Research On Technology Of Assembly Sequence Planning Of Hull Blocks Based On Rule Reasoning And Constraints

For shipbuilding, a systemic project, which is tedious installation, the internal structure is complex, long cycle and the systems involve many complex factors, the construction process is one of the important link of segmentation. Section of the assembly sequence planning plays a significant rule in improving the level of ship construction, reducing the construction cost and shorting the construction period. Based on this background, in this paper, the hull section of assembly sequence planning problem was studied systematically.(1) According to the characteristics of the hull block assembly, the assembly model establishment method was studied, assembly information model which is hierarchical and assembly dividing method which is based on fuzzy clustering analysis method were proposed, through the establishment of fuzzy relations, the membership functions and fuzzy relation matrix,this paper achieve a sub-assembly flat double bottom block division successfully, which laid a foundation for piecewise integral assembly sequence planning.(2) On the basis of assembly information model and the assembly division, combined with the characteristics of ship block, the paper puts forward the rule-based reasoning(RBR)and constraint reasoning method of hull assembly sequence planning.By fabricating the ship industry experience and fabrication process related knowledge, assembling rule base is established, and the hull section structures were composed of rule matching in order to realize the preliminary inference from component to component layer.Through the analysis of the actual space geometric constraint relation of segment structure, establish the relationship between the contact and interference matrix, and finally achieved segmented assembly sequence planning by mathematical operations.(3) In view of the fuzzy and comprehensive evaluation process of the assembly sequence, fuzzy comprehensive evaluation method was proposed, through the analysis of influencing factors on the ship assembly sequence, the fuzzy comprehensive evaluation and alternative sets of factors were established, and through the subjective evaluation method,the weights of evaluation factors were determined;.By establishing the hull block assembly sequence secondary fuzzy comprehensive evaluation process to realize the comprehensive evaluation of assembly sequence, and taking a double bottom section evaluation as an example, the feasibility of this method was verified.(4) The CATIA software was applicated to simulate the assembly process of the assembly sequence which was reasoned out, Based on generated assembly sequences, by constructing a virtual assembly environmentand building the product model and path planning, the simulation of assembly process was realized; By analyzing the dynamic and static interference, verify the feasibility of the assembly sequence, at the same time,the assembly process video files were recorded, provides information feedback for the assembly sequence evaluation.(5) On the basis of theoretical research, assembly sequence planning system is designed and developed, and the system was applicated to realize the block assembly information management, the reasoning for assembly process and comprehensive evaluation of assembly sequence, this provides a solution for assembly process design personnel to improve the assembly process knowledge management level and efficiency of assembly process of the establishment.