NEWS & TECHNOLOGY AUTOMOTIVE
“New mobility and digital transformation are the key trends
that will directly impact the automotive lighting industry”, adds
Pierrick Boulay.
LEDs are rapidly gaining popularity as their cost decreases
and efficiency, luminance, and package size improves. Full LED
headlamps are now being commercialized in emerging markets,
and nearly all car makers and Tier-1 parts suppliers have
developed full LED-based headlamp systems. Such technology
is a must-have in the C and also the D (large vehicle) automotive
segments, with implementation continuing in the lower B (small
car segment). For example the Renault Clio and Opel Corsa are
equipped with full-LED lighting, either as standard on the base
model, or as optional LED matrix headlights in the Corsa’s case.
Today’s moderate market growth is mostly related to the strategies
of light source suppliers – “LEDification” – implementing
lower-cost solutions for emerging markets and to the automotive
market slowdown.
Advanced LED matrix headlights, with more than 50 LEDs
per vehicle, have been implemented in premium car segments.
These attractive headlamps provide different lighting scenarios
and are frequently selected by new-car buyers. As a result,
styling and technological advances have also contributed to the
market’s growth.
Yole’s automotive lighting report presents all AFLS applications
and their associated market revenue for the period
between 2019 and 2024. It details the integration status of
different lighting technologies and systems, recent trends, and
market size by application.
Software stabilizes electric vehicles on winterly roads
SBy Christoph Hammerschmidt now-covered roads present the driver and the stability
control of the vehicle with tough challenges; normal
vehicles slip easily - with potentially dangerous consequences.
Porsche Engineering has now developed a torque
control system for an electrically driven series SUV that optimizes
driving characteristics and ensures driving stability in real
time exclusively via software. The developers were not allowed
to install any additional sensors and had to use the existing
control units.
In principle, an electric all-wheel drive vehicle with several
engines has a major advantage over vehicles with combustion
engines: front and rear axles or all four wheels have their own
electric machines, so that the driving force can be distributed
variably. “It’s like having a separate accelerator pedal for each
axle or wheel,” explains Ulf Hintze of Porsche Engineering. In
conventional all-wheel drive vehicles, on the other hand, only
one engine operates, the
power of which is distributed
to the axles via a central differential
gear. The torque ratio
is usually fixed. In the electric
car, on the other hand, the
torque is controlled purely
electronically, which is much
faster than via mechanical
components. With reaction
speeds in the single-digit millisecond
range, software doses
the forces so that the vehicle
always behaves neutrally.
The software can be used
for different constellations and engine arrangements. As a
rule, the basic distribution is first developed, i.e. software that
regulates how much force is transmitted to the front and rear
axles. For example, a distribution of 50/50 would make sense
when driving straight ahead and evenly distributed weight.
When the driver accelerates, the software switches to complete
rear-wheel drive; in a sharp curve, on the other hand, to pure
front-wheel drive. Since the optimization is purely electronic, it
is theoretically even possible to offer the driver various configurations:
for example, one mode for sports car acceleration,
another for smooth cruising.
The second task of the software is to adapt the torque to the
wheel speed. The algorithms pursue a simple goal: all wheels
should spin at the same speed. When driving on a snowcovered,
winding mountain road, this task is not trivial: If the
front wheels touch an icy surface, for example, they could spin
without electronic intervention. But the torque control recognizes
the non-optimal situation immediately and redirects the
torque in fractions of a second to those wheels that rotate more
slowly and still have grip. The software-controlled control reacts
considerably faster than its mechanical counterpart, the speedsensitive
limited-slip differential.
The third and perhaps most important function of torque
control is to control lateral dynamics, i.e. to defuse critical driving
situations. For example, the control software immediately
prevents understeer or oversteer.
A software module called Driving Condition Observer (“Observer”)
is involved in all decisions to intervene. This constantly
monitors a large number of factors such as steering wheel
angle, position of the accelerator
pedal or yaw torque.
The data for this is provided
by a yaw sensor, which is
already present in today’s
vehicles. The measured
actual condition is compared
with a dynamic model of the
vehicle, which represents the
target condition under normal
conditions. If the “observer”
detects deviations, the software
intervenes.
Although a conventional
driving stability program
(ESP) does all this, the safety system can do more with an electrically
powered all-wheel drive vehicle: while a classic ESP only
brakes, individual wheels can accelerate additionally with an
electric vehicle. In this way, the vehicle is “pulled” back into the
right lane and does not lose speed. In addition, the intervention
is smoother than with hydraulic ESP.
As the customer had specified that no additional sensors
could be installed, the software developers had to ask the software
developers’ creativity for this SUV project. “The observer
must also use the important parameters from unusual data
sources: For example, the torque control communicates with a
sensor that detects the car’s angle of inclination and is usually
used to automatically adjust the headlights.
14 News January 2020 @eeNewsEurope www.eenewseurope.com
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