| In recent years,with the overall transformation and upgrading of the national economy,the consumption structure of residents’ diet has changed significantly,and people’s demand for fresh and perishable food has become increasingly strong,which has greatly promoted the development of China’s cold chain logistics industry.Fresh food has the characteristics of "strong temperature sensitivity,perishable and short shelf life",and the distribution activities must be carried out in a low temperature environment.Compared with normal temperature distribution,cold chain distribution costs more.In addition,under the background that the global warming problem is becoming more and more serious,and countries advocate the development of low-carbon economy,the refrigeration equipment accompanying cold chain distribution brings more carbon dioxide emissions,and enterprises are facing environmental pressure.In the time required by customers,it is a challenge for logistics and distribution enterprises to ensure product freshness,customer satisfaction,reduce carbon emissions and complete the distribution task with as little cost as possible.Therefore,combining the characteristics of fresh perishable goods and cold chain distribution,this paper constructs a vehicle scheduling model for cold chain distribution of perishable goods considering customer satisfaction and carbon emission reduction,designs the corresponding solution algorithm,and studies the route optimization scheme of distribution vehicles,providing reference for the distribution decision of cold chain enterprises.Firstly,the vehicle routing optimization problem of using a single refrigerated vehicle to deliver perishable goods is studied.According to the characteristics of perishable products,a customer satisfaction calculation method based on timeliness and quality is designed.With the goal of minimizing the total cost and the constraint of average customer satisfaction,a vehicle routing optimization model with load and time window constraints is constructed,and a genetic algorithm with local search operation is designed.The numerical results show that the distribution scheme with lower total cost,higher product freshness and less carbon emission can be obtained by using the designed customer satisfaction calculation method.Compared with the traditional genetic algorithm,the improved genetic algorithm has certain advantages in cost saving and customer satisfaction improvement.Then,the vehicle routing optimization problem of mixed distribution of perishable goods with various refrigerated vehicles is studied.Taking minimizing the total cost as the goal and the average customer satisfaction as the constraint,a path optimization model considering the mixed distribution of three types of vehicles is constructed,and an adaptive genetic algorithm is designed to solve the multi-type path optimization problem.The numerical experiment results show that the cost of a single vehicle distribution scheme is lower when the customer scale is smaller.When the customer scale is large,the use of multi-vehicle mixed distribution is more conducive to cost savings.Finally,the vehicle routing optimization problem of perishables cold chain distribution under carbon tax and carbon trading policy is studied.With the goal of minimizing the total cost,a vehicle routing optimization model that does not consider any carbon emission reduction policy,a model that considers carbon tax policy,and a model that considers carbon trading policy are respectively constructed,and a simulated annealing algorithm to solve the optimal distribution scheme is designed.The numerical results show that with the increase of carbon price,the total cost will gradually increase,and the carbon emissions and the average customer satisfaction show a stepwise decline trend,and there is a trade-off relationship between them.When the tax rate is low,the effect of carbon tax policy on emission reduction is not significant. |
PDF Full Text Request