Call Girls Alandi Call Me 7737669865 Budget Friendly No Advance Booking
Modeling Pedestrian and Crowd Behaviour: the case of the Crystals Project
1. Modeling Pedestrian and Crowd Behaviour: the
case of the Crystals Project
Giuseppe Vizzari1,2
1Complex Systems and Artificial Intelligence Research Center
University of Milano-Bicocca
2Crystals Project, Center of Research Excellence in Hajj and Omrah (Hajjcore)
Umm Al-Qura University, Makkah, Saudi Arabia
2. Outline
• The context of application: the Hajj, the Mashaer line and the Arafat I
station
• Groups, as a crowd management concept and a natural, pervasive
presence in pedestrian population
• Groups in the relevant literature
• “In vitro”, “in vivo”, “in silico”: the Crystals Project approach
• Observations about groups (“in vitro” and “in vivo”)
• Modeling and simulation (“in silico”)
• Results in the Arafat I scenario
• Conclusions and future developments
3. Outline
• The context of application: the Hajj, the Mashaer line and the
Arafat I station
• Groups, as a crowd management concept and a natural, pervasive
presence in pedestrian population
• Groups in the relevant literature
• “In vitro”, “in vivo”, “in silico”: the Crystals Project approach
• Observations about groups (“in vitro” and “in vivo”)
• Modeling and simulation (“in silico”)
• Results in the Arafat I scenario
• Conclusions and future developments
4. The Hajj in Brief
• Annual pilgrimage to Makkah,
Saudi Arabia
• Fifth pillar of Islam, a religious
duty that must be carried out at
least once in their lifetime by
every able-bodied Muslim who
can afford to do so
• Over 2,5 millions of people
coming from over 150 countries
• A precise and articulated
system of rituals implying the
mass movement of pilgrims
over several sites that in some
cases are about 20 km distant
5. The Mashaer Line
• Five proposed rail lines
connecting the holy sites with
one another and with Makkah
• The southern rail includes 9
stations: 3 in Mina, 3 in
Muzdalifah and 3 in Arafat, to
replace 35,000 cars and buses
and access the Haram and
Makkah Central Area
• Future lines to the Holy Haram
• Extend the southern rail line to
Jeddah Airport, with an elevated
alignment above the Jeddah
Expressway over an 80 Km
length
7. Outline
• The context of application: the Hajj, the Mashaer line and the Arafat I
station
• Groups, as a crowd management concept and a natural,
pervasive presence in pedestrian population
• Groups in the relevant literature
• “In vitro”, “in vivo”, “in silico”: the Crystals Project approach
• Observations about groups (“in vitro” and “in vivo”)
• Modeling and simulation (“in silico”)
• Results in the Arafat I scenario
• Conclusions and future developments
8. Observations at the Hajj - Groups as a crowd
management organizational instrument
• Pilgrims are subdivided into groups of 250
persons following a leader in their movement
from the nearby tents area to the platform
• The waiting boxes act as waiting areas hosting
groups waiting to use ramps or elevators
• The platform can safely host even more than
3000 pilgrims (the capacity of a train), but the
process is aimed at avoiding overcrowding of the
platform
9. Observations at the
Hajj - Considerations
• Groups are used as an organizational
instrument to manage crowd
• Group arrival is planned, scheduled
• Leaders decide when and where to
move, collaborating with station
officers
• Their size is relatively large, their
cohesion is not extreme...
• ... but inside them smaller sub-
groups can be identified and they
can be much more compact
• Groups have different intermediate
movement targets, although the same
final goal
10. Group influence in
general -
Considerations
• The presence of groups is pervasive in
many events involving large crowds
• Groups are simply out there...
• ... it’s not a matter of deciding if they’re
‘good’ or ‘bad’ for the pedestrian flow
• ... it’s a matter of understanding their
impact, in different relevant conditions
• The presence of groups should be
carefully considered:
• Design choices might make it difficult
for a group to preserve its cohesion,
which is particularly significant in
certain situations (e.g. kids, elderly,
mobility impaired persons)...
