Integration Methodology for Feature-Based Modeling and Recognition

Author(s):  
Heedong Ko ◽  
Myon-woong Park ◽  
Hojin Kang ◽  
Youngtae Sohn ◽  
Hyun Suk Kim

Abstract This paper presents an integration method that constructs a feature model either by inserting new features or by recognizing features from existing geometric model. The integration is made possible by keeping the feature model data structure that is identical whether constructed by the feature insertion or the recognition. This overcomes the representational mismatch between the procedural feature-based modeling framework and the feature recognition framework. The integrated framework has been implemented as a CADCAM system for mould die manufacturing, which can interactively modify the geometric model by deleting recognized features.

Author(s):  
Xun Xu

Conventional CAD models only provide pure geometry and topology for mechanical designs such as vertices, edges, faces, simple primitives, and the relationship among them. Feature recognition is then required to interpret this low-level part information into high-level and domain-specific features such as machining features. Over the years, CAD has been undergoing fundamental changes toward the direction of feature-based design or design by features. Commercial implementations of FBD technique became available in the late 1980’s. One of the main benefits of adopting feature- based approach is the fact that features can convey and encapsulate designers’ intents in a natural way. In other words, the initial design can be synthesized quickly from the high-level entities and their relations, which a conventional CAD modeller is incapable of doing. However, such a feature-based design system, though capable of generating feature models as its end result, lacks the necessary link to a CAPP system, simply because the design features do not always carry the manufacturing information which is essential for process planning activities. This type of domain-dependent nature has been elaborated on in the previous chapter. In essence, feature recognition has become the first task of a CAPP system. It serves as an automatic and intelligent interpreter to link CAD with CAM, regardless of the CAD output being a pure geometric model or a feature model from a FBD system. To be specific, the goal of feature recognition systems is to bridge the gap between a CAD database and a CAPP system by automatically recognizing features of a part from the data stored in the CAD system, and based on the recognized features, to drive the CAPP system which produces process plans for manufacturing the part. Human interpretation of translating CAD data into technological information required by a CAPP system is thus minimized if not eliminated.


2012 ◽  
Vol 197 ◽  
pp. 750-754
Author(s):  
Yao Chen ◽  
Guo Yuan Zhang ◽  
Jun Chao Wei ◽  
Xiu Tian Yan ◽  
Miao He

Traditional engineering design and realization typically follows a sequential pattern as described by many research publications such as French, Pahl and Beitz. These design methodologies face challenges when time is essence in product realization lifecycle. In contrast, as the design process of a product evolves,this new method incrementally creates machining feature model and realizes concurrent design feature and machining feature modeling based on an algorithm developed for local feature recognition. In addition, the method accelerated the determination of the area that require to be recognized by utilizing a dynamic link list to record the changing information of topological elements, the design features of the model generated by the feature-based design, processing and feature recognition is generated through feature model.


Author(s):  
Xun Xu

Feature interaction tends to have a wide range of consequences and effects on a feature model and its applications. While these may often be intended, it is also true that feature validity can be violated, one way or another, by feature interactions (Shah & Mäntylä, 1995, Gao & Shah, 1998, Lee & Kim, 1998). They may affect the semantics of a feature, ranging from slight changes in actual parameter values, to some substantial alterations to both geometry and topology or even complete suppression of its contribution to the model shape. To certain extent, successful applications of feature recognition and feature-based techniques have been hindered by interactions among the features. Feature interaction was first studied in relation to feature recognition systems. As an alternative to feature recognition, feature-based design methodology has also become prevalent in recent years. Although a number of successful and commercially available feature-based design systems have been reported, current CAD technology is still unable to provide an effective solution for fully handling the complexity of feature interactions. Very often in a feature-based design system, the interaction between two features gives rise to an unintended feature, nullifying the one-to-one mapping from design features to manufacturing features. The resulting manufacturing feature is usually of a form that the system cannot handle or represent. Thus feature interaction resolution is equally essential for a feature-based design system (Dereli & Baykasoglu, 2004). As discussed in Chapter IV, features can be represented either as a set of faces or as a volume. The interactions between surface features are different from those occurring between volumetric features. This chapter discusses different types of interactions that arise from these two feature representation schemes and uses the interacting entities to classify them. There are two types of surface feature interactions, basic feature interaction and complex feature interaction. Three types of basic feature interactions are discussed. They are nested, overlapping, and intersecting types. Interacting patches are used to classify volumetric feature interactions. These interacting patches can be of a containing, contained, or overlapping type. The significance of feature interactions lies in their effect on the machining sequence of the features involved. This is also discussed in this chapter. When features are close to each other but do not share any geometric entities, interactions may also happen for structural reasons. This type of feature interaction can be called interaction by vicinity. The main aim of this chapter is to take a holistic approach toward feature interaction solutions. The example parts used are from the “Catalogue of the NIST (National Institute of Standards and Technology) Design, Planning and Assembly Repository” (Regli & Gaines, 1996). A case study is provided in the end of the chapter.


1994 ◽  
Vol 116 (3) ◽  
pp. 763-769 ◽  
Author(s):  
Z. Fu ◽  
A. de Pennington

It has been recognized that future intelligent design support environments need to reason about the geometry of products and to evaluate product functionality and performance against given constraints. A first step towards this goal is to provide a more robust information model which directly relates to design functionality or manufacturing characteristics, on which reasoning can be carried out. This has motivated research on feature-based modelling and reasoning. In this paper, an approach is presented to geometric reasoning based on graph grammar parsing. Our approach is presented to geometric reasoning based on graph grammar parsing. Our work combines methodologies from both design by features and feature recognition. A graph grammar is used to represent and manipulate features and geometric constraints. Geometric constraints are used within symbolical definitions of features constraints. Geometric constraints are used within symbolical definitions of features and also to define relative position and orientation of features. The graph grammar parsing is incorporated with knowledge-based inference to derive feature information and propagate constraints. This approach can be used for the transformation of feature information and to deal with feature interaction.


