BMW 5 - Manual (Page 24)

BMW
Media
Information
11/2009
Page 24
with a steady steering angle, on the other hand, the consumption of energy
is reduced to zero.
Precise, smooth and harmonious set-up of the steering with the feedback
typical of BMW ensures maximum steering accuracy at all times. In the Sport
mode of Dynamic Drive Control and with DSC switched off, the degree of
steering forces is slightly increased in accordance with the style of motoring
desired.
EPS serves to control steering feedback from the system with particular
precision. At the same time EPS comes as standard on the new BMW 5
Series Sedan with Servotronic gearing steering assistance to the speed
of the car. When parking and steering at low speeds, for example, the driver
hardly has to make any effort, while at higher speeds power assistance is
intentionally reduced for optimum contact to the road and in the interest
of well-balanced directional stability.
A further point is that EPS eliminates bumps coming from the steering
and any other adverse vibrations very effectively. And by evaluating dynamic
driving signals in an appropriate process, EPS gives the driver authentic
steering feedback particularly under very dynamic driving conditions.
Integral Active Steering: greater agility in town,
enhanced comfort in a quick lane change.
Available as an option, Integral Active Steering is another innovation
exclusive to the new BMW 5 Series Sedan in the upper midrange segment.
IAS combines the Active Steering on the front wheels already available on
the former model with rear-axle steering, the steering angle and steering
assistance therefore being controlled for the first time both front and rear
by electric motors.
On models fitted with Integral Active Steering, steering forces are
controlled by Servotronic and the steering angle is masterminded by an
additional active steering transmission acting on the front axle, in each case as
a function of road speed. At the same time the system also varies the steering
angle of the rear wheels through a concentrically arranged motor acting
through spindle drive on the rear axle.
Both front and rear, Integral Active Steering adjusts the steering angle
through an electric motor masterminded by a control unit receiving data
on wheel rotation speed, movement of the steering wheel, the yaw rate
and lateral acceleration to ensure optimum steering behaviour under all
conditions.