Multi-agent Based Modeling And Simulation Of Vessel Traffic Flow In Inland Multi-bridge Waterway

The quantity,size and velocity of ships and traffic flow density are increasing with the rapid development of inland shipping,and the number of bridges acorss inland rives is also increasing with the rapid development of the highway transportation network.The bridges deteriorate sailing environment of the bridge area,reduce the navigation efficiency,and increase the difficulty of supervision and navigation risk.To solve these problems,vessel traffic flow need to be researched.However they are influenced and restricted by various factors such as people,ship,environment and management etc.;they are also with the temporal and spatial dynamic change;it is difficult to use accurate mathematical model to describe them;and ship traffic flow is not suitable for the real ships to do experiments.Therefore,this paper presents a modeling and simulation method based on Multi-Agent to simulate the traffic flow of multi-bridge waterways of the Wuhan Changjiang River.The contents of this thesis are as follows:1.The elements of navigation environments of the Wuhan Changjiang River waterway are analyzed from the Baishazhou waterwy to Tianxingzhou waterway.Firstly,the elements are introduced inculding a brief glimpse of characteristics of the waterway,locations of bridges in the waterway,hydrological and meteorological conditions and features of the bridges includeing the Baishazhou Bridge,the Yingwuzhou Bridge,the First Yangtze River Bridge,the Second Yangtze River Bridge,the Erqi Bridge and the Tianxingzhou Bridge in the waterway;then this analysis is made about the influence of navigation environment on ship behavior,track distribution and sizes of ships.2.The Ship Agent simulation model is established.The feasibility analysis of Ship Agent modeling is made and the processes of Agent modeling and ship traffic flow modeling are present respectively;a framework of Multi-Agent based ship traffic flow simulation system is structured according to characteristics of ship traffic flow;each ship is regarded as an Agent and a structure of a Ship Agent is defined according to characteristics of ship's behavior;the collaboration and communication mechanism between Ship Agents is discussed and the decision models of Ship Agents about free navigation,following and overtaking are researched.3.The methods of generating Ship Agents and their routes are proposed.Probability distributions of ship traffic flow are obtained through the analysis of historical data of ship traffic flow in the bridge area waterway;the ship generation model and the route generation model are setup using the Monte Carlo method.4.A simulation platform is constructed.Architecture of the simulation platform is constructed according to functions of the ship traffic flow simulation system and the operating environment of the simulation platform is determined;key technologies of the simulation platform about Inland ElectronicNavigation Charts,database design,description of classes and process of the Ship Agent based simulation are researched;then the user interface is designed;finally the simulation models and algorithms are verified and the results show that the simulation system is feasible.5.The two simulation applications are finished base on the simulation platform.The first one is to assess the ability of the inland multi-bridge waterway;and the second one is evaluate risk of ship collision in the inland multi-bridge waterway.The researches of this thesis can quantitatively or visually analyse characteristics and laws of the ship traffic flow,and offer means and methods for the evaluation of transit capacity and navigation risk in inland multi-bridge waterway.