Optimization Of The Placing-in And Taking-out Wagons Operation In The "Last Kilometer" Railvway

The placing-in and taking-out wagons operation in the loading and unloading area is an important task of shunting operations in the operation of a large freight station and a large number of technical stations.It is an important basis for ensuring the "last mile"cargo delivery capacity of railway freight transport,vehicle operation efficiency and freight service.Reasonably determine the order of pick-and-place operations in the loading and unloading area,so that the technical station freight station arrival,disintegration,grouping,send,and technical operation can be closely combined with the pick-and-place and shunting operation,which can effectively shorten the waiting time,sengding time and the waiting time generated by non-production for the vehicle at the end of the railway.Improve the efficiency of the shunting locomotive,and the acceleration of the vehicle’s turnover is also in essence to save costs and obtain greater profits.On the basis of researching and drawing on the academic achievements of the predecessors in placing-in and taking-out,this paper focuses on the study of the "last mile" placing-in and taking-out system operation problem,from special to general,starting from the study of the radial loading and unloading area to pick up the problem,Finding the similarities and differences between the mixed and radial loading and unloading areas will lead to the establishment of the "last mile" mixed loading and unloading area model.Mainly done the following work:(1)Describe in detail the contents of the "last mile" placing-in and taking-out work,the shape of the loading and unloading area layout,the characteristics of the placing-in and taking-out system,and the introduction of the calculation method of the delivery deadline in the "last mile" vehicle from the technical station freight station to the loading and unloading station,and the loading and unloading station to the loading and unloading point.Finally analyzed some influencing factors in the process of the "last mile" placing-in and taking-out operation.(2)The paper Studies the problem of the placing-in and taking-out wagons in the radial layout loading and unloading area,analyzes the characteristics of the loading and unloading area under the layout and the characteristics of the operation,and points out the conditions for the batching of the placing-in and taking-out operation,and the constraints of the reverse order of the operation as the constraint conditions for the model solution,in order to meet the generality of the model,the time window constraint of the vehicle group is increased.The solution model is established under the set conditions,and the solution value generation function is constructed for the two optimization objectives of the minimum occupancy time of the tuning and the optimal vehicle system hour.(3)Studying on the problem of placing-in and taking-out wagons in the mixed shape loading and unloading area,combined with the characteristics of the operation of the branch loading area,pointing out the influencing factors of the batch dividing,based on the characteristics of the two loading and unloading areas.The different branches radiated from the mixed shape layout loading and unloading area are seen as radial shapes,and the sub-branch that is radiated out of the branch is seen as a branch shape,setting conditions,and establishing "last mile" mixed shape loading and unloading area model with a time window on the basis of the two loading and unloading areas.and the solution value generation function is constructed for the two optimization objectives of the minimum occupancy time of the tuning and the optimal vehicle system hour.(4)The basic principle of genetic algorithm and its application in this paper are briefly described.On the basis of analyzing the problem and the characteristics of the model,a chromosome coding form consisting of job numbers is designed.A large number of initial populations are generated by model constraints,and according to the characteristics of the problem,an improved genetic mechanism was designed.Finally,the data of the shunting operation plan within 12 hours of a planning stage of Qingjian freight station of Taiyuan railway bureau was obtained.and the batches of the operation sequence were obtained under different optimization objectives.The results of different optimization objectives were analyzed and compared in detail.And give specific recommendations to strengthen the "last mile" of the railway to the time limit.