228 research outputs found
Performance analysis with network-enhanced complexities: On fading measurements, event-triggered mechanisms, and cyber attacks
Copyright © 2014 Derui Ding et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Nowadays, the real-world systems are usually subject to various complexities such as parameter uncertainties, time-delays, and nonlinear disturbances. For networked systems, especially large-scale systems such as multiagent systems and systems over sensor networks, the complexities are inevitably enhanced in terms of their degrees or intensities because of the usage of the communication networks. Therefore, it would be interesting to (1) examine how this kind of network-enhanced complexities affects the control or filtering performance; and (2) develop some suitable approaches for controller/filter design problems. In this paper, we aim to survey some recent advances on the performance analysis and synthesis with three sorts of fashionable network-enhanced complexities, namely, fading measurements, event-triggered mechanisms, and attack behaviors of adversaries. First, these three kinds of complexities are introduced in detail according to their engineering backgrounds, dynamical characteristic, and modelling techniques. Then, the developments of the performance analysis and synthesis issues for various networked systems are systematically reviewed. Furthermore, some challenges are illustrated by using a thorough literature review and some possible future research directions are highlighted.This work was supported in part by the National Natural Science Foundation of China under Grants 61134009, 61329301, 61203139, 61374127, and 61374010, the Royal Society of the UK, and the Alexander von Humboldt Foundation of Germany
Consensus Control for Leader-follower Multi-agent Systems under Prescribed Performance Guarantees
This paper addresses the problem of distributed control for leader-follower
multi-agent systems under prescribed performance guarantees. Leader-follower is
meant in the sense that a group of agents with external inputs are selected as
leaders in order to drive the group of followers in a way that the entire
system can achieve consensus within certain prescribed performance transient
bounds. Under the assumption of tree graphs, a distributed control law is
proposed when the decay rate of the performance functions is within a
sufficient bound. Then, two classes of tree graphs that can have additional
followers are investigated. Finally, several simulation examples are given to
illustrate the results.Comment: 8 page
Leader-following consensus for lower-triangular nonlinear multi-agent systems with unknown controller and measurement sensitivities
summary:In this paper, a novel consensus algorithm is presented to handle with the leader-following consensus problem for lower-triangular nonlinear MASs (multi-agent systems) with unknown controller and measurement sensitivities under a given undirected topology. As distinguished from the existing results, the proposed consensus algorithm can tolerate to a relative wide range of controller and measurement sensitivities. We present some important matrix inequalities, especially a class of matrix inequalities with multiplicative noises. Based on these results and a dual-domination gain method, the output consensus error with unknown measurement noises can be used to construct the compensator for each follower directly. Then, a new distributed output feedback control is designed to enable the MASs to reach consensus in the presence of large controller perturbations. In view of a Lyapunov function, sufficient conditions are presented to guarantee that the states of the leader and followers can achieve consensus asymptotically. In the end, the proposed consensus algorithm is tested and verified by an illustrative example
Robust Distance-Based Formation Control of Multiple Rigid Bodies with Orientation Alignment
This paper addresses the problem of distance- and orientation-based formation
control of a class of second-order nonlinear multi-agent systems in 3D space,
under static and undirected communication topologies. More specifically, we
design a decentralized model-free control protocol in the sense that each agent
uses only local information from its neighbors to calculate its own control
signal, without incorporating any knowledge of the model nonlinearities and
exogenous disturbances. Moreover, the transient and steady state response is
solely determined by certain designer-specified performance functions and is
fully decoupled by the agents' dynamic model, the control gain selection, the
underlying graph topology as well as the initial conditions. Additionally, by
introducing certain inter-agent distance constraints, we guarantee collision
avoidance and connectivity maintenance between neighboring agents. Finally,
simulation results verify the performance of the proposed controllers.Comment: IFAC Word Congress 201
Distributed Delay-Tolerant Strategies for Equality-Constraint Sum-Preserving Resource Allocation
This paper proposes two nonlinear dynamics to solve constrained distributed
optimization problem for resource allocation over a multi-agent network. In
this setup, coupling constraint refers to resource-demand balance which is
preserved at all-times. The proposed solutions can address various model
nonlinearities, for example, due to quantization and/or saturation. Further, it
allows to reach faster convergence or to robustify the solution against
impulsive noise or uncertainties. We prove convergence over weakly connected
networks using convex analysis and Lyapunov theory. Our findings show that
convergence can be reached for general sign-preserving odd nonlinearity. We
further propose delay-tolerant mechanisms to handle general bounded
heterogeneous time-varying delays over the communication network of agents
while preserving all-time feasibility. This work finds application in CPU
scheduling and coverage control among others. This paper advances the
state-of-the-art by addressing (i) possible nonlinearity on the agents/links,
meanwhile handling (ii) resource-demand feasibility at all times, (iii)
uniform-connectivity instead of all-time connectivity, and (iv) possible
heterogeneous and time-varying delays. To our best knowledge, no existing work
addresses contributions (i)-(iv) altogether. Simulations and comparative
analysis are provided to corroborate our contributions
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