The automatic collision avoidance for vessels on sea is an important and difficult problem for modern navigation. We propose a new Vessel Automatic Collision Avoidance System (VACAS) based on Multi-agent System (MAS) and Automatic Identification System (AIS). Each ship can be regarded as an agent, and multiple ships which have potential collision danger compose a MAS. The vessels move toward their goals step by step. Before each step, they should reserve the next sea areas. By exploring the functions of AIS, we use Self Organizing Time Division Multiple Access (SOTDMA) to coordinate vessels automatically. The simulation result demonstrates that our system can automatically avoid collision for multiple vessels successfully. And our method is also suitable for other vehicle's automatic collision avoidance.
Aiming to the lack of the considering of the issue that the routes may across pieces of charts existing in current automatic routing methods,this paper proposed a method for multi-scale routing based on ECDIS.Taking into account the chart's features,the multi-scale expression of chart data was designed and the multi-scale automatic routing was realized.The experimental results demonstrated that the proposed method could achieve multi-scale generation for long-distance routes based on the seamless of pieces of ECDIS,and generate the LOD layers according to the latitude and longitude coordinates of a voyage's starting and ending point,thus provide the user with different scale charts routes.
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