大型建筑内人员疏散计算机仿真研究评述

在大量人员聚集的场所须预先做好各种应急的疏散预案,否则一旦紧急事件发生,由于人群的拥挤踩踏极有可能造成大量人员的伤亡,因此对人群的疏散动态进行深入研究,具有极大的现实意义.介绍了疏散动力学的产生背景和研究现状,分析比较了两种最具代表性的疏散模型,总结疏散仿真可视化模拟过程,最后指出了当前研究中存在的问题,并对这一领域的发展提出了建议.     

大型建筑物人员疏散仿真系统及实现

人员疏散仿真的关键是模型的选择,为了使仿真结果更加接近实际,基于元胞自动机模型,改进和优化了人员疏散仿真算法,设计了目标元胞选择算法,提出个体竞争力的定义和计算方法,在疏散仿真模型中引入环境熟悉程度和运动方向等因子,设计并实现了疏散仿真系统,实验结果表明,系统能够更加真实地仿真紧急状况下人员疏散的全过程.     

基于多智能体的森林火灾人员疏散仿真

森林火灾发生时, 对在林火蔓延过程中灾区人员疏散进行建模与仿真能够检查疏散方案是否合理, 从而为合理救灾提供指导意义. 目前对人员疏散模拟与仿真虽然有很多研究, 但对于森林火灾下人员疏散尚缺乏合适的仿真模型, 给科学救助决策带来很大困难. 为此, 提出将多智能体引入森林火灾蔓延及灾区人员疏散模型研究中, 并借助于Repast平台进行仿真, 实验结果表明本文方法能够为森林火灾人员疏散模拟与仿真提供正确的解决途径.     

大型商场人员安全疏散的计算机仿真研究

大型商场潜藏着很大的安全隐患.为此,在基本元胞自动机的基础上建立了人员安全疏散的二维随机元胞自动机模型,模型中考虑了人员距出口的距离、局部吸引力、绕行、墙壁和障碍物的排斥力等因素.用该模型对广州某大型商场一层平面内人员疏散进行了仿真研究,开发了人员疏散演示系统.该系统可动态演示人员疏散全过程,每个人员每步时都有确定的位置,为找出建筑结构中的不合理之处提供了依据.对比分析了元胞邻域选取不同时的疏散情况,发现Moore型邻域比Von. Neumann型邻域有更高的疏散效率.     

基于元胞自动机的人员疏散仿真研究

在人员聚集的大型场所,如果紧急事件发生则极有可能造成人员的大量伤亡,因此对人员疏散行为进行深入研究,具有极大的现实意义.通过分析已有的理论基础,利用元胞自动机原理建立了人员疏散数学模型.模型采用二维元胞自动机技术,确定了元胞空间和元胞状态,建立了人员疏散行为规则并着重探讨了从众行为和建筑结构不同对疏散时间的影响.试验结果表明,该疏散仿真模型更具真实性和合理性.     

基于元胞自动机模型的人员疏散仿真研究

公共安全是经济发展和社会稳定的基础。近年来由于火灾、地震、恐怖活动等突发因素诱发的公共场所人员安全事故屡见报道,在公共场所的安全设计中,安全疏散性能已成为至关重要的因素。为解决上述问题,人员疏散的计算机仿真对提高公共场所的安全疏散性能具有重要意义。对于出口距离最近的原则建立人员疏散的二维随机元胞自动机模型,其中考虑人员绕行的影响,并利用Matlab软件编写了疏散过程的程序,对大空间疏散人群进了仿真,得到了人员疏散基本规律及疏散时间。研究表明:考虑人员绕行的模型更能体现真实的疏散情景。     

基于行为的人员疏散仿真

在城市和建筑物中，人群疏散的模拟仿真是城市规划、建筑设计和安全评估的不可缺少的有力工具。本系统中，人群的心理和行为模式是仿真的基础，首先对人群的行为特点进行分析，再依据需要建立合适的模型，设计一定的算法，最终在计算机上仿真实现并直观显示。使用启发式的A＊算法查找最短路径，加以一定改进构成基本算法。本文最后对人员所处的环境进行仿真分析、得到仿真的疏散结果并能够帮助提出改进建议。     

建筑物火灾中的人群疏散研究

建筑物火灾是我国频发的安全事故,所以应研究建筑物火灾人群安全疏散问题。由于在建筑物火灾中,人群疏散时出现拥堵,存在不安全因素,造成人员伤亡。针对在现有的研究中未考虑人员行为的影响,提出了智能体(Agent)的人群行为建模技术在建筑物火灾中的人群疏散仿真中的应用方法。仿真结果显示基于Agent的行为模型可以仿真出人员特性及决策过程对人群疏散的影响,弥补现有的人群疏散模型的不足。仿真结果证明,Agent的行为建模技术具有仿真火灾全过程中人员疏散行为的功能,适用于建筑物火灾中的人群优化疏散策略。     

