Granular oor plan representation for evacuation modeling ?

Abstract

In this paper we describe the architecture of a simple evacuation model which is based on a graph representation of the scene. Such graphs are typically constructed using Medial Axis Transform (MAT) or Straight Medial Axis Transform (S-MAT) transformations, the former being a part of the Voronoi diagram (Dirichlet tessellation) of the oor plan. In our work we construct such graphs for oor plans using Voronoi diagram along with the dual Delaunay triangulation of a set of points approximating the scene. Information supplied by Delaunay triangulation complements the graph in two ways: it determines capacities of some paths associated with edges, and provides a bijection between graph vertices and a set of regions forming a partition of the oor plan. We call the representation granular for this reason. We provide an exposition of the representation of re scene that aids egress time calculations, discuss the algorithm of construction of this representation and brie y discuss the applicability of network ow models (e.g. the Ford-Fulkerson method or the push-relabel method) in our setting.

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ICRA project (http://icra-project.org) aims to build modern engineering tools to support re commanders during re operations. In this paper we focus on the problem of modeling evacuation process. While there are various questions one may want to ask regarding evacuation, e.g. related to nding optimal (static or dynamic) evacuation plans, in this paper we focus on the problem of evacuation time estimation and bottleneck analysis. There are four ICRA modules that are being developed that are relevant to evacuation modeling.

Wojciech Swieboda, Van Mai Nguyen Thi, and Hung Son Nguyen { re and smoke localization module, which determines the placement and spread of re and smoke, { occupant localization module, which aims to estimate occupant density in various parts of a buildings or determine occupant locations, { building topology construction, which builds a geometric network of the re scene, { evacuation module, which estimates the egress time, determines bottlenecks and is used in setting priorities during nd and rescue operations. IFC model of building

Building metadata

Behavioral model Geometric network construction

Unobstructed movement model

Occupants localization Fire and smoke localization

Obstructed movement model

In our exposition we discuss the typical model of an evacuation process from re protection engineering literature [ 3, 1 ], the desired re scene representation, and nally the algorithm of geometric network construction that aids egress time estimation. We stress that the discussed egress model is based on a ne network representation and models occupants globally (as groups of people rather than tracking each individual during the simulation) [ 5 ]. See e.g. [ 5 ],[ 4 ],[ 2 ] for discussion of alternative approaches.

In our earlier paper we discussed a simpli ed model coupling a partial behavioral model (accounting for typical pre-movement times) and a tra c model. We provide a clearer exposition of the representation of re scene and brie y discuss the applicability of network ow models (e.g. the Ford-Fulkerson method or the push-relabel method) in our setting.

Granular oor plan representation for evacuation modeling

References

1. The application of re safety engineering principles to re safety design of buildings: part 6 : Human factors: Life safety strategies : occupant evacuation, behaviour and condition (sub-system 6) . BSI, London ( 2004 )

2. Galea , E. , Lawrence , P. , Gwynne , S. , Filippidis , L. , Blackshields , D. , Cooney , D. : buildingEXODUS v6.0 . University of Greenwich, Greenwich, London ( October 2013 )

3. Gwynne , S.M.V. , Rosenbaum , E.: In: DiNenno, P.J. , Drysdale , D. , Beyler , C.L. (eds.) SFPE Handbook of Fire Protection Engineering, chap . Employing the Hydraulic Model in Assessing Emergency Movement , pp. 373 { 395 of section 3 . National Fire Protection Association, Quincy, MA, 4th edn. ( 2008 )

4. Korhonen , T. , Hostikka , S. : Fire Dynamics Simulator with Evacuation: FDS+Evac { Technical Reference and User's Guide . Julkaisija-Utgivare, VTT Working Papers 119 ( 2009 )

5. Kuligowski , E.D. , Peacock , R.D. , Hoskins , B.L.: A review of building evacuation models, 2nd edition . Technical Note 1680 , National Institute of Standards and Technology ( 2010 ), http://evacmod.net