| The number of urban lines with a focus on urban travel has risen sharply.Express/local mode is used on many lines to meet the specific travel needs of passengers.With the diversification of passenger travel purposes,the traditional express/local mode is increasingly difficult to adapt to the environment of complex and diverse passenger flow.The paper addressed the shortcomings of the traditional express/local mode and proposed a combined express/local train operation mode with express-medium-local.Then,the optimization methods of multi-mode mixed express/local train capacity allocation and operation plan were established to improve the efficiency of urban lines as well as enriching the methodology of urban rail transit operation.The existing express/local mode was defined and classified according to the different operation patterns in the paper.The conditions of applicability and capacity influencing factors of the traditional express/local mode were analyzed.Then,the special express/local mode with multiple mode combinations were analyzed.Further,the shortcomings of current express/local mode were discussed.Considering the shortcomings of the current express/local mode,a new combined operation mode of multi-mode express/local train was proposed based on the Japanese express/local mode.The similarities and differences between this mode and conventional express/local mode were analyzed,as well as their advantages,disadvantages and conditions of application.The operation pattern and the departure pattern of express-medium-local mixed mode were classified.The principle of balanced departure is clarified as well.In order to select the appropriate train operation mode for the urban line,various indicators were combined to propose the selection method of different operation modes from the qualitative and quantitative perspectives.Various passenger flow data required for line capacity allocation was analyzed.Common data acquisition and processing techniques were presented later.By improving the capacity allocation method of the traditional express/local mode,a method for calculating the ratio and number of different trains in express-medium-local mixed mode based on group passenger flow was proposed.Considering the cyclical operation mode of express/local trains,a method that could calculate the departure cycle of express-medium-local mixed mode is proposed.Further,the optimal departure sequence of each train within the cycle was selected.Based on the capacity allocation method of express-medium-local mixed mode,a multiobjective optimization model was constructed with the objective of minimizing the total passenger travel time and the total enterprise operating cost.The decision variables of this model were the stopping scheme,the overtaking scheme and the headways of each train.The constraints such as train stops,crossing,intervals were considered in the model.Further,a linear weighting method was used to transform the multi-objective optimization model into a singleobjective optimization model.Then,a Differential Evolution(DE)algorithm based on Genetic Algorithm was designed to solve the model.Numerical examples from Guangzhou Metro Line 14 were conducted to verify the model.We discriminated whether the line could be operated by express/local mode.The capacity allocation methods for different express/local modes were proposed.This method could be verified by practical application schemes.Further,the train operation schemes under different express/local modes were optimized.The advantages and disadvantages of different schemes were comprehensively evaluated in terms of the total passenger travel time,the enterprise operating cost,and the waiting time of stranded passengers.The results indicated that the expressmedium-local mixed mode was more suitable for urban lines with uneven passenger flow than the traditional express/local mode.Besides,it could meet the travel needs of different types of passengers and improve passenger comfort. |
PDF Full Text Request