| China’s passenger railways are constantly under construction and the overall structure is developing in a network-like manner,but the range of train services is still limited.In order to meet the direct demand for cross-line passenger traffic,the number of cross-line trains is increasing day by day.The trains run across the line to form a common section with a mix of trains of different speed classes.In the common section,there are two speed classes of trains to choose from for both interline and local passenger traffic,and the choice of trains by passengers determines the number of trains and stopping options.The choice of train is based on its own attributes and on the service characteristics of the train,which change when a particular service characteristic changes.In addition,the different speed levels of interline trains and local trains in a shared section can cause passenger flows to shift in response to changes in the service characteristics of the trains,which in turn affects the way trains stop and the number of stops they run,changing the extent to which capacity is utilized.Therefore,it is necessary to study the operation scheme of cross-line trains and local trains,and determine the operation scheme and the train service characteristic parameters under better conditions.(1)This paper first analyzes the types of passenger flow and transport organization,focusing on the analysis of cross-line passenger transport organization mode.According to the definition of train operation scheme,this paper expounds the number,type,section,marshalling and stop scheme of train operation which should be considered in the formulation of train operation scheme,and the additional consideration in each aspect of train operation scheme.The passenger flow factors,infrastructure conditions,train operation organization factors,railway enterprise income and cost factors affecting the formulation of the operation plan are analyzed,and the preparation principle and module process of the operation plan are determined.(2)This paper introduces the relationship between the operation scheme and train service characteristics,the meaning of train service characteristics,and comprehensively analyses the train service characteristics and the indicators contained in them.Taking the operation of medium-speed trains on line as an example,the train service characteristics related to passenger flow selection are analyzed,and a passenger flow selection ratio calculation model is constructed based on the logit model function form to calculate the proportion of passenger flow attracted to each OD section when trains are mixed from the perspective of the transport service characteristics provided by trains,which is transferred to the stopping scheme to solve the constraints.(3)The service characteristic indexes related to the passing capacity are determined,and the passing capacity of the common line section is calculated by the deduction coefficient method.The possible conditions of the deduction coefficient of the medium-speed train in the mixed operation of trains with different speed grades are analyzed one by one,and the changes of the passing capacity under different service characteristic indexes are compared and analyzed.The service characteristics related to the passing capacity are determined as the train speed matching,the proportion of high-speed train stops and the proportion of medium-speed trains.Through further analysis,the service characteristics that can be subjectively adjusted are determined as the train speed matching,and the adjustment of the index value is determined.(4)According to the formulation process of train operation plan,based on the line structure of the third chapter,the method of determining the train operation section and the number of trains is determined in turn,and the optimization model of train stop scheme is constructed.The objective is to minimize the cost of passenger stop time and the cost of empty seats in railway enterprises,and the constraint conditions are to meet the demand of passenger flow selection proportion,the limit of cross-line train stop and the train operation attendance rate.When solving the model,we first determine the maximum number of trains required under the minimum occupancy rate,and then optimize the number of trains and the train stop scheme simultaneously through the designed genetic algorithm for solving the model.Finally,the comparative evaluation index of train operation scheme is expounded.(5)The basic data verification model and algorithm of cross-line train operation lines are constructed.Based on the third chapter,the proportion of passenger flow selection under different service characteristic indexes is calculated,and the change trend of passenger flow proportion with service characteristic is analyzed to determine the adjustment of service characteristic parameters by operation scheme.The model and solution algorithm established in Chapter 4 are used to obtain the train operation scheme under the corresponding service characteristics,and the comparative analysis is carried out to determine the optimal operation scheme and the corresponding service characteristic parameters of the medium-speed train online operation,so as to verify the feasibility of the model and the solution idea. |
