SAE Update - May 2024 - 21

TECH FOCUS:
TESTiNg AND DigiTAl TwiN
These vehicles also typically have several module
control units (MCUs), essentially small onboard
computers, that control the functions of major
subsystems such as the engine, transmission, and
charging system. To properly test these components,
the test system needs to be able to communicate with
one or more of these units via high-speed in-vehicle
networks. The technology exists to ensure proper
testing and realization of the energy-efficiency
benefits promised by hybrids and EVs.
Types of hybrid/EV driveline testing
Hybrid or electric driveline testing is conducted at
several stages during the development of a vehicle,
and each has an important role to play.
Engineering testing: Accurate measurements are
critical so design engineers can extract every bit of
efficiency from their designs. Most vehicles use threephase
AC motors driven by inverter technology, so
sophisticated power analyzers are needed to properly
measure three-phase AC power with a large amount
of harmonic content. These test systems tend to be
rather complex and are usually the most
sophisticated, with many elements to be tested and
coordinated.
in-process and end-of-line testing: Manufacturing
end-of-line testing is usually performed to verify that
no defects were introduced in the manufacturing
process and that the components will perform to
specifications. Typical tests include operational
validation, quick performance testing, as well as
rigorous testing to validate that high-voltage electrical
systems are properly isolated and are therefore safe to
use in vehicles. In-process testing also may be
conducted to test partial assemblies along the
production line. This improves manufacturing
UPDATE
efficiency and significantly
reduces the chance that faulty
components will find their way
into the finished product.
Quality control testing:
Quality control (QC) testing is
usually done on a percentage of
the components to verify that
they perform over the specified
range and are relatively free of
defects. For example, a forklift
company may conduct QC
testing on a shipment of
imported electric motors. The
company would use QC testing
to verify that the shipment
coming from its supplier
performs as specified and will
not experience high failure rates
in the field. This type of test
system is typically less complex
because it does not have to
measure as many items, nor to
the degree of accuracy, as those
tested in engineering systems.
Electrical system testing
Traditional ICE testing typically
measures speed, torque and a
few temperatures, pressures, and
flows. Very precise control of
speed and torque is typically not
required in testing IC engines, so
dynamometers used for standard
combustion-engine testing (for
example, water brake and eddy
May 2024
21
SAE Update - May 2024

Table of Contents for the Digital Edition of SAE Update - May 2024
