Research On Urban Logistics Distribution Network Planning Based On Subway

As an important part of urban public transportation,metro has the characteristics of high density,large transportation capacity,all-weather,high efficiency and low pollution,etc.Using metro to carry out urban logistics distribution meets the requirements of green logistics,and can effectively alleviate traffic congestion and improve the efficiency of logistics distribution.Therefore,this paper researches the urban logistics distribution network based on metro,firstly analyzes the feasibility and operation mode of urban logistics distribution using metro,then makes a general planning of urban logistics distribution network based on metro,and on this basis,focuses on the node selection problem and path optimization problem in the distribution network.The main research contents are as follows.(1)The feasibility of using metro for urban logistics distribution is analyzed from three aspects: the time period when metro can carry out urban logistics distribution,the transportation capacity of metro and the economic benefits of metro to carry out urban logistics distribution,and the operation mode of metro when carrying out urban logistics distribution is determined.On this basis,the overall planning of the urban logistics distribution network based on metro is carried out,that is to say,the nodes and routes of the distribution network are decided,and the distribution mode of the urban logistics distribution network based on metro is designed.(1)Decision-making of nodes of distribution network:firstly,the nodes are classified into logistics center,distribution center and transit nodes,then the functions of each node,its workflow and the facilities and equipment it contains are designed,and finally,the general description of how to choose various types of nodes are given in terms of selection principles and so on.(2)Line decision of distribution network: In the urban logistics network based on metro,the lines include ground lines and metro lines,the transportation tools are mainly ground trucks,metro cars used for cargo transportation,freight straight ladders,forklifts and other related loading and unloading equipment,and the connection between above-ground transportation and underground transportation is mainly completed by freight straight ladders and forklifts.(3)The operation mode of urban logistics distribution carried out by metro is: "logistics center + distribution center(based on metro station)+ transit node(based on metro station)+ end demand point".(2)On the basis of the above overall planning of the distribution network,the selection methods of various nodes are described in detail,and the selection scheme of nodes is established.(1)Location selection method of logistics center: The logistics center of urban logistics distribution network based on metro is determined by integrating the existing logistics centers accordingly;(2)Location selection method of distribution center: The metro departure or arrival stations near the logistics center with larger radiation range are used as alternative distribution centers,and the AHP-fuzzy comprehensive evaluation method is applied to evaluate each alternative distribution center comprehensively,and the final location of distribution center is determined according to the evaluation results;(3)Location selection method of transit node: firstly,based on the selection principle of the alternative transit node,the metro interchange station in the central city is selected as the alternative transit node,and then,considering the transportation cost,transit cost,fixed operation cost,management cost and investment cost,the transit node location model is established with the objective of minimizing the total cost,and an improved immune genetic algorithm is designed to solve the model,so as to complete the final location of the transit node.(3)On the basis of the aforementioned overall planning of distribution network and node location selection,the distribution path of urban logistics distribution network based on metro is optimized.On the premise of not changing the operation scheme of metro,considering the transportation cost,fixed operation cost of end distribution vehicles and carbon emission penalty cost,taking the remaining capacity of metro,truck capacity and hard time window limitation of customer service as constraints,and the total cost minimization in the distribution process as the optimization objective,the distribution path optimization model of metro-based urban logistics distribution network is constructed,and the improved adaptive genetic algorithm is designed to solve the model.(4)A case study is conducted with Shanghai as an example.By analyzing the metro network structure of Shanghai,substituting the corresponding data,and using the determined selection methods of various nodes,the locations of logistics centers,distribution centers and transit nodes of the metro-based urban logistics distribution network in Shanghai are obtained,and the selection results are reasonable,which proves the rationality and effectiveness of the selection methods of various nodes.On this basis,the data is brought in,the optimal distribution path,distribution cost,distribution distance and carbon emission penalty cost of Shanghai metro-based urban logistics distribution network are obtained by programming and running the program in MATLAB,and the results are compared with the results when the trucks are delivered alone,and the comparison results show that the distribution cost of metro-based urban logistics distribution is lower,the distribution distance is less,and it is more environmental friendly and efficient,which proves the practicality and efficiency of the path optimization model and algorithm.In view of the current problems faced by urban logistics distribution,this paper introduces metro into urban logistics distribution system and conducts a study on urban logistics distribution network based on metro.On the basis of the overall planning of distribution network,the node location and path optimization of distribution network are focused on the study.Finally,a case study is conducted.The case study proves the rationality and efficiency of the node location method and path optimization method,and at the same time,shows the advantages of metro-based urban logistics distribution,which provides some theoretical support for the future development of urban logistics distribution.