Hsin-chi Chang, Wen F. Lu, Xiaoqing Frank Liu
This research focuses on the development of a retrieval and modification system for reusing a machining process plan of an axisymmetric part for a new part. The proposed system is capable of retrieving the most relevant case of which the finished part is similar to the new desired part, and then modifying the retrieved case to meet the new requirements. The system uses a feature-based representation scheme to represent mechanical parts and processes. According to the cutting process of a part, two kinds of indexes: two-dimensional indexing and feature indexing, are used to organize the case library, and a hierarchical structure of cutting processes is employed to store the cutting history of previous cases. Based on the part representation, indexes, and the hierarchical structure, an effective similarity metric which incorporates geometric shape, material, precision, and cutting process is developed to re-rieve the most similar case from the case library. In addition, a modification mechanism is provided to modify the retrieved case. The system is implemented on a Sun workstation using ACIS geo-metric modeler and C++.