• ... and this would cause stress in
group members and congestions,
delays in the whole system
11. Outline
• The context of application: the Hajj, the Mashaer line and the Arafat I
station
• Groups, as a crowd management concept and a natural, pervasive
presence in pedestrian population
• Groups in the relevant literature
• “In vitro”, “in vivo”, “in silico”: the Crystals Project approach
• Observations about groups (“in vitro” and “in vivo”)
• Modeling and simulation (“in silico”)
• Results in the Arafat I scenario
• Conclusions and future developments
12. Groups in the
literature -
Observations
• At least two studies report observations
about groups
• Willis A, Gjersoe N, Havard C,
Kerridge J, Kukla R, 2004, "Human
movement behaviour in urban spaces:
implications for the design and
modelling of effective pedestrian
environments" Environment and
Planning B: Planning and Design 31(6)
805 – 828
• Michael Schultz, Christian Schulz, and
Hartmut Fricke. “Passenger Dynamics
at Airport Terminal Environment”,
Pedestrian and Evacuation Dynamics
2008, Springer-Verlag, 2010
• Observations carried out in low density
conditions
• Groups of small size were most frequently
observed
13. Groups in the literature -
Modeling and
Simulation
• Extensions to the social force model
• Helbing, Theraulaz et al. 2009, 2010
• Small groups (2,3,4), unstructured
• Low to moderate densities
• Validation based on actual observations
• Xu and Duh, 2010
• Only couples (groups of 2 pedestrians)
• Low to moderate densities
• Shallow validation based on literature (Daamen,
2004)
• CA models
• Sarmady, Haron, Zawawi Hj, 2009
• Leaders and followers
• Groups of 2 to 6 members experimented
• Not validated
• Agent-based models
• Qiu and Hu 2010
• Structured groups (intra and inter group matrices)
• Large groups experimented (60 pedestrians)
• Not validated
• Group members tend to stay close to other group
members (additional behavioural component)
14. Outline
• The context of application: the Hajj, the Mashaer line and the Arafat I
station
• Groups, as a crowd management concept and a natural, pervasive
presence in pedestrian population
• Groups in the relevant literature
• “In vitro”, “in vivo”, “in silico”: the Crystals Project approach
• Observations about groups (“in vitro” and “in vivo”)
• Modeling and simulation (“in silico”)
• Results in the Arafat I scenario
• Conclusions and future developments
16. Outline
• The context of application: the Hajj, the Mashaer line and the Arafat I
station
• Groups, as a crowd management concept and a natural, pervasive
presence in pedestrian population
• Groups in the relevant literature
• “In vitro”, “in vivo”, “in silico”: the Crystals Project approach
• Observations about groups (“in vitro” and “in vivo”)
• Modeling and simulation (“in silico”)
• Results in the Arafat I scenario
• Conclusions and future developments
17. Experiments in
Tokyo
• Experiments carried out by the
Research Center on Advanced
Science and Technology of The
University of Tokyo
• Aimed at evaluating the impact of the
presence of groups in experimental
situations
• Specifically their impact on the
formation of lanes and total
travel times in relatively high
density situations
• Results still not published...
• ... However, we can already say that
more experiments and observations
are needed to draw conclusions
• The influence of groups is not
trivial
18. Admission test
University of Milano-Bicocca
• Admission test of the Faculty of
Psychology at the University of Milano-
Bicocca - September 1, 2011
• Counting activity supported by video
footages of the event
• About two thousand students attended the
test
• About 34% individuals, 50% couples,
13% triples and 3% groups of 4
members (!)
