GENERATIVE CAPP APPROACH BASED ON RESOURCE MODEL AND FEATURE MODEL

ＧＥＮＥＲＡＴＩＶＥＣＡＰＰＡＰＰＲＯＡＣＨＢＡＳＥＤＯＮＲＥＳＯＵＲＣＥＭＯＤＥＬＡＮＤＦＥＡＴＵＲＥＭＯＤＥＬ＊ＮｉＱｉａｎｆｕ（倪前富）ＤａｉＧｕｏｈｏｎｇ（戴国洪）ＹａｎＪｕｎｑｉ（严隽琪）ＭａＤｅｎｇｚｈｅ（马登哲）（Ｄｅｐｔ．ｏｆＭｅｃｈ...

A Feature-Based Parametric Product Modeling System in CIMS Environment

This paper proposes an approach of developing the feature based parametric product modeling system which is suitable for integrated engineering design in CIMS environment.The architecture of ZD--MCADII and the characteristics of its each module are introduced in detail. ZD--MCADII’s product data is managed by an object--oriented database management system OSCAR, and the product model is built according to the standard STEP. The product design is established on a unified product model, and all the product data are globally associated in ZD--MCADII. ZD--MCADII provides various design features to facilitate the product design, and supports the integrity of CAD, CAPP and CAM.

DIMENSION VARIATION OF FEATURE-BASED MODEL BY OPERATING DIRECTLY ON B-REP

ＤＩＭＥＮＳＩＯＮＶＡＲＩＡＴＩＯＮＯＦＦＥＡＴＵＲＥ┐ＢＡＳＥＤＭＯＤＥＬＢＹＯＰＥＲＡＴＩＮＧＤＩＲＥＣＴＬＹＯＮＢ┐ＲＥＰＨＥＸｉａｏｚｈａｏ（何小朝），ＷＡＮＧＺｏｎｇｙａｎ（王宗彦）ＰＥＮＧＷｅｉ（彭维），ＺＨＡＮＧＴｉｅｃｈａｎｇ（张铁昌...

Feature-based and objectoriented product information model for welding structure

Product information model for welding structure plays an important role for the integration of welding CAD/CAPP/CAM. However, existing CAD modeling systems are not capable of providing enough information for subsequent manufacturing activities such as CAPP and CAM. A new design approach using feature technique and object oriented programming method is put forward in this paper in order to create the product information model of welding structure. With this approach, the product information model is able to effectively support computer aided welding process planning, fixturing, assembling, path planning of welding robot and other manufacturing activities. The feature classification and representing scheme of welding structure are discussed. A prototype system is developed based on feature and object oriented programming. Its structure and functions are given in detail.

A FORMAL REPRESENTATION FOR FEATURE-BASED DESIGN

Feature based design has been regarded as a promising approach for CAD/CAM integration.This paper aims to establish a domain independent representation formalism for feature based design in three aspects: formal representation,design process model and design algorithm.The implementing scheme and formal description of feature taxonomy,feature operator,feature model validation and feature transformation are given in the paper.The feature based design process model suited for either sequencial or concurrent engineering is proposed and its application to product structural design and process plan design is presented. Some general design algorithms for developing feature based design system are also addressed.The proposed scheme provides a formal methodology elementary for feature based design system development and operation in a structural way.

CONSTRUCTION AND MODIFICATION OF FLEXIBLE FEATURE-BASED MODELS

A new approach is proposed to generate flexible featrure based models (FFBM), which can be modified dynamically. BRep/CSFG/FRG hybrid scheme is used to describe FFBM, in which BRep explicitly defines the model, CSFG (Constructive solid feature geometry) tree records the feature based modelling procedure and FRG (Feature relation graph) reflects different knids of relationship among features. Topological operators with local retrievability are designed to implement feature addition, which is traced by topological operation list (TOL) in detail. As a result, FFBM can be modified directly in the system database. Related features' chain reactions and variable topologies are supported in design modification, after which the product information adhering on features will not be lost. Further, a feature can be modified as rapidly as it was added.