Author(s):  
Yong Se Kim ◽  
Eric Wang ◽  
Choong Soo Lee ◽  
Hyung Min Rho

Abstract This paper presents a feature-based method to support machining sequence planning. Precedence relations among machining operations are systematically generated based on geometric information, tolerance specifications, and machining expertise. The feature recognition method using Alternating Sum of Volumes With Partitioning (ASVP) Decomposition is applied to obtain a Form Feature Decomposition (FFD) of a part model. Form features are classified into a taxonomy of atomic machining features, to which machining process information has been associated. Geometry-based precedence relations between features are systematically generated using the face dependency information obtained by ASVP Decomposition and the features’ associated machining process information. Multiple sets of precedence relations are generated as alternative precedence trees, based on the feature types and machining process considerations. These precedence trees are further enhanced with precedence relations from tolerance specifications and machining expertise. Machining sequence planning is performed for each of these precedence trees, applying a matrix-based method to reduce the search space while minimizing the number of tool changes. The precedence trees may then be evaluated based on machining cost and other criteria. The precedence reasoning module and operation sequence planning module are currently being implemented within a comprehensive Computer-Aided Process Planning system.


Author(s):  
Shyam V. Narayan ◽  
Zhi-Kui Ling

Abstract Feature based modeling has been used as a means to bridge the gap between engineering design and manufacturing. Features can represent an artifact with higher level entities which relate directly to its design functionalities and manufacturing characteristics, such as surface finish, manufacturability, fits, tolerance etc. In this study, a heuristic based feature recognition approach is proposed by using the graph representation of a design. The process consists of two steps: subgraph construction, and subgraph to feature identification. In this study, the subgraph construction is accomplished by using a set of heuristic rules. The process of subgraph to feature identification is carried out with a set of integers and characters which represent the geometric, topological, and semantic characteristics of the corresponding feature. This feature recognition scheme is used for the identification of machine features in a design.


Author(s):  
Jae Yeol Lee ◽  
Hyun Kim ◽  
Sung-Bae Han

Abstract Network and Internet technology open up another domain for building future CAD/CAM environments. The environment will be global, network-centric, and spatially distributed. In this paper, we present Web-enabled feature-based modeling in a distributed design environment. The presented approach combines the current feature-based modeling technique with distributed computing and communication technology for supporting product modeling and collaborative design activities over the network. The approach is implemented in a client/server architecture, in which Web-enabled feature modeling clients, neutral feature model server, and other applications communicate with one another via a standard communication protocol. The paper discusses how the neutral feature model supports multiple views and maintains naming consistency between geometric entities of the server and clients as the user edits the part in a client. Moreover, it explains how to minimize the network delay between the server and client according to dynamic feature modeling operations.


Author(s):  
Yan Wang

Current CAD systems only support interactive geometry generation, which is not ideal for distributed engineering services in enterprise-to-enterprise collaboration with a generic thin-client service-oriented architecture. This chapter presents a new feature-based modeling mechanism, document-driven design, to enable batch mode geometry construction for distributed CAD systems. A semantic feature model is developed to represent informative and communicative design intent. Feature semantics is explicitly captured as trinary relation, which provides good extensibility and prevents semantics loss. Data interoperability between domains is enhanced by schema mapping and multi-resolution semantics. This mechanism aims to enable asynchronous communication in distributed CAD environments with ease of design alternative evaluation and reuse, and improved system throughput and utilization


Symmetry ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1075
Author(s):  
Md Rashedul Islam ◽  
Md Amiruzzaman ◽  
Shahriar Nasim ◽  
Jungpil Shin

This article concerns smoke detection in the early stages of a fire. Using the computer-aided system, the efficient and early detection of smoke may stop a massive fire incident. Without considering the multiple moving objects on background and smoke particles analysis (i.e., pattern recognition), smoke detection models show suboptimal performance. To address this, this paper proposes a hybrid smoke segmentation and an efficient symmetrical simulation model of dynamic smoke to extract a smoke growth feature based on temporal frames from a video. In this model, smoke is segmented from the multi-moving object on the complex background using the Gaussian’s Mixture Model (GMM) and HSV (hue-saturation-value) color segmentation to encounter the candidate smoke and non-smoke regions in the preprocessing stage. The preprocessed temporal frames with moving smoke are analyzed by the dynamic smoke growth analysis and spatial-temporal frame energy feature extraction model. In dynamic smoke growth analysis, the temporal frames are segmented in blocks and the smoke growth representations are formulated from corresponding blocks. Finally, the classifier was trained using the extracted features to classify and detect smoke using a Radial Basis Function (RBF) non-linear Gaussian kernel-based binary Support Vector Machine (SVM). For validating the proposed smoke detection model, multi-conditional video clips are used. The experimental results suggest that the proposed model outperforms state-of-the-art algorithms.


Author(s):  
Yan Wang

Current CAD systems only support interactive geometry generation, which is not ideal for distributed engineering services in enterprise-to-enterprise collaboration with a generic thin-client service-oriented architecture. This chapter presents a new feature-based modeling mechanism, document-driven design, to enable batch mode geometry construction for distributed CAD systems. A semantic feature model is developed to represent informative and communicative design intent. Feature semantics is explicitly captured as trinary relation, which provides good extensibility and prevents semantics loss. Data interoperability between domains is enhanced by schema mapping and multi-resolution semantics. This mechanism aims to enable asynchronous communication in distributed CAD environments with ease of design alternative evaluation and reuse, and improved system throughput and utilization


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