MP-IST-209-1760.pdf — page 6

The use of a military radio in the UGV is only for commu-
nication with CNR and depends on the weight and volume
of the radio, taking into account the payload capacity of the
UGV. The G-Mouse GPS VK-162 with a USB connection
to the Raspberry Pi was adopted. The hardware used in the
LAFVIN UGV for Wi-Fi communication is represented by
Figure 7.
Fig. 7: Hardware in LAFVIN UGV for Wi-Fi communication.
The GCS consists of the following components:
• Computer;
• Gembird Gamepad;
• Radio.
As with the UGV, military radios are used in the GCS only
for communication with CNR. It is important to note that
in this study, the camera used for transmission is from the
same manufacturer as the onboard unit. This makes it easier to
integrate the camera with the onboard unit; it is only necessary
to configure the camera in the settings without the need for
specific software.
D. Software Modules
In this section, three software scripts were developed, which
will be described in the corresponding subsections. The soft-
ware developed was also integrated with the GCS software.
The delay block in sending heartbeat logic allows the
control of the frequency of sending HEARTBEAT messages.
The delay block, in send position logic, present in both
scripts allows adjusting the frequency of position messages,
GPS RAW
INT in the case of Figure 8, and XML messages
to the BMS with the identification of the UGV and its position,
in the case of Figure 9. This frequency adjustment makes
it possible to communicate in scenarios with less bandwidth
available.
1) Script 0 — Arduino: The LAFVIN UGV manufac-
turer code, represented by Script 0 in the general archi-
tecture, had to be adapted as communication is now via a
serial cable, and the manufacturer did not plan this mode
of communication; it runs on the Arduino. In Arduino,
the function processRaspberryPiCommand(String
command) allows commands to be received via a serial
connection to the Raspberry Pi. The manufacturer code did
not include this communication mode. To avoid problems, all
the other communication modes — Infrared and Bluetooth —
were deactivated.
2) Script 1 — Management of the link between Raspberry
Pi, Arduino, and GCS: Script 1, shown in Figure 8, represents
a link between the UGV and the ground station used to send
the UGV position to the GCS. It also is used to send command
controls to the UGV. This script runs on the Raspberry Pi.
In the case of communication using military radios, it is
necessary to initiate two connections to MAVProxy, one for
the radios and the other for Wi-Fi, since both are used.
The Raspberry Pi ↔Arduino connection is used to send the
control commands to the Arduino. All commands between the
GCS and the Raspberry Pi are sent via Wi-Fi in the configura-
tion using Wi-Fi. In the case of the configuration using tactical
radios, the heartbeats are sent by both communication channels
so that the availability of both can be seen. The UGV position,
through the send position(latitude, longitude,
altitude) function, is only sent using tactical radios.
This is the most critical communication component since it
displays the UGV position. By using military radios, it is
possible to exploit the encryption they offer and thus make
communication more secure.
Fig. 8: Script 1 — Management of the link between Raspberry Pi,
Arduino, and GCS.
3) GPS: To get the UGV position, the “gpsd”, “gpsd-
clients”, and “python-gps” libraries were used to obtain the
GPS data using the get_gps_data() function. These li-
braries had to be installed on Raspberry Pi. The initial step
was to start the session, and then the latitude, longitude and
altitude variables were updated in real-time.
Once
it
had
the
variables
to
update,
it
created
Integration of a Commercial 
Unmanned Vehicle into the Army Communications System
STO-MP-IST-209 
1760 - 6