Euro NCAP Whiplash Rating Toyota Position & Proposal … · 3 Schedule 2011 7 14 21 28 February Folksam Chalmers TNO BASt (15.03) TRL (11.05) June B. Fildes (ESV) Euro NCAP (TBC)

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Euro NCAP Whiplash Rating -

Toyota Position & Proposal

May 2011

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Content

• Background and Priority

• J-NCAP

• Extended Review

• Overall Conclusion

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Schedule 2011

2821147

February

Folksam

Chalmers

TNO

BASt (15.03)

TRL (11.05)

June

B. Fildes (ESV)

Euro NCAP (TBC)

ADAC

4

Background:Past TOYOTA presentation

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6

7

8

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Marginal ratingGood real-life effectiveness

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1st Priority Improvement

– Remove HRCT, T1Gmax, RV– No relevance in real life safety– Design restrictive

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J-NCAP

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J-NCAP criteria and thresholds are based on the work of Ono et al.

Evaluation Criteria for the Reduction of Minor Neck Injuries during Rear-end Impacts Based on Human Volunteer Experiments and Accident Reconstruction Using Human FE Model Simulations Koshiro Ono1), Susumu Ejima1), Kunio Yamazaki1), Fusako Sato1), Jonas Aditya Pramudita2), Koji Kaneoka3), and Sadayuki Ujihashi 2) 1) Japan Automobile Research Institute , 2) Tokyo Institute of Technology, Japan , 3) Waseda University, Japan

13New Car Assessment Japan 2010, page 7http://www.nasva.go.jp/mamoru/en/panf_2010_en.pdf

J-NCAP criteria and point generation

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J-NCAP thresholds: sliding scale between 5% and 95% WAD 2+ risk

5% WAD2+ risk

95% WAD2+ risk

JAPAN NEW CAR ASSESSMENT PROGRAM FOR MINOR NECK INJ URY PROTECTION IN REAR-END COLLISIONSTakahiro IKARI, Kenichi KAITO National Agency for Automotive Safety and Victims’ Aid (NASVA), JAPANTaichi NAKAJIMA, Kunio YAMAZAKI, Koshiro ONO Japan Automobile Research Institute (JARI), JAPANESV Paper Number 09-0364

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Extended Criteria Review

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(1) gtr7(2) Biomechanics of Whiplash(3) Real life data analysis

(4) Criteria proposal (5) Implications

(6) Threshold proposal (7) Implications

(8) New rating scheme

(9) Evaluation of real life relevance

Today’s Agenda

For a later day

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Whiplash Regulation , Assessmentstarted under making

～2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

GTR

JP

EU

US

JP

EU

US

Korea

China

Ass

ess

ment

Regu

ration

FMVSS202a(FR)

(RR)

★GTR-Phase1 ☆GTR-Phase2　（Step1)？

☆GTR-Phase2　（Step2)？

ECE17-10？

ECE17-10？

New FMVSS202a？

J-NCAP

E-NCAP

IIHS

K-NCAP

C-NCAP？

Folksam

Thatcham

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Purpose and situation of Head Restraint GTR makingPurpose and situation of Head Restraint GTR making

1.Evaluation by Injury Criteria･ Japan proposed the assessment based on Ono 2009 (completed). ･ An original research that uses PMHS is being conducted in the United

States (until end of 2011). → Injury Criteria of GTR7 is to be considered by a joint research of

JARI(Ono) and NHTSA.

Solving the following problem of the Whiplash evaluation of the current state is necessary. Governments and the industry are jointly working on it withinWP29/GRSP. .

Japan proposal NHTSA study

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2.Guarantee of Repeatability･Reproducibility･ The Cause of variability is studied in each country. ･ Improvement of BioRID Ⅱ calibration is studied by Humanetics Co..･ Reduction of dummy setting tolerance (Completed at GTR7-Phase1).

→When establishing the regulation, improvement of Repeatability･Reproducibility is requested and necessary.

PDB studyHumanetics Co.Calibration study

Dummy set proposal(Fixed at GTR7-Phase1. )

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3. Test method to reflect the real world･ Seat back angle to be set (and tested) at design angle is considered in

each country.･ Test speed appropriate for permanent injury reduction is considered in each country.

