4,132 research outputs found
Designing Fully Distributed Consensus Protocols for Linear Multi-agent Systems with Directed Graphs
This paper addresses the distributed consensus protocol design problem for
multi-agent systems with general linear dynamics and directed communication
graphs. Existing works usually design consensus protocols using the smallest
real part of the nonzero eigenvalues of the Laplacian matrix associated with
the communication graph, which however is global information. In this paper,
based on only the agent dynamics and the relative states of neighboring agents,
a distributed adaptive consensus protocol is designed to achieve
leader-follower consensus for any communication graph containing a directed
spanning tree with the leader as the root node. The proposed adaptive protocol
is independent of any global information of the communication graph and thereby
is fully distributed. Extensions to the case with multiple leaders are further
studied.Comment: 16 page, 3 figures. To appear in IEEE Transactions on Automatic
Contro
Dynamic Resilient Containment Control in Multirobot Systems
In this article, we study the dynamic resilient containment control problem for continuous-time multirobot systems (MRSs), i.e., the problem of designing a local interaction protocol that drives a set of robots, namely the followers, toward a region delimited by the positions of another set of robots, namely the leaders, under the presence of adversarial robots in the network. In our setting, all robots are anonymous, i.e., they do not recognize the identity or class of other robots. We consider as adversarial all those robots that intentionally or accidentally try to disrupt the objective of the MRS, e.g., robots that are being hijacked by a cyber–physical attack or have experienced a fault. Under specific topological conditions defined by the notion of (r,s)-robustness, our control strategy is proven to be successful in driving the followers toward the target region, namely a hypercube, in finite time. It is also proven that the followers cannot escape the moving containment area despite the persistent influence of anonymous adversarial robots. Numerical results with a team of 44 robots are provided to corroborate the theoretical findings
H2 suboptimal containment control of homogeneous and heterogeneous multi-agent systems
This paper deals with the H2 suboptimal state containment control problem for
homogeneous linear multi-agent systems and the H2 suboptimal output containment
control problem for heterogeneous linear multi-agent systems. For both
problems, given multiple autonomous leaders and a number of followers, we
introduce suitable performance outputs and an associated H2 cost functional,
respectively. The aim is to design a distributed protocol by dynamic output
feedback that achieves state/output containment control while the associated H2
cost is smaller than an a priori given upper bound. To this end, we first show
that the H2 suboptimal state/output containment control problem can be
equivalently transformed into H2 suboptimal control problems for a set of
independent systems. Based on this, design methods are then provided to compute
such distributed dynamic output feedback protocols. Simulation examples are
provided to illustrate the performance of our proposed protocols.Comment: 15 papges, 7 figure
Differential Inequalities in Multi-Agent Coordination and Opinion Dynamics Modeling
Distributed algorithms of multi-agent coordination have attracted substantial
attention from the research community; the simplest and most thoroughly studied
of them are consensus protocols in the form of differential or difference
equations over general time-varying weighted graphs. These graphs are usually
characterized algebraically by their associated Laplacian matrices. Network
algorithms with similar algebraic graph theoretic structures, called being of
Laplacian-type in this paper, also arise in other related multi-agent control
problems, such as aggregation and containment control, target surrounding,
distributed optimization and modeling of opinion evolution in social groups. In
spite of their similarities, each of such algorithms has often been studied
using separate mathematical techniques. In this paper, a novel approach is
offered, allowing a unified and elegant way to examine many Laplacian-type
algorithms for multi-agent coordination. This approach is based on the analysis
of some differential or difference inequalities that have to be satisfied by
the some "outputs" of the agents (e.g. the distances to the desired set in
aggregation problems). Although such inequalities may have many unbounded
solutions, under natural graphic connectivity conditions all their bounded
solutions converge (and even reach consensus), entailing the convergence of the
corresponding distributed algorithms. In the theory of differential equations
the absence of bounded non-convergent solutions is referred to as the
equation's dichotomy. In this paper, we establish the dichotomy criteria of
Laplacian-type differential and difference inequalities and show that these
criteria enable one to extend a number of recent results, concerned with
Laplacian-type algorithms for multi-agent coordination and modeling opinion
formation in social groups.Comment: accepted to Automatic
Secure rendezvous and static containment in multi-agent systems with adversarial intruders
In this paper we propose a novel distributed local interaction protocol for networks of multi-agent systems (MASs) in a multi-dimensional space under directed time-varying graph with the objective to achieve secure rendezvous or static containment within the convex hull of a set of leader agents. We consider the scenario where a set of anonymous adversarial agents may intrude the network (or may be hijacked by a cyber-attack) and show that the proposed strategy guarantees the achievement of the global objective despite the continued influence of the adversaries which cannot be detected nor identified by the collaborative agents. We characterize the convergence properties of the proposed protocol in terms of the characteristics of the underlying network topology of the multi-agent system. Numerical simulations and examples corroborate the theoretical results
A Survey of Resilient Coordination for Cyber-Physical Systems Against Malicious Attacks
Cyber-physical systems (CPSs) facilitate the integration of physical entities
and cyber infrastructures through the utilization of pervasive computational
resources and communication units, leading to improved efficiency, automation,
and practical viability in both academia and industry. Due to its openness and
distributed characteristics, a critical issue prevalent in CPSs is to guarantee
resilience in presence of malicious attacks. This paper conducts a
comprehensive survey of recent advances on resilient coordination for CPSs.
Different from existing survey papers, we focus on the node injection attack
and propose a novel taxonomy according to the multi-layered framework of CPS.
Furthermore, miscellaneous resilient coordination problems are discussed in
this survey. Specifically, some preliminaries and the fundamental problem
settings are given at the beginning. Subsequently, based on a multi-layered
framework of CPSs, promising results of resilient consensus are classified and
reviewed from three perspectives: physical structure, communication mechanism,
and network topology. Next, two typical application scenarios, i.e.,
multi-robot systems and smart grids are exemplified to extend resilient
consensus to other coordination tasks. Particularly, we examine resilient
containment and resilient distributed optimization problems, both of which
demonstrate the applicability of resilient coordination approaches. Finally,
potential avenues are highlighted for future research.Comment: 35 pages, 7 figures, 5 table
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