Automotive Engineering - October 2018 - 18

TECHNOLOGY REPORT

AUTOMATED VEHICLES

Autonomous vehicles present passive-safety challenges

18 October 2018

Autoliv engineers are designing airbag and seatbelt systems for reclined and relaxed seating
positions for autonomous vehicles.
the occupant's head won't be within the
curtain airbag's protection zone when
seated in the 'normal recline' position.
"We've been talking about raising the
seat up as you recline. That does two
things: It gets the head back into the
curtain area during a side impact. It also
puts the head above the vehicle's belt
line and back into the window area so
the occupant doesn't get motion sickness," he said, referring to a malady
that's possible when riding in an autonomously-driven vehicle.

Simulation first

Autoliv's typical testing process for passive safety systems starts with computer
simulations. That's followed by static
testing to determine what happens to
crash test dummies when airbags deploy
during sled crashes into fixed barriers.
"It's not uncommon to go back to the
beginning if we want to tweak an underdevelopment technology," he said. The
final testing stage involves actual vehicles.
Autoliv technicians likely won't conduct
crash tests with dummies inside physical
vehicles before the 2020 timeframe.
"Some vehicle manufacturers are looking
to do autonomous mobility as a delivery
service, so those are likely to be first inline for actual vehicle testing," he said.
Passive safety systems offer protection during a vehicle crash, but those
same technologies could be vital in instances of accident avoidance.
"There will be evasive maneuvers by

This modular seat frame, created by Adient,
contains an airbag mounted to the frame and an
integrated seatbelt system. Autoliv is working
with seat manufacturers to incorporate its airbag
and seatbelt systems into vehicle seats.
autonomously driven vehicles that prompt
a quick lane change or emergency braking to avoid a collision with another vehicle, pedestrian, bicyclist, deer, or some
other object," said Dershem. "Imagine if
the occupants are in 'living room' seating
position and the vehicle does 1G braking
and no one is belted. It's going to get ornery inside that vehicle."
Kami Buchholz

AUTOMOTIVE ENGINEERING

BOTH IMAGES: AUTOLIV

Reclined and rotated seating positions
are commonly depicted for autonomously driven vehicles. But for the
Autoliv engineers tasked with developing occupant safety for tomorrow's selfdriving vehicles, those previously improbable seating positions dictate innovative new passive safety protections.
"Passive safety for autonomous vehicles is a pretty complicated problem to
solve, which is why we're starting out
with the simplest scenario: a frontal crash
with a front occupant in a partial-recline
position," E. Scott Dershem, Autoliv's Vice
President of Product Development, said
in an interview with Automotive
Engineering at the safety supplier's
Auburn Hills, Michigan technical center.
Safety engineers know occupants in
self-driving vehicles might be seated in
unconventional positions. "For us, it's not
really about a particular level of autonomy; it's more about the level of seating
flexibility inside the vehicle," he said.
That's why "seat-centric" safety is vital.
"There are laws and regulations now as to
where seatbelt anchors have to be. But as
seats rotate and recline, today's anchor
points aren't in the optimum location.
That issue could be solved with a change
in the anchor point, such as moving it
further forward to get the seatbelt off the
abdomen area," he offered.
In-cabin features heavily influence
the packaging of airbags. But if a selfdriving vehicle is without a conventional
instrument panel or other traditional
cabin fixtures, the seats are the prime
packaging locale for airbags.
"We've been working on our Life Cell
concept since 2014. It's a curtain airbag
with two inflators," said Dershem. The
Life Cell airbag deploys from the seat
and when fully deployed essentially
envelopes the occupant's head and
shoulders. "The product has evolved.
Our first-generation version didn't go
over the occupant's head," he said.
Researchers and engineers are looking for ways to address what happens
during a so-called 'normal-recline seating position.' Computer simulations and
testing with crash dummies show that

Automotive Engineering - October 2018

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