Research On Calculation Method Of Railway Traffic Flow

Accurate traffic flow prediction method helps the railway bureau to make full use of existing equipment,ensure the reasonable distribution of railway freight vehicles,achieve balanced and efficient transportation,improve the precision of the freight plan,at the same time to strengthen the accuracy of the transit period.It is of great significance to the railway transportation department.The starting point of the paper is to design a complete calculation method for heavy and empty vehicles.The basic principle is that linking theory with practice.Based on the existing research,we apply the basic theories and methods such as graph theory,mathematical programming theory,qualitative and quantitative analysis,and complete the prediction of railway traffic flow.The research content of this paper mainly includes the following aspects:1.Based on the analysis of both domestic and foreign research,the concept of traffic flow calculation is defined,the task and origin-destination point of traffic flow calculation is made clear,and the railway operation process,the contents of train operation and the plan of railway operation are combed.Further,the information transfer structure of railway traffic flow is clarified.2.Analyze the existing calculation method of heavy vehicle systematically,and put forward the idea of improvement in view of its limitations.Based on the improvement idea,an automaton model for heavy vehicle calculation is established,and a heavy vehicle calculation algorithm is established based on the model design.So the unloading plan and heavy vehicle delivery plan of each station is formed according to the calculation results.With the analysis of the advantages and disadvantages of the method,it can be found that the method is accurate,efficient and operable,which makes up for the limitations of the existing method of vehicle flow calculation.3.With analysis of the existing models for the empty vehicle calculation,aiming at the limitations,the optimization idea is proposed,which transforms the problem of dynamic empty vehicle allocation into a typical TP problem by using the spatio-temporal network map.Distribution model of dynamic empty vehicle is estabilished to complete the vehicle application decision.The model can be solved by Matlab software.And then,form the application scheme of empty vehicle according to the result of the solution,and calculate emptying plan.It can be found that the model can be applied to situations of imbalance between supply and demand,alternative use of vehicle and the convective constraint of empty vehicle through the analysis model's promotion form.4.The combined heavy and empty traffic flow calculation method forms a complete and circular railway traffic prediction system.First of all,it is necessary to determine the source information of the heavy vehicle,and calculate the heavy vehicle through the finite automata model and algorithm.Secondly,the unloading plan is extracted,through the dynamic deployment model under the time and space network,the decision-making scheme of empty vehicle is solved by programming.After that,the empty vehicle decision is used to complete the empty vehicle traffic calculation.Finally,the heavy vehicle flow is calculated from the arrival of the empty vehicle,and the whole process of the calculation of the railway traffic flow is realized.At the same time,the real-time correction method of the important node data and the periodic updating method of vehicle flow prediction stage are given to ensure the timeliness,accuracy and effectiveness of vehicle flow prediction.5.Taking the problem of traffic flow prediction in Chengdu Railway Bureau as the background,and simplify the actual road network by district center optimization method,select some information of trains and vehicles to design examples.According to the methods described in the previous article,Matlab is used to solve the example,and the unloading plan for heavy vehicle,delivery plan fot heavy vehicle,application decision plan for empty vehicle,arrival plan for empty vehicle,and emptying plan for empty vehicle are obtained to form the whole result of vehicle flow calculation.The results are basically consistent with the practice of railway production,which proves the feasibility and effectiveness of the proposed method of vehicle flow calculation described in this paper.