Evacuation Sign Perception And Group Behavior Modeling Of Virtual Crowd Evacuation

Indoor crowd evacuation simulation is the research frontier of indoor geographic information system,virtual geographic environment and crowd simulation.It is an applied research focus of indoor building planning,emergency evacuation drill,safety assessment and other fields.However,it still difficult to either obtain the data of evacuation behavior in disasters or simulate the group perception evacuation behavior in complex scenes.By combining virtual geographic experiment and crowd evacuation modeling,this paper introduced the theory and method of virtual crowd evacuation geographic experiment.From the perspective of sign perception and group behavior,with the help of virtual reality and eye tracking technology,we carried out the research on modeling and simulation of group perception behavior under complex scene.Combining the sign perception evacuation model,the group evacuation model and the complex scene evacuation model proposed in this paper.We took a subway station in Beijing as the experimental area to simulate and analysis the crowd evacuation process.The main research results and innovations of this paper are as follows.(1)The basic theories,principles and experimental tools of virtual geographic experiment was generalized and the framework of virtual crowd geographic experiment was constructed.Under the application of crowd emergency evacuation,we classified the virtual crowd geographic experiment into reality rehearsal experiment,physical restoration experiment,real person participation experiment and digital simulation experiment.(2)A crowd evacuation model based on the social force model was proposed combining local information perception and path planning.It can handle the problems that the classical social force model suffered from,such as multiple exits,channels and intersections.Firstly,an experiment was carried out to extract the sign perception time,distance and angles and optimize the emergency evacuation sign system.Secondly,the crowd evacuation model was proposed,which composed of the sign search algorithm,the decision point search algorithm and the desired velocity update algorithm.The model was validated by the experimental data.Finally,the model was used to evaluate the evacuation efficiency of the sign system before and after optimization.The simulation results of two different initial locations showed that the evacuation efficiencies of the optimized sign system were improved by 37% and 28%,respectively.(3)A group evacuation model based on the social force model was proposed considering group avoidance and subgroup coordination behavior.Due to existing researches barely consider the influence of group behavior in crowd evacuation simulation,we carried out a virtual group evacuation experiment.Based on the experimental data and the video data of crowd,the group evacuation model which can simulate group avoidance and subgroup coordination behavior was presented.The group avoidance behavior includes the same direction and the opposite direction avoidance,while the subgroup coordination behavior includes distance aligning and distance maintaining behavior.The simulation results were compared with the video data to verify the effectiveness of the group evacuation model.This model was used to simulate the evacuation process with different exit sizes and desired velocities in typical scenarios such as the single exit scene,the double exit scene and the narrow corridor.The simulation results showed obvious group avoidance behavior and subgroup coordination behavior,the “arch” and the “fast is slower” phenomena were also been observed.(4)Aiming the complex dynamic scenes which were often ignored in existing crowd evacuation models,we proposed an evacuation model which can adapted to complex dynamic scenes combining with the object spatial index and group random algorithm.Taking a subway station in Beijing as the research area,the crowd evacuation processes with different desired velocities were simulated by modeling the static and dynamic elements in the area.The simulation results proved the existence of groups in the evacuation crowd could increase the evacuation time and reduce the evacuation efficiency,however the influence of groups decreased with the increase of the desired velocity.