SMART fortwo 2015, Руководство пользователя, Страница: 42 / 228

Operation
During the first stage of a collision, the
restraint system control unit evaluates
important physical data relating to vehicle
deceleration or acceleration, such as:
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duration
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direction
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intensity
Based on the evaluation of this data, the
restraint system control unit triggers the
seat belt tensioners in the event of a head-on
or rear collision.
A seat belt tensioner can only be triggered if:
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the ignition is switched on
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the components of the restraint system are
operational. You can find further informa-
tion under: "Restraint system warning
lamp" (
Y
page 33)
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the belt tongue has engaged in the belt
buckle of the respective seat
If the restraint system control unit detects a
high severity accident, in certain head-on
collisions, additional components of the
restraint system are deployed independently
of each other:
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Driver's airbag
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front-passenger front airbag
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driver's kneebag
The front-passenger front airbag can only be
deployed in an accident if the PASSENGER AIR
BAG ON indicator lamp is lit. Observe the
information on the PASSENGER AIR BAG indi-
cator lamps (
Y page 34).
The activation threshold for the seat belt
tensioners and airbags is determined based
on the evaluation of the vehicle's rate of
deceleration or acceleration at various
points in the vehicle. This process is pre-
emptive in nature. The triggering/deploy-
ment process should take place in good time
at the start of the collision.
The rate of vehicle deceleration or acceler-
ation and the direction of the force are
essentially determined by:
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the distribution of forces during the col-
lision
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the collision angle
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the deformation characteristics of the
vehicle
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the characteristics of the object with
which the vehicle has collided
Factors which can only be seen and measured
after a collision has occurred do not play a
decisive role in the deployment of an airbag,
nor do they provide an indication of airbag
deployment.
The vehicle may be deformed significantly
without an airbag being deployed. This is the
case if only parts which are relatively easily
deformed are affected and the rate of decel-
eration is not high. Conversely, an airbag
may be deployed even though the vehicle suf-
fers only minor deformation. This is the case
if, for example, very rigid vehicle parts such
as longitudinal body members are hit, and
sufficient deceleration occurs as a result.
If the restraint system control unit detects a
side impact, the applicable components of
the restraint system are activated independ-
ently of each other.
The head/thorax bags are deployed on the side
on which the impact occurs, independently of
the belt tensioner and of the use of the seat
belt.
i
Not all airbags are deployed in an acci-
dent. The different airbag systems work
independently of each other.
How the airbag system works is determined
by the severity of the accident detected,
especially the vehicle deceleration or
acceleration, and the apparent type of
accident:
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frontal collision
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side impact
Children in the vehicle
Important safety notes
If a child younger than 12 years old and under
1.50 m in height is travelling in the vehicle:
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always secure the child in a child restraint
system suitable for smart vehicles. The
child restraint system must be appropriate
to the age, weight and size of the child
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be sure to observe the instructions and
safety notes in this section in addition to
40
Children in the vehicle
>>
Safety.