Aerospace and Electronic Systems - March 2019 - 50

ARIES: An Autonomous Controller For Multirobot Cooperation

Figure 9.
Experimental scene in V-REP used for the experimental demonstration of ARIES.

Mars, such as taking pictures around a cliff, a crater or a
mountain ridge, which the current UGVs cannot accomplish due to safety and operational constrains. Thus, we
propose a UAV to accomplish these targets. However,
UAVs are robotic systems with limited energy resources
to complete large duration missions on its own. Then, our
mission proposal defines a cooperative scenario where the
UGV acts as a moving charging station carrying the UAV
between secure locations, such as a cliff edge surroundings, where the UAV can take off and obtain pictures
around the cliff without flying long distances. Also, the
UGV acts as a charging station which provides autonomous recharging to the UAV during the exploration mission. In such mission proposal, a hybrid UGV-UAV
system executing ARIES would be empowered to accomplish long-term explorations with a high level of autonomy. This mission represents just one of many future
Mars missions examples that will help to open new horizons of knowledge.
Following the described mission proposal, the ARIES
instance deployed for this demonstration defines the UGV
as the Leader Agent and the UAV as the Follower Agent.
For the UGV, we have modeled a PDDL domain
and problem with the exploration mission. For the UGV
deliberative layer, we have modeled the UGV's locomotion system through the state variable UGVBase and
the UGV's on-board charging station as UGVStation.
For the UAV, we have modeled the locomotion system
with the UAVBase state variable, the zenithal camera with
UAVCamera, and the energy resource with UAVEnergy.
The UAV energy resource allows us to model the boundaries that the UAV can reach from a take off point. Please
note that this demonstration only considers a nominal scenario without anomalous events, so fail-safe configurations have not been taken into account.
The experimental scene was simulated in the Virtual
Robot Experimentation Platform (V-REP) [38], a flexible
and scalable simulation framework. V-REP allows us to
use different programming techniques to implement the
controllers (kinematics or dynamics, for instance) of the
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robotic systems. Moreover, it provides functionalities to
deploy highly customizable scenes. Our experimental
scene consists of a specific area extracted from a real Mars
Digital Terrain Model (DTM)D1 as Figure 9(a) shows;
and a simulated hybrid UGV-UAV system as shown in
Figure 9(b). Also, V-REP provides a remote interface to
interact with an external entity via socket communication.
We take advantage of this interface to set the communication link between ARIES and V-REP. In particular, the
GER of the Leader and Follower Agents were set up to
communicate with the V-REP remote interface of each
robotic system.
The demonstration consists of acquiring different samples in a Mars-like environment. The hybrid UGV-UAV system starts and ends at the same position [Home in Figure 10
(a)]. Due to the lack of simulated models of exploration
UGV-UAV systems, these robotics systems have been modeled as Dubins vehicles [39]. Also, we assume that the UGV
does not have energy constraints, so it has enough energy
resources to complete the exploration mission. Instead, the
UAV energy constraint has been modeled as the maximum
flight time with a high capacity battery fully charged. The
nominal scenario used for the ARIES demonstration starts at
the home location with the UGV carrying the UAV, which
has full battery. Their objective is to take six pictures (TP16) [see Figure 10(a)]. A high capacity battery allows the
UAV to reach farther targets without performing too many
charging stops. Figure 10(b)-(d) shows different screenshots
taken during the simulation.

EXPERIMENTAL RESULTS
The simulation starts by defining the goals and the initial
state of the mission, i.e., reaching the targets TP1-6 starting
from the home location with the UAV. Once the UP2TA
planner of the Leader Agent receives the goals, it generates
a complete plan to achieve one-by-one the targets. Figure 11
1

https://www.uahirise.org/dtm/dtm.php?ID=ESP_030808_1535

IEEE A&E SYSTEMS MAGAZINE

MARCH 2019

https://www.uahirise.org/dtm/dtm.php?ID=ESP_030808_1535

Aerospace and Electronic Systems - March 2019

Table of Contents for the Digital Edition of Aerospace and Electronic Systems - March 2019