Study On Express Route Optimization Problem With Simultaneous Delivery And Pickup Under Dynamic Demands

The rapid development of e-commerce industry has raised higher requirements for express delivery,People hope that express companies can provide faster and better logistics services.With the help of convenient and fast mobile Internet,people can submit,cancel or change their orders and express needs anytime and anywhere.Facing the dynamic changing demands with high frequency,small batch and scattered distribution,it is a difficult problem for the express company to respond and adjust the distribution scheme quickly and scientifically,so as to make use of the transportation resources reasonably and reduce the logistics cost under the premise of ensuring customer satisfaction.In this paper,express route optimization problem with simultaneous delivery and pickup under dynamic demands is studied,and a theoretical method of responding to customer's dynamic demands rapidly and optimizing the vehicle routing in real time is proposed.(1)The solving process of express problem with simultaneous delivery and pickup under dynamic demand is divided into two processes: demand processing and routing optimization.For demand processing,this paper analyzes the types of dynamic demands in the process of express delivery in detail and puts forward transformation processing strategy for these demands.For routing optimization,the intelligent algorithm is embedded in the scheduling process to design a new scheduling strategy for solving the problem.In order to solve the express simultaneously delivery and delivery problem,according to the classification of routing optimization problem and different research scenarios this problem is subdivided into express vehicle routing problem with simultaneous delivery and pickup(EVRPSDP)and express traveling salesman problem with simultaneous delivery and pickup(ETSPSDP),and different scheduling solution strategies are designed respectively.(2)Express vehicle routing problem with simultaneous delivery and pickup under dynamic demands is studied.Aiming at the dynamic demands for express delivery,a rolling cycle scheduling strategy which combines batch processing with emergent scheduling is proposed.And the EVRPSDP model is built.Combined with the rolling cycle dynamic scheduling process,the m-TSP algorithm framework is designed,and a hybrid Ant Colony algorithm is used to optimize the route in this algorithm framework.Finally,it is proved by calculation example that using the rolling cycle scheduling solution strategy can effectively solve the EVRPSDP problem under dynamic demand.It can realize the rapid response to dynamic demands and reduce the logistics cost of express company while ensuring customer satisfaction.(3)Express traveling salesman problem with simultaneous delivery and pickup in real time is studied.Aiming at the real-time demand submitting in the process of single vehicle delivery,a strategy of vehicle autonomous scheduling which combines centralized scheduling with decentralized scheduling is proposed.An autonomous scheduling algorithm framework is designed for independent decision-making,such as dynamic requirements processing,path planning and updating.And an autonomous decision-making model is constructed to solve the conflict of requirements processing and achieve more complicated decisions through collaboration between multiple vehicles.Finally,a comparison experiment is designed to verify the feasibility and effectiveness of the solution strategy.And a practical application example with the actual map data of Yubei District in Chongqing is designed to apply the vehicle autonomous solution strategy to the actual express delivery process.