july2023 - 9

" Humans are fallible. Sometimes truck drivers
are distracted or fatigued, " noted Zach Cahalan,
executive director of the Truck Safety Coalition.
" AEB is effective even when humans make
mistakes. This is a slam dunk for roadway safety. "
But that doesn't mean that this technology
cannot also make mistakes. Even though AEB
is generally proven to be safe and reduce accidents
on the road, at times the technology can
act unpredictably.
NHTSA has investigated complaints of AEBs
exhibiting 'phantom braking,' or incidents where
the system brakes hard, without warning, and
seemingly at random. When Fleet Maintenance
reached out to AEB manufacturers to discuss this
phenomenon, none wished to provide specific
comment on the matter
While OEMs and fleet leadership tout the safety
benefits of AEB, intermittent issues such as
phantom braking can put a wedge between fleet
management and drivers.
" Fleets need to take driver complaints
about these systems very seriously
because they
can cause
a lot of
issues, " said
Daryl Bear, COO and
lead engineer of Mesilla Valley
Transportation Solutions (MVTS).
Though safety and trucking organizations
agree that AEBs are successful and should be
mandated, drivers and testing facilities aren't
convinced. This makes it all the more important
to explore these systems, how to service them,
and where they need to improve.
How AEB works
At its highest level, AEB is meant to account for
human limitations. For instance, if a driver is
distracted or has trouble seeing a vehicle ahead,
the AEB provides an alert, a feature that some fleets
have found useful for training purposes.
" The presence of automatic braking systems
has increased driver awareness of their technique
by alerting them to the reality of how close they
are to an impending accident, " said James D.
Moore, Ryder senior manager of technical maintenance
support. " Over the course of a long day
and in all traffic and weather conditions, the
automated systems provide 100% efficiency
to allow safe operation, even
when the conditions are
challenging. "
AEBs do this by reducing the
engine's throttle, applying the engine
retarder, and then partially or completely
engaging a vehicle's foundation brakes, all while
providing the driver with a dashboard alert if it
detects an impending collision. Some examples
in use today include Bendix Wingman Fusion,
Detroit Assurance, Volvo Active Driver Assist,
and ZF OnGuardACTIVE. While they were
developed with different manufacturers, all of
these systems integrate with several parts of the
vehicle, including the air lines, engines, transmissions,
and brakes.
" When the AEB system determines it must
override the operator and apply the brakes due
to a safety concern, the system will communicate
to the air brake valve and open it, " said Joe Kay,
director of engineering, Cummins-Meritor. " This
allows air to flow to the foundation brake, thus
applying the brake. "
This air system engagement also requires
deep connectivity between AEB systems, stability
controls, and anti-lock braking systems for
proper functionality.
» While many vehicles benefit from
AEBs, autonomous vehicles especially
do so as a safety failsafe.
Kodiak Robotics
July 2023 | FleetMaintenance.com
9
N SPEEDS AHEAD
http://www.FleetMaintenance.com
july2023

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