Study On Heterogeneous Fleet Routing Optimization Of Fresh Distribution Center Under Carbon Emission Regulation

In September 2020,China put forward the goal of carbon neutrality,and strive to achieve this goal,in 2060 and the rapid development in recent years,domestic logistics,highway transportation caused a large number of greenhouse gas emissions,the problem has been an extensive concern of various countries,fresh,with the rapid development of electrical business make fresh distribution logistics of rapid increases,become one of the important cause of greenhouse gas emissions.The process of fresh distribution is affected by many factors.Therefore,to study the vehicle routing problem of fresh distribution,we must fully consider all kinds of internal and external factors that affect fresh distribution and include them into the model.Domestic and foreign studies on perishable food vehicle routing mainly focus on reducing costs and improving customer satisfaction,and the carbon emission factor is not considered much.This paper intends to consider including cost,time window and carbon emission into the model,and further comprehensively study the fresh distribution cost and carbon emission optimization vehicle routing problem.Fresh market demand changes quickly,in response to changing needs,consider private teams combined with leasing team mixed team distribution,heterogeneous team has a different weight and unit transportation cost,easier to achieve flexible arrangement,this paper will cost included in the model heterogeneous teams,study the effect of heterogeneous team for fresh changes in the cost of distribution,and heterogeneous fleet has positive effect to reduce the punishment cost and carbon emissions.Considering that the vehicle distribution process is affected by traffic congestion and speed,this paper plans to introduce the speed-related carbon emission factor,establish a carbon emission calculation formula that comprehensively considers speed,load and distance,and study the impact of different traffic congestion conditions on carbon emission changes.In this paper,an optimization model of heterogeneous fleets for fresh distribution under carbon emission regulation is established,and the rental vehicle method is introduced into the model.In order to solve the model,an improved TS algorithm is designed in this paper.Combined with the model factors,the initial solution is constructed by using two greedy strategies,namely,high demand of priority service and earlier delivery time of priority service,and the neighborhood search rules of three kinds of mobile combination are designed.The numerical example results show that this algorithm can solve the model quickly.Sensitivity analysis of the model shows that under different traffic conditions,heterogeneous fleets can effectively reduce costs and carbon emissions,and some combinations are effective in reducing penalty costs.In addition,the study shows that in the long run,reasonable ownership scale of private fleets can further reduce costs,and rental fleets can effectively cope with short-term demand changes.