Research On Fast Traffic Strategy Of Emergency Vehicles In Intelligent Network Environment

Urban emergency is always very destructive,and the rapid arrival of emergency vehicles at the scene of the accident can effectively prevent the expansion of accident disaster,so shortening the travel time of emergency vehicles is essential to improve the quality of emergency service and reduce the loss caused by accident disasters.However,the frequent occurrence of urban traffic congestion makes it difficult to achieve priority traffic of emergency vehicles.How to improve the traffic efficiency of emergency vehicles in urban roads so as to shorten the travel time of emergency vehicles is an urgent problem to be solved at present.In recent years,the rapid development and application of intelligent transportation system and intelligent connected vehicle technology have changed the traditional traffic management mode and provides a new solution to alleviate traffic congestion.Therefore,this paper studies the fast traffic strategy of emergency vehicles in the intelligent network environment.The content of this paper is as follows:(1)A strategy of rapid passage for emergency vehicles with collaborative yielding was put forward to solve the problem of insufficient space for emergency vehicles in urban road sections,especially on crowded roads.In order to optimize the fuel consumption and passenger discomfort of the vehicles in the process of collaborative yielding,the problem of collaborative giving way was regarded as the optimal control problem,and variational method was introduced to solve the optimal control input of the vehicles.Three traffic simulation experiments with different vehicle densities verified the effectiveness of the proposed strategy in ensuring the rapid passage of emergency vehicle in urban sections.(2)In order to improve the traffic capacity of unsignalized intersections,the conflict point model was introduced to model the unsignalized intersection,and the traffic control architecture was established.Based on the above model and control architecture,a conflict point-based cooperative traffic control algorithm(PCTCA)was proposed to plan the moment of crossing the intersection for vehicles.In this collaborative algorithm,the occupancy rate of conflict points was optimized,that’s to say,the number of vehicles passing through the intersection within one second was increased.By comparing with other two mature traffic control algorithms,it was proved that PCTCA algorithm can increase the traffic capacity of unsignalized intersections.(3)Based on the PCTCA algorithm,a cooperative control algorithm considering emergency vehicle priority(EVTCA)was proposed to ensure the rapid passage of emergency vehicles at unsignalized intersections.In this collaborative algorithm,inserting the transit time of emergency vehicles into the regular vehicle traffic time series was adopted to ensure the priority right for emergency vehicles at the intersection,and the time crossing the intersection for the regular vehicles affected by the emergency vehicle was rescheduled to prevent the collision of vehicles at the intersection.The simulation experiment results showed that the EVTCA algorithm can achieve the priority and delay-free crossing of emergency vehicle at the intersection,and reduce the impact on the travel time of non-emergency vehicles.