Research On Emergency Rescue Vehicles Route Selection Of Urban Road Networks Based On Time-Dependent Network

In recent years,various kinds of emergencies occur frequently in China,such as earthquakes,fires,traffic accidents,etc.,which cause serious casualties and property losses,and affect the stability of economy and society.In order to find the shortest path from the emergency rescue site to the accident site in the first time,reasonably invest the rescue resources,improve the efficiency of emergency rescue,reduce the loss of people’s lives and property,considering the dynamic real-time / time-varying traffic characteristics of the road network,the research direction of this paper is determined to be the shortest path selection problem based on the time-varying network emergency vehicle travel time.The research work of this paper is as follows:First of all,this paper summarizes the research status at home and abroad from three aspects of time-varying shortest path,emergency vehicle path and emergency resource scheduling,finds the shortcomings of current research,introduces the basic theory of path selection,time-varying network,emergency path and resource scheduling,and prepares for the construction of emergency vehicle path model based on time-varying network.Secondly,in view of the complexity of time-varying dynamic road network,taking the speed model as the basis,the optimized BP neural network is used to predict the speed of each section in each period.In order to improve the prediction accuracy,the time-space correlation characteristics of traffic flow are analyzed,and the data set for prediction is calibrated.Thirdly,the travel time of emergency vehicles is calculated by using the predicted speed value of each road section;considering the initial path selection and real-time path updating mechanism of emergency vehicles,the dynamic path selection strategy of emergency vehicles is proposed;an emergency vehicle path model based on the shortest time of the road section under the condition of time-varying is established,and the optimal path of emergency vehicles is solved by using the improved genetic algorithm.Finally,considering the priority degree of each accident point,a model of the shortest total transportation time of each kind of materials according to the priority of the accident place is established to realize the reasonable allocation of emergency resources.This paper selects a road network in Jinan City,analyzes the emergency vehicle path selection and emergency resource scheduling in multiple accident areas,and verifies the effectiveness of the model and algorithm in this paper.