頁籤選單縮合
題 名 | A Feature-Based Approach for Design of Free-Form Objects=特徵式自由曲面造形設計 |
---|---|
作 者 | 呂維成; 黃俊明; | 書刊名 | 中國機械工程學刊 |
卷 期 | 19:2 1998.04[民87.04] |
頁 次 | 頁199-212 |
分類號 | 448.945 |
關鍵詞 | 自由曲面; 造形設計; Reverse engineering; Feature-based design; Hermite data; CAD; |
語 文 | 英文(English) |
中文摘要 | This paper presents a method to build a Hermite-based surface model generated form an existing free-form object. Such a method provides both C2 continuity across abljacent patches in a surface region and G+ continuity acress adjacent surface regions. The model then serves as the basis for new shape designs of the free-form object. Among objects of comples-shaped features, human masks, shoes, gloves and artificial limbs are instances of particular intrest. The method not only determines surface regions ( the highest-level features) in an object and sub-features (lower-level features)in each region; both also demonstrates how low-level features be blended into high-level ones. By means of parameterized features, new products are created according to the change of parameter values. Variables and constraints of features are regarded as key elements in defining design rules for a free-form design system. The coordinate measuring machine (CMM) obtains 3D data points of an object while a criterion selects the measuring path of fewest points so as to extract surface features for a variational design. A range of shoe-last designs exemplifies the practice of this proposed methodology. |
英文摘要 | 本文提出一種從具有自由曲面造形的實物轉換成Hermite 式曲面模型的方法;所 產生的曲面模型中,每分段曲面內為 C2 連續,而各分段曲面之間的接合具有 C1 連續性。 此產生的幾何模型可做為重新設計自由造型產品的基準;一些像面具,皮鞋,手套,義肢. ..等有複雜特徵造型的產品是本研究有興趣的範疇。本研究不僅決定實物表面各分段特徵 曲面(最高階特徵)以及區分局部較低階的特徵曲面外,並提出如何將數個低階特徵曲面熔 合成一個高階特徵曲面的法則。經由參數化特徵的表示以及變更參數值的方法,而能達到產 品自動化造型設計的目的。特徵的參變數以及限制條件為一自由曲面設計系統內設計準則的 關鍵要素,要以變更式設計為導向,來定義並粹取實物之曲面特徵時,本文提出最少量測點 法則,以決定量測路徑,經由 CMM 量床取得實物造形的特徵點資料。 文中以鞋楦造型設計 為實例說明所提出的法則。 |
本系統中英文摘要資訊取自各篇刊載內容。