Study On Tractor Scheduling Problem And Trailer Configuration Of Drop And Pull Transport Based On Shared Trailer-pool

In order to achieve the reform of railway freight and improve the efficiency of road transport,road-railway multimodal transport has become a key measure.The combination of drop and pull transport and multimodal transport can improve the efficiency of multimodal transport.Since the launch of the pilot project of drop and pull transport in 2010,the rapid development of drop and pull transport has been accompanied by the shortage of funds and source of goods for small or medium-sized freight enterprises,the lack of vehicle standardization and other problems,which have limited the transport efficiency.Therefore,the mode of shared trailer-pool drop and pull transport has gradually derived,that is,the transport enterprises establish the drop and pull transport alliance with the source of goods enterprises,and jointly invest in the construction of shared trailer-pool,which with standardized transport equipment,and the information interconnection and transport equipment sharing among members of the alliance;while the effect of tractor scheduling and trailer configuration of the shared trailer-pool drop and pull transport directly affect the transport efficiency and cost,so this paper carries out the relevant research based on the above background.After sorting out the theories related to drop and pull transport and birth and death process,this paper analyzes the application scenario and the process of shared trailer-pool drop and pull transport,and makes it clear that the tractor scheduling problem of shared trailer-pool drop and pull transport studied in this paper is the closed type,full load,with delivery and pick-up vehicle scheduling problem;and compared with the tractor scheduling model of ordinary drop and pull transport,it needs to take extra consideration of the task of empty trailer transfer,the number of available empty trailers in customer points and the execution sequence of different types of tasks;and the method to study the configuration of trailers according to the state balance equation in the steady state of the birth and death process system are clarified.On the basis of the above research,the tractor scheduling model and the trailer configuration model are established with the example of shared trailer-pool drop and pull transport in the application scenario of road-railway multimodal transport.The steps of solving the tractor scheduling model by using the genetic algorithm with local search operation are clarified,and the expression of trailer quantity in the trailer configuration model is derived.Finally,using the actual data of S enterprise’s shared trailer-pool drop and pull transport,the paper solves the tractor scheduling model and the trailer configuration model,and compares the tractor scheduling scheme of shared trailer-pool drop and pull transport with the traditional one.The result shows that under the same transport task,the number of tractors used in the shared trailer-pool drop and pull transport is reduced by 30.8%,the total mileage is reduced by 17.18%,and 14.39% savings in transportation costs.After apportioning the fixed configuration cost of the tractor,the total actual operation cost is reduced by 22.41%,which shows that the shared trailer-pool drop and pull transport mode can effectively improve the efficiency of tractor,at the same time reduce the ineffective transport and the cost.In terms of trailer configuration,it is found that the number of trailers configured by S company is 51 in ideal condition,ratio of tractor to trailer is 1:2.833,and it is suggested that in the actual operation process,enterprises should consider the benefit brought by the waiting probability reduced of the tractor and the reduction of the trailer configuration cost.There are 38 figures,24 tables and 60 references in this dissertation.