66,397 research outputs found
Cooperative Robust Output Regulation Problem for Discrete-Time Linear Time-Delay Multi-Agent Systems
In this paper, we study the cooperative robust output regulation problem for
discrete-time linear multi-agent systems with both communication and input
delays by distributed internal model approach. We first introduce the
distributed internal model for discrete-time multi-agent systems with both
communication and input delays. Then, we define so-called auxiliary system and
auxiliary augmented system. Finally, we solve our problem by showing, under
some standard assumptions, that if a distributed state feedback control or a
distributed output feedback control solves the robust output regulation problem
of the auxiliary system, then the same control law solves the cooperative
robust output regulation problem of the original multi-agent systems.Comment: arXiv admin note: text overlap with arXiv:1508.0420
Internal Model Approach to Cooperative Robust Output Regulation for Linear Uncertain Time-Delay Multi-Agent Systems
In this paper, we study the cooperative robust output regulation problem for
linear uncertain multi-agent systems with both communication delay and input
delay by the distributed internal model approach. The problem includes the
leader-following consensus problem of linear multi-agent systems with
time-delay as a special case. We first generalize the internal model design
method to systems with both communication delay and input delay. Then, under a
set of standard assumptions, we have obtained the solution of the problem via
both the state feedback control and the output feedback control. In contrast
with the existing results, our results apply to general uncertain linear
multi-agent systems, accommodate a large class of leader signals, and achieve
the asymptotic tracking and disturbance rejection at the same time.Comment: 15 pages, 3 figure
Event-Triggered Cooperative Robust Practical Output Regulation for a Class of Linear Multi-Agent Systems
In this paper, we consider the event-triggered cooperative robust practical
output regulation problem for a class of linear minimum-phase multi-agent
systems. We first convert our problem into the cooperative robust practical
stabilization problem of a well defined augmented system Based on the
distributed internal model approach. Then, we design a distributed
event-triggered output feedback control law together with a distributed
output-based event-triggered mechanism to stabilize the augmented system, which
leads to the solvability of the cooperative robust practical output regulation
problem of the original plant. Our distributed control law can be directly
implemented in a digital platform provided that the distributed triggering
mechanism can monitor the continuous-time output information from neighboring
agents. Finally, we illustrate our design by an example.Comment: This paper has been accepted for publication in Automatica on May 21,
201
The Cooperative Output Regulation Problem of Discrete-Time Linear Multi-Agent Systems by the Adaptive Distributed Observer
In this paper, we first present an adaptive distributed observer for a
discrete-time leader system. This adaptive distributed observer will provide,
to each follower, not only the estimation of the leader's signal, but also the
estimation of the leader's system matrix. Then, based on the estimation of the
matrix S, we devise a discrete adaptive algorithm to calculate the solution to
the regulator equations associated with each follower, and obtain an estimated
feedforward control gain. Finally, we solve the cooperative output regulation
problem for discrete-time linear multi-agent systems by both state feedback and
output feedback adaptive distributed control laws utilizing the adaptive
distributed observer.Comment: 7 pages, 4 figure
Observer-based Adaptive Optimal Output Containment Control problem of Linear Heterogeneous Multi-agent Systems with Relative Output Measurements
This paper develops an optimal relative output-feedback based solution to the
containment control problem of linear heterogeneous multi-agent systems. A
distributed optimal control protocol is presented for the followers to not only
assure that their outputs fall into the convex hull of the leaders' output
(i.e., the desired or safe region), but also optimizes their transient
performance. The proposed optimal control solution is composed of a feedback
part, depending of the followers' state, and a feed-forward part, depending on
the convex hull of the leaders' state. To comply with most real-world
applications, the feedback and feed-forward states are assumed to be
unavailable and are estimated using two distributed observers. That is, since
the followers cannot directly sense their absolute states, a distributed
observer is designed that uses only relative output measurements with respect
to their neighbors (measured for example by using range sensors in robotic) and
the information which is broadcasted by their neighbors to estimate their
states. Moreover, another adaptive distributed observer is designed that uses
exchange of information between followers over a communication network to
estimate the convex hull of the leaders' state. The proposed observer relaxes
