A virtual-reality-based feasibility study of evacuation time compared to the traditional calculation method

The purpose of this pilot research is to conduct a virtual-reality-(VR)-based feasibility study of evacuation time compared to traditional calculation method for evacuation planning in Japan and Taiwan. The difference between traditional assumptions and VR test results of occupant evacuation is compared. The study shows that most of the subjects tested, as occupants, choose different exits from the ones pre-assumed in the space zoning stage. A significant difference exists between the result derived from traditional calculation method and VR simulation. The function used to calculate evacuation time seems to be effective only when egress signs work properly. Very few subjects choose the shortest egress route as expected, although zoning-based calculation may conclude that a building is secure based on tolerable evacuation time. The route indicated by evacuation signs is not necessarily the shortest one. A case associated with four scenarios is simulated and tested. The result reflects the importance of layout in the planning strategy applied in zoning and egress routes due to building fire.     

Evacuation travel paths in virtual reality experiments for tunnel safety analysis

A case study on the analysis of evacuation travel paths in virtual reality (VR) tunnel fire experiments is presented to increase the understanding on evacuation behaviour. A novel method based on the study of the parametric equations of the occupants’ evacuation travel paths using vector operators inspired by functional analysis theory and the new concept of interaction areas (IAs) is introduced. IAs are presented and calculated in order to represent the distance of an occupant from a reference point (e.g., an emergency exit, the fire source, etc.) over time. The method allows comparisons of travel paths between experimental groups as well as comparisons with reference paths (e.g. user-defined paths, real-world paths, etc.). Results show that a common assumption employed by evacuation models (the use of a hypothetical path based on the shortest distance) may be an over-simplistic approximation of the evacuation paths.     

基于改进的A*和人工势场算法的火灾路径规划

传统火灾疏散过程中疏散指示灯指示方向固定,无法根据火灾情况改变疏散方向,为了解决这种情况,提出改进的A*算法和人工势场算法,对火灾发生时的人群疏散路径进行规划。通过优化g 值、改进OPEN 列表存储结构的方法改进A*算法,通过改进引力函数、加入虚拟侧向力的方法改进人工势场算法,以达到火灾应急疏散的要求,即快速找到疏散路径的同时远离着火区域。通过实验仿真验证了两种改进算法的可行性,可以在时间和环境双重约束情况下成功避开障碍、远离起火位置、找到安全出口。     

应急疏散仿真技术及其研究进展

介绍了应急疏散仿真技术提出的背景及其特点,阐述了所涉及到的群体行为的社会心理学研究、应急疏散的计算机仿真研究和各种应急疏散应用技术等,并对其发展趋势以及未来的研究方向进行了展望。     

教学建筑室内火灾应急疏散路径寻优算法研究

为解决建筑内人员疏散模拟时间长、效率低、无法根据火灾情况改变疏散方向的问题,提出一种新型的混合路径规划算法。首先,在A*算法中加入奖惩机制并对启发函数进行改进。其次,通过改进斥力函数解决人工势场算法易陷入局部极小值的问题。最后,将两种算法组合,构成一种混合路径规划算法。通过对某教学建筑应用BIM和PyroSim软件进行建模与分析,验证混合路径规划算法的可行性。结果表明,所提算法不仅能够快速找到最优疏散路径,还可以避免疏散路径经过危险区域。与单一算法相比,混合路径规划算法遍历节点个数更少,路径平滑性与路径规划效果更好,路径规划效率更高。     

火场人员疏散的虚拟现实模拟研究

虚拟现实技术的发展使得观察者能够借助计算机模拟增强对危险场景的理解与认识。本文针对火灾场景下的人员疏散,结合虚拟现实与数值模拟开发了原型系统AutoEscape。系统采用FDS对火场的发生发展进行模拟,基于GIS技术设计并实现了疏散计算引擎。在此基础上,构建了虚拟现实表现模块,结合数值模拟结果对场景各要素的分布状况及行为特征进行综合描述。应用实例表明,系统有助于观察者对火场人员疏散形成深入全面的认识,从而为应急疏散演习、消防救援指挥等提供虚拟训练环境。     

基于时间着色Petri网的建筑火灾疏散系统建模与仿真

为缓解建筑火灾疏散时间长且效率低问题,基于时间着色Petri网的理论,针对某建筑的结构特点进行建模并进行性能分析。通过算法计算与分析,合理规划不同类型人员的不同疏散通道选择,并对模型进行时间模拟仿真,提高建筑内人员疏散效率。提出带有建筑火灾疏散因素的管理疏散方法,增加相关的颜色集和时间戳,并在原模型中融入算法计算,模拟火灾疏散时间,并提出不同类别人员疏散引导的方案。达到疏散用时更短、效率更高、伤亡率更低的目标。实验结果表明,相比于其他模型,融入管理疏散算法的时间着色Petri网模型,人员平均疏散时间降低6.9 s,具有较高疏散效率。     

