17,048 research outputs found
Reentrant phase transitions of higher-dimensional AdS black holes in dRGT massive gravity
We study the criticality and phase transition in the extended phase
space of anti-de Sitter (AdS) black holes in higher-dimensional de Rham,
Gabadadze and Tolley (dRGT) massive gravity, treating the cosmological constant
as pressure and the corresponding conjugate quantity is interpreted as
thermodynamic volume. Besides the usual small/large black hole phase
transitions, the interesting thermodynamic phenomena of reentrant phase
transitions (RPTs) are observed for black holes in all -dimensional
spacetime when the coupling coefficients of massive potential satisfy
some certain conditions.Comment: 14 pages, several references are added, v2: published in EPJ
Control of one-dimensional guided formations using coarse information
Motivated by applications in intelligent highway systems, the paper studies
the problem of guiding mobile agents in a one-dimensional formation to their
desired relative positions. Only coarse information is used which is
communicated from a guidance system that monitors in real time the agents'
motions. The desired relative positions are defined by the given distance
constraints between the agents under which the overall formation is rigid in
shape and thus admits locally a unique realization. It is shown that even when
the guidance system can only transmit at most four bits of information to each
agent, it is still possible to design control laws to guide the agents to their
desired positions. We further delineate the thin set of initial conditions for
which the proposed control law may fail using the example of a three-agent
formation. Tools from non-smooth analysis are utilized for the convergence
analysis.Comment: 13 pages, 4 figure
Reentrant phase transitions and triple points of topological AdS black holes in Born-Infeld-massive gravity
Motivated by recent developments of black hole thermodynamics in de Rham,
Gabadadze and Tolley(dRGT) massive gravity, we study the critical behaviors of
four-dimensional topological Anti-de Sitter(AdS) black holes in the presence of
Born-Infeld nonlinear electrodynamics by treating the cosmological constant as
pressure and the corresponding conjugate quantity is interpreted as
thermodynamic volume. It shows that besides the Van der Waals-like SBH/LBH
phase transitions appears, the so-called reentrant phase transitions (RPTs) are
also observed when the coupling coefficients of massive potential and
Born-Infeld parameter satisfy some certain conditions.Comment: arXiv admin note: text overlap with arXiv:1612.08056; text overlap
with arXiv:1402.2837, arXiv:1306.5756 by other autho
Taming mismatches in inter-agent distances for the formation-motion control of second-order agents
This paper presents the analysis on the influence of distance mismatches on
the standard gradient-based rigid formation control for second-order agents. It
is shown that, similar to the first-order case as recently discussed in the
literature, these mismatches introduce two undesired group behaviors: a
distorted final shape and a steady-state motion of the group formation. We show
that such undesired behaviors can be eliminated by combining the standard
formation control law with distributed estimators. Finally, we show how the
mismatches can be effectively employed as design parameters in order to control
a combined translational and rotational motion of the formation.Comment: 14 pages, conditionally accepted in Automatic Control, IEEE
Transactions o
Controlling rigid formations of mobile agents under inconsistent measurements
Despite the great success of using gradient-based controllers to stabilize
rigid formations of autonomous agents in the past years, surprising yet
intriguing undesirable collective motions have been reported recently when
inconsistent measurements are used in the agents' local controllers. To make
the existing gradient control robust against such measurement inconsistency, we
exploit local estimators following the well known internal model principle for
robust output regulation control. The new estimator-based gradient control is
still distributed in nature and can be constructed systematically even when the
number of agents in a rigid formation grows. We prove rigorously that the
proposed control is able to guarantee exponential convergence and then
demonstrate through robotic experiments and computer simulations that the
reported inconsistency-induced orbits of collective movements are effectively
eliminated.Comment: 10 page
Distributed scaling control of rigid formations
Recently it has been reported that biased range-measurements among
neighboring agents in the gradient distance-based formation control can lead to
predictable collective motion. In this paper we take advantage of this effect
and by introducing distributed parameters to the prescribed inter-distances we
are able to manipulate the steady-state motion of the formation. This
manipulation is in the form of inducing simultaneously the combination of
constant translational and angular velocities and a controlled scaling of the
rigid formation. While the computation of the distributed parameters for the
translational and angular velocities is based on the well-known graph rigidity
theory, the parameters responsible for the scaling are based on some recent
findings in bearing rigidity theory. We carry out the stability analysis of the
modified gradient system and simulations in order to validate the main result.Comment: 6 pages In proceedings 55th Conference on Decision and Control, year
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