Download 1 Complete Vehicle Testing of Car Occupant Muscle Responses for

Complete Vehicle Testing of Car Occupant Muscle
Responses for Integrated Safety Simulation
Jonas Östh, Jóna Marín Ólafsdóttir, Johan Davidsson, and Karin Brolin
Division of Vehicle Safety, Applied Mechanics
Chalmers University of Technology
1
Background
Chalmers Active Human Body Model Project
Aim:
Model occupant pre-crash responses with
an FE HBM.
Achieved through modeling of
neuromuscular control.
Requires validation data in relevant test
cases.
2
Volunteer Test Aims
•
Generate sets of validation data for ”Active HBM”
•
Investigate occupant kinematic and muscle
responses in potential pre-crash scenarios
References:
Östh J, Ólafsdóttir JM, Davidsson J, Brolin K (2013) Driver Kinematic and Muscle Responses in Braking Events with Standard and Reversible Pre-tensioned
Restraints: Validation Data for Human Models. Stapp Car Crash Journal 57:1–41.
Ólafsdóttir JM, Östh JKH, Davidsson J, Brolin K (2013) Passenger Kinematics and Muscle Responses in Autonomous Braking Events with Standard and
Reversible Pre-tensioned Restraints. Proceedings of the IRCOBI Conference; Gothenburg, Sweden, pp. 602–617
3
Volunteers
•
•
•
11 males and 9 females
No history of neck injury
Sampling criteria: M50 and F50 +/- 10 kg and +/- 10 cm
0
0
Male
Female
200
80
70
100
80
60
Weight (kg)
Height (cm)
120
60
50
40
30
40
20
20
10
0
0
Height
Weight
40
80
F50
140
45
M50
F50
M50
35
60
40
Age (years)
160
100
M50
F50
Sitting Height (cm)
180
90
30
25
20
15
20
10
5
0
Sitting Height
0
Age
4
Electromyography
•
•
Surface electrodes on major muscles of upper body
Normalized with MVCs in driving posture
5
Test Cases
Driver and Passenger
Autobrake PT
Autobrake SB
Driver Brake
Belt
pulls
170 N
0.2 s
11 m/s2
6
Test Vehicle
7
Passenger Side
8
Rear Seat…
9
”Test Track”
10
Autobrake PT
Autobrake SB
Driver Brake
11
Autobrake PT
Autobrake SB
12
6
Head Displacements: Drivers
200
Male
Female
Head X displacement (mm)
180
>
*
160
140
120
100
80
60
40
20
0
Autobrake PT2–4 Autobrake SB
Driver Brake
* p<0.05
In steady-state braking (1.5–1.7s)
13
Shoulder Belt and Steering Wheel Forces: Drivers
Autobrake PT
Autobrake SB
Driver Brake
14
Muscle Responses: Drivers
Autobrake PT
Autobrake SB
Driver Brake
15
Model Validation
Autonomous Braking (SB)
Driver Braking
References: Östh J, Eliasson E, Happee R, Brolin K (2014) A Method to Model Anticipatory Postural Control in Driver Braking Events.
Gait and Posture 40(4):664–669.
Östh J, Brolin K, Bråse D (2014) A Human Body Model with Active Muscles for Simulation of Pre-Tensioned Restraints in
Autonomous Braking Interventions. Traffic Injury Prevention, 16(3):304–313.
16
Conclusions
•
•
•
•
Seat-belt pre-tension affects occupant postural responses
– Pre-tension induces startle response in some volunteers
Driver Brake postural responses are different from postural
response to Autobrake
Low muscle activations in normal driving (<5% for most
muscles)
Co-contraction of antagonist muscles in steady state braking
17
Future work
•
•
•
Extend AHBM to cover lateral (steering) emergency avoidance
maneuvers
Conduct new volunteer for validation data and investigation of
postural control in these events
Challenges
– Repeatability of steering maneuvers with non professional
drivers
– Effect of external threat (crash risk)
– Large test matrix (many combinations, pre-tensed belt,
combined with braking)
18
Acknowledgements
Project partners
Autoliv Research, Volvo Group, Volvo Cars, and Umeå University
Funding
VINNOVA – Swedish Governmental Agency for Innovation
Systems, through the FFI – Vehicle and Traffic Safety research
program
19