• Statistically validated relationship between
group size and velocity
• Additional quantitative analyses about
the arrival and entrance process, LOS
• Qualitative analysis of group shapes and
related phenomena
19. Vittorio Emanuele II
Gallery, Milan
• Popular commercial-touristic
walkway in Milan’s city centre
• Goals of the survey:
• level of density and walkway level
of service (A and B);
• presence of groups (over 84%);
• group size and proxemics spatial
patterns, trajectories and walking
speed (groups are slower but
their trajectories are shorter);
• group proxemics dispersion (they
preserve cohesion, even if
large ones occupy more space)
• still hard to evaluate spatial
arrangement of group members
Group
dispersion
Couples Triples 4 Members
Distance
Centroid
0.58 m
(sd 0,22)
0.76 m
(sd 0,11)
0.67
(sd 0.12)
20. Outline
• The context of application: the Hajj, the Mashaer line and the Arafat I
station
• Groups, as a crowd management concept and a natural, pervasive
presence in pedestrian population
• Groups in the relevant literature
• “In vitro”, “in vivo”, “in silico”: the Crystals Project approach
• Observations about groups (“in vitro” and “in vivo”)
• Modeling and simulation (“in silico”)
• Results in the Arafat I scenario
• Conclusions and future developments
21. A model considering
groups
• Based on the floor-field CA approach,
with significant difference on movement
choice
• Employing traditional factors for
movement destination choice
• Goal orientation
• Presence of obstacles
• Presence of other pedestrians
(basic proxemics)
• A notion of group has been introduced
• To generate a generalised effect of
cohesion among members of
groups
• ... able to overcome goal
orientation for certain types of
groups (e.g. families, close friends)
• Speed heterogeneity also introduced
(poster on Monday afternoon)
22. A few formal details
• Stochastic choice of destination cell; for each cell c, the probability of choosing
an action a leading to it is
• The “utility” value of the cell is defines as follows:
where
• Goal is associated to the static floor field and Obs to the wall potential
• Sep is associated to the proxemic repulsion
• D is an inertia factor
• Over regulates the possibility of having two pedestrians sharing the same cell in
case of high density
• Coh and Inter represent group cohesion factors respectively for small simple
groups and large potentially structured groups
23. Overlapping
• Overlapping is a transient
situation in which pedestrians
share the same cell
• ... it can sometimes be
observed in counterflow
situations in which there is not
enough space for avoidance
• It can only happen if local
density exceeds a given
threshold
• The choice is still penalised
(Over ≤ 0)
• No more than two pedestrians
can share a single cell
[Kretz et al., 2006]
24. Simple and
structured groups
• Simple groups are made up of family
members, friends, people that know each
other
• They often adapt their behaviour to
preserve the cohesion of the group
• Large groups can include perfect
strangers that share for some time a
common goal
• Members of this group have a tendency
to stay close to each other...
• ... but this tendency is not so strong to
prevent group fragmentation
• And generally they are actually
structured (they can include other -
often simple - groups), so we call them
structured
25. • Multipliers of the different components of movement “utility” are adjusted
according to the state of the group
• The dispersion of the group causes an increased impact of simple group
cohesion and a reduced effect of goal attraction (static floor field)
Adaptive group cohesion mechanism
26. Modelling groups - some qualitative results
Counterflow of two structured groups including simple groups of various size, in a 2.4 m wide corridor
27. Aggregate effects of groups
Counterflow of two structured groups including simple groups of various size, in a 2.4 m wide corridor;
shuffled sequential update - ongoing tests with parallel update strategy
28. Aggregate effects of
groups analysed
• We can interpret the results making
considering two phenomena
1.Wide groups offer a large profile to the
counter flow, so they have a higher
probability of facing conflicts
2.Once a group has formed a line, instead,
the leader has the same conflict
probability of an individual, but the
follower has often an advantage
• In low density situations phenomenon (1)
prevails, leading to a lower average
combined flow for groups of pedestrians
whose size is larger than 2
• Pairs in fact can easily form a line, turning
phenomenon (1) to (2)
• In high density situations the probability of
facing conflicts is very high also for
individuals, so phenomenon (2) prevails,
leading to higher average combined flow for
even large groups (size 5)
29. Effectiveness of simple group cohesion
mechanism
Counterflow of two structured groups including simple groups of various size, in a 3.6 m wide corridor
(Dispersion measured in terms of area covered by the group)
30. Additional results in “experimental” scenarios: T
junction
Plot of experimentally observed data
[Zhang et al., 2012]
[Vizzari et al., 2013]
31. Outline
• The context of application: the Hajj, the Mashaer line and the Arafat I
station
• Groups, as a crowd management concept and a natural, pervasive
presence in pedestrian population
• Groups in the relevant literature
• “In vitro”, “in vivo”, “in silico”: the Crystals Project approach
• Observations about groups (“in vitro” and “in vivo”)
• Modeling and simulation (“in silico”)
• Results in the Arafat I scenario
• Conclusions and future developments
41. Dynamically managing The tactical level:
Introduction to the paths tree
• Given an arbitrary environment, the agent should
be able to plan a path toward its target,
considering:
• The types of environment that will be crossed
static elements
• The emergence of congestion or other
elements influencing the path conditions
dynamic elements
• The choice among paths is performed according
to the expected traveling time, dynamically
changing.
