Catálogo de publicaciones - libros

In the present work we studied the room evacuation problem using the social force model introduced by Helbing and coworkers. The ‘faster is slower’ effect induced by increasing desired velocities was analyzed. A steady state version of the problem was implemented by reinserting outgoing pedestrians into the room. It shows that, from a macroscopic point of view, the optimal evacuation efficiency correspond to the state at which the difference between the average system desire force minus the average system granular force is maximum.

In the occurrence of an emergency such as a fire, we must be able to come out of the structure we are staying at before its collapsing or fire spreading over it to save our lives. We can estimate the required safe egression time (RSET) for people to evacuate from structures such as a building and a passenger ship with Evacuation Model (EM). Although there are many EM’s currently available, most of them can not simulate evacuation behaviors in the dark. This is fatal to the credibility of simulation by evacuation models. This paper describes a behavior module for evacuation models that can simulate evacuation behaviors in the dark, which is based on Intelligent Agent (IA) technology, to generate more a credible RSET. The module can generate (virtual) evacuees’ key movements in the dark: (1) moving toward a wall, (2) following the wall to come out of the structure, and (3) reducing their travel speed to avoid collisions.

Evaluation and optimization of emergency route systems can be accomplished with different engineering methods. These methods are based on two different principles: the macroscopic and the microscopic approach. Both allow forecasting of evacuation times for various settings. In the work presented simple settings are investigated, consisting of rooms, corridor and stairs with regard to evacuation times. These calculations use current computer simulation programs, based on microscopic models, and the macroscopic method of Predtechenskii and Milinskii []. For the computer simulation we used ASERI 3.4c, buildingEXODUS V4.0 Level 2, PedGo Version 2.1.1 and Simulex 11.1.3. The comparison of the results shows that even for the simplest systems evacuation times vary considerably for different simulation programs and deviate from experimental results. Furthermore we investigated effects of geometric boundary conditions on the evacuation time.

Safe egress in case of a fire emergency is a major challenge for all parties responsible for the design and operation of underground railway stations. Since empirical data on egress behaviour, evacuation efficiency and smoke spread is scarce, numerical simulations are an important tool in order to determine available and required safe egress time. Egress times for different types of stations and various occupant distributions are calculated using the microscopic evacuation model ASERI. Required egress times are related to corresponding available egress times obtained from CFD smoke spread simulations by applying evaluation criteria included in the German vfdb Guideline “Methods of Fire Safety Engineering”. These investigations were part of a larger project including the local fire authorities to develop methods and criteria for fire safety concepts of existing and new subway stations in the city of Frankfurt.

Airport terminals have to cope with both safety and security aspects. A terminal is divided into public and non-public areas which have different security levels and require several ways to control passengers (EU 2320/2002). The developed model must consider the mix of screened and unscreened passengers, the ever-changing traffic volume, the use of emerging technologies, and the changes made to legal requirements. Inside the terminal heterogeneous groups of people are located with different personal profiles. The discrete microscopic simulation model for passenger motion behavior presented here is based on an enhanced cellular automata model. This model considers repulsion potentials, friction effects, and path finding/guidance algorithms. To control the evacuation process, the route choice approach can be used to integrate different evacuation strategies. The model reacts fast to changes in the surrounding area and provides multiple simulation runs with an altering parameter set in a short time. To ensure a reliable result a multi-level diagnostic of the evacuation process is necessary for considering the overall evacuation time, the identification of potential bottlenecks, the analysis of the critical path through the airport terminal, guidance system influences on pedestrian dynamics, and the effects of adjusted structural measures.

The empirical relation between density and velocity (fundamental diagram) of pedestrian movement is not completely analyzed, particularly with regard to the ‘microscopic’ causes which determine the relation at medium and high densities. The simplest system for the investigation of this dependency is the single-file movement. We present experimental results for this system and discuss the following observations. The data show a linear relation between the velocity and the inverse of the density, which can be regarded as the required length of one pedestrian to move. Furthermore we compare the results for the single-lane movement with literature data for the movement in a plane. This comparison shows an unexpected conformance between the fundamental diagrams, indicating that lateral interference has negligible influence on the velocity-density relation.

For the modelling we treat pedestrians as self-driven objects moving in a continuous space. On the basis of a modified social force model we analyze qualitatively the influence of various approaches for the interactions of pedestrians on the resulting velocity-density relation. The one-dimensional system allows focusing on the role of the required length and remote force. We found that the reproduction of the typical form of the fundamental diagram is possible if the model increases the required length of a person with increasing current velocity. Furthermore we demonstrate the influence of a remote force on the velocity-density relation.

This paper presents a model for office building usage simulation which is part of the research project “User Simulation of Space Utilisation”. The aim of this project is to develop a model for the simulation of human movement to predict space utilisation in office buildings.

The underlying model takes two main types of input: firstly the workflow of the organisation and secondly the design of the building in which the organisation is (or will be) housed. The latter refers to the spatial conditions. The model generates data about the activity the members of the organisation perform and their location in the building space for the specific time interval of the simulation run. Proceeding from these data, performance indicators can be deduced, like average/maximum walking distance per individual, time occupied per space and number of persons per space. These indicators can be used to analyse the performance of a design or can act as input for other engineering methods and models.

Discrete Event Simulation (DEVS) is a widely used approach for modelling and simulation of dynamic discrete systems. The modern object-oriented DEVS world view regards active objects (entities) passing passive objects (stations) along given path. An event mechanism updates movement of entities, being capable also of collisions and other state-dependent phenomena. Consequently; DEVS can be used for simulation of pedestrian and evacuation dynamics. Classical straightforward modelling approaches, based on abstract classical queuing systems, do not take into account the spatial distributions primarily — only for animation a spatial component is used. But modern object-oriented tools allow modelling of a spatial distribution primarily by means of topological attributes as well in active and passive objects at the modelling level. This contribution discusses the “spatial” features of DEVS simulation systems The chosen simulation tool, Enterprise Dynamics, offers a high flexibility due to its programming language 4d script that allows adding further functionality to the provided elements as well as creating completely new ones.

Software agents that use direct (or active) perception of the environment have recently been shown to correspond well with pedestrian movement within building and urban systems. The algorithm, based on Gibson’s theory of affordances, combines random selection of destination from their field of view with reassessment of the destination every few steps. However, although the agents correlate with human movement on aggregate, as individuals they progress more erratically than people do. It might seem necessary to add higher cognitive functions in order to guide them more convincingly, but here we show that it is possible to improve their behavioral response through artificial evolution of their existing navigation rules. First we show that the destination selection method approximates stochastic direction choice by length of line-of-sight. Then we use the lines of sight to provide a set of inputs to the agents, or animats, which we evolve to fit human usage patterns within a building as best possible. We demonstrate that while agents using informational change inputs fail to evolve to fit movement patterns, an input that compares sight-line lengths improves models qualitatively, but not quantitatively, which further implies that the individual guidance mechanism may be independent of the instant spatial properties acting on direct perception.

A one-dimensional cellular automaton model for pedestrian flow that describes the movement of pedestrians in a long narrow corridor is investigated. The model is equivalent to the asymmetric simple exclusion process (ASEP) with periodic boundary conditions and shuffled dynamics. In this type of update, the positions of the pedestrians are updated in a random order during one discrete time step. We derive expressions for the fundamental diagrams that are in very good agreement with simulation data. Finally we make a generalization to higher velocities and to two dimensions without lane-changing of the pedestrians.