussed. We believe our work is a first step in producing computergeneratable and computer-interpretable similarity assessment techniques that will be useful for applications such as variThis work is supported in part by NSF grants NSF EEC 94-02384, IRI9306580, and DDM-9201779, by ARPA grant DABT63-95-C-0037 and ONR grant DABT63-95-C-0037, and by in-kind contributions from Spatial Technologies and Bentley Systems. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the funders. Current position: Visiting Research Engineer, Engineering Design Research Center, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213-3980 ant and hybrid variant/generative process planning systems, indexing schemes for large part inventories, access methods for “smart catalogs,” and for performing component searches through product catalogs and on the Internet.

REEB GRAPH BASED SHAPE RETRIEVAL FOR CAD

Our recent work has described a framework for matching solid of mechanical artifacts models based on scale-space feature decomposition. In this work we adopt a method of comparing solid models based on Multiresolutional Reeb Graphs (MRG) similarity computations. This method was originally proposed by Hilaga et al. in [1]. Reeb Graph technique applies MRG structure to comparisons of approximate models found in the graphics community, such as polygonal meshes, faceted representation and Virtual Reality Modeling Language (VRML) models. First, we provide a brief review of shape matching using Multiresolutional Reeb Graphs and present an approach to matching solid models. Second, we show the performance of the Reeb Graph technique when handling primitive CAD models, such as cubes and spheres; then we perform experiments with more complex models, such as LEGO models and mechanical parts, and we discuss Reeb Graph technique’s performance on complex CAD models. Third, we emphasize several problems with the existing technique. Finally, we conclude with discussion of future work.

Role-Based Viewing Envelopes for Information Protection in Collaborative Modeling

Information security and assurance are new frontiers for collaborative design. In this context, information assurance (IA) refers to methodologies to protect engineering information by ensuring its availability, confidentiality, integrity, non-repudiation, authentication, access control, etc. In collaborative design, IA techniques are needed to protect intellectual property, establish security privileges and create “need to know” protections on critical features. Aside from 3D watermarking, research on how to provide IA to distributed collaborative engineering teams is largely non-existent. This paper provides a framework for information assurance within collaborative design, based on a technique we call role-based viewing, in which information security relationships are roles assigned to users based on their permissions and privileges. Role-based viewing is achieved through integration of multi-resolution geometry and with the security model. In this way, 3D models are geometrically partitioned, and the partitioning is used to create multi-resolution mesh hierarchies that obscure, obfuscate, or remove sensitive material from the view of users without appropriate permissions. This approach is the basis for our prototype system FACADE (the Framework for Access-control in Computer-Aided Design Environments), a synchronous, multi-user collaborative modeling environment. In FACADE, groups of users worked in a shared 3D modeling environment in which each user viewing and modeling privileges are managed by a central access control mechanism. In this manner, individual actors see only the data they are allowed to see, at the level of detailed they are permitted to see it.