The Simulation Research Of Multi-gate Dynamic Operation Based On Yard Traffic Flow

With the rapid development of international trade in recent years,the container transportation was developed rapidly and container traffic has increased accordingly.The original operation mode of the terminal can not adapt to the ever-increasing traffic volume.Although some intelligent equipments have been used to improve the efficiency of containers passing the gate--which is regarded as an essential channel for containers going in or out of the port,the congestion is still serious.A container terminal in Tianjin Port makes use of its own gate conditions in the spot,transform the original intelligent gate into a multi-stage intelligent gate(hereinafter referred to as multi-stage gate).The collection trucks classification management and the ways of shunting segmented control,which are employed in order to reduce the time of container trucks through the gate,at the same time,improve the operation efficiency of the terminal gate.At present,the multi-stage gate has not widely been used in domestic and international terminals,and few literatures on the multi-stage gate operation can be retrieved.The existing literatures mainly focused on the intelligent transformation of multi-stage gate facility equipment and operation technology.During the actual operation,terminals control the gate channel and the traffic flow just according to the experience,lacking the corresponding theoretical analysis and research.In this paper,the intelligent gate system is introduced,the structure layout and function of the multi-stage gate are introduced emphatically.Then,after using queuing theory to analyze the multi-stage gate operation process,the multi-stage gate operation mode is put forward,which is based on the yard traffic flow and channel dynamic allocation.By introducing the dynamic operating factor of the multi-stage gate(hereinafter referred to as the multi-stage gate factor)and the yard traffic flow density factor(hereinafter referred to as the yard factor),the dynamic operation rules of multi-stage gate based on the yard traffic flow are developed.Secondly,according to the practical research data,the probability distribution of the input variables of simulation model and the working time of loading and unloading machinery are analyzed statistically.The operation system of multi-stage gate in container terminal is simulated with the software--Plant Simulation,and then the dynamic allocation of the entrance channel in multi-stage gate is realized.The queuing theory evaluation index is used to evaluate the simulation output data of the many factor schemes,and the optimal value of the factor is determined,so as to obtain the optimal scheme of the multi-stage gate entrance channel allocation.Finally,comparing the simulation data between the multi-stage gate operation mode and single-stage gate operation mode,it can be concluded that the former can effectively improve the passing capacity of the gate,and reduce the residence time of the container trucks at the gate,then improve the operation efficiency and the throughput of the terminal at meanwhile.