Comprehensive Optimization And Adjustment Of District Train And Pick-up And Drop Train Operation Plan

District train and pick-up and drop train operation plan undertakes the task of transporting car flow in district,which is a major guarantee for the logistics of railway transportation.Reasonable,effective and operable district train and pick-up and drop train operation plan can improve the quality of railway transportation service and the utilization rate of transportation resource while meeting the freight transportation demand.This paper studies comprehensive optimization and adjustment method of district train and pick-up and drop train operation plan from the following four aspects:(1)Through the contrast and analysis of express freight train operation plan,combined with the characteristics of district train and pick-up and drop train,the optimization contents of district train and pick-up and drop train operation plan are determined,which including optimizing the number of district train and pick-up and drop train,the stopping plan of pick-up and drop train and the distribution plan of car flow into pick-up and drop train.Based on the contents of district train and pick-up and drop train operation plan,this paper points out that district train and pick-up and drop train operation plan is influenced by some factors such as accumulation consumption,dwell time of pick-up and drop train,train operation cost,section carrying capacity,and so on.This paper also analyzes the method of compiling district train and pick-up and drop train operation plan.(2)The optimization model,aiming at minimizing the comprehensive cost including accumulation cost of district train and pick-up and drop train,running cost of district train and pick-up and drop train,operation cost of district train and pick-up and drop train,and stopping cost of pick-up and drop train,is established.The model applies the idea that district car flow can be used to complement pick-up and drop train.At the same time,in order to make the optimization plan more reasonable,the model limits the volume of district car flow that can be transported by each pick-up and drop train.In addition,the model adopts alternate stopping mode to operate pick-up and drop train to meet the stopping demand of intermediate station in district.(3)Due to the fluctuation of district car flow and pick-up and drop car flow with the change of time,the train operation plan compiled at the present stage may not be able to adapt to the future car flow transportation demand.When the car flow fluctuates,it is necessary to judge whether the current train operation plan can still transport the car flow reasonably.If not,the current train operation plan needs to be adjusted.Therefore,the adjustment mechanism of district train and pick-up and drop train operation plan is introduced.This paper puts forward an evaluation method for judging the matching degree between the car flow in district and district train and pick-up and drop train operation plan.The evaluation method is taken as the basis for judging whether the train operation plan needs to be adjusted.Referring to the feedback control system,the feedback control process of district train and pick-up and drop train operation plan is analyzed,and on this basis,the adjustment process of district and pick-up and drop train operation plan is summarized.(4)Taking the district from Lhasa to Golmud as an example,this paper verifies the comprehensive optimization model of district train and pick-up and drop train operation plan.In order to speed up the solution of the model,this paper combines the characteristics of step function to simplify the model,and the branch and bound algorithm is proposed to solve the model.Lingo software is used to write the program.The result shows that the established optimization model is feasible.Finally,taking the district from Nanxiang to Qiaosi as an example,it is further verified that the optimization model and adjustment mechanism given in this paper are reasonable and feasible.This paper includes 23 figures,21 tables and 76 references.