Study On Sound Induced Evacuation Technology Of Long And Narrow Channel Based On Haas Effect

In emergencies such as fires in long and narrow confined spaces,people are faced with dangerous environment of high temperature,toxic smoke and low visibility,and need to be evacuated quickly.The transmission and acquisition of evacuation information is the key to rapid evacuation of people.Compared with general buildings,long and narrow channels have poor lighting conditions and few access exits to the outside world.Induction facilities have a direct impact on the evacuation of people and are a key way of transmitting information to evacuees.However,in low visibility environments,evacuation signs and emergency lighting are obscured by smoke,which has an impact on their induction effect.Therefore,aiming at the evacuation environment of low visibility,this paper carried out the parameter setting research of sound induction system and evacuation experiment based on The Haas effect in the narrow passage by utilizing the directional discernability of sound.It is of great significance to analyze the optimal parameter setting scheme of the sound induction system and study the evacuation characteristics and typical evacuation behaviors under the sound induction,so as to improve the probability of escape and guarantee the life safety of the personnel.In this paper,an experimental scheme for the evacuation of people induced by sound in long and narrow channels was constructed,and studies on evacuation time,evacuation speed,evacuation route selection,typical evacuation behaviour and psychological characteristics of people with/without sound induction,under different conditions of sound induction parameters and different visibility were carried out.The main contents and conclusions are as follows:(1)Firstly,by carrying out experiments on the sound induction arrangement based on the Haas effect and the perceptual characteristics of personnel to the Haas effect,the variation law of the sound signal delay time under different speaker setting spacing and electrical signal delay time is studied and the optimal parameter setting scheme of the sound induction system is proposed.The results show that the delay time of the acoustic signal measured at the same spatial location increases gradually with increasing speaker spacing and electrical signal delay time.Due to the propagation characteristics of the Haas effect,the sound is perceived to be least directional at the position directly below speaker A(0m test point)compared to the same speaker spacing and electrical signal delay time;The sound is most directional at each spatial position in the channel when the speaker spacing is 10 m and the electrical signal delay time is50 ms,this is the optimal arrangement of the sound induction system.(2)A sound induced evacuation behaviour and path selection experiment based on the Haas effect was carried out in a long and narrow channel,and a questionnaire survey was conducted after the experiment.The key parameters such as evacuation time and evacuation speed after the introduction of sound induction are studied.The path selection and typical evacuation behavior of people with/without sound induction under different visibility conditions are analyzed.And the behavioral characteristics and psychological characteristics of people in different evacuation environments are explored.(3)Under the condition of normal visibility,the sound induction based on haas effect had no significant effect on evacuation time,evacuation speed and evacuation behavior,but had a certain guiding effect on path selection.Under the condition of low visibility,sound-induced facilities can greatly shorten the evacuation time,improve the evacuation speed of personnel,and have a significant impact on the evacuation route selection and evacuation behavior,which has a good guiding effect on evacuation.(4)By analysing the evacuation behaviour of the personnel,most of the participants escaped by running,under normal visibility conditions,with a clear objective,heading straight for the exit and walking almost near the centre line of the corridor.Under the condition of low visibility,participants showed tentative behaviour,such as waving their arms and stretching their legs to find their way.When there was no sound guidance,they wandered around the exit for a long time and even turned back;When there was sound guidance,participants were able to find the exit correctly and evacuated quickly.At the same time,participants’ tentative behaviour and walking behaviour by holding the wall decreased.(5)Compared with normal visibility,participants in low visibility were more nervous,and the sound-induced facilities could not effectively relieve the tension in the evacuation process,and the main factor affecting the tension was visibility.