Joint Optimization Of Storage Yard Stacking And External Trucks Retrieving In Container Terminals

The container terminal yard is the main area for container loading and unloading.Optimizing the storage and location of containers entering and leaving the terminal can improve the operation efficiency of the terminal.At the same time,the external truck company is undertaking the task of transporting containers to or from the terminal and optimizing picking method to reduce the relocation rate.In the past,the optimization of the two aspects was often carried out separately.With the rapid growth of the global container trade,the demand for container storage and pick-up has increased rapidly,which has brought complex operational challenges to the terminal yards and external truck companies.The joint optimization of storage location and external truck retrieving is urgently an issue need to be solved.In addition,whether to introduce automated terminals and how to coordinate the competition and cooperation between automated terminals and external truck companies is another important issue that needs to be solved urgently in the container supply chain.The research aims to improve the operation efficiency of the terminal yard,reduce the relocation rate of the yard and optimize the container supply chain.Based on the optimization and game method,we have researched on the joint optimization of storage location and container pick-up at the container terminal yard,the game of automated terminal introduction and the collaborative optimization of the automated terminal and external truck retrieving.Then we propose the corresponding mathematical model and design different algorithms to solve the problem based on the characteristics of the model.The main research work is as follows:1.The problem of joint optimization of container yard allocation and container picking up of ordinary container terminal is studied.Considering how to choose the storage location of containers to minimize the number of relocations in the yard,a mixed integer programming model is established to solve the allocation of containers in the yard with the minimum number of relocations.The worst case and the best case are analyzed based on the model.At the same time,the lower bound of the model is proposed and a heuristic algorithm is established.Numerical analysis shows that small and medium-scale data can be solved by the model,and the heuristic algorithm proposed in this paper can get a better conclusion for large-scale data.The results show that when considering the unloading sequence of the container and the pick-up sequence of the external truck,the number of relocations in the yard will be significantly reduced.It provides a strong theoretical support for the container yard location allocation and container relocation.2.The optimization problem of retrieving container with waiting area is studied.The main consideration is to enter the waiting area(or buffer area)of the terminal yard first after the external truck arrives at the gate,and then retrieve the container according to the container's position in the yard.And the container can be picked up within the acceptable waiting time,so that the number of relocations at the terminal yard is the minimized.A mix linear integer programming model is proposed.Based on the model,the relationship between the number of slots in the waiting area and the waiting time is analyzed.Numerical examples illustrate the effectiveness of the model.According to the actual situation,the results show that the containers with waiting area can improve the efficiency of the terminal yard better than ordinary retrieving.3.The decision to introduce automated terminals is studied.It is mainly considered whether two competing terminal operators need to introduce automated terminals to improve the overall operation strength of the terminal.Firstly,the two terminal operators decide whether to introduce the automatic terminal at the same time.If one is introduced,further determine the unit operating cost collected from the automatic terminal,secondly.Lastly,the two terminal operators and the automatic terminal simultaneously determine the output level to maximize their profits.The equilibrium results are analyzed by a model and are illustrated by numerical examples.The results show that the simultaneous introduction or the introduction of an automated terminal by both parties are equilibrium results.4.The supply chain model of the automated terminal and the external trucks company is studied.According to the two different cooperation modes of the automated terminal and the two different market positions of the external trucks company,four possible cooperation modes are formed and got the Nash equilibrium solution.Numerical analysis shows the effectiveness of decision-making.The results show that the integrated operation of the automated terminal and the external trucks company is a kind of equilibrium,but it is not absolute.The type of services provided by the external trucks company and the degree of network externalities need to be considered.5.The collaborative optimization of the automated terminal and the external truck appointment system is studied.Considering the dynamic collaborative truck appointment system,a centralized truck appointment system model and a decentralized truck appointment system model are proposed.The purpose is to adjust the truck's arrival time at the gate and to minimize terminal congestion.The numerical analysis shows the effectiveness of the model.The results show that the dynamic collaborative truck reservation system can significantly reduce the waiting and congestion costs of the external truck company,so as to reduce the congestion of the terminal.The research focuses on the joint optimization of container terminal storage yards and the external truck retrieving.Specifically,we study the container storage location selection and the container retrieving,the problem of relocation containers in the waiting area,and the collaborative optimization of automated terminals and the external truck companies.At the same time,from the perspective of the supply chain,the decision-making of the introduction of the automatic terminal mode and the supply chain mode of the automatic terminal and the external truck company are studied.The research results can provide a theoretical basis for the scientific decision-making of relevant transportation government departments,port groups,etc.And the results are guiding significance for the optimization of the ordinary container terminal and the automatic terminal container relocation and retrieving.