A FEATURE－BASED PRODUCT MODELLING SYSTEM ON PC （CASE STUDY OF PARTS DESIGN FOR PRESS MACHINE）

This article reports on the design and implementation of feature modelling system for the CAPP of rotational symmetric components. The work deals with design by features, feature parts database design, and parts information modelling techniques realized in Personal Computer. The modular software provides utilities such as interactive component synthesis, dimensioning, tolerancing and graphical display.

3D Model Retrieval Method Based on Affinity Propagation Clustering

In order to improve the accuracy and efficiency of 3D model retrieval,the method based on affinity propagation clustering algorithm is proposed. Firstly,projection ray-based method is proposed to improve the feature extraction efficiency of 3D models. Based on the relationship between model and its projection,the intersection in 3D space is transformed into intersection in 2D space,which reduces the number of intersection and improves the efficiency of the extraction algorithm. In feature extraction,multi-layer spheres method is analyzed. The two-layer spheres method makes the feature vector more accurate and improves retrieval precision. Secondly,Semi-supervised Affinity Propagation ( S-AP) clustering is utilized because it can be applied to different cluster structures. The S-AP algorithm is adopted to find the center models and then the center model collection is built. During retrieval process,the collection is utilized to classify the query model into corresponding model base and then the most similar model is retrieved in the model base. Finally,75 sample models from Princeton library are selected to do the experiment and then 36 models are used for retrieval test. The results validate that the proposed method outperforms the original method and the retrieval precision and recall ratios are improved effectively.

Feature Modeling and Variability Modeling Syntactic Notation Comparison and Mapping

Feature Model (FM) became an important role in Software Product Line Engineering (SPLE) field. Many approaches have been introduced since the original FM came up with Feature Oriented Domain Analysis (FODA) introduced by Kang in 1990. The main purpose of FM is used for commonality and variability analysis in domain engineering, to optimize the reusable aspect of software features or components. Cardinality-based Feature Model (CBFM) is one extension of original FM, which integrates several notations of other extensions. In CBFM, feature model defined as hierarchy of feature, with each of feature has a cardinality. The other notation to express variability within SPLE is Orthogonal Variability Model (OVM). At the other hand, OMG as standard organization makes an effort to build standard generic language to express the commonality and variability in SPL field, by initiate Common Variability Language (CVL). This paper reports the comparison and mapping of FODA, CBFM and OVM to CVL where need to be explored first to define meta model mapping of these several approaches. Furthermore, the comparison and mapping of those approaches are discussed in term of R3ST (read as “REST”) software feature model as the case study.

The Feature-Based a New Object Coding Approach for Prismatic Parts at the Part Modeling

Use of features in order to achieve the integration of design and manufacture has been considered to be a key factor recent years. Features such as manufacturing properties form the workpiece. Features are structured systematically through object oriented modeling. This article explains an object coding method developed for prismatic workpieces and the use of that method in process planning. Features have been determined and modeled as objects. Features have been coded according to their types and locations on the workpiece in this given method. Feature codings have been seen to be very advantageous in process planning.

Coding of Topological Entities in Feature-Based Parametric Modeling System

How to identify topological entities during rebuilding features is a critical problem in Feature-Based Parametric Modeling System (FBPMS). In the article, authors proposes a new coding approach to distinguish different entities. The coding mechanism is expatiated,and some typical examples are presented. At last, the algorithm of decoding is put forward based on set theory.

A Feature Definition Hierarchy for Supporting Design Process

The adaptability of features definition to applications is an essential condition for implementing feature based design. This paper makes attempt to present a hierarchical definition structure of features. The proposed scheme divides feature definition into application level, form level and geometric level, and provides links between different levels with feature semantics interpretation and enhanced geometric face adjacent graph. respectively. The results not only enable feature definition to abate from the specific dependence and become more extensive, but also provide a theoretical foundation for establishing the concurrent feature based design process model.

A Method for Head-shoulder Segmentation and Human Facial Feature Positioning

ＡＭｅｔｈｏｄｆｏｒＨｅａｄｓｈｏｕｌｄｅｒＳｅｇｍｅｎｔａｔｉｏｎａｎｄＨｕｍａｎＦａｃｉａｌＦｅａｔｕｒｅＰｏｓｉｔｉｏｎｉｎｇＨｕＴｉａｎｊｉａｎＣａｉＤｅｊｕｎＤｅｐａｒｔｍｅｎｔｏｆＥｌｅｃｔｒｉｃａｌａｎｄＩｎｆｏｒｍａｔｉｏｎＥｎｇｉ...

