Aerospace and Electronic Systems Magazine October 2017 - 40

Electronics and Vision System of a Projectile-Drone Hybrid System

the operational flight allowing hovering and maneuvering
flights for the scene observation.

At the beginning of the project in 2008, a review of MAVs
showed that there was no similar identified product existing in the
market [3]. Maintaining a technological watch on the subject, it is
only at the end of 2012 that some cheap hybrid expandable systems
were emerging as an attractive option to provide an instantaneous
operational picture [4]-[7], [11]. All these recent systems are based
on fixed-wing concepts. The launching only serves for the initialization of the MAV flight with the appropriate speed ensuring the
platform stability for the takeoff. These systems are discussed in
[8].
The present research deals with the research studies of the
GLMAV project carried out in the frame of a contract between
the French Research Agency (ANR for Agence Nationale de la
Recherche) and a consortium led by French-German Research Institute of Saint-Louis (ISL) from 2010 to 2014. The ISL coordinated with the University of Lorraine (CRAN), the CNRS (Centre
National de Recherche Scientifique)joint unit of research of the
University of Technology of Compiègne (HEUDIASYC), and the
company SBG Systems SAS. The GIGN (Groupe d'Intervention
Gendarmerie Nationale) and the DGA (Direction Générale de
l'Armement) as operational experts and MBDA-Systems in France
as an industrial expert were associated with the steering committee
of the project. The paper [9] reports the organization of the consortium in the frame of the ANR financial support.
The GLMAV platform is composed of electronic, optical, and
mechanical components. The technical content of the present article is focused on the electronics and the vision system with the

Figure 2.

Block diagram of the different mechatronics parts of the GLMAV.

image transmission, whereas the conception and the manufacturing of the mechatronics parts are detailed in [10]. The different
flight phases with validation tests are also investigated separately;
the studies are detailed in [8].

EMBEDDED ELECTRONICS
The electronic architecture is dedicated to the real-time control of
the actuators on the basis of control laws computed by the onboard
processor, from high-level instructions coming from the ground
station and from sensor measurements. It can also handle the video
acquisition and its transmission to the ground station.

MOTHERBOARD OF THE GLMAV, HARDWARE PART
Figure 2 presents a block diagram of the motherboard, the brain of
the GLMAV.
The motherboard is in charge of all onboard tasks, such as
C

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interfacing various sensors and actuators: inertial unit, range
finder, G-switch (sensor to detect the acceleration of the projectile), pitot tube, swash plate, rotor engines, and trigger for
rotor deployment,
executing the control laws,
performing the wireless communication between the platform and the ground station; the WiFi protocol is used for
video transmission and the ZigBee protocol is used for highlevel command transmission, and
acquiring, processing, and transmitting the image streaming
from the camera to the ground station.
The computer on module (COM) of the Gumstix Overo product is the main onboard computer, which integrates the electronics needed for
wireless communications via WiFi (Figure 3,
left), used for video transmission. The Gumstix
computer communicates through the universal
asynchronous receiver-transmitter (UART) port
with an XBee Pro (Figure 3, middle), which is
used for telemetry and set-point transmission via
the ZigBee 2.4-GHz protocol. The microSD card
stores the image of the real-time Linux operating system (Figure 3, right). It also allows data
storage or video recording during the GLMAV
flight.
A dsPIC microcontroller is present on the
motherboard and communicates via I2C with the
Gumstix system. It is dedicated to low-level tasks
such as the generation of control signals (pulse
width modulation [PWM]) for up to four actuators, according to the instructions from Gumstix.
Currently, only three are used: two for the control
of the orientation of the swash plate and the third
one for triggering the deployment of the rotors.
With two metal-oxide semiconductor field-effect
transistors, the dsPIC also controls the power

IEEE A&E SYSTEMS MAGAZINE

OCTOBER 2017

Table of Contents for the Digital Edition of Aerospace and Electronic Systems Magazine October 2017