Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/2639
標題: 整合型CAD/CAM軟體系統之研發
Advancement of Integrated CAD/CAM Software System
作者: 賴元隆
Lai, Yuan-Lung
關鍵字: CAD/CAM;電腦輔助設計/製造;Industrial Design;Software Engineering;Pocket Machining;Offset;NURBS;工業設計;軟體工程;袋型加工;偏置;NURBS
出版社: 機械工程學系
摘要: 
電腦輔助設計/製造系統可說是個複雜的產品,因為要成就一個成功的CAD/CAM系統,在軟體應用開發上涵蓋了一些最複雜困難的技術。泛用型CAD/CAM系統具備有高效能的影像顯示、複雜的計算幾何理論與進階的人機介面技術。本研究的主要目地是利用軟體工程、工業設計與CAD/CAM核心技術發展一整合型軟體系統。
系統整合是一種趨勢也是在CAD/CAM產品快速變遷下保持競爭力的重要因素。一般而言,CAD/CAM軟體提供三大類不同的功能:設計流程、加工製造規劃與數值控制程式,整合CAD與CAM模組將可幫助資訊/檔案在這三個主要功能間獲得完整的轉換。CAD/CAM設計者在一個以圖像為主的環境中工作,創新、辨識、啟發、評估與操控為工作過程中的重要內容,這些必須藉由幾何關係間的圖像來促成。通常在一般的CAD/CAM操作工作都是相類似與重複,此時,幾何操作上的自動化過程就變的相當重要,在市場上也成了必備條件。此外,一套整合完善的CAD/CAM系統不只是能提供豐富的特性資訊讓複雜的產品設計變為可能並且設計上靈活方便具彈性;而且要能夠針對不同的機械系統需求來定義加工指令,自動產生完整的加工程式來生產設計產品。
在本研究中除了對複雜人機介面的互動提出軟體開發的準則,並提出重要的核心技術作為成就CAD/CAM軟體的重要資源。藉由一些新方法與理論來提升CAD/CAM軟體的功能,例如強健的平面曲線偏置與NURBS曲線格式之應用,這些是本研究的重要技術核心。而由強健的曲線偏置發展出含島嶼之袋型銑削加工,此方法不只可應用在五面加工上亦可應用在曲面之粗銑與精修加工上。利用對NURBS曲線格式的解析,本研究對NURBS曲線的偏置與降階也作深入的討論並提出新方法,可直接利用CAD/CAM軟體輸出高速銑削所需之NURBS加工格式碼,符合各類工業加工控制器標準。最後我們將前面的研究成果應用在一個既簡單又複雜的圖形上-橢圓,看似簡單卻又難以駕駑一直以來就是工具機加工上既存的問題。本研究提出利用連續相切弧與NBRBS格式兩種方法來模擬橢圓,這兩種方法都可以取代以密集線段描繪橢圓而準確地模擬橢圓並滿足加工上所需的所有條件。
要找出製造程序規劃應用上的解決方案,直接衝擊一些演繹上的問題,本研究致力於將計算幾何的方法應用在製造程序上。所有的理論與方法已整合在CAD/CAM軟體的開發上,並且成功地應用在市場的生產使用上。

CAD/CAM systems are complex products, the first and foremost reason is that they involve several of the most sophisticated technologies used in the development of software applications. General CAD/CAM systems require high performance visualization, computational geometry complex algorithms, and advanced ergonomic user interfacing techniques. In this research, an integrated software system will be developed by various methodologies including software engineering, industrial design and CAD/CAM technology.
Integration is the way forward and is responsible for keeping pace with the rapidly changing CAD/CAM products. Generally speaking, CAD/CAM software systems serve three distinct functions: design process, manufacturing operation and NC programming. Integrating CAD with CAM helps streamline the transfer of information/files between these three functions. CAD/CAM designers work in a predominantly graphical environment. Creation, recognition, inspiration, evaluation and manipulation are required by graphics of geometric relationships are central to their work. Usually, the routine CAD/CAM operations are similar and reiterative. The importance of automating processes of geometric operations is conspicuous and prerequisite. A commendably-integrated design and manufacturing system should not only provide a rich set of features making it possible to design complex parts with greater flexibility, but also be able to automatically generate programs for various numerical control machines to produce the designed parts.
During the research we not only proposed some principles for Human-Computer Interaction on software organization but also developed new methods and algorithms to advance CAD/CAM software such as robust curves offset and NURBS curves representation. From robust curves offset technologies, a reliable automatic tool-path generation and pocket machining with islands were developed. Such method can be applied on surface roughing and sculpture surface machining. By using NURBS curves format, we proposed optimum processes to offset NURBS curves and reduce the degrees of NURBS curves. Finally, we dealt with a simple but complex shape — Ellipse to verify our efforts. There are two ways to approximate ellipses in our study, one is tangent arcs and the other one is NURBS format. Both of these methods are all more efficient than to connect points laboriously determined in a CNC system.
Applications in manufacturing process planning require solutions to challenging algorithmic problems, this thesis is devoted to the study of some problems from manufacturing to which methods of computational geometry can be successfully applied. Based on these efforts and empirical experience, a complete CAD/CAM software system has been developed for market applications.
URI: http://hdl.handle.net/11455/2639
Appears in Collections:機械工程學系所

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