Digital Product Assembly Sequence Generation Algorithm And Related Technologies

With the rapid development of the new computer technology, In order to adapt the quickly changeable market requirement in the field of product manufacture, new technology, new philosophy, new pattern and new ideology, such as Computer-Aided Design and Computer-Aided Manufacture , Computer Integrated Manufacture, No-paper Design in different place, Concurrent Engineering etc., emerge in endlessly. In Concurrent Engineering, Digital Product Assembly Planning and assembly sequence generation using computer can provide foundation for guaranteeing assembly feasibility and optimization during actual product assembly procedure, and is very important in improving product quality, decreasing product cost and shortening production time. Being one of the key problem of Digital Product Assembly Planning, assembly sequences generation is the core of Digital Product Assembly Planning, the precondition of evaluating, optimizing and selecting assembly sequences, the foundation of selecting assembly device and fixture, and the basis of realizing assembly procedure simulation. So, assembly sequences generation is worthy of researching. Due to the combinatorial exploding problem with the increasing of part number in assembly sequences generation, this paper presents the method of solving assembly sequences generation of large-scale assembly. The creative researches of this paper is as follows: (1) In order to ensure correct and efficient generating assembly sequences of large scale assembly, a kind of hierarchical assembly model towards assembly planning is built, which stores assembly information needed by assembly sequences generation completely. The hierarchical assembly model towards assembly planning divides assembly information into two levels: the concretely lower level geometrical information and abstractly high level model information, including assembly hierarchical relation tree, connection relation graph, fastener attribute structure, connection relation attribute matrix, knowledge rules etc. This kind of assembly model provides sufficient information for assembly sequences generation to visit the needed information quickly and exactly. (2) In order to overcome the limitation of solving large-scale assembly sequences generation using cut-set method, this paper presents combining assembly hierarchical relation tree and connection relation graph and infers a hierarchical connection relation graph using hierarchical relation in assembly tree and part relation in connection graph. The hierarchical connection relation graph transforms a large and complicated assembly sequences generation problem into several small and simple problems, reduces the complexity of cut-set Ill Abstract method enormously, is an effective way to solve large-scale assembly sequences generation problem. (3) Based on the hierarchical connection relation graph and the coherence between disassembly procedure and partitions of connection relation graph, the cut-set method partitions every sub-connection-graph of the hierarchical connection relation graph and generates every sub-assembly抯 assembly sequences representing by AND/OR graphs. This method combines the preciseness of cut-set method and the conciseness of the hierarchical connection relation graph. (4) For the sake of pruning all assembly cut-sets that do...