HIMA 19.2_1

The FJM layout for the Robogreen mower makes remote control easy and intuitive
With the launch and development
of Autec’s Dynamic series of safety
remote controls, the electronics specialist
has expanded its target application fields
by providing completely flexible and
adaptable solutions. One example of its
recent successful case histories involves a
tracked, radio remote-controlled mower
from Energreen, an Italian manufacturer
of innovative mowers.
The Robogreen model is used for the
maintenance of areas such as motorway
embankments, roundabouts and steep
river banks that would be too tough or
dangerous for an operator to tackle. It
offers high stability even on difficult
terrain (slopes up to 55°) due to its highgrip tracks, as well as power and precision
through a wide range of available flails and
attachments. The machine is completed
with a user-friendly radio remote control
that enables excellent manoeuvrability.
Its intuitive finger-tip commands make it
even easier to control its direction and
movements, ensuring operation from a
safe distance (up to 100m working range).
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The FJM radio remote control
The radio remote control chosen to
control the Robogreen mower is an FJM
transmitting unit combined with an ARM
receiving unit. The configuration of the
transmitter has been specifically engineered
to respond to the specific requirements
and needs of the application. The system’s
main actuators are two dual-axis joysticks,
two potentiometers and several switches
(see main image, above).
The layout has been designed so as to
make using the radio remote control easy
and intuitive. This remains the case even
if different equipment is mounted, as the
commands have been studied so that they
can be easily adapted to each tool.
The left joystick is a proportional
controller that is used to move the mower
forwards and backwards. This joystick also
controls the machine’s groundspeed (up to
7km/h), whereas the upper potentiometer
acts as a sort of analogue speed selector,
setting the maximum speed in a 0-100%
range. This way, operators can customise
speed to match their personal preferences.
The right joystick, used in combination
with the left one, is used for steering the
Robogreen. On the other hand, if that
joystick alone is completely moved to the
left or to the right, the mower performs
counter-rotation. The y-axis is used to
move the flail head up and down.
The lower potentiometer is used for
steer control. When working on sloping
meadows or steep banks, the speed of a
track can be changed in relation to the
other. This way, any downhill slipping due
to gravity can be neutralised by reducing
the speed of the upper track, so that the
machine maintains a straight direction.
Several switches and pushbuttons are
also available on the radio remote control,
which are used for the operation of
attachments or for auxiliary functions.
Operators can also control the engine’s
functions and perform the start-up and
switch-off of the machine directly from
the remote control system, as well as
adjusting the engine’s rpm.
The ARM receiving unit is a DCsupplied receiver that provides up to 12
Dynamic series
technical data
at a glance
Robogreen mower working at the Mugello Formula 1 racing track
analogue and up to 64 digital functions.
Digital, analogue and serial inputs are also
available. ARM can also be integrated in a
CANopen network, so that the receiver
can communicate with the machine
controller (if present), or collect data from
the machine. Such data is then shown on
a graphic display on the transmitting unit.
ARM outputs are designed to be
programmed to meet the machine’s exact
requirements. For instance, timed and
pulse functions, as well as logical functions
(e.g. preventing movements if an opposite
movement is active) can be obtained with
proper programming.
Possible future developments
Autec is now working with the machine’s
manufacturer to develop an improved
solution to control the Robogreen. The
Dynamic series CRS receiver will be used
in place of the ARM – this is considerably
smaller than ARM because all controls are
sent via the CAN network. Furthermore, it
can easily communicate with an electronic
control unit that will be integrated on
the machine to completely manage the
machine functions. Engine management
(which is currently performed through
separate electronics) will also be carried
out by the same ECU. The transmitting
unit will also be replaced by the new FJR
model, which features marginally more
compact dimensions, providing further
advantages in ergonomy and usability.
The special features that have been
implemented in this application are the
result of a process involving different
players, both on Autec’s side and on
Energreen’s side. Intense cooperation
between Autec’s engineering unit and the
manufacturers and suppliers of the main
components of the machine (such as the
hydraulic banks, hydraulic pump and
engine) helped provide a tailored solution
responding to the requirements.
Autec’s R&D department was involved
in defining and designing the system’s
firmware to manage the track control,
whereas the configuration unit was
engaged to define the most suitable
transmitter layout (to meet the customer’s
needs) and the receiver’s characteristics.
This exemplary teamwork led to several
improvements, proving that optimal
results can be reached whenever the
Dynamic series ARM, ARS and CRS receivers (from left to right)
Frequency bands: 863-870MHz /
915-928MHz/430-470MHz (up to 256 available
Typical operating range: 100m;
Number of proportional commands: Up to
12 (+16 digital commands for direction);
Number of digital commands: Up to 64;
Commands typical response time: <80ms;
Safety category for the Stop protection:
PL e, cat. 4/SIL 3;
Safety category for the protection against
unintended movement from standstill
(UMFS): PL d, cat. 3/SIL 2;
Autonomy with fully charged battery: Up
to 11 hours;
Operating temperature range: -25° to + 70°C;
Receiving unit power supply: 8-30V DC.
relationship between OEM and customer
starts out with the analysis of specific
requirements, and proceeds with fruitful
cooperation on both sides.
The Dynamic series at a glance
FJM is just one of the transmitters
belonging to Autec’s leading range of
products: the Dynamic series for mobile
hydraulic machines. The series is certified
for functional safety by TÜV SÜD. For
example, the Stop function complies with
the requirements of EN ISO 13849-1
Performance Level ‘e’, Cat. 4 and EN IEC
62061 Safety Integrity Level 3, while the
UMFS function (which protects actuators
against unintended movement from
standstill) provides PL ‘d’, Cat. 3/SIL2.
The Dynamic series has recently been
expanded with the introduction of the
new ARS receiver and FJR transmitter. ARS
combines the CAN interface with some of
the features of an analogue receiver in a
compact casing, particularly designed for
installation on vehicles. The FJR transmitter
boasts compact dimensions, while also
offering excellent configuration options.
This makes the transmitter the ideal
solution for machines such as concrete
pumps, telehandlers, mid-size MEWPs, or
autonomous vehicles. A new, transflective
graphic display that offers optimised
visibility for outdoor usage is also available
in the Dynamic series of transmitters. iVT
Daniele Oliviero is application engineer for mobile
hydraulics at Autec Safety Remote Control; Chiara
Righele works in Autec’s marketing department
[email protected]
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