･ Large stature (AM95-three dimensional manikin) is considered by the Netherlands &TNO.

Small design torso angle Dummy setting study

Test speed for injury reduction study

High height person study

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Today’s Agenda

For a later day

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Biomechanics of Whiplash injuries – Injury criteria review

“None of the proposed injury criteria were found to have a definite biomechanical basis and their validity in predicting the risk needs to be established. None of the criteria can be recommended on a strictly biomechanical basis.”

Considered were main injury criteria proposed in literature: Nij, Nkm, LNL, IV-NIC, NDC, NIC, other: Head RV and Seatbelt load.

Dummy Requirements and Injury Criteria for a Low-speed Rear Impact Whiplash Dummy. EEVC WG12 report, p.29, September 2007

However, some valuable insight can gained from a biomechanical review of Whiplash injuries.

On the following pages, “Mainstream findings” will be presented, Controversial research findings are not included.

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Biomechanics of Whiplash injuries

The biomechanical evidence for Whiplash injuries

Symptoms (short and long term)

Physiological damage(injury)

Injury mechanism

Injury criterionthresholds

corr

elat

ion

Injury criterion with thresholds

Classic injury criteria development For whiplash

Effe

ctiv

enes

s re

view

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Biomechanics of Whiplash injuriesWhiplash

Injuries

Injury mechanism

Criteria

Thresholds

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Symptoms

Neck pain, headache, vision disorder, dizziness, unconsciousness, neurological symptoms and other

EEVC WG12 report, p.24, September 2007Schmitt, K.U. Trauma Biomechanics, 2nd Edition, p.91

Syptoms and injuries are related:“Nociceptors have been shown to exist in various

components of spinal tissues, namely the muscle (Bogduk & Marsland 1988), disc annulus and facet joint ligaments (McLain 1994). Consequently, injury to any of these tissues has the potential to cause neck pain.”

Whiplash associated disorders: a comprehensive review, p. 31. Anderson et al. Centre for Automotive Safety Research. University of Adelaide. April 2006

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Physiological damage (injuries)

Yoganandan et al. (2000) reported injuries to several ligaments, the intervertebral discs and the facet joint structures.

Taylor et al. (1998) and Svensson et al. (2000) reported damage in cervical spinal root ganglia

Brault et al. (2000) reported muscle injuriesEEVC WG12 report, p.24, September 2007

But muscle stiffness following the impact typically last only a few days

Whiplash associated disorders: a comprehensive review, p. 31. Anderson et al. Centre for Automotive Safety Research. University of Adelaide. April 2006.

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Physiological damage (injuries)

“The structures most likely to be injured in whiplash are the facet capsule, the intervertebral discs and the upper cervical ligaments. Injuries to other structures may occur but the available evidence appears to suggest that these are less common”

Whiplash associated disorders: a comprehensive review, p. 31.

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Facet joint Disc Ligaments Muscles Spinal root ganglia Injuries

Injury mechanism

Criteria

Thresholds

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Injury mechanism

Hyperextension of the neck – not relevant any moreMuscle strains – unlikely and pain only last for a few daysSpinal column pressure pulses – could cause ganglion

damageCervical spine motion (local hyperextension/flexion) - has

been shown to be able to lead to facet joint impingement Neck shear force can cause excessive facet joint strain.Neck compression can cause the facet capsules to stretch

and possibly torn, resulting in inflammation and pain.

Whiplash associated disorders: a comprehensive review, p. 36-38

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Injury mechanism

“Many causes for soft tissue neck injuries are hypothesised, … In practice, the S-shape deformation is regarded to play a crucial role when discussing possible injury mechanism”

Schmitt, K.U. Trauma Biomechanics, 2nd edition p.94

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Facet joint Disc Ligaments Muscles

local hyperextension

/ flexionMuscle strain

Spinal root ganglia

Pressure pulseNeck shearNeck

compression

Injuries

Injury mechanism

Criteria

Thresholds

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Several injury criteria (response measurement)

Associated injury mechanismItem Who? Year Where?

