以加工特徵導向之製程規劃系統

Abstract

電腦輔助設計（CAD）和電腦輔助製造（CAM）技術日趨成熟，但兩者整合仍有許多問題存在；主要問題是CAD所提供的加工資訊不足。目前為止有關研究，大多以加工特徵做為媒介，傳遞CAD的加工資訊，再利用一些介面軟體配合資料庫所提供資料處理後，使加工特微成為直接輸入CAM的資料，達成電腦整合製造之目的。 這些介面軟體常被稱為電腦輔助製程規劃（CAPP）系統，其主要功能是：求得每一加工作業計劃所需用的機器、刀具、夾具、切削路徑及參數，以及加工作業先後順序的限制。 本論文研究針對切削加工製程，以DSG此加工特徵為輸入資料，由DSG所提供的幾何資訊，透過特微有向圖之推導，可得出具可加工性之修正特徵，再配合刀具庫及機器的製程能力，可推導加工特徵的整體可加工性及各修正特徵之可進刀方向，等加工資訊，做為CAPP製程決策依據，求得加工作業規劃所需用的機器、刀具及工作業先後順序限制之合理解，並產生切削路徑，成為電腦輔助設計及電腦輔助製造間的橋樑。

The techniques of CAD and CAM are getting mature recently while there are still exist some problems in integrating CAD and CAM. The main problem is that the machining information provided by CAD is insufficient. Most of current reseaches use the machining features as the media to transfer the machining information from CAD. Then some software interfaces and mchining databases are used to transfer the machining features dirrectly into CAM for the goal of Computer-Integrated-Manufacturing (CIM). Such softwares are often called CAPP system. The main functions of CAPP include:(a)finding the required machines, tools , fixtures, cutting paths, and parameters of the machining operations planing; (b)deciding the precedence constraints of the operation plannings. In this pater, we focus on the machining process of cutting and use the DSG data, a kind of machining features, as input. to finding an approprate process planning. Through the feature refinement process of feature digraph construction the DSG features are first transferred into corresponding machinable refined feature. Under the consideration of the tool bases and the machine capabilities, the proposed system can determine the machining information of (a) the refined features (b) the machinability of machining features and (c) the cutting direction. Such information can be used to decide the required machines, tools and the machining sequences. The proposed system can also generate the Nc paths of the input DSG data for verifying the feasiblity of the outputted process plan.