Study On Urban Distribution Vehicle Routing Problem Based On Pure Electric Logistics Vehicle

In recent years,with the rapid development of urban distribution and the increasing number of urban logistics distribution vehicles,urban environmental pollution and traffic congestion problems have become increasingly prominent."Green logistics" has become the direction and goal of urban distribution transformation,the pure electric logistics vehicles have become the preferred means of transportation to replace traditional fuel trucks to solve urban distribution needs and environmental problems.From the Party Central Committee to the local government,and then to the major service providers of urban distribution,our country is actively promoting the application of pure electric logistics vehicles.Most cities have open access to pure electric logistics vehicles,allowing vehicles to enter at any time of the day.However,as pure electric logistics vehicles are still in the initial stage of development,the construction of various technologies and supporting facilities are still immature,which resulting its actual operational efficiency of urban distribution is far less than that of traditional fuel trucks.At this stage,limited power battery technology has led to a generally shorter theoretical mileage for pure electric logistics vehicles,coupled with the urban traffic congestion,external environment(wind,temperature,road conditions,etc.),cargo capacity,drivers,driving technology and other factors,the actual driving range is less than the calibration driving mileage.Therefore,on the one hand,in order to ensure vehicles' safe and normal driving,the vehicle must meet the power constraint during the entire distribution process;on the other hand,in order to improve vehicles' distribution efficiency,the vehicle must enter the charging station to charge according to the actual situation.However,at this stage,the number of social-dedicated/public charging facilities for pure electric logistics vehicles is very limited,and its layout is still not perfect,which makes the charging of vehicles very difficult,and the limited charging technology also leads to a longer charging time.Therefore,in order to improve the urban distribution efficiency of pure electric logistics vehicles,this paper studies the urban distribution vehicle routing problem(EVRP)based on the pure electric logistics vehicles from the following aspects:(1)Analyzing the main characteristics of pure electric logistics vehicles used in urban distribution,finding that it have four major characteristics:vehicle's travel network is time-varying,driver style significantly affecting power consumption,waiting for charging and charging time is long,the overall power performance is insufficient.Then based on these characteristics,the specific analysis of EVRP is carried out for each feature,which lays a foundation for the subsequent establishment of EVRP model.(2)Calculating the important driving and charging parameters of EVRP,and combining the characteristics of insufficient power performance to adjust the load and the power constraints appropriately.Finally,based on a time-varying network,considering the driver style,allowing the midway charing,considering the difference in queuing time of charging stations,considering the time window,the EVRP model of single-distribution and single-vehicle is established,the corresponding ant colony algorithm is designed to solve this complex model.(3)By using the demonstration operation data of a logistics company in Beijing,the case analysis is carried out.By using the ant colony algorithm,the best distribution route is obtained,which simultaneously optimizing the delivery route and charging route.According to the three factors of traffic network status,driver style and charging strategy,the sensitivity analysis of the EVRP solution is analyzed,and the reasonable optimization suggestions for the actual operation of the logistics enterprise are provided based on the analysis results.