NIC Bostrom '96 IRCOBI Pressure pulses in spinal ganglia

Nkm Schmitt '01 ESV Excessive load (some relation with facet injury)Combination of Fx and My

LNL Heitplatz '03 ESV

MIX Kullgren '03 ESV - (combination of NIC and Nkm)

WIC Muñoz '05 ESV - (excessive load?)

Excessive load (some relation with facet injury)Combination of lower Neck Fx, Fz, My

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Several injury criteria (response measurement) contd.


T1G - (Seat design parameter)

Fx (upper) Facet injury (via cervical strain)

Fz (upper)

Fx (lower)

Fz (lower)

My (lower)

'07 IRCOBIStemper

My (upper)

'07 IRCOBIStemper

'09 IRCOBIOno

'09 IRCOBIOno

Facet injury (excessive load and/or motion)

Facet injury (via cervical strain)



Facet injury (excessive load and/or motion)

'07 IRCOBIStemper

'09 IRCOBIOno

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Several injury criteria (kinematic measurement)


IV-NIC Panjabi '99 IRCOBI Facet joint, Disc and ligament (excessive rotation)

VT1 Muser '00 IRCOBI - (excessive load in rebound phase)

NDC Viano '02 SAE - (Kinematic measurement for excessive load)

PWI Mallory '05 ESV - (Head rotation)

Head RV - (excessive load in rebound phase)

T-HRC - (Head to headrest contact timing)

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Whiplash


local hyper-extension/

flexionMuscle strain

Spinal root ganglia

Pressure pulse

NIC

Neck shearNeck

compression

Injuries

Injury mechanism

Criteria

Thresholds

Fx, Fz, My, IV- NICNkm, LNL as combination

MIX, NDC T1G, T-HRC, Head RV, VT1

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Ono 2009

Injury-risk curves for thresholds derivation

Kullgren 2003

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Injury criteria thresholds with correlation to Whiplash injuries

Derived thresholdsItem Who? Year Where?

NIC

Nkm

BostromKullgren

20002003

BookESV 15 m/s2 (20% risk for long term injuries) (1)

8/30 (5%/95% risk of WAD2+)

Kullgren 2003 ESV 0.8 (20% risk for long term injuries) (2)1Schmitt 2001 ESV

Fx (upper)

Fz (upper)

Fx (lower)

Fz (lower)

My (lower)

My (upper)

Kullgren 2003 ESV5Nm (20% risk for long term injuries) (3)(recommended to use NIC and Nkm only)

Ono 2009 IRCOBI 340/730N (5%/95% risk of WAD2+)

475/1130N

12/40Nm

340/730N

257/1480N

12/40Nm

“

Ono 2009 IRCOBI

Ono 2009 IRCOBI

Values for 5%/95% risk of >1m symptoms are approx. (1) 11/28 (2) 0,5/1,7 (3) 3/8

Fairly old findings. Nkm might correlate because Fxand My do. Thus, Fx and My should be used

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Whiplash




Fx: 340-730N

Spinal root ganglia

Pressure pulse

NIC

NIC8-30

15

Neck shear Neck compr.

My: 12-40Nm

Fz: 475-1130N

Injuries

Injury mechanism

Criteria

Thresholds

(Nkm), (LNL), Fx, Fz, My, IV- NICMIX, NDC T1G, T-HRC, Head RV, VT1

MIX: 3.2

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Biomechanics of Whiplash injuries – Injury criteria reviewSummary (1): Injury criteria based on an underlying injury

mechanism and are correlated with whiplash injuries exist

12/40Nm

5Nm (recommended not to use)

Ono ’09

Kullgren ’03


Ono ’09Stemper ‘07

My lower

12/40NmOno ’09Facet injury (via cervical strain)

Ono ’09My upper

340/730N475/1130N

Ono ’09Facet injury (via cervical strain)

Stemper ‘07Ono ’09

Fx (lower)Fz (lower)

340/730N475/1130N

Ono ’09Facet injury (via cervical strain)

Ono ’09Fx (upper)Fz (upper)

10.8

Schmitt ‘01Kullgren ’03

Excessive load (some relation with facet injury)

Schmitt ‘01Nkm

15 m/s28/30 m/s2

Bostrom ’00Kullgren ’03Ono ‘09

Pressure pulses in spinal ganglia

Bostrom ‘96NIC

ThresholdsCorrelationMechanismEstablishedItem

Nkm might correlate because Fx and My do. Thus, Fx and

My should be used

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Summary (2) : Any other injury criterion should only be used after further thorough evaluation

