Integration of Feature Based Design and Feature Recognition

Author(s):  
JungHyun Han ◽  
Aristides A. G. Requicha

Abstract Process planning for machined parts typically requires that a part be described through machining features such as holes, slots and pockets. This paper presents a novel feature finder, which automatically generates a part interpretation in terms of machining features, by utilizing information from a variety of sources such as nominal geometry, tolerances and attributes, and design features. The feature finder strives to produce a desirable interpretation of the part as quickly as possible. If this interpretation is judged unacceptable by a process planner, alternatives can be generated on demand. The feature finder uses a hint-based approach, and combines artificial intelligence techniques, such as blackboard architecture and uncertain reasoning, with the geometric completion procedures first introduced in the OOFF system previously developed at USC.

Author(s):  
Xu Zhang ◽  
Chao Liang ◽  
Tiedong Si ◽  
Ding Ding

In process planning of machined part, machining feature recognition and representation, feature-based generative process planning, and the process intermediate model generation are the key issues. While many research results have been achieved in recent years, the complete modeling of machining features, process operations, and the 3D models in process planning are still need further research to make the techniques to be applied in practical CAPP systems. In this paper, a machining feature definition and classification method is proposed for the purpose of process planning based on 3D model. Machining features are defined as the surfaces formed by a serious of machining operation. The classification scheme of machining features is proposed for the purpose of feature recognition, feature-based machining operations reasoning, and knowledge representation. Recognized from B-Rep representation of design model, machining features are represented by adjacent graph and organized by feature relations. The machining process plan is modeled as operations and steps, which is the combination and sequencing of machining feature’s process steps. The process intermediate models (PIM) are important for process documentation, analysis and NC programming. An automatic PIM generation approach is proposed using local operations directly on B-Rep model. The proposed data structure and algorithm is adopted in the development of CAPP tool on solid modeler ACIS/HOOPS.


Author(s):  
Nicholas J. Yannoulakis ◽  
Sanjay B. Joshi ◽  
Richard A. Wysk

Abstract The increasing application of CAE has lead to the evolution of Concurrent Engineering — a philosophy that prescribes simultaneous consideration of the life-cycle design issues of a product. The Concurrent Engineering (CE) systems that have been developed so far have relied on knowledge bases and qualitative evaluations of a part’s manufacturability for feedback to the design engineer. This paper describes a method for developing quantitative indicators of manufacturability. Feature-based design and estimation of machining parameters are used for ascertaining a part’s manufacturing requirements. These requirements are then combined into indices which lead the designer to features that must be redesigned for improved manufacturability. This method is illustrated on a system for rotational machined parts: the Manufacturability Evaluation and Improvement System (MEIS).


Author(s):  
C. Jebaraj ◽  
D. Kingsly Jeba Singh

This work explains the development of an integrated modeler, which is applied in the design-to-manufacturing stages of manufacturing processes namely machining, sheet metal processing and forging. Its system architecture is broadly divided into four modules namely, Feature Based Design (FBD), Virtual Factory Environment (VFE), Process Based Feature Mapping (PBFM) and Process Planning (PP). Feature based design is used for the design, modeling, synthesis, representation and validation of the components for manufacturing applications. New set of features namely integrated features are pre-defined as feature templates and instanced to get / derive the information required for the design-to-manufacturing stages of the components. VFE defines the factory, which provides the database for operations, machines, cutting tools, work pieces etc. The knowledge base of the developed system maps validated features of the component into operation sets in the first phase of the PBFM. Each operation in the operation sets can be executed using different machines and tools in a factory. All these possible choices are obtained in the second phase of PBFM. Genetic algorithm is used to find the optimal sequence of operations, machines and tools for different criteria in the process planning stage. This paper explains the developed system with case studies.


Author(s):  
Reinholt Geelink ◽  
Otto W. Salomons ◽  
Fjodor van Slooten ◽  
Fred J. A. M. van Houten ◽  
Huub J. J. Kals

Abstract In this paper, interactive “constraint based feature definition” is used to drive both feature based design and feature recognition. At present, hardly any feature based CAD or CAPP system does offer adequate facilities to easily define application specific features. Feature definition by means of programming is an error prone and difficult task. The definition of new features has to be performed by domain experts in the fields of design and manufacturing. In general they will not be programming experts. This paper elaborates on interactive feature definition, aiming at facilitating the definition of features by non-programming experts. The interactive feature definition functionality is implemented in a re-design support system called FROOM. It supports feature based design. Feature definition is also used in a Computer Aided Process Planning system, called PART, for the definition of features to be recognized. Conceptual graphs are used as an aid in the definition of features and for the representation of the features. The conceptual graphs are automatically transformed into feature recognition algorithms. Degrees of freedom (DOF) analysis is used for support during feature definition and for solving geometric constraints related to the feature to be defined.


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.


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