逆向工程是一種由實物重建CAD模型的技術，對於無原始CAD模型的工件，應用逆向工程技術以重建其CAD模型，為產品研發中重要的工作，業界仿製現有產品的方式大都使用商用CAD系統繪製工件CAD模型，據以產生加工路徑，再輸出至多軸加工機器加工，目前的技術面臨以下兩項問題：(1)無法保證複雜曲面CAD模型的正確性。(2)誤差分析的功能不完整。本研究結合渦輪葉片之量測程式及CAD模型之曲面重建技術，建立完整的CAD模型。多軸同動加工一般用來處理三軸加工無法達到的特殊曲面或幾何造型的應用，由於在加工路徑規劃上較複雜，現有的CAD/CAM軟體在過切、干涉、下刀及提刀等問題的處理上仍然尚未完全解決，本研究以Pro/MFG模組模擬NC加工路徑並探討幾種不同方式建立之曲面模型的可加工性。而曲面加工產品的誤差比對在一般泛用的軟體並不完善，對於座標系統沒有辦法一致的情形下，就無法做誤差比對。本研究整合曲面誤差比對及截面曲線誤差比對，運用此兩種方式可以比較複製件及CAD模型曲面形狀及葉片葉形的差異性，也可以比較同一工件中不同葉片間的形狀差異。 For those objects without original CAD models, the application of reverse engineering technology to reconstruct the CAD model is essentially important for product development. The reconstruction of industrial products usually has two problems, (1) The reconstruction method can’t guarantee the accuracy of CAD model. (2) The function of error evaluation in commerce software is incomplete. This work focused on the development of an integrated approach, combining three—dimensional digitization, and reverse engineering technology, for the construction of complete CAD models.Multi-axes machining is typically used to deal with the problems that involve complex sculptured surfaces which cannot be handled by three-axes machining. However, due to the complexity in path planning for multi-axes machining, the problems related to gouging, interfering, engaging and retracting still exist in current CAD/CAM systems. The objective of the this project is that a reverse manufacturing technology is developed. Such a technology combines three-dimensional measurement, reverse engineering, CAD/CAM and 5-axes NC machining for the reproduction of complex sculptured surfaces. The function of error evaluation in commerce software is incomplete. When the coordinate system of two different component isn’t the same, the error evaluation doesn’t work. This work focused on the development of an integrated approach, combining surface error evaluation, and cross-section error evaluation, for the compare of difference with reproduction and original CAD model.