• The decision tree contains the average traveling
time of each minimal path to a destination,
estimated by considering static elements and the
average speed of the agents.
42. An evacuation of a large population of
pedestrians
1000agentsat~10p/sec
1000agentsat~10p/sec
Step 50 Step 200
Step 350 Step 500
44. Outline
• The context of application: the Hajj, the Mashaer line and the Arafat I
station
• Groups, as a crowd management concept and a natural, pervasive
presence in pedestrian population
• Groups in the relevant literature
• “In vitro”, “in vivo”, “in silico”: the Crystals Project approach
• Observations about groups (“in vitro” and “in vivo”)
• Modeling and simulation (“in silico”)
• Results in the Arafat I scenario
• Conclusions and future developments
45. Conclusions and
discussion
• Groups are relevant and significant
• Results of simulations are partly validated
• Fundamental diagram and spatial
utilisation in tune with results from the
literature… without groups
• Group cohesion mechanism generates
results about dispersion that are in tune
with Vittorio Emanuele Gallery’s
observation…
• … but we don’t have data about groups
in high density situations (and it’s hard to
obtain such data)
• More observations, experiments and
simulations are necessary to improve our
understanding of the phenomenon
• Closer collaboration between researchers
working on synthesis and analysis of
crowds is promising and possibly beneficial
for both
46. Future works
• Of course, improvements...
• of the model, of our understanding about the phenomena...
• Of course, additional applications to real world scenarios...
• for providing additional success stories and collecting additional issues,
limits, directions for improvements
• Strengthening the connections with automated analysis/computer vision
• Exploiting the model for supporting smart environment, smart city systems
• In the vein of what was discussed by Ulrich Wagoum for stadium
evacuation assistant, Georgios Sirakoulis work on anticipative
technologies and robotic evacuation assistant...
Per illustrare le motivazioni e l’idea di architettura ibrida, è utile partire che l’entità modellata è una persona, ed è quindi naturale pensare alla parte già esistente nel modello base come il “corpo”. Con il termine corpo non si vuole indicare solamente la parte di attuazione dell’agente, perché infatti questo corpo implementa già comportamenti reattivi che vanno al di là della semplice attuazione
Inoltre il corpo per eseguire i suoi compiti si basa su una conoscenza di molto legata alla geometria dell’ambiente, proprio perché molto legato alla parte di attuazione, alla parte della fisica.
A questo punto quello che si è voluto fare con questo lavoro è aggiungere la parte mancante, la mente.
Il termine mente risulta comodo per rendere l’idea che questa parte avrà a che fare con aspetti cognitivi anziché fisici, ma in realtà non vuole modellare esattamente i processi mentali, bensì vuole rappresentare la parte di ragionamento dell’entità modellata.
Dovendo trattare aspetti più distanti dalla rappresentazione geometrica, sarà necessario dotare la mente anche di una differente conoscenza che permetta di eseguire i ragionamenti necessari.
In questo lavoro, considerata la complessità dei compiti svolti al livello tattico e strategico, ci siamo concentrati sul dotare l’agente della capacità di pianificare i propri percorsi all’interno dell’ambiente, gettando le basi per poter sviluppare la mente in tutte le sue funzionalità.
Chiaramente, le due componenti dell’architettura ibrida devono essere necessariamente in comunicazione, e quello che si è voluto fare con questo lavoro è di costruire la mente sopra al corpo, senza alterare il funzionamento precedente.
