Research On Ship Traffic Organization Through Channel Based On Tide

Maritime transportation plays an important role in global economic development.It is one of the main transportation modes to complete the cargo trade between regions and countries.As the connecting point of marine transportation,port channel has become one of the important factors affecting the trade pattern and the smooth flow of cargoes.For some port channels with extremely busy traffic and the further increase of ship traffic density,traffic jams and even accidents may be happened,therefore,it is of great significance to study the characteristics of ship traffic flow in port channel and the organization of ship traffic.At the same time,the development trend of large-scale ships makes ships to pass through many port channels(such as the Yangtze River Estuary channel,Antwerp port channel,Tianjin port channel,etc.)need to use tide for safe passage.Therefore,the influence of periodic tide should be considered when studying the model and algorithm of ship traffic organization through channel.Firstly,this dissertation analyzed the traffic characteristics of port channel(including water depth,tide,ship navigation rules and customs,traffic management rules and means,etc.)and the factors affecting ship traffic organization.At the same time,this dissertation systematically analyzed the characteristics of tide in port channel and the influence on ship navigation,trained and learned the tide data by using back propagation neural network algorithm,and established the tide prediction and calculation model of the whole channel varied with time and position,which provided the basis for determining the navigable time window for subsequent ship traffic organization.In addition,the traffic system elements of typical oneway channel,two-way channel and compound channel were analyzed,and the ship traffic organization mechanism of channels was obtained.On the basis of comprehensively considering the influence of periodic tide and taking the shortest total waiting time as the optimization objective,the ship traffic organization models of one-way channel,two-way channel and compound channel were established.According to the traffic organization mechanism of different modes,in addition to the consideration of tide,the main problems solved by the three traffic organization models are as follows:One-way channel: it mainly solved the problems of navigable window of each ship,safe distance between two adjacent ships when entering channel,safe speed in channel,time slot conflict between ships,and giving balanced consideration between the navigation priority of large draft ships and first come ships.Two-way channel: based on the research of traffic organization through one-way channel,it also solved the conversion of navigable window and navigation mode caused by bidirectional traffic flow and the breadths limitation of two-way ships.Compound channel: based on the research of traffic organization model of one-way channel and two-way channel,it focused on solving the problems which include navigation mode conversion problem caused by breadth restriction,the traffic flows conflicts between different traffic flows of main and auxiliary channels,and the traffic flows conflicts in the complex intersection of channel and in the main and auxiliary channels entrance and exit.Then,according to the requirements and optimization objectives of the traffic organization models,genetic algorithms were designed to verify the models.In order to avoid premature convergence and find the optimal solution,the algorithms were improved appropriately.Finally,the rationality and effectiveness of three traffic organization models and algorithms considering tide prediction were verified by using multiple groups of data of navigation ships in the actual port channels such as north channel of the Yangtze River,Tianjin port channel and Huanghua port channel,and the ship navigation organization sequence scheme,navigable time of each ship and total waiting time were output.Then the results were analyzed and compared with other traffic organization modes(including the results of the first come first served mode,large draft ship priority mode,manual traffic organization mode and random traffic organization mode).The rationality and progressiveness of the models and algorithms of ship traffic organization established by this dissertation were verified from the total waiting time and the reasonable utilization of tide,and the research of this dissertation had made contribution to the ship traffic organization through channel with tide consideration.