Entity Burst Discriminative Model for Cumulative Citation Recommendation

Knowledge base acceleration-cumulative citation recommendation(KBA-CCR)aims to detect citation-worthiness documents from a chronological stream corpus for a set of target entities in a knowledge base.Most previous works only consider a number of semantic features between documents and target entities in the knowledge base,and then use powerful machine learning approaches such as logistic regression to classify relevant documents and non-relevant documents.However,the burst activities of an entity have been proved to be a significant signal to predict potential citations.In this paper,an entity burst discriminative model(EBDM)is presented to substantially exploit such burst features.The EBDM presents a new temporal representation based on the burst features,which can capture both temporal and semantic correlations between entities and documents.Meanwhile,in contrast to the bag-of-words model,the EBDM can significantly decrease the number of non-zero entries of feature vectors.An extensive set of experiments were conducted on the TREC-KBA-2012 dataset.The results show that the EBDM outperforms the performance of the state-of-the-art models.

GS-CAD98: A Windows-Based Product Modeling System

GS CAD98, a feature based parametric product modeling system that facilitates dexterous manipulation of mechanical design is presented. The system allows designer to make substantial changes to a part or assembly at any time during the design process. User can develop his/her own special CAD system with the help of GS CADS98s macro language PPL or kernel routines. Furthermore, it is flexible enough to exchange product data with other CAD/CAE/CAM systems according to neutral file. GS CAD98s product data is managed by an object oriented database management system called OSCAR, and the product model is built according to the standard STEP. As a result of the unified product model, all product data are globally associated in GS CAD98. GS CAD98 supports the integration with CAPP, CAM and PDM.

Feature Technology in Product Modeling

A unified feature definition is proposed.Feature is form-concentrated,and can be used to model product func- tionalities,assembly relations,and part geometries.The feature model is given and a feature classification is introduced including functional,assembly,structural,and manufacturing features.A prototype modeling system is developed in Pro/ENGINEER that can define the assembly and user-defined form features.

CASE STUDY OF CAD/CAPP INTEGRATION FOR ROTATIONAL PARTS

A design-with-feature system of rotational parts has been linked with a process planner bydirect file transfer. Although both systems take the feature-based approach, inconsistency exists inthe way of defining correlation between adjacent form features, the representation schema of featurehierarchies, the way of dimensioning and tolerancing etc. Such discrepancies are outlined in this pa-per and expected to be taken into consideration in working out an improved Integrated Product Infor-mation Model for the CIM and concurrent engineering environment.

A Method for Integrating Modelling with Decomposition

To make a bridge between engineering information and the geometry of product model, it is crucial to manipulate product model with form features containing high-level engineering information. In recent years much research has been undergone in the area of form feature recognition. In many previous works form feature recognition usually starts with a finished CAD model. The shape of a finished model consisted of a number of features is much more complex than that of a single feature. This problem was ignored by many previous works. In this paper a completely context-independed method is provided. In designing the part,. the feature-based model is decomposed into a quasi-feature-based one that can be converted into various context-oriented feature models required by specific context-oriented applications. In order to decompose features into quasi-features which have convex volumes, this paper proposes a method which integrates modelling with decomposition.

CAPP 专家系统中工艺决策的实现

结合杭州叉车总厂ＨＣ—ＣＡＰＰ工程应用项目，构造了一种基于知识推理的创成式ＣＡＰＰ专家系统模型。原型系统中，工艺设计、机床选择、刀具选择、夹具等知识库的管理独立于推理机，不仅为知识库管理、推理机改进、零件特征排序、知识库系统移植等提供方便，而且系统采用ＲＤＢ（关系型数据库管理）技术、ＯＤＢＣ（开放式数据库互连）技术，为ＣＡＰＰ、ＣＡＤ、ＮＣＰ（数控编程）子系统内部不同模式数据交换提供接口。