元胞自动机地铁人员疏散模型仿真

基于元胞自动机模型对地铁人员疏散进行研究,通过对地铁的疏散个体微观建模,构建出元胞的移动规则,从而确定元胞下一时间步长的移动路径。针对地铁紧急情况下的疏散情形,提出了两种基于元胞自动机的疏散规则:概率计算方法和元胞空间场吸引法。利用VC++开发环境与OpenGL图形库对地铁的人员疏散情况进行仿真,描述不同疏散规则下的地铁疏散整个动态过程,并分别模拟得出不同的疏散效率,从而为指导地铁紧急情况下人员疏散提供理论依据。     

煤矿井下人员安全疏散建模与仿真

针对煤矿井下出现安全事故时人员的安全疏散问题,建立了煤矿井下人员安全疏散模型。该模型中井下巷道被划分为网格,通过设置成员流势来反映网格距离疏散出口的位置,从而确定疏散人员移动方向和路径,同时结合疏散成员移动速度、成员响应时间、灾害检测时间获得疏散时间。仿真结果表明,该模型能直观呈现人员疏散动态过程,为制定安全疏散方案提供数据参考。     

An emergency aircraft evacuation simulation considering passenger emotions

The evacuation behavior of passengers was formulated as an autonomous agent and multi-agent model (AAMAS) evolving over a two-dimensional grid cell that represents aircraft cabins and passengers. In this model, the autonomous agents are initially placed in seat squares and move toward an emergency exit after an aircraft accident occurs. The autonomous agent mimics the behavior of passengers in the cabin, who must not only view their surroundings to collect the useful information but also select a route to an emergency exit. As the situation evolves, the agents feel the mental stress or strong fear or anxiety; thereby reacting unfavorably in the situation that they panic at. This abnormal evacuation behavior of panic agents generates time delays in the evacuation flow towards the exits. Therefore, such panic and its effect on evacuation behavior should be considered as an important factor in evacuation simulations. In this paper, it is supposed that the level of panic depends on three factors: remaining time, frequency of waiting and the difficulty of finding an exit. The dependencies of these factors on the time needed to complete an evacuation and the number of the panic agents in the aircraft were determined by the simulation. Considering the simulation results and situations of the actual aircraft accident “Garuda Indonesia Airways Accident”, it was possible to develop aircraft evacuation scenarios that considered passenger emotions.     

Estimation of the evacuation time in an emergency situation in hospitals

In this paper, a prediction model is presented that estimates the evacuation time in an emergency situation for hospitals. The model is generic enough to be used in various hospital settings. This model can provide incident managers with estimates of the evacuation times of different types of patients and can offer support to the managers with their resource allocation decisions in emergency situations. The major advantage of the prediction model is that the computation time is very short and the model does not need a lengthy and costly design. The model was applied for several different evacuation scenarios and the results were compared with those of a simulation model which had already been designed for use by the hospital. The comparison shows that the prediction model can provide estimates of the evacuation time that are similar to the results found by using costly and time-consuming simulation models.     

Defining static floor field of evacuation model in large exit scenario

The floor field model has been widely used to study pedestrian movement. But the traditional methods of setting the static floor field would lead to highly insufficient utilization of the exit region when the exit width is very large. In order to solve the problem and to study the utilization of wide exit, in this paper we put forward an idea of “virtual reference point” and propose a new method of building static floor field. A virtual reference point can be regarded as a point sink of the floor field, it has minimum field value. The position of the virtual reference point decides the distribution of static floor field values in the model. We further explore the relationship between the virtual reference point position and the exit width using regression analysis. It seems that a proper position of virtual reference point will make the exit be fully used and get high evacuation efficiency. We then analyze how to lead people to fully utilize the exit by changing the configuration of exit guidance, and give a primary scheme.     

Two-phase evacuation route planning approach using combined path networks for buildings and roads

This paper addresses the problem of modeling evacuation routes from a building and out of an affected area. The evacuation route involves pathways such as corridors, and stairs in buildings and road networks and sidewalks outside the building. To illustrate such an approach, we consider the problem of finding evacuation paths from an urban building and out of a predetermined neighborhood of the building on foot. A case study for a college campus building and small set of road around it is provided. There are a pre-defined set of exit points out of the target building and out of the road network serving the building. A two-step approach with an uncapacitated network model for route finding and a capacitated scheduling algorithm for evacuation time computation is proposed. A recent efficient heuristic algorithm is selected as a reference for comparative analysis. The process of creating a combined building and road path network data is discussed. The key results are the competitive evacuation time provided by the proposed uncapacitated route planning model, simple pedestrian flow capacity formulas for corridors and roads from readily available geometric data, and the illustration of the creation and use of combined building and road path network.     

