2003-01-0954 Safety Belt Fit, Comfort, and Contact ... - Delphi

One objective of the study is to determine the shift in the
contact pressure while changing the seat back angle and
the location of the seat belt upper attachment points (Dring)
by utilizing a body pressure measurement system.
Another is to identify how seat belt contact pressure and
fit affect users’ subjective feelings of comfort.
METHOD
Each participant was tested with 54 experimental
scenarios to investigate the seat belt pressure levels, seat
belt fit, and subjective comfort ratings resulting from
various geometric configurations of the D-ring, seat back
angles, and different anthropometric dimensions.
SET-UP
The set-up consists of a universal seating buck to
simulate a passenger car interior package. The threepoint
belt system was configured to represent an
adjustable "D"-ring anchor with three different levels of
seat back angle. Extra webbing was provided to allow
measuring the seat belt comfort and fit for extreme
geometric configurations. In addition, the seat was in a
fixed position during the entire test.
MEASUREMENTS
Tekscan ISCAN V4.23 pressure measurement system
was utilized to sample the pressure distribution on the
seat belt. For convenience in describing the pressure
distribution patterns, the pressure sensor with a resolution
of 44 x 52 is virtually divided into 8 even segments.
Segment number 1 to 8 indicate the relative seat belt
portion from top of the shoulder to the buckle location
(Figure 2). A Metrecom 3D Digitizer was also utilized to
collect the participants’ 17 standard anthropometric
measurements, e.g., standing height, seating height,
shoulder width, etc.
8: ASIS/Buckle
4: Sternum
6: Abdomen
1: Top of Shoulder
3: Upper Chest
Figure 2. Seat Belt Segments Definition
2
TEST PARTICIPANTS
A total of 15 volunteers, including 11 males and 4
females, participated the test. Their height and Body
Mass Index (BMI) data are summarized in Table 1.
Table 1. Anthropometric Data for Test Subjects (N=15)
Height (inch) BMI
MEAN 68.48 25
STDEV 3.20 6.50
MAX 72.30 43
MIN 61.70 17
Table 2 lists the height and BMI in three categories:
• 4 short stature females (66%-ile)
Table 2. Grouping information for Test Participants
BMI (Body
Mass Index)