Output consensus of heterogeneous linear multi-agent systems
異構線性多智能體系統的輸出一致性
Student thesis: Doctoral Thesis
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Award date | 3 Oct 2014 |
Link(s)
Permanent Link | https://scholars.cityu.edu.hk/en/theses/theses(276a5e74-545d-4542-a7b7-859ac98f096e).html |
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Other link(s) | Links |
Abstract
Multi-agent systems are usually used to describe a class of systems consisting of
multiple subsystems, which have independent capabilities of computing, sensing,
communicating, and are connected by communication networks, such as multi-robot
systems, networked micro-satellite systems, mobile sensor networks, and so on. Benefiting from their advantages such as good scalability, high working efficiency, and
fault tolerance, multi-agent systems have attracted great attention in their cooperative
control from control community. Consensus is one of the cooperative control
problems of multi-agent systems, and can be widely applied in the fields of formation
control of Unmanned Aerial Vehicles (UAVs), environment surveillance, networking
of multiple satellites, and so on.
In the past decade, great progress has been made for consensus of multi-agent
systems. However, heterogeneity of agents, time-varying topology, disturbances, and
system uncertainty still present some challenges for consensus protocol design. This
thesis focuses on the cooperative output regulation problem and output consensus
problem of heterogeneous multi-agent systems subject to different disturbances for
individual agents under fixed or switching topology. General dynamics of high-order
linear multi-agent systems are considered, and some novel distributed control laws
are proposed. Furthermore, adaptive control techniques are applied to design feedback
gains such that they will be independent of Laplacian matrix of the underlying
system topology, and internal model principle is used to solve robust output consensus
of discrete-time multi-agent systems with structural uncertainty. The main
contributions of this thesis are summarized as follows:
Firstly, the cooperative linear output regulation problem of a class of heterogeneous
multi-agent systems subject to different disturbances for individual agents is
investigated. A novel distributed control law is presented based on dynamic measurement output feedback. It is shown that the overall networked closed-loop control
system is asymptotically stable and the output regulation errors asymptotically approach
zero as time goes to infinity under a sufficient and necessary condition.
Secondly, since the feedback gains of high-order multi-agent systems are usually
dependent on the Laplacian matrix of the underlying system topology, which is
of global nature, we further apply adaptive control techniques to investigate the
cooperative output regulation problem of heterogeneous multi-agent systems subject
to different disturbances for individual agents. Two classes of distributed adaptive
control laws are presented based on state feedback and dynamic output feedback
respectively. It is shown that the outputs of all agents can track the reference input
asymptotically under the proposed adaptive control laws.
Thirdly, we further investigate the cooperative output regulation problem of heterogeneous
multi-agent systems with periodic switching topology, which has only a
subgroup of agents accessing to the information of the exosystem. A novel distributed
adaptive control law is presented based on dynamic state feedback with
the feedback gain independent of the Laplacian matrix of the underlying system
communication topology. It is shown that the overall networked closed-loop control
system is asymptotically stable and the regulation errors approach zero as time goes
to infinity.
Fourthly, the output consensus problem of heterogeneous multi-agent systems
without a common reference input is further studied. A distributed control law is
first presented for leaderless output consensus based on internal reference models,
which are designed to generate a virtual reference input. It is shown that the internal
reference models of agents can achieve consensus to a common trajectory which is
determined by the underlying system topology and the initial states of the internal
reference models. Then a necessary and sufficient condition is presented for the
leaderless output consensus. Moreover, the approach is extended to leader-following
output consensus of heterogeneous linear multi-agent systems with the leader also
being subject to a disturbance.
Finally, the output consensus problem of heterogeneous discrete-time multiagent
systems with individual agents subject to structural uncertainty and different
disturbances is investigated. A novel distributed control law based on internal reference models is first presented for output consensus of heterogeneous discrete-time
multi-agent systems without structural uncertainty, where internal reference models
embedded in controllers are designed with the objective of reduced communication
costs. Then based on the internal reference models and the well-known internal
model principle, a distributed control law is further presented for output consensus
of heterogeneous discrete-time multi-agent systems with structural uncertainty. It
is shown in both cases that the consensus trajectory of the internal reference models
determines the output trajectories of agents.
- Multiagent systems