-Ono ’09--Head RV

--- (excessive load in rebound)

Muser ‘00VT1

---Viano ’02NDC

---Mallory ’05PWI

----T-HRC

--Facet, disc and ligament injury (excessive rotation)

Panjabi ’99IV-NIC

----T1G

---Muñoz ’05WIC

3.2Kullgren ’03-Kullgren ’03MIX

--Excessive load (some relation with facet injury)

Heitplatz '03LNL

ThresholdsCorrelationMechanismEstablishedItem

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Whiplash




Fx: 340-730N

Spinal root ganglia

Pressure pulse

NIC

NIC8-30

15

Neck shear Neck compr.

My: 12-40Nm

Fz: 475-1130N

Injuries

Injury mechanism

Criteria

Thresholds

(Nkm), (LNL), Fx, Fz, My, IV- NICMIX, NDC T1G, T-HRC, Head RV, VT1

MIX: 3.2

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Today’s Agenda

For a later day

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0.0640.071 0.07

0.092

0.146

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

Good Acceptable Marginal Poor Not tested

W/O, Cars after 97 With Anti_whiplash System

W/O, Cars before 97

With Anti Whiplash System

IIWPG rating & injury risk

Slight differences

Rel

ativ

e LT

Ris

k (%

)

Kullgren et al. (ESV 2007)

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Pro

port

ion

of L

Tin

jurie

s(%

)

Farmer et al. (Traffic Injury Prevention 2007)

3.8%

4.7%

3.6%

5.8%

4.6%

0.0%

1.0%

2.0%

3.0%

4.0%

5.0%

6.0%

7.0%

good acceptable marginal poor all


“Good” significantly better than “poor”

Only “marginal” significantly better than “all”

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Not all questions are answeredIt is still a valuable exercise to compare rating and real-life risk

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Injury and seat performance criteria versus injury risk

Methods:

- Analysing real life risk from Swedish insurance data (1995-2008) of rear impacts with filed Whiplash claim-Taking proportions of Symptoms > 1 month and permanent disability

-Grouping similar seats (e.g. all Volvo Whips seats)-Taking representative test values (medium pulse) for injury and seat performance measurements

EEVC WG12 Report Document Number 578Evaluation of Seat Performance Criteria for Rear-end Impact Testing (Interim report) January 2011Johan Davidsson, Chalmers University of TechnologyAnders Kullgren, Folksam Research

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Findings: Some injury and seat performance criteria correlate with injury risk

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Findings: Some injury and seat performance criteria do not correlate with injury risk

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Findings: Some injury and seat performance criteria correlate with injury risk some do not

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Conclusion

NIC, Fx (upper), Head to T1 rotation and Nkm are suggested to be included in performance evaluation of seat systems in rear-end impact.

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Findings: Some injury and seat performance criteria have limited correlation with injury risk (after removal of outliers)

Conclusion

Fz (lower) , My (lower) are candidates for performance evaluation of seat systems in rear-end impact.

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Effectiveness of different seat concepts

Kullgren and Krafft, IRCOBI 2010GENDER ANALYSIS ON WHIPLASH SEAT EFFECTIVENESS: RESULTS FROM REAL-WORLD CRASHES

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Effectiveness of seat concepts for malesRelative risk of permanent medical impairment for m ales

0

1

2

3

4

5

6

7

8

standard seat RHR Saab other RHR WhiPS WIL

%

All concepts are effective

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Relative risk of permanent medical impairment for f emales

0

2

4

6

8

10

12

14

standard seat RHR Saab other RHR WhiPS WIL

%

Effectiveness of seat concepts for females

Do RHR protect females?

