Research On Vehicle Evacuation Strategy Based On Micro Simulation

At present,major accidents in local areas of the city occur frequently,which create a great threat to the safety of urban residents.For the major urban hazards such as dangerous gas leakage5fires caused by explosions and nuclear leakage,it is urgent to develop an effective evacuation method.Traffic flow distribution models,multi-objective optimization models,mathematical modeling analysis,computer simulation and so on are commonly used to study evacuation study,vehicles evacuation by signal control are usually based on timing parameter optimization5path planning and so on.There is not enough researches about the different flow combinations when vehicles pass through intersections.In the case of sudden accidents,the vehicles are the main evacuation objects when the large area of city is affected.lgnoring the direction of flow will affect the evacuation efficiency.At the same time,the accident scene is eomplex and most of the cases are difficult to predict.It is not appropriate to get the mathematical analysis of the disaster data by experiment.Therefore,this study aims to build a relatively complete micro-evacuation simulation system to formulate strategies and simulate the vehicles for efficient and safe evacuation through the deep research on the directions of flow.The construction of the vehicle evacuation strategy simulation system is divided into three modules.(1)Evacuation simulation model construction.The C++program is used to implement road network structure simulation,vehicle operation simulation and signal control simulatiomn.A complete model that can load,analyze,evaluate and optimize simulation effects for various scenarios,different vehicles and multiple strategies.(2)Analysis of gas leakage and fire scenes.The Gaussian gas diffusion model and the BLEVE fireball dynamic calculation model are used to check and determine the scope of accidents in different scenarios.The evacuation area is divided into hazardous areas and buffer zones according to the concentration standards that cause damage to the human body?so as to formulate different evacuation measures of corresponding levels.(3)Layer-by-layer optimization signal control strategy.For the high complexity of vehicle flow combination and the range of accidents of different emergency levels5the local signal control strategy optimization from the inner hazardous area is used to find the local optimal control strategy?and then the outer buffer is used to optimize the global signal control strategy.The method finally creates an efficient signal control evacuation strategy for the entire road network.