Truck & Off-Highway Engineering - October 2021 - 8

TECHNICAL INNOVATIONS
the succeeding compression stroke. The
valve inlet is fed with H2
gas direct from
the supply tank with no requirement for
an additional pressure pump.
A range of range extenders
Garside's plan is to develop a modular
series of range-extender engine sizes
aimed at different vehicle sectors, starting
with a 225-cc engine with an initial
test power rating of 12 kW (16 hp) at
5,000 rpm, based on a 30-kW UAV engine
with a core engine weight of 10 kg
(22 lb). Applications would be urban
taxis and smaller cargo vans.
A 650-cc variant is planned for urban
buses, local distribution vehicles, garbage
trucks and off-highway applications.
Dry weight is approximately 24
kg (53 lb) and it would produce 34 kW
(46 hp) at 4,000 rpm.
A 2.0-L engine with an output of
about 93 kW (125 hp) also is proposed
for trucks with one, two, or three engines
based on vehicle size. Even higher
swept volumes may be practical,
Garside suggested, and that additional
power could be extracted from this engine
by using a turbocompound system,
harnessing exhaust gases to drive a
turbine which in turn would drive a
high-speed generator.
" The exhaust port opens much faster
than a [conventional IC engine's] valve
lifts and all the exhaust gases would be
exiting from a single port, not multiple
ports, " explained Garside. " Hence the
turbine could be fitted very close to the
exhausting chamber and collect some
of the blowdown energy, as well as the
expansion energy. "
Roller bearings are used for both the
rotor and main shaft and lubrication is
by total loss. The quantities of oil involved
are extremely small because the
total areas requiring lubrication are far
smaller than in a reciprocating engine
and experience no violent accelerations
or direction changes. Rotor apex seals
are made from extremely hard, lowfriction
Si3N4 material. The engine requires
neither filter nor oil changes, reducing
engine servicing to infrequent
sparkplug changes.
John Kendall
8 October 2021
HUMAN-MACHINE INTERFACE
Next-gen HMI crucial for ADAS efficacy
Displays based on powerful computing technology assist the implementation of object detection,
demonstrated by this view from CrossControl's CCpilot V700 display.
Next-generation HMI (human-machine
interface) technology platforms allow
off-highway OEMs and system designers
to support productivity tools like
computer vision - including object detection,
advanced driver-assistance systems
(ADAS) and semi-automatic
equipment control - as well as traditional
HMI features such as engine monitoring,
navigation and instrumentation
clusters. For example, CrossControl's
CCpilot V700, V1000 and V1200 displays
are equipped with a powerful
quad core SoC (system on a chip) that
delivers triple the graphical performance
of former industrial ARM design
to the construction, agriculture, mining
and material-handling sectors.
More computational power enables
systems to provide more advanced functionality
- aka " soft functionality " - to
aid the operator, but it also can increase
the operator's mental stress.
CrossControl invests in research into
Interaction and UX design and performed
two recent studies in conjunction
with Mälardalen University that shed
some insight into best practices for system
deployment. The research was carried
out through both field and laboratory
studies. The field-work study of actual
work situations performed by forestry
and construction equipment took
place in Sweden. The operator's attention
and visual focus was analyzed using
eye-tracking glasses. The benefit of
glasses compared to, for example, display-fitted
eye-trackers, is that they also
capture everything the operator sees.
Optimizing display placement
Studying the operators gives some interesting
insights into HMI design - specifically,
cabin design and display placement.
The forestry operators, engaged in thinning
(removing unwanted trees to encourage
more growth), spent nearly 95% of
their attention through the front windscreen.
One reason for the high focus
straight-ahead is because the whole cabin
rotates with the crane; this way the operator
is always facing the area of operation.
The setup of the forestry vehicle featured
two screens arranged in the lower
section of the front windscreen. While
the display provided constantly updated
information, it primarily was used to
adjust settings and, through quick
glances, obtain system information
when operation was not behaving as
expected. This trend was similar for
most vehicles and even more evident
for vehicles with the display placed to
the lower side of the cabin; the operaTRUCK
& OFF-HIGHWAY ENGINEERING
ALL IMAGES: CROSSCONTROL

Truck & Off-Highway Engineering - October 2021

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