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Today’s Agenda

For a later day

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Current J-NCAP

Current Euro NCAP

( )**My upper

My lower

Head - T1 rotation

T1 x-acceleration

Head restraint contact time

( )**

( )*

Ideas for Euro NCAP(open discussion)

Real-life justification

Biomechanical justification

Criterion

NIC

Nkm

Head RV

Fx upper

Fz upper

Seatback opening

Fz lower

Fx lower

Head RV used to measure violence of rebound.- Head velocity relative to T1 (early phase) or Neck Forces (late phase with Seatbelt interaction) seem more appropriate.-Difficult to measure (video tracking problems)-No injury-risk curves available

Seatback rotation used to measure seatback stability for high impact loads. (no biomechanical criterion)

Head – T1 rotation difficult to measure(video tracking problems). Correlation with My exists. Rotation rate might be more important than amount

WrongGood / use

CandidateNot used

Dou

ble

eval

uatio

n

*further research needed. Fx might be more appropriate.Ono et al. conclude no correlation with facet strain. Should be excluded to avoid double evaluation**further research needed.Ono et al. showed correlation with facet strain, butKullgren and Davidsson showed no correlation to real-life risk

(EEVC WG12)

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Today’s Agenda

For a later day

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Removal of T1 acceleration, head restraint contact time, Head rebound velocity

0

1

2

3

4

0 1 2 3 4

current rating score

calc

ulat

ed ra

ting

scor

e w

ithou

t T1g

, T-H

RC

, HR

VUnchanged performance limits

59-0.8

-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1 8 15 22 29 36 43 50 57 64 71 78 85 92 99 106 113 120 127 134 141 148 155 162 169 176 183 190 197 204 211 218 225

chan

ge in

sco

re

On average, score increases by 0.12 when T1G, T-HRC, HRV are excludedThis could be compensated for setting good-average-poor limits up by 0.12(High increase when HRV exceeded capping value before)

Removal of T1 acceleration, head restraint contact time, Head rebound velocity

Unchanged performance limits

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0

1

2

3

4

0 1 2 3 4


calc

ula

ted

ratin

g sc

ore

with

out T

1g, T

-HR

C, H

RV

0

1

2

3

4

0 1 2 3 4


calc

ula

ted

ratin

g sc

ore

with

out T

1g, T

-HR

C, H

RV

0

1

2

3

4

0 1 2 3 4


calc

ulat

ed r

atin

g s

core

with

out

T1g

, T-H

RC

, HR

V

0

1

2

3

4

0 1 2 3 4


calc

ulat

ed r

atin

g s

core

with

out

T1g

, T-H

RC

, HR

V

Toyota Volvo & Saab

PSA BMW &Mercedes

Removal of T1 acceleration, head restraint contact time, Head rebound velocitySome implications by OEM

Unchanged performance limits

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Today’s Agenda

For a later day

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0.8

15

Kullgren 200320% risk symptoms >1month

270/610 – 360/750 –470/770

30/110 – 30/190 –30/210

0.12/0.35 – 0.15/0.55 – 0.22/0.47

9/15 – 11/24 – 13/23

Current Euro NCAP(low-mid-high)

12-40My upper

12-40My lower

Ono 20095%-95% risk WAD2+

Davidson and Kullgren 2010<6% risk of permanent injuries given initial symptoms

Criterion

8-3020NIC

0.35Nkm

340-730150Fx upper

475-1130Fz upper

257-1480Fz lower

340-730Fx lower

Thresholds

J-NCAP

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Extended Criteria Review Summary

From the presented evidence, it is recommended to• Continue using criteria with biomechanical and real life justification

– NIC, [Nkm], (Upper Fz), Upper Fx• Discontinue using criteria without justification

– T1G, T-HRC, Head RV• Consider introducing additional criteria with have a justification

– (Lower Fx), Lower Fz, Lower My, (Upper My)• Consider introducing

- Injury-risk based thresholds to effectively prevent injury and not to only benchmark seats

() further research for real-life effect needed[] discontinuation suggested as Fx and My should be measured

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• Toyota recommends to harmonise with J-NCAP– A good step towards a scientifically founded

rating can be achieved.

– J-NCAP’s criteria have the best scientific justification of the ratings available and can be adopted easily.

• Toyota recommends to follow gtr phase 2 developments and consider harmonising

Conclusion

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Thank you!

Documents

Euro NCAP Whiplash Rating Toyota Position & Proposal … · 3 Schedule 2011 7 14 21 28 February Folksam Chalmers TNO BASt (15.03) TRL (11.05) June B. Fildes (ESV) Euro NCAP (TBC)