Study On Optimization And Application Of Delivery And Pickups Vehicle Routing Problem With Dynamic Demand Considering Time Constraints

In recent years,the logistics economy has developed rapidly,and enterprises have put forward higher requirements for logistics service levels.Land delivery and timely delivery have become the key goals pursued by enterprises.This has made vehicle allocation in the logistics distribution link more complicated.The driving paths are also related to each other,and the impact on them is more obvious for large-scale multi-center site selection and path planning.At the same time,under the condition of personalized service,Competition between companies is fiercer.For small and multi-batch orders,on the basis of meeting customer requirements.increase business revenue and reduce distribution costs,which has become a company’s concern.At the same time,picking up the delivery will become an effective way to improve efficiency.Now meeting the customer’s time constraints has become a necessary condition.The increase in service level requirements will make courier delivery staff face higher requirements in order to ensure delivery.The travel time of people and vehicles.This article not only meets the latest time requirements of customers,but also requires vehicle travel time restrictions.Under this premise,this article takes into account the longest working hours of delivery staff and specifies the latest customer requirements.By the deadline,the cost of the delivery vehicle route is combined with the location selection,and multiple distribution centers are selected to optimize the distribution route.Based on the static demand of the delivery vehicle route planning,dynamic requirements are added to rationally optimize the delivery route.Delivery path to improve service quality.This article combines the professional expertise during postgraduate studies and refers to the relevant research results in the direction of logistics,starting from the category of uncertain factors,the main work of this article:(1)Considering the issue of determining customer demand and taking delivery at the same time,combining site selection and routing.and selecting multiple optimized distribution centers through the interaction between the two,and calculating from changing customer nodes and customer requirements To calculate the cost of the distribution center in multiple cycles,consider the rent of the distribution center.load balancing and other factors,apply entropy weight-topsis method to select alternatives,use the improved ant colony algorithm to build and solve the multi-cycle LRP model.and It is combined with practical problems to find the least cost location plan and to plan static pick-up and delivery routes.(2)Considered three kinds of requirements for the optimization of vehicle routing,including determining demand,choosing dynamic demand and emergency dynamic demand,and rationally planning vehicle paths in different situations.On the basis of deterministic needs,insert new customers,and perform customer analysis on dynamic needs,determine whether emergency customers who must service or pick customers who can choose,analyze the time changes and capacity brought by adding new customers Changes.as well as customer time constraints and emergency customer time requirements,a reasonable model is built,time penalty costs are added,dynamic customer benefits.and dynamic problems are solved through an improved ant colony algorithm.(3)Case study.Collect relevant data such as nodes and requirements,combine the model built with the actual situation,and solve and analyze the programming software to make reasonable site selection and path planning,and verify the reasonable situation of adding dynamic requirements.and improve the distribution company’s service quality.This paper considers the impact of the vehicle routing optimization problem of three types of requirements,and proposes solutions for simultaneous delivery of LRP models and the insertion of dynamic requirements,which enriches the current research content on dynamic requirements and improves the level of customer service.The new scheme is improved,which has important practical significance and application value.