ANNUAL
SHOWCASE
SPECIAL
Heavyweight, technical
papers written for the
industry, by the
industry!
Audi proves that V engines are here to stay as it
teams up with Bentley to create a 4-liter monster
January 2012
ALL WRAPPED UP
Coatings are finally making the
automotive mainstream, but does this
technology have a long-term future?
LIQUID ENGINEERING
The outlook is murky for those
working on new fuels. We map
out what the next decade holds
LUX LOWDOWN
GM’s head of powertrain for
Opel/Vauxhall reveals what’s
next after the Ampera
www.enginetechnologyinternational.com
// CASE STUDY // ROTOTEST
Rethinking
the test cell
LINKÖPING UNIVERSITY CHOSE AN INNOVATIVE SOLUTION WHEN
IT RECENTLY BUILT A NEW, STATE-OF-THE-ART POWERTRAIN
TEST CELL FOR ADVANCED RESEARCH IN ENERGY OPTIMIZATION
Total cost of ownership (TCO) is an economic
term often used when describing the overall
cost of an investment. For a passenger car, the
TCO might involve aspects such as purchase price,
maintenance costs, fuel costs and depreciation.
The calculation is similar for test equipment,
including purchase price, maintenance costs
and running costs, but a few additional factors
come into play. One is the cost of installing
the equipment, another is the cost for any
construction work necessary to house the
equipment, and finally the projected lifetime
of the test equipment and cell.
For businesses that are based on project
work, such as universities with fund-based
research, the lifetime of any investment is
of utmost importance. This is because the
total lifespan might not be related to the test
equipment, but rather the duration of the project
work, as the next development program might
be completely different. Traditional ways
of designing test cells have in many cases
prohibited investments for these businesses
due to the TCO being prohibitively high for each
individual project.
Cost-effective test cell
When Linköping University recently invested in
test equipment for its department of electrical
engineering and vehicular systems division,
The test system can be controlled from inside
the vehicle or from the purpose-built operator room
42 // January 2012 // Engine Technology International.com
it chose an innovative and alternative route.
By emphasizing flexibility, functionality and
simplicity, it managed to create a cost-effective
test cell with superior versatility.
What is striking when visiting the university’s
facility for the first time, is the entrance with
large windows, offering a panoramic view into
the new powertrain test cell, or laboratory for
vehicle propulsion. The construction of the test
cell is very generic in its design with a concrete
floor and acoustic paneled walls, which makes
it highly adaptable to different types of projects.
The test equipment chosen for the cell
was provided by Sweden-based company
Rototest, which specializes in hub-mounted
dynamometers. The company has supplied one of
its regenerative chassis dynamometer models,
the Rototest Energy, together with multiple
options and accessories, such as a headwind
// CASE STUDY // ROTOTEST
View of the test cell through the
panoramic window at the entrance
“We have an exciting
future ahead of us
in terms of vehicle
propulsion systems.
This will in turn put
demands on having
test systems capable
of keeping up with
this development”
The main power unit houses
the regenerative motor drives
fan with windspeed correlated to vehicle speed.
One of the university’s criteria for selecting
Rototest’s solution was that it should be flexible
and multifunctional to cover a wide range of
applications. It should also be upgradeable
in terms of testing functionality and easy
to relocate without extensive groundworks.
Another key criterion was the overall cost.
The chassis dynamometer arrived in a
turnkey state and precommissioned. Excluding
the installation of mains feed to the system,
installation on-site took less than a day and was
followed by a couple of days of training. With the
complete cell installed, one of the first projects it
will handle involves research into a method called
‘look ahead control’, where the geographical
landscape is tracked to optimize driving in order
to reduce energy consumption and CO 2.
For a test system to be truly versatile, it
needs to be able to switch swiftly between
applications to minimize downtime. The ability
of the system at Linköping to adapt quickly to
different applications allows several research
projects to be run in parallel, thereby lowering
the cost of ownership for contractual research.
One example is the university’s advanced
turbocharging concepts project, which runs in
parallel with the look ahead control research.
Future EV projects
With close cooperation with the automotive
industry, future projects planned in the test cell
include the development of gearbox control, as
well as research into propulsion systems such
as electrical and hybrid solutions. As the test
system has a front-end mounted measurement
system and is directly coupled to the vehicle’s
wheel hubs, it can measure accurately the
energy flow in both directions, such as during
driving and braking (energy storage). The
system can also be upgraded to include what
Rototest calls a high-resolution torque system
that would enable energy efficiency studies of
bearings and engine auxiliaries.
As a leading automotive supplier, Rototest
closely monitors worldwide powertrain
advances to continuously refine and update its
technology to meet future demands. Feedback
from Linköping University over the next five
years will be important to Rototest and its future
product evolution.
“We have an exciting future ahead of us in
terms of vehicle propulsion systems,” states Lars
Nielsen, professor at the division of vehicular
system, Linköping University. He adds: “This
will in turn put demands on having test systems
capable of keeping up with this development.”
Engine Technology International.com // January 2012 // 43