The Research On Spatial Scheduling Method Oriented To Curved Block Construction In Shipbuilding

The Shipbuilding Industry is one of the important symbols of the country's economy and the technical strength. The traditional shipbuilding pattern is transformed into modern shipbuilding pattern, presenting higher standard of production planning and spatial allocation for shipbuilding. For curved blocks assembly is the bottleneck in shipbuilding, efficient scheduling for curved block assembly is vital for shipbuilding productivity.Oriented to scheduling for curved block assembly in shipbuilding, spatial scheduling problem is analyzed, and based on the formulation of spatial scheduling, the mathematical model is built, heuristics and particle swarm optimization algorithm is designed respectively, and then planning module is developed for curved block assembly scheduling. Contents and achievements of the dissertation are mainly as follows:Firstly, considering curved block assembly scheduling in shipbuilding, spatial scheduling problem is analyzed on spatial and temporal dimension, and compared with paralleled machine scheduling and bin-packing problem, the spatial scheduling problem is described with definitions, assumptions and constraints.Secondly, three-dimensional bin-packing problem is used to provide the mixed integer linear programming and the lower bound is given, this method can be applicable for rectangular items layout on rectangular plate.Thirdly, two-stage scheduling is proposed to solve dynamic layout problem of trapezoid items layout on rectangular plate, the spatial scheduling problem is divided into two problems: blocks sequencing and spatial allocation.As the main parts of spatial scheduling, spatial allocation of trapezoid items to rectangular plate is important. In this paper, pixel is used to denote the available space; local search is limited to feasible boundary point sets to improve the effectiveness and efficiency of the algorithm.According to different blocks sequence, different solutions are obtained. The sequencing rules include temporal-based, spatiotemporal-based and random-based on the framework of particle swarm optimization.Fourthly, a series of examples will be provided to validate effectiveness of methods in this study.Finally, the spatial scheduling model of hull curved block in shipbuilding based on two-dimensional layout is developed.Spatial scheduling algorithm oriented to curved block assembly in shipbuilding can be extended to painting workshop and others. In addition, it has good prospect of application for large-scale, heavy product manufacturing such as the airplane, the bridge and so on.