Research On Train Plan With Express/Local Trains For Urban Rail Transit With Full-length And Short-turn Routing

With the rapid development of urbanization,residents' travel distance is gradually expanding at the same time.Under the support and guidance of the government,urban rail transit can develop at such a high speed,providing convenient and fast travel services for urban residents.For a long time,most of China's urban rail transit only has one single long-routing without stopping in the intermediate stations,which is easy to comply.But for the long-distance lines with larger station spacing and uneven distribution of passenger flow,this simple operation mode can not match the passenger demand well and maybe cause a certain amount of capacity waste.Neither dose it when it is during off-peak hours.Therefore,it is necessary to optimize the train plan under the above circumstances.Based on the existing research,this paper summarizes and analyzes the composition content and influencing factors of the railway train plan,and establish an optimization model with a single urban rail transit line as the research object.This model is related to long/short-turning and express/local operational mode,and it has the advantage of conforming the passenger flow distribution.After model establishing,the immunodominance clone multi-objective optimization algorithm is used to solve the problem.The main work is as follows:Firstly,the relevant research results at home and abroad and the experience of operation organizations are collated and summarized,and the main content and influencing factors of the train plan are also analyzed.Based on the above work,this paper describes the suitable conditions for the train plan.At the same time,a method of dividing the running time period based on agglomeration hierarchical cluster analysis is used here to make the operational scheme more in line with the passenger flow distribution.Secondly,establish the optimization model.In order to simplify the analysis process and reduce the difficulty of solving,firstly,the passenger flow of the section is used as the calculation index to judge whether some kind of short-turning can fit the passenger flow distribution characteristics,and then the suitable ones is selected,which constitute an set.The essence of the routing plan is to the traverse all the options in the set and obtain the best operational scheme for each one.Considering the limiting factors such as line capacity,occupancy rate,and stop mode adaptability,the model aims at minimizing operating costs and travel costs and maximizing supply and demand matching,and the best stopping plan under a certain combination is found.Thirdly,the existing solution of constrained multi-objective optimization problem is analyzed.According to the characteristics of this model,the immunodominance clone multi-objective optimization algorithm is used to complete the model solving.By defining the metrics for violation of the constraints,the constraint conditions in the model are transformed to an objective function,then the evolutionary algorithn is used to find a better solution during every iteration.Finally,the calculation method of "particle density fitness"is proposed to select an optimal solution from the population.Fourthly,a case study is carried out by taking a real urban rail transit line as an example,and the results are analyzed to verify the validity and feasibility of the model.The results of case analysis show that for the urban rail transit lines suitable to adopt train plan with short-turnings and express trains,the solution obtained in this paper can significantly reduce the operation cost and travel cost.