Research On A Novel Dynamic And Fuzzy Ship Domain

The samples based on the definition of ship domain which could represent the change regulation of ship domain are chosen for the research.The Automatic Identification System(AIS)data from Bohai Sea and Northern Yellow Sea are used for processing to obtain the samples.Ship domain influenced by many uncertainty factors,including human factors,ship factors,environmental factors and management factors etc,so many influencing factors make it difficult to determine the relationship between ship domain and the influencing factors.The accessed literatures not have relevant researches of the magnitude of the effect of different influencing factors on the size of ship domain.The principal component regression algorithm and rough set algorithm are used to analysis the importance of the ship domain influencing factors,and then make a reduction of the influencing factors,so the complexity of the ship domain is reduced.The importances of the ship domain influencing factors are determined by comparing the results of the two methods.In order to make the qualitative and quantitative research of the relationship between the ship domain and its influencing factors,firstly the ship domain changed with its influencing factors are analised by the method of statistical and wavelet decomposition algorithms,and the change regulation between ship domain and its influending factors are obtained.Then the relationship between the ship domain and its influencing factors is modeled using the method of wavelet transform and neural network.In order to establish a ship domain applicable for both restricted water and open water,the safety domain needed between the give way vessel and the stand-on vessel is calculated based on the ship's handling performance,when the give way vessel completes the avoidance task and the stand-on vessel does not take the avoidance measures,the domain is suitable for ship collision avoidance and ship automation.The model takes into account the ship maneuverability factors,ship track fluctuation,ship wave and the distance of the ships close to each other during the process of collision avoidance.Last the Automatic Identification Systems(AIS)data is applied to determine the ship domain and verify the performance of the domain model,and the dynamic changes of the ship domain are discussed.The results show the shape of ship domain is oval which take a full consideration of meeting angle of the encounter ships,and the size of it is dynamic changed with the maneuverability factors.In order to establish a dynamic fuzzy ship domain taking into account both own ship factors and other ship factors,the factors of the other ship are considered.The choice of factors and the determination of the dynamic relationship are as the previous stated,and the psychological function is used to fuzzy the ship domain,so the dynamic fuzzy ship daomain considers the factors of own ship and others are obtained.We test and obtain the new model on AIS data and the reasonableness and superiority of establishing a model takes into the influencing factors of own ship and other ships are discussed.The results show that the new model with the factors chosen reasonable,the domain changed with its factors dynamicly and can assess the spatial collision risk of the navigational situation,it is reasonable considered the factors of own ship and other ships.The research eatablished the novel dynamic fuzzy ship domain from the point of collision avoidance,which the factors affecting the ship domain are analysed and selected firstly,with the data based on AIS data.