Experimental study of high-density pedestrian flow

field characteristics at a crossing Liping LIAN1,2, Weiguo SONG1, YUEN Kwok Kit

Richard2, and Chunlin WU1

1State Key Laboratory of Fire Science, University of Science and Technology of China 2Department of Civil and Architectural Engineering, City University of Hong Kong

Main Content

Background Research status Experiment setup Motion detection and tracking Results Summary

2

Background

3 Hajj, 2015, Mecca Love Parade, 2010, Germany

Research status Local variables

4

( ) ( )( ), jj

r t f r t rρ = −∑

( )( )( )( )( ), j jj

jj

v f r t rV r t

f r t r

−=

−∑∑

Local density:

Local velocity:

Time-averaged velocity field

Dynamics of crowd disasters: An empirical study，Physical review E, 2007, 75(4) Dirk Helbing, Anders Johansson, Habib Zein Al-Abideen

( )( ) ( ) 2 22

1 expj jf r t r r t r RRπ

− = − −

In which

( ) :jr tPosition of pedestrian j

:R Measurement parameter

:jv Instantaneous velocity of pedestrian j

Research status Traffic design at a crossing

5 Self-Organized Pedestrian Crowd Dynamics: Experiments, Simulations, and

Design Solutions, Transportation science, 2005, 39(1)

Dirk Helbing, Lubos Buzna, Anders Johansson, Torsten Werner

Rotary Traffic

Rotary Traffic

Research status Ant evacuation in panic

6

Investigating collective escape behaviours in complex situations, Safety science, 2013, 60(87-94)

Charitha Dias, Majid Sarvi, Nirajan Shiwakoti, Omid Ejtemai, Martin Burd

Experiment setup

7

Builbing

15m

Sketch

ground

3.2 m

11.2 m

3.2 m

11.2 m

Waiting area(North pedestrian stream)

Waiting area(South pedestrian stream)

Waiting area

(West pedestrian stream

)

(East pedestrian stream)

Waiting area

x

y

1.0m0.8m

(Height:1.1m)

Experiment setup

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Conditions for each experiment scenario

Scenario Name Obstacle Walking instruction N(w) N(e) N(n) N(s)

1 OO-WS ---- straight 100 88 96 80

2 OO-WR ---- right 91 97 76 99

3 WOH-WR horizontal right 100 92 90 72 4 WOV-WR vertical right 86 100 71 95

Note: OO (without obstacle) WOH (with obstacle in horizontal direction) WOV (with obstacle in vertical direction) WS (walk straight) WR (walk on the right hand side).

Scenario 1 Scenario 3

Motion detection and tracking

9

-6 -4 -2 0 2 4 6

-6

-4

-2

0

2

4

6

x (m)y

(m)

a

b c

d

Mean-shift Algorithm

Position exaction Direct Linear Transformation

Data rectification

Drawing by Matlab

Pedestrian trajectory

Results

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-6 -4 -2 0 2 4 6

-6

-4

-2

0

2

4

6

y (m

)

x (m)

OO-WS

-6 -4 -2 0 2 4 6

-6

-4

-2

0

2

4

6

x (m)

y (m

)

OO-WR

-6 -4 -2 0 2 4 6

-6

-4

-2

0

2

4

6

x (m)

y (m

)

WOH-WR

-6 -4 -2 0 2 4 6

-6

-4

-2

0

2

4

6

x (m)

y (m

)

WOV-WR

Trajectories

Results

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Pedestrian Positions Instantaneous Velocities

Experiment OO-WS

Results

Pedestrian gap

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-6 -4 -2 0 2 4 6

-6

-4

-2

0

2

4

6

x (m)

y (m

)

Density in the cross area: 9.08 ped/m2 Majian et al TGF2013

Experiment OO-WS

Results

13 -6 -4 -2 0 2 4 6

-6

-4

-2

0

2

4

6

x (m)

y (m

)Instantaneous Velocity

-6 -4 -2 0 2 4 6

-6

-4

-2

0

2

4

6

x (m)

y (m

)Contour

(local velocity)

Experiment OO-WS

6.4s 8.1ped/m2

20s 9.5ped/m2

Results

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-6 -4 -2 0 2 4 6

-6

-4

-2

0

2

4

6

x (m)

y (m

)

Instantaneous Velocity Streamlines(local velocity)

Experiment OO-WR

Results

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OO-WS

WOH-WR

OO-WR

WOV-WR

Results

Turbulence intensity (I)

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'2 '2'

2 2

1 ( )2 x y

x y

u uuIU U U

+≡ =

+

' :::

u fluctuation velocity fieldV local velocity fieldU average velocity field

Local density distribution in experiment OO-WS

'u V U= −

17 -1.5 -1 -0.5 0 0.5 1 1.5

-1.5

-1

-0.5

0

0.5

1

1.5

x (m)

y (m

)

-1.5 -1 -0.5 0 0.5 1 1.5

-1.5

-1

-0.5

0

0.5

1

1.5

x (m)

y (m

)

-1.5 -1 -0.5 0 0.5 1 1.5

-1.5

-1

-0.5

0

0.5

1

1.5

x (m)

y (m

)

-1.5 -1 -0.5 0 0.5 1 1.5

-1.5

-1

-0.5

0

0.5

1

1.5

x (m)

y (m

)

Results

Time-averaged velocity field(U) in cross area

(WOH-WR)

(OO-WS) (OO-WR)

(WOV-WR)

Results

“Turbulence intensity”

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0 15 30 45 60 750

1

2

3

4

OO-WS OO-WR WOH-WR WOV-WR

tu

rbul

ence

inte

nsity

time (s)

Summary

Four-directional intersecting pedestrian flows are

conducted

Local density in the cross area can exceed 10 ped/m2

Density in the cross area is higher than in corridor

Pedestrian gap at high densities in the cross area

People are easy to fall

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Summary

Local velocity contour and streamlines at a crossing are obtained

Local velocity distribution and pedestrian flow field can be clearly seen

An approximate rotary traffic is formed

Traffic in the cross area will be relatively stable when putting an obstacle in the cross area

Turbulence intensity will be smaller

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October 17–21, 2016 Professor Weiguo Song E-mail: ped2016@ustc.edu.cn Tel: +8655163606419 Website: http://ped2016.ustc.edu.cn

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Thank you! &

Any questions?