Research On Design And Optimization Of Urban Underground Logistics System

Traffic congestion is one of the difficulties encountered by the world's major cities.The main reason for the traffic congestion in the city is the huge increase in the number of vehicles and vehicles on the ground roads caused by the surge in traffic demand,and part of that is the increase in demand for cargo logistics.A large number of practices have proved that it is neither scientific nor realistic to increase the ground transportation facilities to meet the ever-increasing traffic demand,and the ground road cannot be increased without limit The underground logistics system does not occupy the ground roads,reducing the traffic pressure on the ground roads,thus alleviating urban traffic congestion.However,the research and practice of ULS has only just begun.So far,there has not been a successful case of city scale in the world.There are several failures.Therefore,it is urgent to conduct forward-looking research on the scale of the city to explore the theory and practice of developing underground logistics systems.The research results of the thesis are mainly reflected in the following aspects:The thesis takes the urban underground logistics system as the research object,and studies the analysis of the concept of ULS on the basis of the theory of urban underground logistics system.From the perspective of traditional logistics system and rail transit,the paper compares and analyzes the similarities and differences between traditional logistics system,urban subway and underground logistics system,and summarizes the components and characteristics of urban underground logistics system.According to the related concepts of underground logistics system and logistics network,the concept of urban underground logistics system network is studied and analyzed,and the layout structure classification of logistics network is divided.Finally,by analyzing the difficulties and development status of the logistics network,it summarizes the difficulty and urgency of the current urban underground logistics system research.In view of the network design of urban underground logistics system,this paper starts with the basic principles of model construction,and analyzes several key points that need to be paid attention to in model construction.After analyzing the principles of model construction,the basic assumptions of the model are described and analyzed.Based on the evaluation of the importance of logistics nodes,the index system of logistics node selection model is constructed,the constraint rules of the model are analyzed,and the constraints of the model are refined.Finally,based on the index system foundation and constraint rules,the mathematical model of the node selection model is constructed.For the node selection objective function,this paper selects the iterative self-organizing data analysis algorithm to solve the model clustering.In view of the network optimization problem of ULS,this paper first evaluates and analyzes the nodes selected by the node selection model,and builds a network efficiency evaluation model index system.The analytic hierarchy process is used as the index weight determination method and the ideal point method is the ranking determination method,and the first-level node network level evaluation is obtained.Then,the Q learning algorithm is used to coordinate the selected secondary nodes to optimize the network scheduling and reduce the risk of the network.Finally,this paper demonstrates and verifies the model established in this paper through an example.First,collect and pre-process the data needed for the case,and then use the relevant software to land the clustering algorithm.On the basis of the network optimization index system,the first-level node design model is evaluated by the corresponding sorting method,and the second-level nodes are collaboratively optimized in combination with the Q-learning algorithm.