Research On Cold Chain Logistics Path Optimization Considering Cascading Failure

The problem of vehicle routing is a core issue in logistics management.Unreasonable transportation in logistics will result in wasted transport capacity,increased transportation costs,labor costs,and other costs.It will also result in customer service satisfaction due to missed optimal delivery time,reduced degrees of damage to corporate reputation and image.With the acceleration of urban construction and the increase of urban scale,urban traffic accidents occur from time to time,and the impact of emergencies does not exist alone.A small emergency will trigger cascading failure through the coupling relationship in networks.As a result of the change in network traffic conditions,resulting in changes in network traffic conditions,seriously affect the level of logistics distribution.Cascading failure have wide range of influence,hard to predict and other characteristics.Traditional vehicle routing problems are often based on fixed network status or real-time road network dynamics.And in the face of network burst cascade failure,the original distribution path is no longer applicable.In this circumstance,continue to increase the vehicle transit time according to the original vehicle distribution route,and re-select the route according to the individual behavior of the driver,and also lack the supervision of the delivery vehicle by the enterprise,which increases the uncertainty of distribution.Therefore,establish a cold-chain logistics distribution optimization model that considering the cascading failures of transportation networks has great significance to increase the ability of cold-chain logistics companies to dispatch and command the distribution process,improve the emergency response speed of delivery vehicles in logistics enterprises in the event of traffic network emergencies and improve the market competitiveness of enterprises.This thesis considers the cascading failures of transportation networks,discusses the propagation process and the impact of the results of cascade failures in complex networks,and the optimization of logistics distribution vehicle routing in transportation networks.The main research contents are as follows:1.Studying the propagation process of cascading failure.According to the actual situation,the load condition of the road section is determined according to the driving speed,and a new diversion rule is formulated to describe the cascading failure propagation of the network as practically as possible.2.Studying the distribution cost of cold chain logistics,finding that the distribution cost is not only related to the transport distance,but also to the delivery time.And cascading failure will indirectly affect the transit speed of the edge of the network and then affect the delivery time.Based on those,this thesis optimizes the objective function of distribution cost,and establishes an optimal vehicle distribution routing model for cold chain logistics under cascading failure conditions.3.Considering that most of the nodes in the actual distribution network are not logistics nodes,and multiple paths may exist between logistics nodes.Dijkstra-GA algorithm,which combines the advantages of Dijkstra’s algorithm and genetic algorithm,is proposed to solves the model,and proposes a segmentation method to solve the problem considering that the network conditions are different between before and after the cascade failure.And an example is used to verify the applicability of the proposed model and algorithm.4.Finally,the content and conclusion of this thesis are summarized,and the future research direction is prospected.