07-07-2012, 11:42 AM
Adaptive Air Suspension
Adaptive Air Suspension.pdf (Size: 2.18 MB / Downloads: 602)
Today, designing a chassis must
overcome conflicting requirements. A car
designed to be very comfortable when
driven at the limit, falls short in terms of
driving safety. On the other hand, a car
with exceptional sport tuning achieves
considerably higher cornering speeds
and reaches its limit much later, but is
usually very limited in comfort.
The equipment must deliver not only
universal purposes such as function, safety,
strength and durability, but also comfort,
reduced weight and premium acoustics. To
satisfy these contrary requirements, the
2004 Audi A8L is equipped with a new, fully
load-bearing, Air Suspension System with
electronic dampening control.
Introduction
The basics of Air Suspension Systems are
described in SSP 242 and 243 and are
relevant to the 2004 A8L system.
New Technology
The 2004 A8L introduces a new Adaptive
Air Suspension with innovative technical
content and a wide range of functions. It is
different from the allroad quattro
suspension system used on previous
models. The new features are briefly
described below and later in more detail in
the Components Section of this program.
Computer Dampening Control (CDC)
Computer Dampening Control (CDC)
technology calculates the current driving
status. The wheel movements (unsprung
masses) and body movements (sprung
masses) are recorded.
Using one of four modes (a combination of
the Adaptive Air Suspension Program and
the Dampening Map), different dampening
characteristics are achieved. In the
process, each shock absorber is
independently controlled. As a result,
maximum comfort and driving safety is
achieved.
Adaptive Air Suspension
Adaptive Air Suspension is standard on the 2004 A8L. The following programs can be
selected either manually or automatically
Automatic Mode
In Automatic Mode the vehicle is equipped with a basic leveling, comfort oriented
suspension, with appropriately adapted dampening map. After 30 seconds at speeds
of 75 mph (120 km/h) or more, the vehicle is lowered by 1 inch (25mm) (expressway
lowering). This lowered position improves aerodynamics and reduces fuel
consumption.
Comfort Mode
In Comfort Mode, the vehicle height is the same as in Automatic Mode, however it
provides less dampening at lower speeds. Comfort Mode results in even greater
driving comfort than in Automatic Mode. Comfort Mode does not include automatic
expressway lowering.
Operation and Display System
The process of changing from one mode to
another and the display/monitoring of the
system status are part of the MMI
Operating System. When the CAR button
is pressed, the Adaptive Air Suspension
menu is opened directly in the MMI
display. Adaptive Air Suspension has first
priority. All other functions already in the
display are suppressed in favor of the
Adaptive Air Suspension Operating/Status
Display.
When the control knob is turned to a
different mode and then pressed, a new
mode is activated. System status
information and special settings can be
requested by pressing the SETUP button.
(Refer to the Owner’s Manual and Control
Strategy in the Special System States
Section.)