Vehicle Electrification - August 21, 2013 - 10

Tech Report
also nets handling benefits. “Since our patents-pending design uses a compact electric
axle with two independent electric motors,
we gain torque vectoring capability, which
significantly improves traction and stability,”
Ledford said. Response time for torque vectoring is less than 50 ms.
Micro-hybrid and PHEV/EV applications are
prime targets for the Agilit-e, but even AWD
production vehicles are candidates. “The
Agilit-e system will replace mechanical components, such as the PTU (power transfer
unit), propshaft, coupler, and RDM (rear-drive
module), while adding power and improving
fuel economy,” Maxwell said.
On the SRX demonstrator, the Agilit-e powers the rear wheels in conjunction with the vehicle’s front-drive powertrain. The combination offers four different drive modes: frontwheel drive, EV only (which is RWD powered
by the battery and the electric motors), hybrid, and AWD.
Technical specialists built the demonstrator in nine months, while Linamar’s engineers used data streams from virtual modeling, CAE modeling, and a full-vehicle chassis
dynamometer at AVL’s California Technology
Center.
According to Maxwell, “the majority of the
Agilit-e’s calibrations were done by the time
we finished with the dynamometer. And before we started on-road evaluations, we had
looked at three different types of gearboxes
and a small-displacement engine, although
our demonstration prototype retains the
SRX’s standard 3.6-L V6.”
In a recent test drive evaluation, OEM engineers asked to experience specific vehicle
handling responses.

August 21, 2013

“They wanted the Agilit-e demonstration vehicle to handle differently during hard cornering,” Maxwell said. “Within two weeks our engineers were able to make software changes
so that the vehicle handled the way the customer wanted. The customer was able to see
how easy this system is to tune.”
Another Agilit-e demonstration vehicle is
being prepped and is expected to be ready in
October 2013. “Our first demonstration SRX
is booked through 2013 with events and customer test drives in North America, so the
second SRX demonstration vehicle will be
devoted to the European audience,” said
Maxwell.
Having technologies in the portfolio that
can help automakers meet the 54.5-mpg U.S.
Corporate Average Fuel Economy requirements in 2025, as well as stringent European
CO2 laws, influenced Linamar’s development
plan for the Agilit-e.
“We were very cognizant of the timing. We
would normally have considered this type of
system as a two- to three-year development
effort,” noted Maxwell. “But when the 2025
CAFE regulations went into effect, we said
2013 is when we need to have this technology in front of customers for evaluations.”
He said initial testing shows that the Agilit-e
system in a hybrid AWD configuration can improve city-driving fuel economy by as much
as 80%.
The Agilit-e Hybrid Power Unit will be in the
design validation stage for several months as
Linamar engineers work to refine the gearing
for noise abatement, as well as make modifications to strengthen system durability.
“We expect the first production application will be in the 2018-2019 time frame,”
Maxwell said.

Kami Buchholz

SAE Vehicle Electrification evsae.com

http://www.evsae.com

Vehicle Electrification - August 21, 2013

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