BMW F12 2011, Technical Training Manual, Page: 43 / 68

F12�Chassis�Dynamics
5.�Steering
39
Overall,�lane�changes�and�steering�maneuvers�can�be�mastered�with�a�greater�degree�of�stability�by
coordinating�steering�interventions�at�the�front�and�rear�axle�-�without�compromising�agility�and�con-
trol.
The�combination�of�the�active�steering�with�the�rear�wheel�steering�gives�the�driver�advantages�in�all
speed�ranges.
Stabilization�when�understeering
When�changing�lanes�quickly,�all�vehicles�have�a�tendency�to�produce�a�significant�yaw�response�and
can�sometimes�start�to�oversteer.
If�the�ICM�dynamic�handling�controller�detects�a�difference�between�the�response�desired�by�the�driv-
er�and�the�reaction�of�the�vehicle,�it�initiates�coordinated�steering�interventions�on�the�front�and�rear
wheels.�The�speed�of�the�stabilizing�intervention�is�such�that�it�is�hardly�perceptible�by�the�driver.
Decelerating�DSC�brake�interventions�can�largely�be�dispensed�with�which�improves�the�stability�and
damping�of�the�vehicle.
F12�Possible�driving�dynamics�interventions�during�understeering
Index Explanation
A Prevention�of�understeer�by�individual�brake�modulation�(DSC)
B Prevention�of�understeer�by�rear�axle�steering�intervention�(IAL)
1 Individual�brake�modulation�(DSC)
2 Rear-wheel�steering�intervention�(IAL)
3 Course�of�an�understeering�vehicle
4 Course�of�a�vehicle�with�neutral�drivability
M Yaw�moment�acting�on�the�vehicle�due�to�an�intervention�by�the�driving
dynamics�control
If�the�driver�misjudges�a�bend�when�driving�fast�on�a�country�road,�the�vehicle�may�understeer.