EN12299-Evaluation of Ride Comfort for Rail Passengers (Alternative to ISO2631)

8/17/2019 EN12299-Evaluation of Ride Comfort for Rail Passengers (Alternative to ISO2631)

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ride comfort for rail passengers

Dr Björn Kufver (Ferroplan)



• Introduction / Background (1)

• Basic principles in the CEN comfort standard (1)

• Mean comfort standard method N MV (4)

Cx

,Cy

Cz

• Mean comfort complete methods N VA and N VD (2)

• Comfort on discrete events PDE (5)

• Comfort on curve transitions PCT (3)• Discussion and conclusions (5)

B Kufver - Ferroplan



-• e uropean omm ee or an ar za on -

Technical Committee TC256 - European standards for

• 1999 - a European prestandard for comfort evaluationENV 12299

• The research was conducted by UIC (ORE) and BRR

• –

Germany, Italy, Sweden

• A new standard EN 12299 was ublished in 2009




-• u

• Accelerometers and gyros – vehicle body – –speed – test sections – time intervals

• Full scale tests and com uter simulations

• Low-pass or band-pass filtering• Statistical post-processing

• Scales / interpretation of results

• Ride comfort as such / vehicle assessment




The mean comfort standard

method - 1•

• Calculated for a 5-minute run

• Measurements in the floor

• Accelerations in x-, y-, and z-directions

• Band-passed filtered signals 0.4-100 Hz

…

• 3 * 60 5-second rms-values

• 95 percentile (4th highest value) from each direction

2

95

2

95

2

95 )()()(6 bd d W

ZP

W

YP

W

XP MV aaa N ++⋅=





method - 2

Evaluation scale for N MV :

N < 1.5 Ver comfortable

1.5 < N MV < 2.5 Comfortable2.5 < N < 3.5 Medium

3.5 < N MV < 4.5 Uncomfortable

N > 4.5 Ver uncomfortable





method - 3•

• The controversial point is the 95 percentiles

• In each direction only 1 (of 60) 5-second rms-values isused

Table 1: Three hypothetical five-minute vibration patterns for onedirection (each of sixty five-second rms values, m/s

2).

First highest rms value 2nd

3rd

4th 5

th i

th 60

th

Series A 0.3 0.3 0.3 0.3 0.1 0.1 0.1

Series C 0.9 0.9 0.9 0.3 0.3 0.3 0.3





method - 4

• The 95 percentiles in x-, y-, and z-directions,

respectively, may occur during three different 5-secon n erva s.

• The final N MV -value cannot be well correlated to

oca rac con on s nce e cr ca a era y-value and the critical vertical z-value may be

.




Cx, Cy Cz

• MV - ,substantial loss of information.

• The CEN working group recommends that all 180 valuesare presen e n e es repor , as ree me ser es:Continuous Comfort.

• A preliminary scale is suggested for evaluation of individualrms-va ues

.

C Cy(t ),C Cz(t ) < 0.20 m/s2 Very comfortable

0.20 m/s2 < C C (t ),C Cz(t ) < 0.30 m/s2 Comfortable0.30 m/s

2 < C Cy(t ),C Cz(t ) < 0.40 m/s

2 Medium

C Cy(t ),C Cz(t ) > 0.40 m/s2 Less comfortable




The mean comfort complete

methods - 1e N VA met o ta es v rat ons ot at t e oor an at

the seat into account.

• Seat pan: lateral and vertical directions

•• Based on 95 percentiles

• ore cum ersome o use, o n rea es s ancomputer experiments




The mean comfort complete

methods - 2VD me o s va a e or s an ng passengers.

• Floor: x-, y-, z-directions, median values - ,• Too sensitive to outliers ? (ORE)

•

Both “complete methods” N VA and N VD have the same

disadvantages as the “standard method” N MV




DE -a a e or sea e an s an ng passengers ,

additional tests conducted by UIC/ERRI)

• Very comfortable

•

• Acceptable

• ncom or a e

• Very uncomfortable

uan es e percen age w o vo e“Uncomfortable” or “Very uncomfortable”




DE -Discomfort was found on large track irregularities (Discrete

Events; PDE) and on short transition curves (Curve

Transitions; P )

PDE is derived from conditions on straight track and circular- -

patterns of the lateral acceleration)

• Mean lateral acceleration (due to curvature and cant)

