Truck & Off-Highway Engineering - October 2021 - 9

TECHNICAL INNOVATIONS
Head-up displays twice as helpful
To take the eye-tracking study to the
next level, a mixed-reality excavator rig
was built to evaluate the use of HMI
Wired and wireless interfaces such as CAN,
Ethernet and USB allow for connection to both
traditional machine systems and trending new
peripherals, including Ethernet cameras and lidar.
tors only looked at the system's default
displays for an occasional glance, and
some had no glances all. This might
result in the operator not benefitting
fully from the system or even missing
critical information being presented.
The attention paid to support or addon
displays, usually placed higher up
and to the side of the operator than the
default display, was noticeably different.
Their use naturally related to the
task being performed - for example,
high precision excavator work - but the
higher placement also received additional
glances. But even here there are
limitations. In most cabins the displays
are mounted on the right side, but as
the operator interacts with the surrounding
world and coworkers, attention
gets drawn straight-ahead or to the
left. Thus, we are again in a situation
where information is presented in a
place not benefitting the operator.
Then there is specific operator support
functionality. One such example is
the use of reversing cameras, beneficial
for higher awareness, safety and a better
ergonomic climate for the operator.
For the systems with displays closer to
the natural line of sight, the usage was
higher; the reversing cameras using
TRUCK & OFF-HIGHWAY ENGINEERING
dash displays weren't used at all. The
most-used reversing camera situation
was for a display mounted close to the
rearview mirrors, which meant very little
extra effort to use in the natural attention
process and task execution.
As the eye-tracking study clearly
shows, line of sight is important. Placing
displays within the operator's field of
view provides readily accessible information
that is consumed with less effort
throughout the task. The results of this
study suggest most situations could benefit
from a high A-pillar display allowing
the driver to easily observe key information
and quickly switch focus between
the areas of interest and information.
This solution is now attainable with
relatively high-performance computers
due to low-energy-consuming central
processing units (CPUs) and lightweight
materials. For example, the new Vision
Line display series from CrossControl
has a Valox housing that provides ample
protection (rates to IP65, 66 and 67
and meets the latest electromagnetic
compatibility [EMC] requirements) at a
lighter weight than all-metal enclosures.
The CCpilot V700 weighs just 650
grams (1.43 lb), allowing easy pillar,
post dash, console or roof installation.
solutions in different deployments with
" operators " engaged in performing the
same set of tasks, including both vehicle
navigation and operation of the
boom. In a direct comparison between
two of the display setups, the traditional
head-down display placement -
low and to the left of the operator -
was universally deemed to be the least
helpful and to provide the greatest risk
of missing crucial information or safety
warnings. By contrast, a head-up display
(HUD) placed close to the operator's
natural line of site was more than
twice as helpful and had half the associated
risk of missing key information.
The subjects using this simulator setup
also rated the workload level of using
the HUD as being 20% lower than the
associated workload of the head-down
display, even though the task was identical.
This could lead not only to operators
missing information, but also to operators
becoming fatigued faster, increasing
the risk of accidents. Subjects also recorded
a much higher level of frustration,
nearly 33% more, when using the
head-down display compared to the
HUD. The head-down display also placed
a greater physical toll on the users, nearly
40% more, due to operators needing
Dr. Markus Wallmyr notes " the real power " of
advanced HMI is that it supports the emerging
trend of image processing and real-time
analysis of the video stream.
October 2021 9
Truck & Off-Highway Engineering - October 2021

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