Extracting Alternative Machining Features: Al Algorithmic Approach

Automated recognition of features from CAD models has been attempted for a wide range of application domains. In this paper we address the problem of representing and recognizing the complete class of features in alternative interpretations for a given design. We present a formalism for representing feature- based design alternatives and a methodology for recognizing a class of machinable features. Our approach handles a class of volumetric features that describe material removal volumes made by operations on the three-axis vertical machining centers including: drilling, pocket-, slot-, and face-miling, chamfering, filleting, and blended surfaces. Our approach recognizes intersecting features, and is complete over all features in our class, i.e. for any given part, the algorithm produces a set containing all features in our class that correspond to possible operations for machining that part. This property is of particular significance in applications where consideration of different manufacturing alternatives is crucial. In addition, we have shown that the algorithms are, in the worst-case, euqdratic in the number solid modeling operations. This approach employs a class of machinable features expressible as MRSEVs ( a STEP- based library of machining features). An implementation of these algorithms has been done using the ACISsolid modeler and the NIH C++ class library

Automated Manufacturability Analysis: A Survey

In the marketplace 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 in 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.<P

A Survey of Automated Feature Recognition Techniques

Automated feature recognition has been attempted through many methodologies for a wide range of application domains. This survey focuses on its use for geometric reasoning problems in mechanical engineering. Many of these methods are greatly limited in scope. Often they perform on a restricted class of objects with confining feature definitions. Furthermore, problems with interactions between features can render objects unrecognizable. This survey presents an overview of many of the works in this area. Included are descriptions of the approaches and an analysis of their abilities to provide a definition for and solution to the general problem of recognizing features from a solid model. It is hoped that previous research will provide the guidance for the development of a feature recognition system that is complete over a mathematically definable set of objects

Geometric Algorithms for Recognition of Features from Solid Models

Collaborative engineering has expanded the scope of traditional engineering design to include the identification and elimination of problems in the manufacturing process. Manufacturing features and feature-based representations have become an integral part of research on manufacturing systems, due to their ability to model the correspondence between design information and manufacturing activities. One necessary component of an integrated Computer Aided Design/Computer Aided Manufacturing (CAD/CAM) environment is a tool to automatically recognize manufacturing features from a CAD or solid model. In this thesis we present a methodology for recognizing a class of machining features and for addressing the computational issues involved in building tractable and scalable solutions for automated feature recognition. This approach is described for a class of volumetric features based on material removal volumes produced by operations on 3-axis vertical machining centers. A computational framework is developed for representing different types of common machining features and specifying the recognition problem. Based on this framework, novel serial and multi-processor recognition algorithms are described and analyzed with respect to their completeness and complexity. The goal of this dissertation is to advance the understanding of the basic computational issues that arise in feature recognition from solid models of mechanical artifacts and to facilitate development of effective and efficient systems that can scale to address industrial problems.<P

Managing digital libraries for computer-aided design

This paper describes our initial efforts to deploy a digital library to support computer-aided collaborative design. At present, this experimental testbed, The EngineeringDesign Knowledge Repository, is an effort to collect and archive public domain engineering data for use by researchers and engineering professionals. We envision thiseffort 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 rightcomponents for assembly into new products. This research attempts to begin addressing the critical need for improved computational methods for reasoning about complexgeometric and engineering information. In particular, we focus on archival and reuse of design and manufacturing data for mechatronic systems. This paper presents adescription 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 anddesign retrieval