Research On Delay Propagation And Adjustment Optimization Of Multi-standard Rail Transit Trains Under The Background Of Four-network Integration

With the improvement of the national urbanization level,city clusters and metropolitan areas are also booming,but followed by more and more problems of "urban disease".As a vital transportation mode in our country,rail transit’s integration innovation is a key method to solve "urban disease" problems,and is also an important symbol to measure the level of urbanization in our country.Therefore,the proposal of the four networks(Trunk railway network,intercity railway network,urban(suburban)railway network,urban rail transit network)integration planning of rail transit has far-reaching significance to the development of the metropolitan area.In this paper,under the background of the fusion of four networks of multi-system rail transit,aiming at the train delay propagation problem of the fusion of four networks of rail transit,by constructing the physical complex network and transfer dependent network model of multi-system rail transit,the complexity of train delay propagation under the fusion of four networks of rail transit is studied with the help of complex network.Firstly,by analyzing the geometric form of the multi-system rail transit network,a composite network model of the physical structure of the multi-system rail transit under the background of four-network integration is constructed in this paper.Based on the analysis of the connection relation of multi-system rail transit,the transfer dependent network model of multi-system rail transit under the background of four-network fusion considering delay is constructed,and the method of network fusion is proposed.On this basis,the stability of physical composite networks of different types of metro rail transit under the background of four-network integration is analyzed with examples through the measurement index of network stability.The results show that the network is more vulnerable without considering the weighted cross-section of passenger flow.The passenger perspective network connectivity proposed in this paper can better measure network stability.Secondly,based on the analysis of train delay factors and types under the background of four-network integration,the cascade failure process of train delay propagation reflected in the transfer dependent network under the background of four-network integration is analyzed based on the constructed multi-system rail transit transfer dependent network.That is,the delay of a train on a line will lead to changes in the stability of the transfer dependent network.Based on the above analysis,with the help of complex dependent network,the changes in the stability of multi-system rail transit transfer dependent network caused by train delay propagation are analyzed from two dimensions,namely,the influence of edge failure on the maximum connectivity of network and the influence of node failure on the overload of network.The results of the example show that train delay at important stations has a great influence on the stability of the transfer dependent network,and the maintenance of train operation at important stations should be strengthened.Finally,the arrival and departure time of trains in the delay propagation set of rail transit under the background of four-network convergence is adjusted under the condition that the train number has been determined.By considering train connection time,transfer station connection capacity,train stopping time,minimum safety interval between adjacent trains,number of stations to departure lines,periodicity and other constraints,a multi-system rail transit train connection optimization adjustment model was established with the goal of maximizing the transfer passenger flow and minimizing the waiting time of passenger groups.An improved genetic algorithm is designed to solve the model by setting a case.The stability of cascade failure transfer dependent network before and after train number adjustment is compared and analyzed.The results show that the network stability is stronger after train number adjustment.