Research And Application Of Ship Collision Risk Degree Based On Near Miss

Ship collision risk degree modeling is a key step in maritime traffic risk evaluation,and establishing ship collision risk degree model based on near miss is a new and effective method,which has important theoretical significance and practical guidance value for the navigation safety guarantee.This thesis focuses on the relationship between the spatial and temporal characteristics of near miss and marine traffic risk,and carries out the research of the ship collision risk degree model based on near miss.The quaternion ship domain is used to detect near misses.The whole process of the target ship sailing into the quaternion ship domain of own ship to leaving is defined as a single near miss,and the time experienced by the whole process of a single near miss is defined as the duration of a single near miss.And then,the model for calculating the duration of a single near miss and statistical model of the number of near misses based on grid method are proposed.To measure the overall risk degree of the whole process of a single near miss,the model for calculating the risk degree of a single near miss is proposed.The risk degree of a single near miss and the traffic volume of ships are taken as the independent variables to evaluate the maritime traffic risk,and then the macroscopic collision risk model based on near miss is proposed,which can be used to analyze maritime traffic risk.Taking the Bohai Sea as the research object,the number of near misses and the duration of near misses in Bohai Sea were analyzed by using AIS data;the macroscopic ship collision risk degree based on near miss was calculated and its geographical distribution characteristics were analyzed.The experimental results show that there are some correlations between the duration of near miss and the marine traffic risk,long-duration near miss means high marine traffic risk;in Bohai Sea,the number of near misses of passenger ships is less,and the duration is shorter;the frequency of short-duration near misses is higher,and there are strong correlations between long-duration near misses and ship size and ship speed respectively;the geographical distribution characteristics of number and duration of near misses are similar;the water areas with higher risk of macroscopic ship collision risk degree based on near miss are the waters areas near Tianjin port and the waters areas near Caofeidian port,followed by the south channel of Caofeidian and the waters areas near Huanghua port.Near misses are used to research the ship collision risk degree in this thesis,which can effectively help researchers and ship officers to understand marine traffic risks from the temporal dimension.It provides a new way for the research of marine traffic risks in spatial and temporal dimensions.