692 research outputs found
Safe, Remote-Access Swarm Robotics Research on the Robotarium
This paper describes the development of the Robotarium -- a remotely
accessible, multi-robot research facility. The impetus behind the Robotarium is
that multi-robot testbeds constitute an integral and essential part of the
multi-agent research cycle, yet they are expensive, complex, and time-consuming
to develop, operate, and maintain. These resource constraints, in turn, limit
access for large groups of researchers and students, which is what the
Robotarium is remedying by providing users with remote access to a
state-of-the-art multi-robot test facility. This paper details the design and
operation of the Robotarium as well as connects these to the particular
considerations one must take when making complex hardware remotely accessible.
In particular, safety must be built in already at the design phase without
overly constraining which coordinated control programs the users can upload and
execute, which calls for minimally invasive safety routines with provable
performance guarantees.Comment: 13 pages, 7 figures, 3 code samples, 72 reference
Decentralization of Multiagent Policies by Learning What to Communicate
Effective communication is required for teams of robots to solve
sophisticated collaborative tasks. In practice it is typical for both the
encoding and semantics of communication to be manually defined by an expert;
this is true regardless of whether the behaviors themselves are bespoke,
optimization based, or learned. We present an agent architecture and training
methodology using neural networks to learn task-oriented communication
semantics based on the example of a communication-unaware expert policy. A
perimeter defense game illustrates the system's ability to handle dynamically
changing numbers of agents and its graceful degradation in performance as
communication constraints are tightened or the expert's observability
assumptions are broken.Comment: 7 page
Connectivity-Preserving Swarm Teleoperation With A Tree Network
During swarm teleoperation, the human operator may threaten the
distance-dependent inter-robot communications and, with them, the connectivity
of the slave swarm. To prevent the harmful component of the human command from
disconnecting the swarm network, this paper develops a constructive strategy to
dynamically modulate the interconnections of, and the locally injected damping
at, all slave robots. By Lyapunov-based set invariance analysis, the explicit
law for updating that control gains has been rigorously proven to synchronize
the slave swarm while preserving all interaction links in the tree network. By
properly limiting the impact of the user command rather than rejecting it
entirely, the proposed control law enables the human operator to guide the
motion of the slave swarm to the extent to which it does not endanger the
connectivity of the swarm network. Experiment results demonstrate that the
proposed strategy can maintain the connectivity of the tree network during
swarm teleoperation
A Study on Multirobot Quantile Estimation in Natural Environments
Quantiles of a natural phenomena can provide scientists with an important
understanding of different spreads of concentrations. When there are several
available robots, it may be advantageous to pool resources in a collaborative
way to improve performance. A multirobot team can be difficult to practically
bring together and coordinate. To this end, we present a study across several
axes of the impact of using multiple robots to estimate quantiles of a
distribution of interest using an informative path planning formulation. We
measure quantile estimation accuracy with increasing team size to understand
what benefits result from a multirobot approach in a drone exploration task of
analyzing the algae concentration in lakes. We additionally perform an analysis
on several parameters, including the spread of robot initial positions, the
planning budget, and inter-robot communication, and find that while using more
robots generally results in lower estimation error, this benefit is achieved
under certain conditions. We present our findings in the context of real field
robotic applications and discuss the implications of the results and
interesting directions for future work.Comment: 7 pages, 2 tables, 7 figure
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