A reachability based approach for machining feature sequencing

摘要

Small and medium-sized enterprises (SMEs) are involved in highly personalised machining equipment and customised products. The trend in manufacturing systems towards higher degree of adaptability and automation has urged SMEs to seek new adaptable approaches for production, especially in the area of machining and process planning. In these areas, Cloud-DPP concept and machining feature (MF) based process sequencing have been proposed for increasing adaptability, and have gained attention recently. Both cutting tool conditions and product requirements are required in MF sequencing. In response to this fact, this paper proposes a reachability based method for MF sequencing which aims to reduce the number of tool changes and to meet specific machining requirements. This method is based on an MF path graph, an adjacency matrix, and a reachability matrix. MF path graph is mapped based on four types of mapping principles (MPs). Here, a basic MP is associated with MF sequencing rules, particular requirement MPs are relevant to machining requirements, and cutting tool MPs refer to MF machining strategies. According to MF path graph, adjacency matrix can be determined, which provides a basic matrix for calculating the reachability matrix. This method can be applied to cross-setup MF sequencing (using cross-setup MP) while making adaptive decisions along with unexpected changes of cutting tools. Finally, the results of the machined test part validate that the method can reduce the number of tool changes compared to the current MF sequencing methods.

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