Multi-objective Distribution Routing Problem In Urban Cold Chain Logistics

Cold chain logistics started late in our country,but it has developed rapidly.In recent years,the cold chain logistics industry has received a lot of investment,and the scale and level of facilities and equipment in the industry have also been improved.The cold chain logistics industry has not developed in my country for a long time,and there are still many problems,such as the low efficiency of cold chain logistics and distribution.How to improve the efficiency of cold chain logistics and distribution has very important practical significance.This paper introduces the theory of common distribution into cold chain logistics distribution to improve the efficiency of cold chain logistics distribution.This article first introduces the theory of cold chain logistics,vehicle routing problems and joint delivery,and clarifies the research direction.Then introduce the cooperative mode,resource integration method and six distribution strategies of the joint distribution theory,and combine the theory of cold chain logistics and vehicle routing problem,select two of the distribution strategies as the research focus of this article.Secondly,with the goal of maximizing customer satisfaction with delivery time and lowest logistics delivery cost,establish a multi-depot cold chain logistics common delivery path model based on fixed multi-target vehicle allocation.Combined with the theory of common distribution,the customer resources of multiple distribution centers are integrated,and the customers who originally belonged to different distribution centers are regrouped through the K-means clustering method.In the multi-objective model,the goal of customer satisfaction is treated as a model constraint.Set customer satisfaction as a fixed value,and convert multi-objective problems into single-objective problems for solution.The corresponding genetic algorithm is combined with the model design to solve the problem.Afterwards,research on the common delivery route model of cold chain logistics in multiple depots with unfixed vehicle affiliation.Combined with the theory of common distribution,the distribution vehicles that originally belonged to different distribution centers are shared.Considering that the total cost of logistics and distribution in a single cycle is the smallest,and the delivery volume of each distribution center in the next cycle must match the delivery vehicle capacity of the distribution center,so the logistics cost and the transportation capacity of the distribution center are compared with the delivery volume of the distribution center in the next cycle.The goal is to minimize the inter-variance,establish a multi-depot cold chain logistics common distribution route model based on the multi-target vehicle allocation is not fixed,and combine the model to design the corresponding genetic algorithm to solve it.Finally,the two models proposed in this paper are solved and verified by examples.The multi-depot cold chain logistics common distribution path model based on the fixed multi-objective vehicle assignment is processed,the multi-objective function is converted into a single objective function,and three different customer satisfaction values are set,and comparative analysis is carried out through examples.This paper also verifies the vehicle routing problem of multi-depot and multi-objective cold chain logistics where the vehicle is not fixed.Finally,it proves that the common distribution mode of cold chain logistics has certain advantages in real life,which provides a theoretical basis for cold chain logistics enterprises to adopt the common distribution mode.