Audi A8 2019 Service Training page 95

Collision avoidance assist, example
The vehicle (1) wants to evade the vehicle (2) traveling
ahead.
As described under "Function", the radar sensor, the front
camera and the laser scanner continuously monitor the
traffic in front of one's own vehicle (1). Before collision
avoidance assist can provide the driver with assistance,
Audi pre sense front has already identified a critical situa-
tion and initiated the following actions:
› Visual prewarning.
› Audible prewarning.
› Prefilling of the brake system.
› Adaptation of hydraulic brake assist.
› Acute warning by braking impulse.
Process diagram showing the working principle of Audi pre sense collision avoidance assist
Key:
Steering torque assist
Audible warning beep
System characteristics of the collision avoidance assist function
› Collision avoidance assist is active after the acute
warning (brake warning) is issued.
› Collision avoidance assist is not active if the last possible
evasion point has been surpassed.
› Collision avoidance assist does not provide assistance
unless the driver is actively steering the vehicle.
Collision avoidance assist computes a suitable evasion line
based on various items of information, such as one's own
speed and the lane in which the vehicle ahead in driving. If
vehicle (1) deviates too far from the evasion line within
certain bounds, collision avoidance assist will, after the
acute warning is issued, try to guide the vehicle (1) along
the evasion line by providing steering assistance along the
evasion line of the vehicle (2). The vehicle (1) is additionally
stabilized by braking individual wheels. Collision avoidance
assist can only help the driver (1) when the driver (1)
carries out the evasion process actively by making correc-
tive steering inputs himself. Visual and audible messages
indicating that Audi pre sense is active appear in the instru-
ment cluster. If the last possible evasion point has been
surpassed, no assistance is provided by collision avoidance
assist.
Braking of individual
wheels
› Collision avoidance assist is available at speeds of
between about 18.6 to 93.2 mph (30 to 150 km/h).
› Collision avoidance assist helps the driver to steer
around an obstacle on the left or right.
Visual advance warning
and/or indication of cor-
rective action
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