Active safety systems
• Electronic stability control (ESC) - Uses measurements
from the vehicle such as steering input,
vehicle direction and individual wheel speed to
determine if the vehicle is traveling in the direction
that the driver intends. In most equipped vehicles,
if ESC determines that there is a loss of control,
it can reduce engine power and apply braking to
individual wheels to help steer the vehicle in the
direction that the driver intended.
• Roll stability control - Also known as active
rollover protection, works similarly to ESC to
determine when a vehicle is likely to turn over
on its side. If the system detects excessive lateral
force, caused by unreasonable speed in a turn,
for example, it reduces engine power and applies
braking to the appropriate wheels to avoid a rollover
situation.
• Adaptive cruise control - Also known as autonomous
cruise control (ACC), this system is active
only when the driver has set the cruise control.
It uses forward-facing radar, LiDAR, machine
vision or a combination of these to detect when
the vehicle is approaching the vehicle in front of
it too quickly. It then reduces engine power or, if
necessary, applies the brakes to match the front
vehicle’s speed.
• Autonomous braking - Using the same sensors
as ACC, applies the brakes in ACC situations or in
emergency braking situations such as when there
is a vehicle, pedestrian, animal or object in the
vehicle’s path. It should be noted that pedestrian
and animal detection is one of the newer capabilities
and is not available on all vehicles equipped
with autonomous braking.
• Forward collision mitigation - Uses autonomous
braking and, on some vehicles, autonomous steering,
to avoid an impending collision.
22 Fleet Maintenance | March 2018
• Lane keep assist - Uses machine vision to detect
the vehicle’s position on the road in relation to
clear lane markings. If departure from the lane of
travel (without the use of turn signals) is detected,
the system can steer the vehicle back into
the lane.
• Lane centering - A more advanced version of
lane keep assist, it not only keeps the vehicle
from veering out of the lane, but also keeps the
vehicle centered to avoid swerving back and
forth within the lane.
Aftermarket and OE options
Some safety system manufacturers work almost
exclusively with OEs to provide standard coverage
from the factory.
“Safety systems developed specifi cally for or
by an OEM are tested to the highest degree,” says
Volvo’s Makki. “It’s possible that aft ermarket
systems may not go through the same level of
testing with each truck OEM’s products.”
One example, Wabco, mainly work with OEs.
“Wabco’s ADAS (advanced driver assist systems)
technologies are factory-installed on new vehicles,”
says Jon Morrison, president of Wabco Americas.
Wabco (Wabco-auto.com) is a global supplier
of technologies and services that improve the
» Forward monitoring and driver
monitoring cameras (above and
right) mounted inside the cab.
Photos courtesy of Lytx
Vehicle safety systems
fall into two categories:
passive and active.
/Wabco-auto.com