Lessons from the evacuation of the world trade centre, 9/11 2001 for the development of computer-based simulations

This paper reviews the state-of-the-art in evacuation simulations. These interactive computer based tools have been developed to help the owners and designers of large public buildings to assess the risks that occupants might face during emergency egress. The development of the Glasgow Evacuation Simulator is used to illustrate the existing generation of tools. This system uses Monte Carlo techniques to control individual and group movements during an evacuation. The end-user can interactively open and block emergency exits at any point. It is also possible to alter the priorities that individuals associate with particular exit routes. A final benefit is that the tool can derive evacuation simulations directly from existing architects, models; this reduces the cost of simulations and creates a more prominent role for these tools in the iterative development of large-scale public buildings. Empirical studies have been used to validate the GES system as a tool to support evacuation training. The development of these tools has been informed by numerous human factors studies and by recent accident investigations. For example the 2003 fire in the Station nightclub in Rhode Island illustrated the way in which most building occupants retrace their steps to an entrance even when there are alternate fire exits. The second half of the paper uses this introduction to criticise the existing state-of-the-art in evacuation simulations. These criticisms are based on a detailed study of the recent findings from the 9/11 Commission (2004). Ten different lessons are identified. Some relate to the need to better understand the role of building management and security systems in controlling egress from public buildings. Others relate to the human factors involved in coordinating distributed groups of emergency personnel who may be physically exhausted by the demands of an evacuation. Arguably, the most important findings centre on the need to model the ingress and egress of emergency personnel from these structures. The previous focus of nearly all-existing simulation tools has been on the evacuation of building occupants rather than on the safety of first responders. Thanks are due to J. Appleby, P. Cooper, A. Foss, S. Hailey and B. Jenks who were responsible for the design and implementation of the GES application. They also drove the development of the Boyd Orr evacuation scenarios that are used to illustrate the opening sections of this paper.     

灾难疏散系统的疏散策略分析与研究

在紧急灾害发生时,采取正确的疏散避难策略可以大大提高疏散效率。在计算机疏散仿真模型的基础上,提出三种疏散策略并进行分析和比较,实验结果表明领导行为疏散策略疏散效率最优,协助行为疏散策略其次,随机行为疏散策略效率最低。提出一种基于A*算法的动态分组算法,并利用该算法对多领导者带领下的疏散进行仿真模拟,研究证明疏散效率与领导者数量是非线性关系,设置一定数量的领导者有利于疏散,数量过多反而产生混乱。     

Efficient parallel algorithms for numerical simulation

COUPL+ is a programming environment for applications using unstructured and hybrid grids for numerical simulations. It automates parallelization by handling the partitioning of data and dependent data and maintaining halo interfaces and copy coherency. We explore some algorithms behind this package. A multi-level partitioning method is described which is effective in the presence of skewed data, solving the multi-set median-finding problem. Partitioning elements over a set of pre-partitioned nodes is explored and a novel method is suggested for reducing communication in the resulting distribution.     

Validation of advanced evacuation analysis on passenger ships using experimental scenario and data of full-scale evacuation

Evacuation analysis, which calculates the total evacuation time should be fulfilled for all passenger ships. One of the ways to calculate evacuation time is to use the computer simulation, which models various effects of human behaviors in an emergency situation. In the previous research, SIMPEV (SIMulation system for Passenger EVacuation) was developed for the evacuation analysis based on the latest human behavior algorithms. It has already showed that SIMPEV basically satisfied the eleven test cases suggested in International Maritime Organization (IMO) Maritime Safety Committee (MSC)’s Circulation 1238. The main focus of this paper is the validation of SIMPEV by using “SAFEGUARD Validation Data Set 1 and 2”, which performed real evacuation trials in two full-scale ships to compare simulation data with experimental data. Total evacuation time is computed by SIMPEV based on the validation data sets such as drawings, initial distributions and end locations. The results from 50 times simulation are analyzed to be compared with the experimental data in the statistical methods. From the results, it is found that SIMPEV satisfies the acceptance criteria for each of data sets. Furthermore, the results show a close similarity to those of the other simulation programs.     

Eliminating constraint drift in the numerical simulation of constrained dynamical systems

By means of the Udwadia–Kalaba approach we propose an explicit equation of constrained motion developed to simulate constrained dynamical systems without error accumulation due to constraint drift. The basic idea is to embed a small virtual force and a small virtual impulse to the equation of motion, in order to avoid the drift typically experienced in constrained multibody simulations. The embedded correction terms are selected to minimally alter the dynamics in an acceleration and kinetic energy norm sense. The formulation allows one to use a standard ODE solver, avoiding the need for iterative constraint stabilization. The equation is based on the pseudoinverse of a constraint matrix such that it can be used under redundant constraints and kinematic singularities. The proposed method takes into account the finite word-length of the computational environment, and also accommodates possibly inconsistent initial conditions.     

glsim: A general library for numerical simulation

We describe glsim, a C++ library designed to provide routines to perform basic housekeeping tasks common to a very wide range of simulation programs, such as reading simulation parameters or reading and writing self-describing binary files with simulation data. The design also provides a framework to add features to the library while preserving its structure and interfaces.