Automatic Assembly Sequence Plan Generation
Date Issued
2005
Date
2005
Author(s)
Tsai, Chi-Shen
DOI
en-US
Abstract
本研究提出一個能找出建構Petri net所需的反組裝程序的方法。由於Petri net簡單清淅的符號表示及完整的數學特性，它一直是一種廣泛使用的模擬工具。如果能將所有可行的組裝程序以一個Petri net表示，運用它的數學特性，便可快速地找出最佳的組裝程序或反組裝程序。
本研究利用CAD組裝檔的拘束條件及各零件的幾何特徵，找出組裝檔中各零件相對於其他各個零件可行的反組裝方向。利用反組裝方向及可行性測試可以判定每個反組裝步驟是否可行。再利用反組裝步驟建構該組裝檔的Petri net。不同的是，本研究中的反組裝方向可以是一個任意的方向，而非局限於某個直角座標體系的三軸方向。本研究亦採用simplex algorithm演算法，實作運用Petri net的數學特性找出該Petri net所屬的組裝檔的最佳反組裝程序。最後，本研究也以各包含了四個、八個及十二個的組裝檔測試本研究法則之可行性。
This thesis describes a method to generate all feasible tasks which are the essential information to build the Petri net of a product. Petri net is a powerful modeling tool because of its well-defined semantics and mathematical properties. With the Petri net of a product, the optimal sequence can be quickly found according to its mathematical properties.
The method in this thesis starts from extracting constraints and geometric features of the assembly model of a product. The disassembly orientations of every part relative to the others are obtained from constraints and geometric features. By intersecting related disassembly orientations of a disassembly task and feasible tests, we can gain every practicable disassembly task and hence build the Petri net of the assembly model. What is the most special point is that the disassembly orientations can be arbitrary directions, not merely limited to positive and negative directions of x, y and z axes. The thesis also implemented the searching of the optimal disassembly sequence by employing simplex algorithm. At last, three assembly models which contain four, eight, and twelve parts respectively are employed to verify this method in this thesis.
Subjects
組裝程序規劃
組裝程序
拘束條件
反組裝方向
Petri net
assembly sequence planning
assembly sequence
constraints
disassembly orientations
Type
thesis
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