on Seat Belt Fit Matthew P. Reed Jason J. Hallman Toyota Technical - - PowerPoint PPT Presentation

Effects of Driver Characteristics

• n Seat Belt Fit

Matthew P. Reed Sheila M. Ebert

UMTRI

Jason J. Hallman

Toyota Technical Center USA

Crash Injury Data

Older occupants are at greater risk in crashes

Ridella et al. 2013 IRCOBI

0%! 10%! 20%! 30%! 40%! 20! 30! 40! 50! 60! 70! 80! Risk of AIS 3+ Injury (%)! Age (yr.)! Male, Belted, Driver, Passenger Car,
 51 kph ΔV, BMI=25 kg/m2! Head! Thorax! Spine! Abdomen! UX! LX! 0%! 10%! 20%! 30%! 40%! 20! 30! 40! 50! 60! 70! 80! Risk of AIS 3+ Injury (%)! Age (yr.)! Female, Belted, Driver, Passenger Car,
 51 kph ΔV, BMI=25 kg/m2! Head! Thorax! Spine! Abdomen! UX! LX!

Crash Injury Data

Obese occupants are at greater risk in crashes

Ridella et al. 2013 IRCOBI 0%! 10%! 20%! 30%! 40%! 20! 25! 30! 35! 40! 45! Risk of AIS 3+ Injury (%)! BMI (kg/m2)! Female, Belted, Driver, Passenger Car,
 51 kph ΔV, Age=35! UX (OR=1.16)! LX (OR=1.83)! 0%! 10%! 20%! 30%! 40%! 20! 25! 30! 35! 40! 45! Risk of AIS 3+ Injury (%)! BMI (kg/m2)! Male, Belted, Driver, Passenger Car,
 51 kph ΔV, Age=35! UX (OR=1.16)! LX (OR=1.83)!

*Body Mass Index (BMI) = Body Mass (kg) [Stature (m)]2

Body Shape Data

Human body shape varies widely

Hybrid-III ATD

Laser Scan Data

Research Question

How is driver belt fit affected by age, gender, stature, and BMI?

Methods

Men and women with a wide range of age and body size

Measure Men (N=46) Women (N=51) Stature (mm) 1759 (85) 1601 (67) Body Weight (kg) 87.9 (17) 69.9 (16) Body Mass Index (kg/m2) 28.4 (4.9) 27.3 (5.7) Erect Sitting Height (mm) 913 (40) 845 (42) Age (years) 58 (19) 59 (20)

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + 1400 1500 1600 1700 1800 1900 2000 40 60 80 100 120 140 Stature (mm) Weight (kg)

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + 20 30 40 50 60 70 80 90 1400 1500 1600 1700 1800 1900 2000 Age (years) Stature (mm)

Methods

Driver mockup with 5 sets of belt anchorage locations

Midsize Sedan Package L6 = 550 mm H30 = 270 mm

30˚ 52˚ 75˚ FMVSS 210 Definition Lap Belt Angle:

5 Belt Conditions: 3 lap belt angles with midrange D-ring 2 D-ring angles at midrange lap angle

Methods

Landmarks measured with FARO Arm coordinate digitizer

Methods

Additional body measurements in hardseat and laser scanner

Methods

Belt fit measures

Lap Belt: Top of belt at lateral position of ASIS wrt ASIS Shoulder Belt: Inboard edge of belt at height of top of sternum relative to midline

Methods

Pelvis flesh margin estimates

15 20 25 30 35 40 45 50 100 150 200 250 300 BMI (kg m2) Pelvis Depth (mm) + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++ + + + + + + + +

Uncorrected Corrected

An adjustment was made to correct for the effects of adiposity on the distance between the surface landmark and the bone.

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++ + + + + + + + + +

• 250
• 200
• 150
• 100
• 50

50 50 100 150 200 250 300 <=== Forward Lap Belt X (mm) Lap Belt Z (mm) + + + + + + + + + + + + + + + + + + + + + ++ + + + + + + + + + + + + + + + + + + +

A B

Results

Lap Belt Fit A B

Z = 61 X = -64 Large symbols = obese Male + Female o

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++ + + + + + + + + +

• 250
• 200
• 150
• 100
• 50

50 50 100 150 200 250 300 <=== Forward Lap Belt X (mm) Lap Belt Z (mm) + + + + + + + + + + + + + + + + + + + + + ++ + + + + + + + + + + + + + + + + + + +