Nel modello base la fase di annotazione dell’ambiente permetteva di definire fondamentalmente quattro tipi di oggetti all’interno dello scenario:
Ostacoli, per modellare ad esempio i muri di una stanza;
aree di partenza, dove i pedoni vengono inseriti nella simulazione
Aree di destinazione, ogni pedone poteva avere una e una sola destinazione che gli veniva assegnata nel momento in cui “nasceva” nella simulazione
Scale e Rampe, zone in cui la velocità del pedone veniva alterata per rappresentare sul piano le scale
Siccome con questo lavoro si vuole introdurre la possibilità di avere destinazioni intermedie, sono stati aggiunti anche i tool di annotazione necessari in fase di modellazione dello scenario:
Regioni per strutturare l’ambiente da un punto di vista logico;
Collegamenti di navigazione per rappresentare i passaggi tra le regioni;
Target intermedi per rappresentare destinazioni intermedie di interesse
A questo punto anche target e link di navigazione sono candidati a essere destinazioni per i pedoni.
Con le annotazioni aggiunte allo scenario, il nuovo modello è in grado di calcolare in maniera automatica la mappa cognitiva.
Inoltre due delle notazioni aggiunte, potendo essere utilizzate dagli agenti come destinazioni, necessitano quindi di pathfield, cioè quella parte di conoscenza dell’agente che supporta il meccanismo del corpo per il raggiungimento della destinazione.
Durante la generazione di questi campi per nuovi e vecchi tipi di destinazioni, parallelamente viene costruita anche la mappa cognitiva.
La sua struttura base viene generata durante la generazione dei field relativi ai link tra le regioni.
A partire da ogni marker che collega due regioni, durante la diffusione del suo campo si va alla ricerca dei marker di identificazione della regione, producendo di conseguenza una parte di mappa che viene aggiunta a quella eventualmente esistente.
Ad esempio…
Grazie alla generazione in parallelo , è possibile quindi costruire una forte relazione tra le diverse rappresentazione dell’ambiente.
Nella figura è mostrata proprio questa relazione tra le conoscenze, che permette di collegare la mente al corpo nonostante la distanza e differenza tra le rappresentazioni.
In questo modo, infatti, il ragionamento della mente fatto sulla mappa cognitiva può essere facilmente tradotto in istruzioni operative che il corpo è in grado di eseguire. Ad esempio dalla mappa cognitiva è possibile vedere che esiste un collegamento tra sala e cucina, e che è possibile istruire il corpo di effettuare questo spostamento ordinandogli di seguire il pathfield associato all’arco.
E' tempo quindi di affrontare le modifiche che hanno interessato l'agente nel proprio modo di operare piuttosto che nella conoscenza.
In figura è possibile vedere il ciclo di vita dell'agente precedente alle modifiche apportate da questo lavoro.
Come si può vedere esiste solo la parte relativa al corpo, c'è una fase di percezione, che lavora sulla conoscenza del corpo, dopodichè passa a selezionare il movimento reattivamente, ed infine esegue effettivamente la mossa.
Con questo lavoro sostanzialmente una fase di controllo eseguita dalla mente anticipa il precedente ciclo di vita lasciandolo praticamente inalterato.
L'idea è appunto quella di lasciare il corpo lavorare come sempre, mentre la mente tiene in considerazione un piano, cambiando solamente il supporto della destinazione che il corpo vuole raggiungere.
Questo comporta 3 tipi di attività da parte dell'agente:
Creazione di un piano, cioè valutare la sequenza di destinazioni intermedie necessarie e/o obbligatorie, per raggiungere la destinazione finale di interesse.
- gestione del piano: questo è il controllo che la mente esegue sul corpo, gestendo per passi il piano di destinazioni intermedie, nascondendo al corpo la presenza di un piano e fornendogli solamente l'attuale target. Il corpo infatti è in grado solamente di raggiungere la destinazione che gli si è ordinata, sarà quindi la mente a mantenere traccia dello stato di compimento del piano e fornire di volta in volta il pathfield per il raggiungimento della destinazione intermedia corretto. Il momento in cui il piano avanza viene valutato sulla base di percezioni del corpo, che è l’unico in grado di percepire se si è raggiunta la destinazione voluta.
- attuazione: infine c'è la normale attuazione reattiva che lavora esattamente come se nessuna modifica fosse stata apportata al modello tenendo conto dei gruppi, degli ostacoli,…I comportamenti reattivi