31,474 research outputs found
Consensus tracking in multi agent system with nonlinear and non identical dynamics via event driven sliding modes
In this work, leader follower consensus objective has been addressed with the
synthesis of an event based controller utilizing sliding mode robust control.
The schema has been partitioned into two parts viz. finite time consensus
problem and event triggered control mechanism. A nonlinear multi agent system
with non identical dynamics has been put forward to illustrate the robust
capabilities of the proposed control. The first part incorporates matching of
states of the followers with those of the leader via consensus tracking
algorithm. In the subsequent part, an event triggered rule is devised to save
computational power and restrict periodic updating of the controller involved
while ensuring desired closed loop performance of the system. Switching of the
event based controller is achieved via sliding mode control. Advantage of using
switched controller like sliding mode is that it retains its inherent
robustness as well as event triggering approach aids in saving energy
expenditure. Efficacy of the proposed scheme is confirmed via numerical
simulations.Comment: preprint, "IEEE Transactions on Automatic Control
Consensus of switched multi-agent systems
In this paper, we consider the consensus problem of switched multi-agent
system composed of continuous-time and discrete-time subsystems. By combining
the classical consensus protocols of continuous-time and discrete-time
multi-agent systems, we propose a linear consensus protocol for switched
multi-agent system. Based on the graph theory and Lyapunov theory, we prove
that the consensus of switched multi-agent system is solvable under arbitrary
switching with undirected connected graph, directed graph and switching
topologies, respectively. Simulation examples are also provided to demonstrate
the effectiveness of the theoretical results.Comment: 16 pages, 4 figure
Event-Triggered Communication and Control of Networked Systems for Multi-Agent Consensus
This article provides an introduction to event-triggered coordination for
multi-agent average consensus. We provide a comprehensive account of the
motivations behind the use of event-triggered strategies for consensus, the
methods for algorithm synthesis, the technical challenges involved in
establishing desirable properties of the resulting implementations, and their
applications in distributed control. We pay special attention to the
assumptions on the capabilities of the network agents and the resulting
features of the algorithm execution, including the interconnection topology,
the evaluation of triggers, and the role of imperfect information.
The issues raised in our discussion transcend the specific consensus problem
and are indeed characteristic of cooperative algorithms for networked systems
that solve other coordination tasks. As our discussion progresses, we make
these connections clear, highlighting general challenges and tools to address
them widespread in the event-triggered control of networked systems
Designing Distributed Fixed-Time Consensus Protocols for Linear Multi-Agent Systems Over Directed Graphs
This technical note addresses the distributed fixed-time consensus protocol
design problem for multi-agent systems with general linear dynamics over
directed communication graphs. By using motion planning approaches, a class of
distributed fixed-time consensus algorithms are developed, which rely only on
the sampling information at some sampling instants. For linear multi-agent
systems, the proposed algorithms solve the fixed-time consensus problem for any
directed graph containing a directed spanning tree. In particular, the settling
time can be off-line pre-assigned according to task requirements. Compared with
the existing results for multi-agent systems, to our best knowledge, it is the
first-time to solve fixed-time consensus problems for general linear
multi-agent systems over directed graphs having a directed spanning tree.
Extensions to the fixed-time formation flying are further studied for multiple
satellites described by Hill equations
Distributed Real-Time Non-Linear Receding Horizon Control Methodology for Multi-Agent Consensus Problems
This work investigates the consensus problem for multi-agent nonlinear
systems through the distributed real-time nonlinear receding horizon control
methodology. With this work, we develop a scheme to reach the consensus for
nonlinear multi agent systems under fixed directed/undirected graph(s) without
the need of any linearization techniques. For this purpose, the problem of
consensus is converted into an optimization problem and is directly solved by
the backwards sweep Riccati method to generate the control protocol which
results in a non-iterative algorithm. Stability analysis is conducted to
provide convergence guarantees of proposed scheme. In addition, an extension to
the leader-following consensus of nonlinear multi-agent systems is presented.
