Research On Distribution Route Optimization Model And NSGA-Ⅱ-TS Algorithm For Time-varying Road Network In Cold Chain Logistics

In recent years,the development of market economy and the improvement of mass consumption level have boosted the development of cold chain logistics,but also increased environmental pollution,increased the burden of urban transportation,improved the distribution costs borne by enterprises and reduced the service experience of customers.Therefore,how to combine the operation law of urban traffic and increase the objective function and constraint of vehicle scheduling to comprehensively consider customer satisfaction,carbon emissions and distribution costs has become an urgent problem for related enterprises and logistics and transportation fields.This paper mainly studies the optimization problem and solution algorithm of distribution route of time-varying road network in cold chain logistics.Firstly,combined with the characteristics of the problem,after introducing the traffic congestion index to characterize the time-varying characteristics of the road network,using the segmentation function to calculate the driving time of the road network vehicles,and comprehensively considering the constraints such as time window and vehicle load,a multi-objective optimization model with maximizing customer satisfaction,minimizing carbon emissions,and minimizing total distribution costs is constructed.Secondly,according to the characteristics of the model,an NSGA-Ⅱ algorithm with improved elite retention strategy and adaptive genetic operator is designed as the main framework,and the NSGA-Ⅱ-TS algorithm is designed with the taboo search operator generated by the 2-Opt algorithm for candidate solution domain as the local optimization enhancement component.Finally,nine Solomon studies with different customer sizes and distributions were selected for algorithm experiments,and simulation experiments were carried out using case data.Algorithm experiments show that compared with the standard NSGA-Ⅱ algorithm,the NSGA-Ⅱ-TS algorithm designed in the study has faster convergence speed and solution accuracy while having better optimization ability.The case simulation shows that the time-varying characteristics of the road network will increase the carbon emissions and distribution costs of enterprises.When the minimum customer satisfaction threshold is 90%,enterprises can achieve high customer satisfaction while taking into account carbon emissions and total distribution costs.Changes in the sensitivity of carbon tax rates and temperature differences between the inside and outside of the carriage can have an impact on a company’s carbon emissions and distribution costs.