Head-Up Display.

From May 2004, the innovative Head-Up Display (HUD) will be offered as
an on-cost option (R12 000) across the 5 Series range. An enhancement
of the iDrive concept, HUD makes an important contribution to active
safety and superior motoring comfort by presenting important
information directly in the driver's line of vision. The driver is
therefore able to take up this information without ever taking his eyes
off the road. The virtual picture presented by the Head-Up Display is
generated by a projector integrated in the instrument panel and
transmitting the image on to a special windscreen, where from the
perspective of the driver it appears roughly at the end of the engine
compartment lid. Benefiting from this very ergonomic position of the
image, the driver is able to concentrate on road traffic, not looking
down at the cockpit unless absolutely necessary, and not suffering any
problems in adjusting his eyes when changing his perspective from the
road ahead to the instruments and vice versa. Personal settings such as
the brightness of the instruments are memorised by the Key Memory, the
Head-Up Display being able to present navigation messages and
information on the car's active cruise control, warnings from the
Check/Control, and your current road speed (this latter item being the
only information permanently presented by the Head-Up Display when
activated). The head-up display is able to present the following
information (also shown in part on the instrument cluster): •
Navigation instructions • Instructions and information for the
Active Cruise Control (optional from) • Current road speed (when
chosen, this is the only permanent display) • Check/Control
warnings Important information always where you need it. To provide a
clear, easy-to-read image even under changing light conditions, the
rain/light sensor controls the brightness of the image presented. Even a
wet road or complete darkness will not reduce the quality of the image,
since it adjusts to surrounding conditions at all times. You switch on
the Head-Up Display by means of the lights switch centre. How does it
work? The HUD is mounted above the steering column on the cross-member
of the cowl panel and on the front bulkhead. The influence of
vibrations when driving over cobblestones for instance is not
noticeable. The HUD unit also incorporates four mirrors. These mirrors
reflect the display content onto the windscreen. Three of the mirrors
are curved. These mirrors adapt the display content to the screen. This
mirror determines the size and distance of the HUD projection. The
curved mirrors are made of plastic while the plane mirror is made of
glass. The windscreen is a "special" windscreen and is an
integral component vital to projecting the displays. The outer and
inner glass panes are connected to a plastic film, which is
wedge-shaped over the entire length of the windscreen. The wedge-shape
prevents double displays (ghosts) of the HUD by positioning both images
one above the other. The wedge tip points downwards and starts at a
distance of approximately 10 cm to the bottom edge of the windscreen.
The end of the wedge is located at approximately 2/3 windscreen height.
In the top third of the windscreen, the plastic film runs parallel to
the outer and inner glass panes. The thickness of the wedge tip is 0.8
mm. The thickness of the end of the wedge is 1 mm. If a non-specified
(normal) windscreen is used, the image is reflected on both the outer
and inner glass panes. Overlapping causes the image to be displayed
twice. The plastic wedge in the windscreen places the images of the
outer and inner pane over each other thus preventing double displays
(ghosts). * Customers must start placing orders for HUD from January
2004. Trendsetting Lightweight Construction with Hybrid Technology.
History. - BMW has been using aluminium alloy for a long time. - 502
first with entire aluminium engine in series production. - 3.0 CSL
extensively used aluminium body outer skin components - Z8 had a
complete body of aluminium - 5 Series is breaking new ground in
lightweight design - Each component made from best suited material for
this purpose - For 50/50 weight balance the front end is made from
aluminium Highlights. * First-ever combination of steel and aluminium
construction. * Superior safety on low weight. With the new 5 Series,
BMW is becoming the first car maker in the world to use a new,
trendsetting combination of steel and aluminium structures on the
body-in-white: the combination of an aluminium front section with the
remaining bodyshell around the A-pillars made of steel. A further
point is that the front side panels and the front lid are also made of
aluminium. This new technology is the main reason why the entire car,
depending on the model, is up to 75 kilograms lighter than its
respective predecessor. And there can be no doubt that by introducing
this hybrid construction technology, BMW is opening up a new trend in
lightweight body design. A particular challenge with this new concept
was to join the lightweight aluminium front section with the steel body
structure. Indeed, the use of aluminium goes far beyond the usual
standard, the spring supports resting on the front axle springs and
dampers being made of pressure-cast aluminium. The material used for
the spring supports is an alloy made mainly of aluminium, with small
amounts of magnesium, silicon and manganese, a combination of materials
offering supreme strength and dimensional flexibility all in one.
Innovative production methods allowing a new blend of metals. This
hybrid construction technology requires special measures taking the fact
into account that steel and aluminium have different thermal expansion
coefficients. With the punch rivets joining the panels being 50
millimetres apart, however, even peak tension and deformation remains
within the prescribed limits. A further point is that steel and
aluminium have different electrochemical potentials, the combination of
materials seeking to avoid corrosion therefore requiring consistent use
of a newly developed, insulating glue completely filling the flanges
resting against one another. Even the flange surfaces are specially
designed and contoured, and the process of applying the glue is
automated and monitored by cameras in production. Since this is the
only joining method applied, the joints can be repaired by all
workshops if necessary. Hybrid structure providing superior passive
safety on lower weight. The body structure of the new 5 Series offers
the car's occupants maximum safety with a significant reduction of
weight provided by hybrid construction. Use of high-strength panels in
extra-large support structures with specific reinforcements,
interacting with the front section made largely of aluminium, ensures a
high standard of structural protection in all types of collisions. And
last but not least, the superior torsional stiffness of the body is an
important prerequisite for precise driving dynamics. Overview of
high-tech materials used: Steel alloys: Deep-drawn qualities (e.g. DC
05) - Roof skin, floor plan & boot well IF steels (e.g. H220Y) -
Side frame Isotropic grades (H220 I) - C-post Bake-hardening steels
(e.g. H 220 B) - Door outer skins Micro-alloyed steels (e.g. H 420 LA) -
Engine support Dual-phase steels (e.g. 340 X) - not currently used TRIP
(Transformation Induced Plasticity) steels (e.g. H 400 T) - A-post inner
Complex-phase steels (e.g. D 680 C) - B pillar & bulkhead
Martensite-phase steel (e.g. D 900 MS) - Side impact bars Boron steels
(e.g. BTR 165) - B-pillar top Aluminium alloys: Aluminium-magnesium
alloys - Bulkhead Aluminium magnesium silicon alloys - Bonnet Crash
alloy (Alcan) - Outer engine support leg (chassis leg) Aluminium casting
alloys - Spring support (shock top)