Chun-Fong You

National Taiwan University, Taipei, Taipei, Taiwan

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Publications (3)3.56 Total impact

  • Chun-Fong You, Yi-Lung Tsai, Kun-Yu Liu
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    ABSTRACT: This work improves process planning and die design in automotive panel manufacturing using a novel case-based reasoning (CBR) methodology. An innovative indexing representation and retrieval approach are also addressed. The flat-bend graph, which is utilized to represent a panel model with a B-rep structure, retains geometric and topological data in the Standard for the Exchange of Product model data format. Flat-type faces collected into several groups are represented by graph nodes, and bend-type faces are represented by graph arcs. Based on the topological information between bend-type faces and flat-type faces, a graph is constructed. Additionally, the holes detected are considered another graph node types. Geometric information and stamping parameters are utilized as graph attributes. To retrieve an appropriate case for a potentially huge search space, independent maximal cliques detection is applied. All independent maximal cliques that represent the maximum number of features shared by models are identified. Based on the retrieval result, previous process plans and die sets can be acquired for use by new cases. Experimental results obtained using the CBR system integrated with the product data management system demonstrate the practicality of reusing previous designs to accelerate stamping process planning and die design. KeywordsAutomotive panel stamping-Case-based reasoning-Graph-based representation-Similarity assessment-Process planning and die design
    International Journal of Advanced Manufacturing Technology 01/2010; 51(1):297-310. · 1.78 Impact Factor
  • Chun-Fong You, Yi-Lung Tsai
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    ABSTRACT: For engineering applications, a new design can be developed efficiently from an existing design with the same features, functions, and manufacturing properties. Although several techniques have been developed for assessing the similarity among models, most methods focus on the global shape of models. This work presents an innovative retrieval architecture that can be utilized to acquire similar mechanical artifacts based on the local feature correspondence. This work defines an attributed graph for a B-rep structure to retain the geometric and topological data from Standard for the Exchange of Product model data (STEP) format. Local feature correspondence is evaluated by identifying the size of the common subgraph from the graph descriptor. This work applies a novel scheme, called independent maximal cliques (IMC) detection, and a simulated annealing algorithm to solve the graph-matching problem. The association graph, which is used for IMC detection, is constructed from two attributed graphs while retaining their attributes. All independent maximal cliques, which represent the maximum number of common features between models, are identified using simulated annealing. Therefore, the retrieval framework can achieve the engineering goal of model reuse by measuring the local feature correspondence between solid models via IMC detection. The experimental results, obtained from the retrieval system built on the product data management (PDM) system, demonstrates the practicality of this work for 3D model retrieval for engineering reuse based on local feature correspondence.
    International Journal of Advanced Manufacturing Technology 01/2010; 46(5):649-661. · 1.78 Impact Factor
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    ABSTRACT: This work automates process planning and die design in automotive panel production using a novel knowledge-based engineering (KBE) methodology. Automotive panels are more complicated than common stamped parts because automotive panels are composed of groups of freeform surfaces. Stamping process planning identifies and sequences the necessary operations, finally producing the appropriate press dies. Case-based reasoning (CBR) is integrated into ordinary process planning and die design processes to generate a hybrid KBE system. Utilizing the CBR methodology to plan stamping process and design stamping dies for automotive panels reuses existing designs to develop new designs. In the proposed flexible system, process-planning and die-design functions can adapt existing designs or generate new designs based on stamping knowledge. Tacit knowledge of stamping parts is preserved and automotive panel manufacturing is accelerated by design automation when using the proposed KBE system.
    Computer-Aided Design & Applications CAD Solutions. 01/2010; 7:75-87.