Feature-based Design Systems Research Articles

Special Issue: Highlights From ASME CIE 2018

Special Issue: Highlights From ASME CIE 2018

Form Feature and Tolerance Transfer from a 3D Model to a Set-up Planning System

Currently, most CAD systems, even the feature-based design systems which were developed for the need of CAPP, cannot provide exact information of an object (e.g., dimensions and tolerances). Some feature-based design systems can provide product data directly or indirectly; however, most CAPP systems still does not have interface with those CAD systems. The product data required by these CAPP systems usually has a specific format. In the CAPP system, it is essential for setup planning to ensure the precision of machining processes. Therefore, it is necessary to develop an interface with CAD models that the part data file can be obtained directly from CAD representation. This paper proposes an approach to integrate the setup planning system with a feature-based CAD system. By using an object-oriented approach - Product Data Translator (PDT), the compute-automated extraction of geometry and complete tolerance information is achieved; and the automated generation of tool approach direction was developed.

Application of virtual convex polytope in transforming protrusions for automated process planning

In this paper, a two-tier methodology for the transformation of protrusion design features to manufacturing features is presented. In the first stage of the proposed algorithm, a method is proposed to encapsulate the protrusions with virtual convex polytope and transform them into a set of negative machining volumes. The design feature model is transformed into the intermediate feature model that consists of machining volumes using the concept of generic virtual pocket. In the second stage, called the feature refinement stage, relevant manufacturing information is appended to the negative machining volumes to transform the intermediate feature model into the manufacturing feature model. The proposed methodology can be used in the feature-based design and manufacturing systems to support automated process planning and machining functions. Practical examples and computer implementation in an object-oriented environment are also presented in this paper.

Feature-based design by volumetric machining features

Substantial research efforts have been spent on feature applications towards the integration of CAD and downstream manufacturing functions such as process planning. However, the majority of contemporary feature-based systems cannot handle the interactions of features in practical applications. Feature interactions cause problems in feature recognition as well as feature-based design systems. This paper presents an approach to represent and analyse features in a featurebased design system. In this system, a part is modelled by volumetric machining features, which are then decomposed into air volumes and material volumes. Geometric reasoning is used to evaluate and analyse the features incrementally during the design stage. Feature interactions are detected by the possible interactions among material volumes. Several interacted or face-contacted material volumes can be clustered into a single-material volume. For each material volume, a tool-swept volume is generated to represent the space to be removed in the machining process. The complete feature instancing process is governed by the validation rules to ensure that the part is manufacturable.

Process planning and machining of generic virtual pockets by feature-composition approach

In this paper, a feature-composition methodology is proposed for merging removal volumes and selecting appropriate cutters to improve the machining efficiency in feature-based design and manufacturing systems. Cutter selection and tool path generation are optimized under the local geometric constraint, global geometric constraint, residual material constraint, and machining accessibility constraint. The proposed methodology can be used to support the planning and machining functions in the feature-based design and manufacturing systems.

Feature-composition approach to planning and machining of generic virtual pockets

In this paper, a feature-composition methodology is proposed for the planning and machining of generic virtual pockets encountered in feature-based design and manufacturing systems. Techniques of merging removal volumes and automatic tool selection to improve the machining efficiency are presented. The machining volumes are first identified in terms of basic removal volumes, which are then merged under various constraints. Cutter selection and tool path generation are optimized under the local geometric constraint, global geometric constraint, residual material constraint, and machining accessibility constraint. Merging appropriate removal volumes and assigning the optimal cutters can generate an efficient tool path and can reduce the total machining time for generic virtual pocket machining. The proposed methodology can be used to support the planning and machining functions in the feature-based design and manufacturing systems. Computer implementation and practical examples are also presented in this paper.

Feature-based modelling approaches for integrated manufacturing: state-of-the-art survey and future research directions

Abstract Features capture the engineering significance of a part model and serve as an important support tool for integrated manufacturing. Feature-based design systems typically act as ‘interpreters’ between the CAD and the CAM activities. These systems can be classified broadly into human-assisted feature definition systems, automatic feature recognition systems and design by features systems. Researchers have come to realize that the best system architecture for a feature-based system would be a blend of the above-mentioned approaches. This paper reviews the major developments in the field of feature-based modelling with particular emphasis on automatic feature recognition systems. The approaches used for automatic feature recognition systems are systematically categorized and discussed. Automated feature recognition systems are broadly categorized into volume feature recognition systems and surface feature recognition systems, and the published research in each of these categories is critically discus...

Feature modification framework for feature based design systems

Design features created by a feature based design system could theoretically be directly sent to machining preparation system. This, however, has not been found and feature modification is still necessary. A feature modification framework is proposed in this paper for bridging the gap between the design features and machining features. Feature modification algorithms were also developed for the foundation of the framework. A prototype system is presented and illustrated by an explanation of how the feature modification concept could function in a real situation.

A description of an expert system for finite element modeling and analysis

Finite element analysis is an integral part of the structural analysis process in the design and development of parts and assemblies. Various levels of integration exist between design systems and finite element modeling systems. The feasibility of a knowledge-based system to tightly couple product design systems and finite element analysis systems was investigated. A framework incorporating feature-based design systems, heuristics-based planning modules and procedural pre-processing/solving/adaptive refinement schemes was developed. The pertinent modules of the framework were organized into a prototype and implemented in the VAX environment utilizing the EUCLID geometric modeling system, CLIPS expert system development tools, PATRAN 2.3 finite element pre-processing system, a finite element solver and an adaptive refinement system developed specially for the framework. The scope of the research work was limited to static stress analysis. The results of the research indicated that design systems can be successfully integrated with finite element analysis systems in a knowledge-based framework. The framework was also found to be suitable for finite element-based structural optimization and self-learning processes.

A graph grammar approach to feature representation and transformation

Abstract Feature-based modelling is an approach being studied for the next generation of intelligent CAD environments. In particular, feature mapping, i.e. how to support automatically the different ways specialists view the same object, has been identified as an important element in feature-based design systems. Consequently, feature representation and reasoning tools based on the representation are crucial issues. This paper addresses the problems of representing features in a form more suitable for feature transformation and the related feature reasoning mechanism. Our approach combines methodologies from both design and features and feature recognition. Geometric constraints are used within symbolic definitions of features and also to define their relative positions and orientations. A graph grammar parsing is combined with knowledge-based techniques to derive feature information and propagate constraints. The proposed approach can be used for the transformation of feature information and to facilitat...

Review of research in feature-based design

Research in feature-based design is reviewed. Feature-based design is regarded as a key factor towards CAD/CAPP integration from a process planning point of view. From a design point of view, feature-based design offers possibilities for supporting the design process better than current CAD systems do. The evolution of feature definitions is briefly discussed. Features and their role in the design process and as representatives of design-objects and design-object knowledge are discussed. The main research issues related to feature-based design are outlined. These are: feature representation, features and tolerances, feature validation, multiple viewpoints towards features, features and standardization, and features and languages. An overview of some academic feature-based design systems is provided. Future research issues in feature-based design are outlined. The conclusion is that feature-based design is still in its infancy, and that more research is needed for a better support of the design process and better integration with manufacturing, although major advances have already been made.