基于改进ACO算法的建筑疏散路径优化研究

针对大型公共建筑存在的结构复杂、消防疏散困难等问题,提出了用于优化疏散路径的改进蚁群算法。首先,针对基本蚁群算法(ACO)引入Dijkstra 算法,并利用Dijkstra 算法计算出全局性较好的次优路径进而对蚁群算法初始信息素分布情况进行了加强。其次,根据火灾的实时情况改进了蚁群算法的转移概率、更新规则、信息素挥发系数、启发函数等。最后,对改进的蚁群算法进行对比仿真实验。实验结果表明该算法具有较强的全局搜索能力以及较高的搜索效率,能够避免算法进入局部最优陷阱,有效提高消防疏散路径规划效率。     

Agent-based simulation of alternative classroom evacuation scenarios

Due to the growing number of emergency accidents occurring around students,evacuation issues have become significantly important for both school officials and architects. Simply following construction codes cannot ensure that a building's layout is suitable for evacuation behaviors; therefore, to discover the suitable planning schemes, we have introduced an agent-based simulation model via Netlogo to investigate the interrelationships between evacuation efficiency and classroom layouts. Before conducting modeling experiments, both the simulation structure and the sensitivity to its parameter settings are examined by validation research and sensitivity analysis. Furthermore,to demonstrate the importance of conducting fire drills with students, two differen ttypes of behavior rules are designed to reflect the distinctive characteristics of students evacuating without instructions and students evacuating in good order.The general comparison results show us that the classroom layout with two exits shortens students' evacuation time, and the premeditated behavior rules, meaning that students who follow preset instructions to arrange their activities, not only escape faster but also have some advantages in ensuring their safety during the evacuation process. Moreover, at the end of this paper, several methods of improving this simulation model are proposed for more complex research in the future.     

Evaluating emergency ventilation strategies under different contaminant source locations and evacuation modes by efficiency factor of contaminant source (EFCS)

Emergency ventilation plays an important role in protecting occupants when a hazardous contaminant is released indoors. A number of studies have been conducted to better understand how to protect indoor occupants with effective ventilation strategies. However, little attention has been paid to the impact of the non-uniform and time-dependent distribution of occupants during evacuation. A new concept, Efficiency Factor of Contaminant Source (EFCS), has recently been proposed to evaluate the performance of emergency ventilation by comprehensively considering the spatial and temporal distributions of both the contaminant and occupants. This paper aims to: (1) propose and demonstrate a procedure for determining an optimal ventilation strategy by using EFCS; (2) examine the effects of source locations, ventilation modes, and evacuation modes on the performance of emergency ventilation. One hundred cases with ten ventilation modes, two evacuation modes, and five source locations were investigated numerically. The results show that the EFCS concept can provide a reasonable way to evaluate the performance of emergency ventilation. The threats of different source locations may vary over a large range, and certain measures should be taken to monitor and prevent the releases at high threat locations. A system equipped with multiple ventilation modes is necessary since no universal ventilation mode can successfully mitigate all hazardous situations. The effects of an evacuation mode may be more significant than that of a ventilation mode under certain situations.     

孤立森林算法的灭火救援疏散路径规划方法

针对建筑火灾中人员疏散路径规划问题,提出基于孤立森林算法的灭火救援疏散路径规划的方法。运用布置在火灾现场的无线传感器网络采集火灾环境信息,构建火灾数据样本,随机分割并训练火灾数据样本,创建多个孤立二叉树组建孤立森林,识别火灾异常数据,获得着火点及障碍物位置,并以栅格法构建火灾救援环境动态地图为基础,通过更新位置节点当量距离、信息素浓度以及信息素挥发因子的改进蚁群算法,构建救援疏散路径组合优化模型,规划出最佳灭火救援疏散路径。测试结果表明：该方法可准确检测火灾中的着火点位置,可在多起点、多终点的救援疏散路径规划中更好地避开着火点和障碍物,快速、合理地规划出最佳灭火救援疏散路径。     

Determining the effective distance of emergency evacuation signs

Determination of the effective distance of emergency evacuation signs (EESs) is a basic requirement for optimising and improving emergency sign systems. This paper proposes a computational model for calculating the effective distance of EESs, taking into consideration an inertia effect as well as other factors that influence evacuation processes. The model is then incorporated into an evacuation model by extending the movement rules of cellular automata (CA). Finally, evacuation simulation experiments are conducted to confirm the necessity and rationality of computing the effective distance of EESs. The effective distance computational model can mirror the interaction between the evacuees and EESs, making the evacuation model even closer to the complexity and heterogeneity of a real evacuation.     