A B

Results

Lap Belt Fit

Large symbols = obese

T053 72 years 24 BMI 1697 mm

• 64, 51

T044 24 years 29 BMI 1621 mm

• 53, 83

T029 28 years 20 BMI 1779 mm

• 5, -1

Z = 61 X = -64

T060 80 years 35 BMI 1663 mm

• 99, 117

Male + Female o

Results

Lap Belt Fit LapBeltZ (mm) = -70.1 + 4.7 BMI, R2 = 0.52, RMSE = 22.9 LapBelt X (mm) = 156 + 0.297 ELBA – 0.30 Age – 5.12 BMI – 0.04 Stature, R2

adj = 0.57, RMSE = 25.8

Effective Lap Belt Angle (ELBA, deg): LBA taking into account driver-selected seat position

Negative X is further forward All effects and full model p<0.01

Results

Lap Belt Fit

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + 20 25 30 35 40

• 200
• 150
• 100
• 50

50 100 BMI (kg m2) LapBeltX (mm) + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + 20 25 30 35 40

• 200
• 150
• 100
• 50

50 100 BMI (kg m2) LapBeltX (mm)

+ Men O Women + Age < 60 O Age ≥ 60

belt further forward wrt pelvis BMI dominates effects of age and gender

Results

Shoulder Belt Fit

1500 1600 1700 1800 1900 2000 50 100 150 200 Stature (mm) Shoulder Belt Score (mm) + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +

Shoulder Belt Score (mm) = 338 – 22.3 YZAngle – 0.284 Stature + 0.0189 YZAngle*Stature, R2

adj = 0.60, RMSE = 24.4

No significant effects of gender, BMI, or age 17˚ 21˚ 25˚

Results

Comparison of Factor Effects

LapBeltX LapBeltZ ShoulderBeltScore Stature BMI Age Population Effect (mm)

• 100
• 50

50 100

LapBeltLength ShoulderBeltLength Stature BMI Age Population Effect (mm)

• 50

50 100 150 200 250 300

Over relevant population ranges: Stature (1500-1850 mm), Age (20-80 years), BMI (20 to 40 kg/m2),

Results

Lap Belt Fit

Mean belt locations with respect to ASIS at lateral location of ASIS (not occupant centerline)

Midsize male pelvis in mean posture

Results

Lap Belt Fit

Mean belt locations with respect to ASIS at lateral location of ASIS (not occupant centerline)

Midsize male pelvis in mean posture

ATD Pelvis ATD Pelvis Flesh T184 30 years 23 BMI 1802 mm

Results

Pelvis Locations and Abdomen Contours

Laser scans obtained in slightly different posture Alignment based on measured human pelvis position and orientation

ATD Pelvis ATD Pelvis Flesh T144 38 years 40 BMI 1865 mm

Results

Pelvis Locations and Abdomen Contours

Laser scans obtained in slightly different posture Alignment based on measured human pelvis position and orientation

ATD Pelvis ATD Pelvis Flesh T147 87 years 27 BMI 1566 mm

Results

Laser scans obtained in slightly different posture Alignment based on measured human pelvis position and orientation

Pelvis Locations and Abdomen Contours

ATD Pelvis ATD Pelvis Flesh T070 70 years 31 BMI 1630 mm

Results

Laser scans obtained in slightly different posture Alignment based on measured human pelvis position and orientation

Pelvis Locations and Abdomen Contours

Discussion

Many people could place the lap belt in a lower location, closer to the pelvis Could they be educated to position the belt better?

Narrow range of belt locations Wide range of belt locations

Conclusions

Obesity has a strong effect on lap belt routing: On average, an obese individual places the belt fully above the pelvis and an average of 61 mm forward of the ASIS. Age has a smaller effect on belt routing than BMI across the population range Gender did not have a significant effect after accounting for stature Lap belt anchorage locations have much smaller effects than driver factors. The effects of BMI on lap belt fit were not significantly different for short/tall, men/women, old/young Shoulder belt fit is strongly affected by D-ring location and body size

Implications and Future Work

Current ATDs with standard usage procedures are not capable of representing the large belt-skeleton offset and sub-optimal belt routing observed in this study, so current testing does not evaluate the load-sharing situations encountered by most

• ccupants, particularly those who are obese.

Better Protection for All

Acknowledgments

This research was funded by the Toyota Collaborative Safety Research Center http://www.toyota.com/csrc/