Research On Two-Dimensional Rectangular Piece Layout Problem For Shipbilding

The current international ship market is sluggish,and China's shipbuilding industry is facing a severe challenge.Promoting the upgrading and transformation of shipbuilding technology,developing in the direction of digitization and intelligence,and improving the core competitiveness of enterprises are the development directions of the shipbuilding industry.Shipboard blanking is the core issue for shipbuilding enterprises.On the one hand,it directly determines the utilization ratio and cost of raw materials and reflects the core competitiveness of shipbuilding enterprises.On the other hand,the order of the blanking of parts also determines the subsequent shipbuilding process,directly affecting the process flow and production control.As a NP-C problem,the ship plate blanking problems is not suitable to the exact solution algorithm.The heuristic algorithm and intelligent optimization algorithm have good searching ability and are used to solve the optimal layout problem.Shipboard blanking process has complex constraints,the problem model that meets actual processing conditions must be established in order to design a suitable optimization algorithm.The main research work and results of this article are as follows:1)The detailed process of ship board blanking was studied,and the characteristics of ship board processing and the process constraints were understood.Summarizes the basic concept and mathematical model of the optimal layout of rectangular parts.Combining with the actual conditions of shipboard plate processing,a rectangular model for the layout of shipbuilding industry has been established.Study and analyze the characteristics of heuristic and intelligent optimization algorithms.In order to solve the optimal layout problem of rectangular parts,the two algorithms should be combined to get a mixed algorithm.2)Several common heuristic algorithms are studied and a variety of algorithms are compared and analyzed.The lowest horizontal line algorithm and the surplus rectangle method are selected for better layout effect.Then they are combined with simulated annealing algorithm and ant colony algorithm,two kinds of hybrid algorithm for solving the optimal layout problem of rectangular parts are obtained.Through simulation experiments,the above two hybrid algorithms are proved to be effective for solving the optimal layout problem of rectangular parts.Comparative analysis of the solution performance of the two algorithms,it is proved that the hybrid algorithm combining the ant colony algorithm and the residual rectangle algorithm has strong solving ability when solving the optimal layout of rectangular parts.However,in some cases the ant colony algorithm may converge to the local optimal solution.3)Appropriate improvements have been made to the ant colony algorithm: apply mutation strategy to current optimal solution and improved path selection rules.Make it more capable of global search to avoid falling into a local optimal solution.Applying improved ant colony algorithm to solve optimal layout problem of rectangular parts.The effectiveness of the algorithm is verified by simulation experiments.