44,975 research outputs found
Modelling shared space users via rule-based social force model
The promotion of space sharing in order to raise the quality of community living and safety of street surroundings is increasingly accepted feature of modern urban design. In this context, the development of a shared space simulation tool is essential in helping determine whether particular shared space schemes are suitable alternatives to traditional street layouts. A simulation tool that enables urban designers to visualise pedestrians and cars trajectories, extract flow and density relation in a new shared space design and achieve solutions for optimal design features before implementation. This paper presents a three-layered microscopic mathematical model which is capable of representing the behaviour of pedestrians and vehicles in shared space layouts and it is implemented in a traffic simulation tool. The top layer calculates route maps based on static obstacles in the environment. It plans the shortest path towards agents' respective destinations by generating one or more intermediate targets. In the second layer, the Social Force Model (SFM) is modified and extended for mixed traffic to produce feasible trajectories. Since vehicle movements are not as flexible as pedestrian movements, velocity angle constraints are included for vehicles. The conflicts described in the third layer are resolved by rule-based constraints for shared space users. An optimisation algorithm is applied to determine the interaction parameters of the force-based model for shared space users using empirical data. This new three-layer microscopic model can be used to simulate shared space environments and assess, for example, new street designs
Non-local first-order modelling of crowd dynamics: a multidimensional framework with applications
In this work a physical modelling framework is presented, describing the
intelligent, non-local, and anisotropic behaviour of pedestrians. Its
phenomenological basics and constitutive elements are detailed, and a
qualitative analysis is provided. Within this common framework, two first-order
mathematical models, along with related numerical solution techniques, are
derived. The models are oriented to specific real world applications: a
one-dimensional model of crowd-structure interaction in footbridges and a
two-dimensional model of pedestrian flow in an underground station with several
obstacles and exits. The noticeable heterogeneity of the applications
demonstrates the significance of the physical framework and its versatility in
addressing different engineering problems. The results of the simulations point
out the key role played by the physiological and psychological features of
human perception on the overall crowd dynamics.Comment: 26 pages, 17 figure
Quantitative Description of Pedestrian Dynamics with a Force based Model
This paper introduces a space-continuous force-based model for simulating
pedestrian dynamics. The main interest of this work is the quantitative
description of pedestrian movement through a bottleneck. Measurements of flow
and density will be presented and compared with empirical data. The results of
the proposed model show a good agreement with empirical data. Furthermore, we
emphasize the importance of volume exclusion in force-based models.Comment: 4 pages, 7 figures, 2009 IEEE/WIC/ACM International Joint Conferences
on Web Intelligence and Intelligent Agent Technologies (WI-IAT 2009), 15-18
September 2009, in Milano, Italy, 200
Cellular Automata Models of Road Traffic
In this paper, we give an elaborate and understandable review of traffic
cellular automata (TCA) models, which are a class of computationally efficient
microscopic traffic flow models. TCA models arise from the physics discipline
of statistical mechanics, having the goal of reproducing the correct
macroscopic behaviour based on a minimal description of microscopic
interactions. After giving an overview of cellular automata (CA) models, their
background and physical setup, we introduce the mathematical notations, show
how to perform measurements on a TCA model's lattice of cells, as well as how
to convert these quantities into real-world units and vice versa. The majority
of this paper then relays an extensive account of the behavioural aspects of
several TCA models encountered in literature. Already, several reviews of TCA
models exist, but none of them consider all the models exclusively from the
behavioural point of view. In this respect, our overview fills this void, as it
focusses on the behaviour of the TCA models, by means of time-space and
phase-space diagrams, and histograms showing the distributions of vehicles'
speeds, space, and time gaps. In the report, we subsequently give a concise
overview of TCA models that are employed in a multi-lane setting, and some of
the TCA models used to describe city traffic as a two-dimensional grid of
cells, or as a road network with explicitly modelled intersections. The final
part of the paper illustrates some of the more common analytical approximations
to single-cell TCA models.Comment: Accepted for publication in "Physics Reports". A version of this
paper with high-quality images can be found at: http://phdsven.dyns.cx (go to
"Papers written"
From individual behaviour to an evaluation of the collective evolution of crowds along footbridges
This paper proposes a crowd dynamic macroscopic model grounded on microscopic
phenomenological observations which are upscaled by means of a formal
mathematical procedure. The actual applicability of the model to real world
problems is tested by considering the pedestrian traffic along footbridges, of
interest for Structural and Transportation Engineering. The genuinely
macroscopic quantitative description of the crowd flow directly matches the
engineering need of bulk results. However, three issues beyond the sole
modelling are of primary importance: the pedestrian inflow conditions, the
numerical approximation of the equations for non trivial footbridge geometries,
and the calibration of the free parameters of the model on the basis of in situ
measurements currently available. These issues are discussed and a solution
strategy is proposed.Comment: 23 pages, 10 figures in J. Engrg. Math., 201
Guidelines for assessing pedestrian evacuation software applications
This paper serves to clearly identify and explain criteria to consider when evaluating the
suitability of a pedestrian evacuation software application to assess the evacuation
process of a building. Guidelines in the form of nine topic areas identify different
modelling approaches adopted, as well as features / functionality provided by
applications designed specifically for simulating the egress of pedestrians from inside a
building. The paper concludes with a synopsis of these guidelines, identifying key
questions (by topic area) to found an evaluation
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