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advanced simulation technologies
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In the past, NVH characteristics
of the combustion engine
and transmission, along
with durability analysis, have
been investigated with modelling
AVL EXCITE™ for eAxle
combines accuracy and
usability for transmission
and e-motor simulation
tools such as AVL EXCITE™. With electrified powertrains additional
factors must be considered, such as electromagnetic influences and dynamic
electrical-mechanical interactions. In pure electric vehicles, the combustion
engine is not present to mask the sound and vibration of the e-motor
and the transmission. These systems can generate high-frequency noise
which can be uncomfortable for users, so there needs to be even more focus
on NVH behavior.
Electrified powertrains are highly complex, often lightweight and flexible
in construction, yet operate at extremely high torque loads. Conventional
approaches with statically pre-calculated component deflections and gear
transmission errors are not enough to properly investigate overall eAxle
dynamic behavior. To reduce problems in later development stages, component
flexibility with six-dimensional deflections and full contact interactions
must be considered in a multi-body dynamic simulation model.
However, investigating and optimizing the design of transmission and eAxle
components and systems – especially early in the development process –
can be laborious and time-consuming.
So, we have created AVL EXCITE™ for eAxle. This latest version of our
world-class modelling solution features two new modules – the ‘e-motor
tool’ and the ‘e-axle tool’. These enable quick and easy high fidelity modelling
of interactions between electrical and mechanical systems in greater
detail than ever. With this approach, sensitivity studies can be conducted
to evaluate production and assembly tolerances, focusing on design where
it really matters. Investment in finding the optimal solution here will pay
off in testing and production phases, while reducing costs.
EXCITE for eAxle enables the system to be optimized for efficiency and
durability – vital for preserving driving range and product lifetime. Crucially,
these activities can be carried out at the design stage, rather than in testing
or even during the in-use phase, when issues arise with real hardware.
“A lot of OEMs work in troubleshooting mode,” says Saša Bukovnik, AVL
Solution Manager for Virtual Driveline Development. “Start of production
is getting closer and they are finding problems with the gearbox, for
example, that are impossible to rectify on the testbed. In order to understand
the issue in a really focused way so that the design can be changed,
and the problem solved, simulation
tools are vital.”
Until now several tools were needed
to obtain a detailed view of electrified
powertrain systems. EXCITE
for eAxle brings everything
you need into a single package and
pairs it with a user interface that is
intuitive for ease-of-use. Furthermore,
its open architecture allows
seamless integration into your existing
toolchain, and data sharing with
both AVL and third-party solutions.
“Model set up time and effort are
reduced,” says Bukovnik. “And it
allows calculations of much more
variance in order to investigate
some really interesting engineering
topics.”
The automatic alignment of gears,
including planetary gearset phasing,
is supported, along with the
easy import of e-motor loads or
characteristics. A kinematic solution
for animating the entire system
lets you quickly gain insights
into your designs.
With EXCITE for eAxle you can
view structural loads and calculate
parasitic losses, gear contact losses
and roller bearing losses. These
calculations can be combined with
other factors such as oil splashing
simulations, to give an indication
of system efficiency under different
temperature conditions and different
speeds. This facilitates efficiency
and durability optimization even
before any hardware has been built.
EXCITE for eAxle accelerates the
maturation of electrified technologies
by considering a wider array of
factors at concept stage. Production
and assembly tolerances and operating
wear can also be taken into
account which, while generally
considered to be minor, can result in
noise issues or even failure with highprecision
systems such as e-motors.
“This product allows our customers
to investigate these sorts
of things upfront, which leads to
better product quality” explains
Bukovnik. “With EXCITE for
eAxle we have the most complete
and accurate simulation approach
on the market. You can now consider
effects which you could not
solve with simulation in the past.”