基于人员疏散特征的商场火灾应急管理策略研究

分析商场火灾特点并进行商场火灾风险分析。以广东省茂名市某商场为原型,建立基于 Dijkstra 算法的商场疏散模型,计算疏散时间,分析影响应急疏散的关键因素,从商场环境布局与管理、人员疏散指挥、火灾应急演练等三个方面优化商场火灾应急管理策略。研究结果表明：商场三个楼层的最短疏散时间分别为 83.1、85.5、145.6 s,采取优化措施后示例区域的平均疏散时间减少了 8.9 s,优化率 18.6%。研究可为商场应急管理和公共安全建设提供理论支持。     

基于改进蚁群算法的室内疏散路径优化

针对传统蚁群算法在解决室内疏散问题时存在收敛速度慢、容易陷入局部最优的缺陷问题,将火场的动态参数引入到蚁群算法中,对其路径选择策略、启发函数和信息素更新策略进行改进,为整个疏散群体求解更优的疏散路径。运用改进的蚁群算法对室内人员的疏散路径进行动态规划,考虑了路径的实时拥挤度,避免了疏散人员局部实现路径优化的瓶颈效应。将分析结果与基本蚁群算法的规划结果进行比较验证,研究结果显示,优化算法缩短了疏散时间和规划路径,提高了疏散效率和搜索速度。     

基于Floyd 的化工园区毒气泄漏人员疏散路径规划

提出基于Floyd算法的化工园区有毒气体泄漏人员疏散路径规划,利用高斯烟团模型模拟有毒气体泄漏后在大气中的动态扩散过程,在保证疏散路线安全的条件下,运用Floyd算法计算最优疏散路径。研究给出了一套针对化工园区液氨泄漏事故人员疏散路径选择的优化方案,通过案例研究表明,该模型科学合理,可为化工园区内大多数建筑提供最优疏散路径。     

Location optimization algorithm for emergency signs in public facilities and its application to a single-floor supermarket

Although emergency signs are believed to play an important role in ensuring public safety in facilities during emergencies, in practice, specific and clear standards for placing emergency signs have not yet been established. This paper developed a heuristic algorithm based on the Lagrangian relaxation algorithm for optimizing emergency sign locations with consideration of light-occlusion effects. A cellular automaton (CA) evacuation model was then introduced, and based on this model, the evacuation efficiency of the optimized locations of emergency signs derived from the algorithm was verified, and was compared with the evacuation efficiencies of the same supermarket without and with existing emergency signs. The results showed that the proposed algorithm greatly enlarged the coverage of emergency signs and improved the evacuation efficiency. It was concluded that the proposed algorithm with consideration of light-occlusion effects is valid for application to the problem of location optimization of emergency signs in single-floor facilities.     

基于改进蚁群算法和物联网的消防疏散系统设计

针对大型公共建筑结构复杂、消防疏散困难等问题,以改进蚁群算法为基础构建动态火灾疏散模型,分析火灾 3 个不同阶段并获取最优动态消防疏散路径,并通过数值模拟与其他算法对比,验证有效性;结合物联网技术以 Android 平台为载体设计消防疏散系统移动终端,实时引导用户撤离建筑物并迅速到达安全出口。实验结果表明：所设计的大型公共建筑消防疏散系统能够快速、准确地寻找到最优疏散路径,提高消防疏散效率。     

多出口选择中的几何影响因素定量化研究

成功预测逃生者对出口的选择对于建筑师和消防评估人员都非常重要,它直接关系到设计或评估的可靠性.本研究从建筑学的视角出发,定量分析了空间设计中有关出口的6项几何特征是如何影响逃生者对其的选择的.通过将虚拟逃生实验技术与二元回归统计方法相结合,解决了该领域研究所面临的现实环境中出口几何特征组合案例有限、特征难以以抽象形式独...     

一种用于火灾疏散路径动态规划的算法

针对火灾发生时现有的疏散路径不能根据火情实时更改,可能会将逃生人员引向着火现场从而引起更大危险的问题,提出了一种用于火灾疏散路径动态规划的新型改进蚁群算法(Novel Improved Ant Colony Algorithm,NIACA)。首先通过A*算法提高初始信息素浓度,接着提出受火灾因素影响的当量距离改进启发函数,然后改进信息素更新规则来加快蚂蚁最优路径搜索速度,最后对路径进行平滑策略处理。实验结果表明,与原始蚁群算法相比,本文算法降低了算法前期盲目性,动态搜索能力强,能避免算法陷入局部最优,在火灾发生时能够快速准确地规划疏散路径,将逃生人员快速安全疏散到远离火场的安全出口。     

考虑交叉口特性的疏散交通路线研究

疏散是应急管理中的重要措施,在应急计划中有必要制定合理的疏散路线以确保疏散车辆尽快到达终点。以往有关最佳疏散交通路线的研究没有考虑交叉口延误和通行能力等因素,若疏散路线经过城市内拥挤路段,忽略交叉口的这些特性会导致结果不尽合理。将交叉口分方向延误和通行能力作为节点权重,建立了点权交通网络,通过在点权网络中求解最小费用流来优化事故地点至安全地点的最佳疏散交通路线及相应的疏散流量,设计了一种最小费用路算法求解该点权网络中的最小费用流。最后以一个数值算例说明了方法的应用,并对考虑和忽略交叉口特性2种情况下得出的路线进行了对比。结果表明该方法能很好地兼顾路网特点和疏散路线优化的要求;若执行忽略交叉口特性的疏散路线方案,极易造成交叉口的拥堵,延长车辆的走行时间。