Research On The Composite Modeling And Simulation Of Berth System In Container Terminals

In our country, lots of container terminals’actual berth throughput far exceeded their design throughput capacity which results to series problems such as lacking of yard capacity and poor performance of traffic flow. This indicates that there are defects in the existing berth throughput capacity estimating method. To improve the accuracy of berth throughput capacity estimating and solve parts of the key problems during the berth system design phase, this paper made a systematic analysis of container terminal berth system’s structure, dynamic work procedure and its subsystems’characteristics. According to the different characteristics between the berth system and its subsystems, multiple kinds of modeling theories were chosen to build a composite model. By using this composite model, the new estimating method of berth throughput capacity is proposed and research works on some key design problems of the container terminals berth system is accomplished. More detail research works are listed as follow:(1) Through in-depth analysis of berth system’s structure and input/output objects’characteristics, this paper summarized the main effect factors of berth throughput capacity from three aspects:time, equipment capacity and traffic flow. The goal of the simulation optimization was also defined.(2) The Discrete Events Dynamic System Modeling Theory which including Hierarchical Modeling method, Object-Oriented modeling method and Petri-Net Modeling method was used to build the berth system’s conceptual model. This conceptual model could show berth system’s structure and dynamic work procedure in detail. Asynchronous cellular automata modeling theory was used to build the transportation subsystem’s conceptual model which can describe the self-organized and intelligent behavior of container truck exactly. The way to integrate those two models was also given.(3) The implementation of the composite model of container terminal berth system which includes the model structure, the logic relationships between simulation elements and the model input/output interface based on Witness simulation platform was proposed. After that, the verification work of the composite model by comparing the simulation data with the statistics data from some operated container terminals was accomplished.(4) By using the composite model, this paper also researched some key problems including the best container truck quantity of each quay-crane, the analysis procedure and optimization method of the wharf apron traffic flow and the step to estimating the berth throughput capacity increase which berth group effect brings.Through the research works mentioned above, a new method to build composite model of berth system in container terminals was proposed. Comparing to the existing modeling method, the new composite modeling method can build a model which can estimate the berth throughput capacity more accurate. It also provided a new solution to optimize the design of berth system in container terminals.