Study On Optimization Of Train Planning Of Urban Rail Transit Under The Through Operation Mode

With the rapid development of urban rail transit network in China,the traditional single route operation mode cannot meet the diversified needs of passengers,and it is difficult to achieve the optimal efficiency of urban rail transit system.Taking the operation mode of multiple routes and express-local trains under the condition of through operation as the research object,on the basis of establishing the probability model of passenger route selection with transfer times modification and the model based on station importance,the optimization model of through operation train planning is constructed.The main research contents and achievements are as follows:(1)The necessity and feasibility of through operation are introduced,and the characteristics of network passenger flow are analyzed based on the actual data of Beijing Metro.The purpose of optimizing the train planning of Urban Rail Transit is shown.(2)The probability model of passenger path selection and the model based on station importance are constructed.When establishing the probability model of passenger travel choice,the correction probability model of passenger path choice is established by introducing the correction coefficient of transfer times.When the station importance model is constructed,two important indexes,the number of nodes and the strength of stations,are mainly used.The weight of the two indexes is distributed by the method of variation coefficient,and the rationality and applicability of the station importance model are verified by an example.(3)The optimization model of train operation planning under the condition of through operation is constructed.The total cost of enterprise operation and the total travel time of passengers are taken as the optimization objectives.The routing scheme,departure frequency and stop scheme are taken as the decision variables.And the constraints of total number of routes,accessibility of line,length of route,upper and lower limits of departure frequency of each route,passenger flow demand,departure interval of each route in the same section and train stop plan are mainly considered.And an algorithm for solving the optimization model of train planning based on NSGA-Ⅱ is designed.In order to verify the validity and applicability of the model,this paper analyzes the model from three aspects: different line forms,different passenger flow conditions and different turn back conditions.The results show that the model can not only solve the optimization scheme under the conditions of passenger flow and station turn back conditions.When the conditions are partially determined,decision support can also be provided on whether to operate cross-line trains,organize express-local trains,and turn back location design,etc.(4)Taking Changping line and Line 8 of Beijing Metro as the research object.NSGA-Ⅱ algorithm be used to get the optimization result in the morning peak period and the normal period of the working day,and the optimization effect is evaluated and analyzed.The theoretical optimization results show that,the optimization model constructed in this paper can reduce the total operation cost of the enterprise and the total travel time of passengers while meeting the needs of passengers.