Research On Irregular Block Dynamic Spatial Scheduling And Stacking Problem In Shipbuilding Industry

With the transformation of modern shipbuilding mode, Chinese shipbuilding industries strengthentheir competitive power with continuous improvement of production technology. But the constructionand storage problem seriously affects the construction efficiency and turnaround efficiency ofconstruction site and stockyard. So, effective research and application of space scheduling methods andoptimization stacking techniques can be used to improve the production efficiency and resourceutilization, thus enhancing the competitiveness of enterprises and has good economic and social benefits.The dynamic layout problem of rectangle blocks in the rectangular workplace has been solved. Onthis basis, in view of one ship heavy industry corporation actual demand in Jiangsu province, we designthe spatial scheduling system and block dynamic stacking system for solving the construction and storageof irregular blocks in shipbuilding. The main research works are:(1) Simplify the spatial scheduling problem of irregular blocks as the dynamic layout problem of thedownward projected convex polygons in a rectangular workplace, and then we use the minimum gravitycenter strategy which based on no-fit polygon to achieve the spatial layout of polygons.(2) Considering the different points between the production process and the stacking problem, theload of transportation in stockyard is quantified, and we design an algorithm for calculating theobstructive blocks that stacking into the stockyard when moving one block into or out of the stockyard.For solving the block stacking problem, the storage location of assembly blocks in thethree-dimensional space are determined by the average maximal free rectangle space strategy based onthe no-fit polygon algorithm. This strategy can not only make better use of free space, but also can dealwith the coupling of time and space.(3) The genetic algorithm is responsible for scheduling and stacking optimization. In order to avoiddestroying the optimal individuals, we introduce simulated annealing algorithm to genetic operators,crossover probability and mutation rate are gradually reducing with the increasing iterative times.(4) With the actual production data of a large shipyard, we use Matlab language to verify theeffectiveness of the scheduling algorithm and stacking strategy in practical application. By comparisonwith existing methods, the scheduling algorithm and stacking strategy have been indicated that they allhave the strong global optimization capability and can also improved resource utilization greatly.Through modifying the spatial scheduling algorithm and dynamic stacking algorithm in this article,they can be extended applied to the production process of container handling and aircraft manufacturing.They have the important theoretical research sense and industry application prospect.