Audi Q7 2017 Manual page 34

Warnings against a possible collision
These warnings are given within a certain time frame ahead
of the last braking opportunity for braking or collision
avoidance before the actual collision occurs. The timing of
warnings depends on the driver's degree of activity.
Depending on steering, pedal and turn signal inputs, the
system classifies the driver as active or inactive and, conse-
quently, as attentive or inattentive.
If the driver is classed as attentive, the warning will be
issued later than a warning for a driver classed as inatten-
tive. At the same time, ABS Control Module J104 prefills
the brake system and modifies the deployment algorithms
for hydraulic brake assist. This means that hydraulic brake
assist starts to build up brake pressure even at low brake
pedal actuation speeds.
Braking intervention phase
If the driver does not respond to the warning jolt, ABS
Control Module J104 will automatically initiate emergency
braking. Maximum braking pressure is applied. If the
vehicle automatically comes to a halt without driver input,
further audible signals will sound.
Flowchart
Precharging of the braking system, hydraulic
brake assist reacts more sensitively
Audible and visual driver warnings
(early warning)
30
If driver does not respond to the warnings, however, J104
generates an acute warning by jolting the brakes. The
warning jolt is a very brief but easily noticeable braking
impulse which does not serve to slow the vehicle down. It
alerts the driver to the traffic situation and indicates to the
driver that he must react immediately in order to prevent
an impending collision. Depending on how attentive the
driver is considered to be, the warning jolt will be produced
within a certain time window ahead of the last opportunity
to brake or take evasive action to avoid a collision.
These signals alert the driver to the fact that he must
actively take control of the vehicle (for example, by apply-
ing braking). If the driver fails to take control of the vehicle
for example, in a model with automatic transmission, the
system will release the brake and the vehicle will start to
move.
Warning jolt Emergency or full braking Collision
637_064