Simulation And Research On Port Traffic Flow Based On The Theory Of Cellular Automaton

With the rapid development of the global economy, maritime trade has become increasingly frequent. A large number of ships transport between major ports frequently, which bring large pressure to port traffic. Because of the throughput of ports and low efficiency which can not meet the needs, so ship collisions occurred frequently. Therefore, it has become an inevitable trend to research characteristics of port traffic flow system, establish new and effective model of simulation for ship motion.The technology of cellular automata is a new field of computer science which was originated in the areas of computer science and technology. It has simple structure and flexible rules of evolution, but it can simulate rich and complex phenomenon with simple structure and discrete components. It has been successfully applied in many fields. The research based on the technologies of cellular automata was carried out actively, and a lot of aehievenment has been made in road traffic flow. A lot of technology of cellular automata has been applied to engineering practice, and many good results have been achieved. However, the study of technology which is used in port transport system is still very limited, and a lot of technology is still in the initial stage of the study.Firstly, the port vessel traffic flow characteristics were studied and analyzed, the focus of the state of movement of ships in port, the main factors affect the navigation and composition and characteristics of port transport system, and then refer to the existing traffic flow models, traffic flow modeling were analyzed, respectively, based on 184 rules, based on NaSch, based on slow start, based on the three-phase traffic flow model of port. Based on the analysis in the modeling, reference to the actual characteristics of the port traffic flow, traffic flow model were established consistent with the actual characteristics of the port's vessel traffic system. Each model was simulated and the characteristics of each model were studied and analyzed.Then, in the establishment of the port vessel traffic flow model, considering the actual characteristics of the port transport system, the model which is based on the idea of following and queuing traffic flow model were established. The simulations of the models were carried out. The state of port traffic flow were simulated, particularly for the influence of traffic flow by density, the deceleration probability, service time, a safe distance and other factors. Then the characteristics of each model were summarized.Finally, based on Windows, VC6.0 software development platform, with application of software engineering methods, the visual simulation system with Man-machine interface which was based on the port vessel traffic flow was designed, and the models which were based on car-following thoughts and queuing theory werel simulated. Simulation results show that models of cellular automaton traffic flow which were based on car-following thoughts and queuing theory can simulate the real conditions for the movement of the shipping line, crowding, congestion, etc.