MP-IST-209-1760.pdf — page 7

the
send_position(latitude, longitude,
altitude)
function.
This
function
sends
MAVLink
GPS RAW INT
messages
with
latitude,
longitude,
and
altitude data to the Mission Planner.
4) Control
commands:
The
MAVLink
MAN-
UAL CONTROL messages are received by the Raspberry
Pi
using
the
handle _manual_control
function.
Depending on the parameters received, the corresponding
message is sent to the Arduino to operate the UGV:
• Front: send_command_to_arduino(%F#);
• Back: send_command_to_arduino(%B#);
• Right: send_command_to_arduino(%R#);
• Left: send_command_to_arduino(%L#).
To send control commands to the UGV, the Gembird
Gamepad was first connected to the GCS and then paired
with the Mission Planner. When connected to the Mission
Planner, two axes of movement were used, allowing the
UGV to move in four different directions. The axes were
chosen automatically by the Mission Planner, considering the
movement of the controller’s analog, selected by the user.
For movements in different directions on the same axis, the
“Reverse” option was used. The mode chosen was “Manual
Control”, which will be important in the type of MAVLink
messages generated at the GCS.
5) Script 2 — Management of the link between GCS and
BMS: Script 2, shown in Figure 9, runs on the GCS and
represents a link to the BMS. It creates an XML, and it is
sent to the BMS. This script aims to extract the UGV position
from MAVLink messages and generate an XML according to
STANAG 5527. The connection is established with port 14552,
where MAVLink messages are forwarded via MAVProxy. This
script can run on GCS if MAVProxy is forwarding messages
to port 14552 on localhost or on another machine.
The used XML model is the A2 of the STANAG 5527.
Depending on where the BMS is running, the XML must be
sent there. In a configuration where the BMS is running on
the GCS, it is enough to send it to localhost; otherwise, it
requires the IP of a machine on the network that is running
the BMS. In the tactical radio scenario, this sending is done
via military radios. The IP to which the XML is sent must be
configured in the function send_xml_file(filename,
server_ip, server_port) used to send the file.
In the BMS, in addition to the standard configuration, which
includes creating a mission with some mandatory parameters,
such as the configuration of the stack and GPS, a gateway must
be configured in the BMS with the port where the report will
be received, in this case, port 48882, and the message template
which will be used, in this case, FFT Systems—STANAG
5527 A1/A2.
Fig. 9: Script 2 — Management of the link between GCS and BMS.
6) Mission
Planner
Configuration:
This
subsection
presents the main aspects to be configured in the Mission
Planner, namely, receiving the video and sending the control
commands. The Mission Planner is configured on port
14551. Once the software is open, after running Script 1 and
then starting GCS with MAVProxy, a UDP connection is
automatically started on port 14551.
First, the configuration of video reception on the Mission
Planner and its capture and sending on the Raspberry Pi is
presented using the Raspivid and GStreamer libraries, respec-
tively. Then, in this section, the configuration of the joystick
in Mission Planner and the configurations to send control
commands are presented.
7) Video streaming: Image capture was first initiated using
the Raspivid application on the Raspberry Pi. Then, the
GStreamer application was used to send the video stream to
the Mission Planner, running on the GCS.
The quality of image capture has an influence on the band-
width required for communication. The quality of the image
is adjusted according to the characteristics of the transmission
channel, which will be analysed in the results.
IV. RESULTS
The solutions for the tests in the SIC-T project team will
be presented. To achieve this, tests were carried out using Wi-
Fi technology alone and a hybrid configuration using tactical
radios and Wi-Fi. The tactical radios fill an existing gap in
Wi-Fi communication — security — since the UGV position
is considered critical data.
STO-MP-IST-209 
1760 - 7 
Integration of a Commercial 
Unmanned Vehicle into the Army Communications System