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Dalian, China

Wu J.,Dalian University of Technology | Ji Z.,Dalian University of Technology | Chang H.,COSCO Shipyard Group Co.
Harbin Gongcheng Daxue Xuebao/Journal of Harbin Engineering University

Hull parts mark-line marking, which is done with the numerical control cutting operations at the same time, was one of the important taches in modern shipbuilding. The marking path planning problem would be regarded as the traveling salesman problem. According to the special of the marking path, a planning model was proposed based on an improved ant colony optimization algorithm and max-min ant system was applied to optimize the problem. By analysis and simulation, the best value range and combinatorial optimization settings of parameters was given. Then the comparison with genetic algorithms was given. The simulation results show that the optimization model is effective, which can effectively reduce the idle marking path. Source

Wu J.-J.,Dalian University of Technology | Ji Z.-S.,Dalian University of Technology | Chang H.-Q.,COSCO Shipyard Group Co.
Dalian Ligong Daxue Xuebao/Journal of Dalian University of Technology

Hull markline marking, which is done with the CNC operations for hull parts at the same time, is one of the important parts in modern shipbuilding. According to the features of the marking, taking the marking order and the marking direction as the parameters and taking the minimum idle marking path as the objective, a mathematical model of marking optimization is established on the basis of hybrid encoding in genetic algorithm. The different genetic strategies are used for evolution of the marking order and the marking direction. The random mutation operator maintains the diversity of the population and the self-evolution of elite operator accelerates the evolution process. The use of "greedy strategy" for initial population improves the fitness of the population. The simulation results show that the model is effective, which can effectively reduce the idle marking path and improve the efficiency of shipbuilding. Source

Guo C.,Harbin Engineering University | Zhang Q.,Harbin Engineering University | Zhang Q.,COSCO Shipyard Group Co. | Shen Y.,Harbin Engineering University
Journal of Marine Science and Application

The scale effect leads to large discrepancies between the wake fields of model-scale and actual ships, and causes differences in cavitation performance and exciting forces tests in predicting the performance of actual ships. Therefore, when test data from ship models are directly applied to predict the performance of actual ships, test results must be subjected to empirical corrections. This study proposes a method for the reverse design of the hull model. Compared to a geometrically similar hull model, the wake field generated by the modified model is closer to that of an actual ship. A non- geometrically similar model of a Korean Research Institute of Ship and Ocean Engineering (KRISO)’s container ship (KCS) was designed. Numerical simulations were performed using this model, and its results were compared with full-scale calculation results. The deformation method of getting the wake field of full-scale ships by the non-geometrically similar model is applied to the KCS successfully. © 2015, Harbin Engineering University and Springer-Verlag Berlin Heidelberg. Source

Wu J.,Dalian University of Technology | Ji Z.,Dalian University of Technology | Chang H.,COSCO Shipyard Group Co.
Advanced Materials Research

Generally the process of hull part cutting is that the part can not be cut until the previous part has been cut. This mode is poor cutting efficiency and high cutting cost. Based on the famous Seven Bridges Problems, this paper models the cutting problem and then presents a brand-new cutting technology, the bridge cutting. In this technology, only one pierce point is enough to cut off all the parts that lie in the same level. The example shows that the technology is effective for reducing the numbers of pierce points and shortening the length of idle cutting path, which not only improves the cutting efficiency but also saves the cutting cost. © (2012) Trans Tech Publications. Source

Yi Z.,Dalian Maritime University | Gong Y.,Dalian Maritime University | Gong Y.,Zhejiang University | Wang Z.,Dalian Maritime University | And 2 more authors.

The wall climbing robot for boarding ship rust removal cleaner (WCRSRR) has the characteristics of big loading and heavy robot body. Research status of WCRSRR is reviewed, the main problems are analyzed, the key technologies are summarized, and the development trend is predicted. Source

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