Optimization Research For Y-line Train Operation Plan Of Urban Rail Transit Based On Variable Train Formation

In the operation of urban rail transit,the period passenger flow in different sections is quite different.The fixed train formation mode probably causes the waste of transport capacity in some sections.Variable train formation mode is an effective way to deal with the difference,which can make full use of the branch transport capacity and reduce passenger waiting time,especially on Y-line.Based on the train operation plan as the carrier,variable train formation demands high-quality plan to play the mode advantages.Therefore,it is very important for the improvement of transportation service quality to study the optimization of Y-line train operation plan based on variable train formation.In this paper,research background is Y-line of urban rail transit,research subject is train operation plan,research breakthrough is the application of variable train formation on Y-line,and comparison objects are parallel line mode and the branch independent mode.The optimization models and algorithms of train operation plan of Y-line based on parallel line mode,independent branch mode and variable formation mode were put forward.By comparing the optimization results of different operation modes in the example,the paper verified the superiority of train operation plan under variable train formation condition.And it studied the applicable scenarios of train operation plan based on variable train formation mode by analyzing the sensitivity of passenger flow.The specific work included the following four parts:Firstly,based on the analysis of variable train formation type,technical operation,influencing factors and Y-line shape,passenger flow characteristics and operation organization,the paper proved that the train formation has the application value on Y-line.Secondly,on the basis of elaborating the contents,influencing factors and process of train operation plan,considering the peculiarity of Y-line,taking the lowest operating cost and passenger travel cost as the optimization targets,three train operation plan optimization models were put forward based on parallel line mode,independent branch mode and variable formation mode respectively.Thirdly,based on the characteristics of the model and the application of simulated annealing and genetic algorithm,this paper analyzed the advantages and disadvantages of the two algorithms and the advantages of the hybrid optimization strategy,and introduced the Message Passing Interface(MPI)cluster computing platform to design a parallel simulated annealing genetic algorithm based on MPI.Finally,three models and the algorithm were used in the case.By contrasting the optimization of the operation plans of the variable formation mode and other modes,the paper verified the superiority of train operation plan under variable train formation condition.Based on the example,the sensitivity analysis of traffic flow was carried out.By adjusting the input parameters of the traffic flow,the variation of optimization effect of the train operation plan under the variable formation mode and other modes was evaluated and compared.The paper quantitatively studied the applicable passenger flow scenarios of train operation plan based on variable formation mode.