| In recent years,with the expansion of urban rail transit in the city,rail transit operational interruption and emergencies frequently occur.Bus dispatching has performed well in the evacuation of large passenger flows under operational interruptions.How to plan bus parking depots and emergency rescue and emergency rescue routes is one of the hot topics studied in recent years.In the morning and evening rush hours,which are prone to operational interruptions,road congestion will have a certain impact on the reliability of bus connection rescue.This paper establishes a bus emergency rescue location model and route selection model under the consideration of the travel reliability of the road network,and obtains a parking depot location and rescue route selection plan to ensure travel reliability through case analysis,which is for the interruption of urban rail transit operations.The bus connection rescue provided a theoretical basis.The research content of the thesis is divided into the following five aspects:(1)Road network traffic reliability theory is described,calculation formulas of road traffic reliability and path traffic reliability are introduced,and the reliable shortest path algorithm is introduced.Algorithm flow of the reliable shortest path algorithm is described program improvements in computing is proposed.Feasibility of reliable shortest path algorithm is verified through calculation examples(2)The background of the parking spot selection problem was introduced,and the parking spot selection problem was compared and analyzed.On the basis of considering the reliability of the road network,the objective function is to minimize the total time between the station and the parking point with the shortest transit time under the prescribed probability.Taking the arrival probability,station demand,and the number of parking points as constraints,establish an emergency rescue parking point location model and establish a simple network for analysis.(3)An emergency rescue route selection model considering the reliable shortest path is established to minimize the rescue end time under a certain arrival probability as the objective function.A heuristic algorithm suitable for path selection in this study is designed,and a calculation example is designed to analyze the feasibility of the algorithm.(4)3.7 million pieces of Didi Travel big data in Chengdu were processed,and the string data was identified,cleaned and filtered using Python software.According to the actual road traffic conditions,the network topology model in the research area is established,and the path matching rules are designed to spatially match the travel trajectory data with the road network to obtain the set of travel chains on the road,and thus the set of travel time under different roads.The time distribution is fitted to the lognormal distribution function to obtain the road traffic reliability,and the road network adjacency matrix is established.(5)The parking spot location model in the Chengdu research area is solved,and the location result and the reliable route of the bus connection station under the location are obtained.The probability-time curve of the result is analyzed to obtain the relevant characteristics of the curve.Sensitivity analysis is performed on the location selection results,and the objective function probability-time curve is solved when the number of parking points is 1,2 and 3 respectively.As the parking points increase,the reduction in time decreases.The emergency rescue route is solved,and the route for the bus to continue to run is obtained.The route direction is more feasible,and the designed genetic algorithm has better convergence.Sensitivity analysis is carried out for the interval between the prescribed probability of 75%-95%,and the rescue end time increases as the prescribed probability increases,and the two approximate linear changes. |
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