Several examples are provided to validate and demonstrate the effectiveness of
the presented scheme and the corresponding theoretical results.Comment: (submitted and under review in Applied Mathematics and Computation
On the Synchronization of Second-Order Nonlinear Systems with Communication Constraints
This paper studies the synchronization problem of second-order nonlinear
multi-agent systems with intermittent communication in the presence of
irregular communication delays and possible information loss. The control
objective is to steer all systems' positions to a common position with a
prescribed desired velocity available to only some leaders. Based on the
small-gain framework, we propose a synchronization scheme relying on an
intermittent information exchange protocol in the presence of time delays and
possible packet dropout. We show that our control objectives are achieved with
a simple selection of the control gains provided that the directed graph,
describing the interconnection between all systems (or agents), contains a
spanning tree. The example of Euler-Lagrange systems is considered to
illustrate the application and effectiveness of the proposed approach.Comment: 21 pages, 8 figures. Submitted for journal publicatio
Nonlinear Consensus Strategies for Multi-Agent Networks in Presence of Communication Delays and Switching Topologies: Real-Time Receding Horizon Approach
This paper presents a novel framework which combines a non-iterative solution
of Real-Time Nonlinear Receding Horizon Control (NRHC) methodology to achieve
consensus within complex network topologies with existing time-delays and in
presence of switching topologies. In this formulation, we solve the distributed
nonlinear optimization problem for multi-agent network systems directly,
\emph{in real-time}, without any dependency on iterative processes, where the
stability and convergence guarantees are provided for the solution. Three
benchmark examples on non-linear chaotic systems provide validated results
which demonstrate the significant outcomes of such methodology.Comment: 26 pages, 8 figures (under review). arXiv admin note: substantial
text overlap with arXiv:1510.0779
Containment Control of Second-order Multi-agent Systems Under Directed Graphs and Communication Constraints
The distributed coordination problem of multi-agent systems is addressed in
this paper under the assumption of intermittent communication between agents in
the presence of time-varying communication delays. Specifically, we consider
the containment control problem of second-order multi-agent systems with
multiple dynamic leaders under a directed interconnection graph topology. Also,
communication between agents is performed only at some discrete instants of
time in the presence of irregular communication delays and packet dropout.
First, we present distributed control algorithms for double integrator dynamics
in the full and partial state feedback cases. Then, we propose a method to
extend our results to second-order systems with locally Lipschitz nonlinear
dynamics. In both cases, we show that the proposed approach leads to our
control objectives under sufficient conditions relating the characteristics of
the communication process and the control gains. We also show that our approach
can be applied to solve various similar coordination problems in multi-agent
systems under the same communication constraints. The effectiveness of the
proposed control schemes is illustrated through some examples and numerical
simulations.Comment: Modified version. Paper submitted for publicatio
Fixed-time consensus of multiple double-integrator systems under directed topologies: A motion-planning approach
This paper investigates the fixed-time consensus problem under directed
topologies. By using a motion-planning approach, a class of distributed
fixed-time algorithms are developed for a multi-agent system with
double-integrator dynamics. In the context of the fixed-time consensus, we
focus on both directed fixed and switching topologies. Under the directed fixed
topology, a novel class of distributed algorithms are designed, which guarantee
the consensus of the multi-agent system with a fixed settling time if the
topology has a directed spanning tree. Under the directed periodically
switching topologies, the fixedtime consensus is solved via the proposed
algorithms if the topologies jointly have a directed spanning tree. In
particular, the fixed settling time can be off-line pre-assigned according to
task requirements. Compared with the existing results, to our best knowledge,
it is the first time to solve the fixed-time consensus problem for
double-integrator systems under directed topologies. Finally, a numerical
example is given to illustrate the effectiveness of the analytical results
Time-varying formation tracking of multiple manipulators via distributed finite-time control
Comparing with traditional fixed formation for a group of dynamical systems,
time-varying formation can produce the following benefits: i) covering the
greater part of complex environments; ii) collision avoidance. This paper
studies the time-varying formation tracking for multiple manipulator systems
(MMSs) under fixed and switching directed graphs with a dynamic leader, whose
acceleration cannot change too fast. An explicit mathematical formulation of
time-varying formation is developed based on the related practical
applications. A class of extended inverse dynamics control algorithms combining
with distributed sliding-mode estimators are developed to address the
aforementioned problem. By invoking finite-time stability arguments, several
novel criteria (including sufficient criteria, necessary and sufficient
criteria) for global finite-time stability of MMSs are established. Finally,
numerical experiments are presented to verify the effectiveness of the
theoretical results
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