Study On Multi-group Train Scheme Of Urban Rail Transit Line

With the rapid development of urban rail transit,there have been 165 routes in 34 cities across China by the end of 2017.Urban rail transit network operation has become the development trend of urban rail transit.As an important method of network operation,Multi-group train operations can better adapt to the characteristics of uneven distribution of passenger flow.Therefore,the study on the multi-group scheme of urban rail transit has high theoretical and practical significance.The main work and conclusions are as follows.(1)This paper analyzes different train group forms from the basic concepts,advantages and disadvantages,applicability and application cases.With referencing to practical operation,the paper focuses on the applicability of multi-group train scheme from five aspects,namely,Passenger flow law,train running conditions,infrastructure equipment,operation organization,social and economic benefits.(2)From the perspective of passenger travel expenses and enterprise cost,a multi-objective optimization model of train plan based on multi-group train is established.The target function is the minimum number of passenger waiting time,the vehicle kilometers and the on-line number of vehicles.The frequency of the train and the number of vehicles of a train are the decision variables.The constraint conditions are the train tracking interval,the load factor of trains with different number of vehicles,the number of vehicles of a train and the number of trains.According to the characteristics of the model,the model is solved by using the non-dominant sorting genetic algorithm(NSGA-?).(3)Based on the research object of a single line of urban rail transit,the optimal train operation scheme under the peak and all-day conditions is obtained by using the optimized model of train plan based on multi-group train.Under the conditions of the whole day,The passenger waiting time of train plan based on multi-group train was reduced by 21.55%,the number of vehicles travelling was decreased by 14.27%,and the number of online vehicles increased by 18.64%compared with that of the single group train operation.The average load factor and the equlibrium of load factor between different trains are also higher than that of single group train operation.Multi-group train operations can save the passenger travel cost,reduce business operating costs,as well as to make better use of capacity in each period of time,but will result in an increase in labor costs.(4)The operation effect of the train plan based on multi-group train was analyzed by selecting the peak OD passenger flow,the number of vehicles of a train and the uneven time distribution characteristic of the passenger flow.When the passenger flow of the line is moderate and the unbalance coefficient is more than 0.7,it is suitable for the multi-group train operations.In addition,some consultative suggestions of train plan based on multi-group train are also obtained.