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MOTORINDIA
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April 2012
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ties and clientele.
The company vision also includes development of
leading powertrain technologies that improve fuel
economy, emissions and performance.
The factors contributing for higher AWD demand
are the industry concern over safety, performance
and traction in slippery condition; older and wealthier
consumers demanding vehicle safety, stability and se-
curity; younger generations demanding premium and
luxury vehicles; and legislation insisting on adoption
of new safety technologies.
FWD generally exhibits understeer behavior, and
the front end tends to “push” out. The driving torque
increases the slip angle of the front wheels, limiting
lateral grip. The average of the front tyre slip angle
is greater than the average of the rear tyre slip angle.
Rear-Wheel Drive Dyanics (RWD) generally ex-
pects oversteer behaviour, wherein rear end “comes
around”. Under heavy acceleration, rear drive wheels
lose the lateral grip. The average of the rear tyre slip
angle is greater than that of the front tyre slip angle.
All this is challenging for inexperienced drivers,
since it requires counter steering (in the same direc-
tion that the rear of the vehicle is going).
BorgWarner currently has three three patents for
the disconnect strategy – US Patent – 2010/0262326
A1 and the Auto mode in production (RWD AWD-
based application).
There are three switch models availble. The vehi-
cle will sustain 2WD / AWD regardless of all other
inputs, while it will switch between 2WD and AWD
depending upon driving / environmental conditions
and aggressive driving.
AWD environment variables relate to ambient
temperature, windshield wipers, driving surface
friction coefficient and hill detection, while AWD
driving variables relate to aggressive launch (high
throttle and clutch slip), unintended clutch slip, ex-
cessive lateral / longitudinal acceleration, aggres-
sive steering manoeuvres and ABS events. The driv-
ing and environmental conditions are combined to
create a map that defines when to enter and exit the
AWD mode.
w
Active AWD enables system optimization
Test driving in progress
Focus on Detroit
BorgWarner has been able to maintain substantial
growth not only in the revenue earned but also in
its workforce to deliver world standard innovative
products.