TOUCHSCREEN HMI
excavators is not without challenges.
Whereas a mobile phone can always
be oriented to the ideal viewing
position, a screen’s fixed position
in a machine cabin renders it
susceptible to the glare,
compromising visibility.
“Driving your car on a curved
street in full sun, you can see almost
nothing on your screen; excavators
turn even quicker, so the light
conditions are difficult for these
displays,” says Jendis. “So the screen
must be well-positioned in the
cabin: under the roof, for example,
there’s more shade,” says Jendis.
“Optical bonding can give you good
brightness and contrast”
Environmental factors like dirt can
also cause problems. Touchscreens
are capacitive, translating finger
pressure or movement into
commands to select, swipe, zoom
or rotate. Electromagnetic forces,
temperature changes or a watersplash
can cause touchscreens to
detect a phantom finger and generate
so-called ghost pop-ups. But Preh
can eliminate ghost pop-ups with
corroborative force-sensing
technology behind the screen, while
working to mitigate visibility issues.
“Another important element is haptic
feedback, so it feels like you pushed
a switch on the screen,” adds Jendis.
Agricultural planning
Preh hope to unveil a new,
customized tractor HMI with a well
iVTInternational.com June 2019
34
known OEM later this year. “We’re
talking about the total HMI concept
for such vehicles, because we need
that level of integration,” Jendis
explains. “But we’re still developing
drive-sticks and rockers; nobody
thinks you can drive a tractor on
a screen like a computer game!”
Multi-use components will create
an economy of HMI elements, like
the BMW iDrive Touch Controller
developed by Preh. “This is the
world champion of multi-modal
devices,” Jendis declares. “It turns
and tilts with the touch surface on
top; you can do nearly everything
on a display with this one knob.”
“WE’RE STILL DEVELOPING DRIVESTICKS
AND ROCKERS; NOBODY
THINKS YOU CAN DRIVE A
TRACTOR THROUGH A SCREEN
LIKE A COMPUTER GAME!”
Michael Jendis, executive director of commercial vehicles, Preh
2.5bn
The number of
touchscreen
smartphones
estimated
to be in use
worldwide
in 2019
/iVTInternational.com