the restrictive requirement of knowing the complete knowledge of the leaders'
dynamics by all followers. An off-policy reinforcement learning algorithm on an
actor-critic structure is next developed to solve the optimal containment
control problem online, using relative output measurements and without
requirement of knowing the leaders' dynamics by all followers. Finally, the
theoretical results are verified by numerical simulations
Cooperative Global Robust Output Regulation for a Class of Nonlinear Multi-Agent Systems by Distributed Event-Triggered Control
This paper studies the event-triggered cooperative global robust output
regulation problem for a class of nonlinear multi-agent systems via a
distributed internal model design. We show that our problem can be solved
practically in the sense that the ultimate bound of the tracking error can be
made arbitrarily small by adjusting a design parameter in the proposed
event-triggered mechanism. Our result offers a few new features. First, our
control law is robust against both external disturbances and parameter
uncertainties, which are allowed to belong to some arbitrarily large prescribed
compact sets. Second, the nonlinear functions in our system do not need to
satisfy the global Lipchitz condition. Thus our systems are general enough to
include some benchmark nonlinear systems that cannot be handled by existing
approaches. Finally, our control law is a specific distributed output-based
event-triggered control law, which lends itself to a direct digital
implementation.Comment: This paper has been submitted to a journal on July 17, 201
Robust Consensus Tracking of Heterogeneous Multi-Agent Systems under Switching Topologies
In this paper, we consider a robust consensus tracking problem of
heterogeneous multi-agent systems with time-varying interconnection topologies.
Based on common Lyapunov function and internal model techniques, both state and
output feedback control laws are derived to solve this problem. The proposed
design is robust by admitting some parameter uncertainties in the multi-agent
system.Comment: 11 pages, 4 figures, accepte
Distributed Output Regulation for a Class of Nonlinear Multi-Agent Systems with Unknown-Input Leaders
In this paper, a distributed output regulation problem is formulated for a
class of uncertain nonlinear multi-agent systems subject to local disturbances.
The formulation is given to study a leader-following problem when the leader
contains unknown inputs and its dynamics is different from those of the
followers. Based on the conventional output regulation assumptions and graph
theory, distributed feedback controllers are constructed to make the agents
globally or semi-globally follow the uncertain leader even when the bound of
the leader's inputs is unknown to the followers.Comment: 8 pages, 2 figure
Cooperative Control of Linear Multi-Agent Systems via Distributed Output Regulation and Transient Synchronization
A wide range of multi-agent coordination problems including reference
tracking and disturbance rejection requirements can be formulated as a
cooperative output regulation problem. The general framework captures typical
problems such as output synchronization, leader-follower synchronization, and
many more. In the present paper, we propose a novel distributed regulator for
groups of identical and non-identical linear agents. We consider global
external signals affecting all agents and local external signals affecting only
individual agents in the group. Both signal types may contain references and
disturbances. Our main contribution is a novel coupling among the agents based
on their transient state components or estimates thereof in the output feedback
case. This coupling achieves transient synchronization in order to improve the
cooperative behavior of the group in transient phases and guarantee a desired
decay rate of the synchronization error. This leads to a cooperative reaction
of the group on local disturbances acting on individual agents. The
effectiveness of the proposed distributed regulator is illustrated by a vehicle
platooning example and a coordination example for a group of four non-identical
3-DoF helicopter models
Cooperative Output Regulation of Discrete-Time Linear Time-Delay Multi-agent Systems
In this paper, we study the cooperative output regulation problem for the
discrete linear time-delay multi-agent systems by distributed observer
approach. In contrast with the same problem for continuous-time linear
time-delay multi-agent systems, the problem has two new features. First, in the
presence of time-delay, the regulator equations for discrete-time linear
systems are different from those for continuous-time linear systems. Second,
under the standard assumption on the connectivity of the communication graph, a
distributed observer for any continuous-time linear leader system always
exists. However, this is not the case for discrete-time systems, and the
behavior of a distributed observer is much more complicated. Thus, we will
first study the existence of the discrete distributed observer, and then
present the solvability of the problem by distributed dynamic output feedback
control law
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