Crowd Evacuation In A Hospital Based On Improved Cellular Automata

With the deepening of the people-oriented concept,pedestrian safety has attracted more and more attention.As an important public place,the Grade III Level A hospitals has the characteristics of large flow and high density of people with the advancement of urbanization and the improvement of medical level.Once an emergency occurs,it is easy to cause casualties.At present,there are many studies on emergency evacuation in large public places such as subway stations and high-speed railway stations,but few studies on pedestrian evacuation in hospitals.As a special public place,the staff composition and environmental structure of the hospital are more complicated,and all kinds of patients,especially orthopedic patients,such as people in wheelchairs,are unable to move,which is one of the biggest difficulties in the evacuation of the hospital.In order to study the safety evacuation of pedestrians in hospital emergencies,this paper firstly improves the traditional cellular automata model based on the characteristics of hospital pedestrians,and makes a case study on the evacuation of personnel in the outpatient hall of Shanghai sixth people’s hospital.The improved model mainly includes two aspects.Firstly,the concepts of the improved local density field and the probability cost of pedestrian conflict hesitation time are proposed,which better explains the pedestrian’s judgment of the surrounding environment and the conflict handling mechanism of the cellular automata model.Secondly,modified cellular automata model considering complex populations with different body characteristics and movement speeds is proposed.In addition,avoidance rules are set in the model to better reflect the traditional moral concept of weakness first,and the advantages of adopting avoidance rules are highlighted through the concept of waiting time.The modification of the model can improve the evacuation efficiency of pedestrians.The experimental results show that the mutual interference between normal people,general patients and wheelchairs is reduced after considering the local density field and avoidance rules.In addition,the movement space is more effectively used.The waiting time of wheelchairs is significantly reduced and the movement path is smoother,so the overall evacuation efficiency is higher.The research on pedestrian evacuation in hospitals with improved cellular automata model not only enriches the research ideas in the field of emergency evacuation,but also provides reference and guidance for the design of evacuation strategies in hospitals,and at the same time provides reference for the research on personnel evacuation in other similar large public places.