Research On Route Planning Algorithm For Emergency Rescue Vehicles Under The Environment Of Connected Vehicle

The emergency rescue of emergencies is a common problem faced by all countries in the world today.According to the investigation results of a large number of traffic accidents,the causes of casualties are mostly caused by the untimely rescue.How to plan the rescue route of vehicles becomes the key problem of urban emergency rescue,especially for large-scale emergency rescue.At present,the existing vehicle path planning algorithm has some limitations,and the obtained path cannot reflect the impact of the urban road network traffic condition on the actual road travel time in a timely manner.With the advent of vehicle-to-vehicle and vehicle-to-road communication technologies,traffic impedance information of the road network can be acquired in real time.Therefore,it is of great significance to study the route planning algorithm of emergency rescue vehicles in the context of vehicle-road coordination for formulating rescue plans and improving rescue efficiency.In this paper,the route planning of rescue vehicles under the coordinated vehicle-road environment i5 studied.Based on the ant colony algorithm,the road resistance function reflecting the real-time traffic flow characteristics is introduced,and a route planning algorithm of rescue vehicles adapted to the coordinated vehicle-road environment characteristies is proposed,and the empirical analysis is carried out.Firstly,the research on path planning algorithm in traditional environment and Internet of vehicles environment is summarized,and the research content and technical route are proposed.Then,the theories related to emergencies,classification of vehicle path problems and mathematical models are introduced.On this basis,typical dynamic path planning algorithms are analyzed in detail from the perspectives of theoretical methods,advantages and disadvantages.Then,it introduces the path guidance system from the traditional environment and the vehicle-road cooperative environment,and analyzes the working principles and application cases of the two path guidance systems.Then,on the basis of Ant colony algorithm,the road resistance function reflecting the real-time traffic flow characteristics was introduced into the pheromone updating rule of Ant colony algorithm,the state transition probability of real-time update was established,and a rescue path planning algorithm(Connected vehicle-ant System,CV-AS)adapted to the coordinated characteristics of Vehicle and road was proposed.At the same time,the realization process of the algorithm is given from the aspects of algorithm flow and main functions.Finally,the proposed CV-AS path planning algorithm is verified by an example using the constructed simulation environment of the Internet of vehicles.Using the established index System,Ant System(AS)algorithm and CV-AS path planning algorithm are compared and analyzed respectively from the aspects of rescue time,total length of shortest path of all rescue vehicles and reliability of path travel time.At the same time,from the number of RSU,the number of road network background vehicles,the relative layout of rescue vehicles,etc.,the evaluation index of the CV-AS path planning algorithm is analyzed.Simulation results show that the proposed CV-AS path planning algorithm has good adaptability for emergency rescue under the vehicle-road cooperative environment.Compared with the traditional AS path planning algorithm,the proposed CV-AS path planning algorithm can reduce the rescue time by 48%,reduce the total shortest path length of all rescue vehicles by 19%,and improve the reliability of path travel time by 51%.The influence trend of model parameters on the two algorithms is roughly the same.The reasonable setting range of the number of ants m is 16?20,the reasonable setting range of the expected degree influence factor is 2?5,the reasonable setting range of information heuristic factor is 2?3,and the reasonable setting range of the pheromone volatility factor rho is 0.5?0.7.At this time,the performance of the algorithm is better.For sensitivity analysis of vehicle number increases gradually along with the network background,rescue vehicles to rescue place gradually reduce the amount of time,shows that the proposed CA-AS path planning algorithm in poor road network traffic conditions can improve the efticiency of rescue,along with the increase of the number of RSU all rescue vehicles driving total time gradually reduce,confirmed that the car road synergy technology is applied in route guidance,can solve the traditional route guidance under the environment of the delayed onset of insufficiency in information retrieval,compared to two kinds of rescue vehicles layout,uniform distribution points of the event than distribution point on one side of the event,The total travel time of rescue vehicles is reduced by 20%,indicating that the emergency rescue command center should dispatch rescue vehicles evenly distributed around the emergency occurrence point when emergency rescue is earried out.