关键词: 加工特征, 加工操作, 加工流程设计模型, 加工操作, 优先关系, 语义网络, 排序数学模型

Abstract: In order to convert a series of geometric features into machining operations and sequences in a feasible and money-saving order，a Process-planning (PP) model was proposed. The model consisted of three parts: the features framework of design model, the precedent relationship semantic net and the sequenced mathematical model. A part was decomposed into several basic geometrical units, namely, U1, U2，…，UN. For each unit -Ui, two vectors, namely Fi and Pi, were used to represent the features and machining operations of Ui. Matrix PP was used to memorize the process plan sequences. Matrix PO was used to store the objects of machining operations. The features framework of design model established a mapping between manufacturing features set with machining operations. A semantic net called the precedence-relations-net was used to reflect the precedence relationships among the machining operations. Finally a machining process plan sequences were calculated by vectors and the matrixes under the guidance of precedent relation semantic net. For fully definition of the machining process operation and the guidance to precedent relation semantic net, the solution was feasible and optimized.

Key words: machining features, machining operations, process-planning model, machining operations, precedence-relations, semantic net, sequencing mathematical model