• Peak-to-peak lateral acceleration

;.7.7.max mean ppDE −⋅+⋅= y yP &&&&




DE -ERRI suggested a more automatic evaluation of Discrete

Events (P DE ) based on continuous evaluation of several

signals

∫+

=2

*

WpP,2s )(1

)(

T t

d yT

t y τ τ &&&&

−

2

t

* ⎞⎛ ⎤⎤−

T T &&&&

⎞⎛ ⎤⎤−− * T T

&&,2

,2

,WpP, pp

⎠⎝ ⎦⎦ ⎠⎝ ⎦⎦ 2,

2,WpP,

0;0.37)(01.27)(62.16max)( 2s ppDE −⋅+⋅= t yt yt P &&&&




DE -or e assessmen o a par cu ar oca even w c w a ec e

two-second sliding window during more than 2 seconds), the local

maximum of PDE(t ) shall be used)

1,4 14

Lateral acc(t)

PDE(t)

0,8

1

,

n [ m / s 2 ]

8

10

2s peak-to-peakPDE(t)

0,4

0,6

A c c e l e r a t i

4

6

0

0,2

0 2 4 6 8 10 12 14 16

0

2


Time t [seconds]



DE -r g na y, e DE unc ons were er ve an va a e or c rcu ar

curves and straight track only. PDE > 0 may be found in short

transition curves without large track irregularities.

1,4 14Lateral acc(t)

2s average

2s eak-to- eak

PDE(t)

0 8

1

,

n [ m / s 2 ]

8

10

PDE(t)

0,4

0,6

,

c

c e l e r a t i o

4

6

0

0,2

0

2

B Kufver - FerroplanTime t [seconds]



CT -CT s er ve rom con ons on rans ons curves o eclothoid type, evaluation starting 1 seconds before thetransition curve to 1.6 seconds after the transition curve

• Maximum lateral acceleration (averaged 1 second)

• Maximum lateral jerk (averaged 1 second)

• Maximum roll velocity (averaged 1 second)

&&&&& ,;...max 1smax1sCT −⋅+⋅= y y

& .

max1s. ϕ ⋅+




CT -

∫

+

⋅=2

*

Wp1s )(

1)(

t

d yT

t y τ τ &&&&

−2

t

1 T T &&&&&&&

⎠⎝ −−+⋅=

22 1s1s1s t yt y

T t y

+

⋅=

2*

)(1

)(

T t

d t τ τ ϕ ϕ &&

−2

T t




CT -

{ ,)(54.28(;0max)(

1sCT

t yt P &&⋅=

,,s.,s gnmax. 1s1s t t yt y A −−∈⋅⋅+ τ τ

] ]( ) 2.283

1s ),s6.1,)(max36.27( t T t A −−∈⋅+ τ τ ϕ &

e parame er A secon s s ou e c osen arge enoug o a ow g a era

jerk and high roll velocity to affect the evaluation even if they occur in the

beginning of a long transition curve,

but small enough in order to exclude these values when they do not belong to the

same transition as the lateral acceleration at the time t .




-

12299) is based on research from

• Missing knowledge #1: Monetary

• Missing knowledge #2: Motion sickness




- MV , VA VD

• Believed to be valid on fairly straight linesut not on curves

• neglect up to 98.3% (59 of 60) of the

measured rms-values• ma combine lon itudinal x lateral

and vertical ( z) vibration values from three

different 5-second intervals.




-

• PCT

- clothoids and linear cant transitions

• PCT - very short straight lines or circular

u ve

• Derived from the same tests and the using

almost – but not exactly - the same post-

processing (see next slide)




-+

T t

∫−

=2

2

*

WpP,2s )(1

)(

T t

d yT

t y τ τ &&&&

∫

+

⋅=2

*

Wp1s

)(1

)(

t

d yT

t y τ τ &&&&

,2

,2

),(max)( *

WpP, pp ⎟⎟ ⎠

⎞⎜⎜⎝

⎛ ⎥⎦

⎤⎥⎦

⎤+−∈=

T t

T t yt y τ τ &&&&

−2

t

⎛ 1 T T &&&&&&&

⎠⎝

−−⋅=22

1s1s1s y y

T

y

⎟⎟ ⎠ ⎞⎜⎜

⎝ ⎛ ⎥⎦

⎤⎥⎦⎤ +−∈− 2

,2

),(min *WpP, T t T t y τ τ

&&

+

⋅=

2*

)(

1

)(

T t

d t τ τ ϕ ϕ &&

−2

T t




-

published, …

… there is still room for further research in

the area of ride comfort evaluation


EN12299-Evaluation of Ride Comfort for Rail Passengers (Alternative to ISO2631)

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