Dynamic Pick-up And Delivery Vehicle Routing Optimization At The End Of The City Based On High-speed Rail Express

The rapid development of express delivery industry has continuously strengthened the competitiveness among enterprises.As a new mode of express delivery,high-speed rail is the key to improve the quality of delivery service.At present,the traditional end-city distribution method is to transfer the goods to the distribution center for centralized storage and sorting before distribution,which cannot meet the diversified market demand,and also brings problems such as high distribution cost and poor distribution efficiency,which hinders the development of high-speed rail express.Therefore,high-speed rail express needs to strengthen terminal distribution and transform to a more efficient and sustainable distribution mode.According to the current end distribution environment of HSR express transportation,the distribution mode of "de-distribution center" is proposed to improve the end distribution efficiency of high value-added and time-sensitive products.Combined with the high-speed train schedule,the city truck is used to deliver high-speed express cargo directly to the delivery point.Considering the truck load and customer time window,a vehicle path optimization model is constructed with the goal of minimizing distribution cost and time.Based on this transportation mode,two transportation modes are proposed to solve the "last mile" distribution: one-way distribution mode and two-way dynamic pickup and delivery mode.The one-way distribution mode takes into account the vehicle carbon emission in distribution,and builds a vehicle path optimization model with the goal of minimizing the distribution cost and time in order to realize green distribution;the two-way dynamic pickup and delivery mode takes into account the customer’s demand for consignment in distribution,and in order to meet the customer’s dynamic demand in a realistic way and obtain the realtime information of new customers and distribution roads,builds a dynamic pickup and delivery model with the goal of minimizing total cost,total time and carbon emission.In order to meet the dynamic demand of customers,we obtain the real-time information of new customers and distribution roads,establish a dynamic pickup and delivery model with the objective of minimizing total cost,total time and carbon emission,and arrange the distribution vehicles to serve the dynamic demand points by using the insertion method.In order to verify the feasibility of the model,a certain period of high-speed rail express in Shanghai station is taken as an example to analyze the distribution model of high-speed rail express terminal "to the distribution center".The results of the case verify the feasibility of "to the distribution center",and compare and analyze the influence of different truck loads on the path planning,and obtain the terminal distribution scheme suitable for high-speed rail express.Then,based on the data results of "going to the distribution center," the delivery point in Shanghai Pudong New Area is selected as an example to analyze the one-way distribution model of high-speed railway terminal,and the impact of carbon emission constraints on the model is analyzed in combination with the case results,from which it is concluded that considering green dynamic demand can effectively reduce carbon emissions.The one-way distribution case is used to analyze the two-way dynamic pickup and delivery model,and the vehicle path optimization results of dynamic and static demand are compared,so as to verify the effectiveness of the two-way dynamic pickup and delivery model in planning the vehicle path.The results show that the dynamic pickup and delivery model can expand the number of service customers,improve the vehicle utilization rate,and improve the distribution efficiency.Finally,by comparing the two distribution modes,this paper analyzes the applicability of the two modes in the terminal distribution of high-speed rail express,which improves the "last mile" distribution service of high-speed rail express,reduces transportation costs while improving distribution efficiency,ensures energy conservation and emission reduction of road transportation,and provides decision support for optimizing the terminal distribution system of high-speed rail express.