Research On Synthesi Channel Transit Capacity Of Seaport By Using Petri Net

Seaport channel transit capacity,of which the definition is that the total tonnage of goods or the total number of ships passed through a channel section in unit time,contributes to port economy and port service level.Calculation and simulation on channel transit capacity can provide the theoretical basis for the design of channel department,the management of port department and the operation of berth.As seaport channel is a typical stochastic,complex,dynamic and discrete system,mathematical formulas cannot calculate the capacity by rule and line and reflect the change of port operation exactly.However,computer simulation technology provides an efficacious way to simulate the seaport channel system,because of its powerful logicality and calculation ability.In this paper the relationship between seaport channel system and its subsystems,which are arriving ships waiting at anchorage for berth subsystem,ship to port subsystem,harbor operation subsystem and ship out of port subsystem,was analyzed and the hierarchical models of seaport channel system and its subsystems were constructed by using Petri net.Subsequently,on this basis,the dynamic simulation model on seaport channel transit capacity was established by SIMIO software.By modifying the properties and logical processes of the “object” in the seaport channel transit capacity dynamic simulation model,the “object” with specific behavior characteristics was obtained,which was connected in accordance with the actual Fangchenggang seaport channel system,and the reliability of the model was verified by inputting the statistical data of ship traffic flow and port throughput of Fangchenggang in 2014.According to the data of 2015,the changes of ship traffic flow,port throughput,average ship in port time,average ship waiting time,average ship berthing time,berth utilization rate and port service level under the conditions of changing ship arrival time interval,berth loading and unloading efficiency and ship dispatching mode were studied respectively.