Research On Multimodal Transport Routes Election Of Cold Chain Logistics In Uncertain Environment

With the development of China’s economy and the improvement of consumers’ living standards,the demand for fresh and perishable goods is increasing day by day,and the market scale of cold chain transportation is further expanding.Multimodal transportation is a new mode of intensive and efficient transportation,combining multiple modes of transportation together,which is in line with the development trend of transportation industry to reduce costs and increase efficiency,energy saving and emission reduction.With the increasing demand of consumers for fresh and perishable commodities in terms of timeliness and economy,the multimodal transport market is gradually changing to specialization and customization,while the uncertainty in the cold chain multimodal transport system is becoming more and more prominent.In order to improve the transportation efficiency and customer satisfaction of cold chain intermodal transportation,it is urgent to study the cold chain intermodal transportation problems under uncertain environment.In view of the uncertainties in the development of cold chain multimodal transport in China,this paper studies the path selection of cold chain multimodal transport under two uncertain conditions of demand and unit transportation cost based on the volatility of the market environment,in order to reduce the waste of capacity and loss of cargo caused by the changes in the market environment and continuously improve the overall level of cold chain multimodal transport in China.The main research contents of this paper are as follows:(1)Study and summarize the research achievements in multimodal transportation,cold chain logistics,and uncertain planning,and explore the applicability of cold chain multimodal transportation in the transportation of fresh and perishable goods in China based on the actual development of cold chain logistics and multimodal transportation in China.Based on relevant theories,summarize the definition and characteristics of cold chain logistics multimodal transportation,construct a transportation network diagram of cold chain logistics multimodal transportation,and analyze the operation process of cold chain multimodal transportation from the perspectives of business and transportation based on the operation links of different types of goods.(2)Organize the relevant factors that affect the selection of cold chain multimodal transportation routes for fresh and perishable goods from the perspectives of nature,economy,and other factors.Conduct specific analysis with the model objectives of total transportation cost,total energy consumption,and cargo damage rate.On the premise of meeting customer transportation time requirements,construct a multi-objective cold chain logistics multimodal transportation route selection model.In response to the various uncertain factors in the multimodal transportation system of cold chain logistics,combined with the impact of changes in market environment,this paper considers the uncertainty of transportation demand and unit transportation cost as uncertain variables,and uses triangular fuzzy numbers to express them.Combined with chance constrained programming,the uncertain model is transformed into an equivalent deterministic model.(3)Based on the analysis of three examples of fresh and perishable goods transportation in China,a corresponding cold chain multimodal transportation network is constructed,and the DE-NSGA-II algorithm is used to solve the problem.A uniformly distributed Pareto solution set is obtained.The results are compared with the NSGA-II algorithm in terms of operation time and number of solutions,proving the effectiveness of the model and algorithm.Through sensitivity analysis of transportation demand and transportation time window,it is concluded that cold chain multimodal transportation has more significant advantages compared to a single transportation mode in the transportation of fresh and perishable goods with low requirements for large quantities and timeliness.Personalized cold chain multimodal transportation plans can be customized according to customer needs,providing a theoretical basis for the decision-making of multimodal transportation operators.