Collaborative Optimization For Loading Operation Planning And Vessel Traffic Organization In Bulk Cargo Ports

As the two most important operation stages of bulk cargo ports,loading operation plan and vessel traffic organization are crucial to improve the overall operation efficiency of bulk cargo ports.As the vessel traffic organization stage involves many restrictive factors such as channels,harbor basins and port navigation rules,and the loading operation plan stage involves restrictions on loading equipment operation and complex loading operation process,it is difficult to improve the overall operation efficiency of bulk cargo ports by preparing the loading operation plan and vessel traffic organization plan respectively in the traditional manual experience way.Especially for the bulk cargo ports with multi-harbor basins and a restricted channel,with the increasing demand of bulk cargo transportation,higher requirements are put forward for their overall operation efficiency.Therefore,this thesis takes the bulk cargo port with multi-harbor basins and a restricted channel as the research object to study the collaborative optimization of loading operation plan and vessel traffic organization in bulk cargo ports.Considering that there are many factors involved in the collaborative optimization of the above two phases,this thesis adopts the idea of optimization at each stage before two-stage collaborative optimization.That is,firstly,the optimization of vessel traffic organization and the optimization of loading operation plan are studied respectively,and then the two-stage collaborative optimization is studied.The following research work is mainly carried out:(1)For the problem of low navigational efficiency of a restricted channel in multi-harbor basins,an optimization method of vessel traffic organization of a restricted channel in multi-harbor basins is proposed.Firstly,a restricted channel in multi-harbor basins model is abstracted.The characteristics of vessel traffic conflicts in each area of the restricted channel in multi-harbor basins are analyzed from macroscopic and microscopic perspectives,and the constraints of traffic flow time slot allocation in the entrance area of the channel,traffic flow conversion in the one-way and two-way connection area,traffic flow coordination in the entrance area of the multi-harbor basins and traffic flow conflict elimination in the harbor basin are constructed.Then,on this basis,a multi-objective mixed integer planning model with the objectives of minimizing the dispatching time and minimizing the waiting time of all vessels is established by considering the constraints of vessel riding tide,vessel navigation continuity,and port navigation rules.A Non-dominated Sorting Genetic Algorithm II and Tabu Search algorithm(NSGA-II-TS)is designed to solve the model and obtain the optimal vessel traffic organization scheme.In the algorithm solution process,the rationalization of navigation mode and the strategy of repairing the same berth by leaving first and berthing later are proposed to avoid the generation of infeasible solutions.Finally,simulation experiments are conducted with the channel of Huanghua coal port as an example to verify the reasonableness and effectiveness of the model and algorithm.The method can effectively improve the navigational efficiency of the port channel.(2)Aiming at the problem of frequent interruptions in the loading operation process due to the conflict of loading equipment operations in bulk cargo ports,a method is proposed to optimize the loading operation plan.Firstly,the loading operation process flow of single reclaiming and single loading operation mode is analyzed,and the operation conflict characteristics of reclaimers and shiploaders are determined.Then,on this basis,a mixed integer planning model with the objective of minimizing the maximum loading operation completion time is constructed.A Heuristic Logic-based Benders Decomposition algorithm(HLBBD)is designed to solve the model and obtain the optimal loading operation plan scheme,considering constraints such as the reclaimer operation in the same track/different track,shiploader operation in the same track,loading scheme,loading sequence,and yard-to-berth transportation distance.The original problem is decomposed into the main problem of loading scheme and loading equipment allocation,and the sub-problem of optimizing the loading operation.Then,in order to overcome the low validity of the optimal cut,a heuristic strategy is designed to generates multiple optimal cuts in each iteration of the sub-problem and introduces them into the master problem.Finally,simulation experiments are conducted with the Phase I and Phase II terminals in Huanghua coal port as an example to verify the reasonableness and effectiveness of the model and algorithm.The method can effectively improve the efficiency of loading operations in bulk cargo ports.(3)For the problem of low overall operation efficiency of bulk cargo ports,a collaborative optimization method between loading operation plan and vessel traffic organization in bulk cargo ports is proposed.Firstly,the factors influencing the synergy between loading operation plan and vessel traffic organization are analyzed from the internal and external conditions of the bulk cargo port system,and the constraints of their synergy are determined.Then,based on the relevant constraints in(1)and(2)above,a multi-objective mixed integer planning model with the objectives of minimizing the waiting time and minimizing the completion time of loading operation is constructed by considering the constraints of stacking capacity,berth allocation,accessibility of loading operation process,berth-shiploader-reclaimer allocation and the preparation time of loading operation for the next vessel.Based on the characteristics of this model,a Non-dominated Sorting Genetic Algorithm II and Variable Neighborhood Search algorithm(NSGA-II-VNS)is designed to solve the model and obtain the optimal synergistic scheme of loading operation planning and vessel traffic organization.In the algorithm solution process,in addition to considering the proposed rational repair strategy for the navigational mode,the same vessel scheduling sequence rationalization and the berth-shiploader-reclaimer allocation rationalization are also proposed to avoid the generation of infeasible solutions.Finally,simulation experiments are conducted with Phase I and Phase II terminals and the channel in Huanghua coal port as an example to verify the reasonableness and effectiveness of the model and algorithm.The method can effectively balance the navigational efficiency of the channel and the loading operation efficiency while improving the overall operational efficiency of the bulk cargo port.