Optimization Research On Vehicle Routing Problem Of Cold Chain Joint Distribution Considering Carbon Emissions

With the rapid development of social economy,people’s living standards improve and consumers’ attitudes toward lifestyle gradually change.Nowadays,the demand of the fresh product is corresponding increased,followed by the improvement of the quality of cold chain logistics.However,the fresh product is vulnerable,which increases the difficulty in storage and transportation,resulting in the problem of high cost.As an important part in the cold chain logistics,the vehicle routing problem of cold chain is a breakthrough to the problem of cost and service time.It provides solutions for reducing the cost of cold chain logistics and improving the service quality from the point of optimizing the route of distribution.On the basis of reading numerous researches,combining with the characteristics of cold chain logistics,this article solves the optimization of the vehicle routing problem of cold chain.First of all,the article reviews the literatures of cold chain logistics,vehicle routing problem with its solutions,joint distribution and time windows,laying foundations for the subsequent research.Secondly,considering the vehicle start-up costs,loss costs,energy costs,time penalty cost,as well as carbon emission cost,this article builds a model of the vehicle routing problem of cold chain.Divide the problem into the single-distribution-centre problem and the multiple-distribution-centre problem according to the number of distribution centres;establish respectively the closed model of vehicles and the semi-open model of vehicles based on whether the vehicles need to return to the starting distribution centre.Last but not least,design the algorithms to solve the above models,using the results obtained by mileage-saving method as the pre-optimization scheme and the results obtained by particle swarm optimization as the optimization scheme.Collect entreprise data and design examples,use the algorithms to solve the specific problem for the case,then get and analyze the results that particle swarm optimization can be used to optimize the vehicle routing problem.The high-cost problem is a challenge of the cold chain.This article proposes an aspect of solving the problem,in order to reduce the cost of delivery with the view of route.The problem of cold chain logistics remains to be further improved.