Almost sure consensus for multi-agent systems with two level switching

In most literatures on the consensus of multi-agent systems (MASs), the agents considered are time-invariant. However in many cases, for example in airplane formation, the agents have switching dynamics and the connections between them are also changing. This is called two-level switching in this paper. We study almost sure (AS) consensus for a class of two-level switching systems. At the low level of agent dynamics, switching is determin- istic and controllable. The upper level topology switching is random and follows a Markov chain. The transition probability of the Markov chain is not fixed, but varies when low level dynamics changes. For this class of MASs, a sufficient condition for AS consensus is developed in this paper

Two fault-tolerant control problems for multiple-integrators networks

The paper considers a network of agents with multiple-integrator internal dynamics, which share partial information on their states according to an arbitrary topology. For this system, two control problems are addressed and solved. The first consists in assigning the dominant closed-loop poles. The second consists in achieving a specified consensus with arbitrarily fast dynamics. In both cases, the regulator is required to be decentralized and the controlled network has to result tolerant with respect to faults in the communication apparatuses of the agents

Distributed Observer and Controller Design for State-Output Decomposed Systems

This paper tackles the networked distributed observer and controller design problem. The observers are designed in a distributed fashion. The computation effort due to high dimension of the whole system is then mitigated. The controllers are designed using linear quadratic regulation theory. A sufficient condition to guarantee the stability of the closed-loop system is derived. A conservative matrix norm bound condition for the controller is provided as well. Numerical simulation is given to verify the design procedure.status: publishe

Consensus-based distributed sensor fusion over a network

This paper studies the distributed filtering of noisy measurements of one scalar quantity. The considered network is composed of two sets of nodes: sensing nodes which perform the measuring task and non-sensing nodes which mediate between the sensing nodes. Inspired by Bayesian sensor fusion, three consensus-based algorithms are proposed. In the algorithms, graph edge weights in effect are determined based on variances of measurements of all the sensors. Evolution of the expected values and covariances of the state estimates throughout the network are analyzed. Numerical simulations are given to examine the fusion performance of the proposed scheme. The results are fairly consistent with the analytical solution regarding the statistical property of the steady-state state estimates in the network.status: publishe

Synchronization of discrete-time multi-agent systems on graphs using H2-Riccati design

In this paper design methods are given for synchronization control of discrete-time multi-agent systems on directed communication graphs. The graph properties complicate the design of synchronization controllers due to the interplay between the eigenvalues of the graph Laplacian matrix and the required stabilizing gains. A method is given herein, based on an H2 type Riccati equation, that decouples the design of the synchronizing gains from the detailed graph properties. A condition for synchronization is given based on the relation of the graph eigenvalues to a bounded circular region in the complex plane that depends on the agent dynamics and the Riccati solution. This condition relates the Mahler measure of the node dynamics system matrix to the connectivity properties of the communication graph. The notion of `synchronizing region' is used. An example shows the effectiveness of these design methods for achieving synchronization in cooperative discrete-time systems

Vibration reduction for structures: distributed schemes over directed graphs

status: accepte

Distributed observer and controller design for spatially distributed systems

This paper tackles networked distributed observer and controller design problem over directed graph topology for spatially interconnected systems. Traditional centralized design methods suffer from a lack of adaptability to graph variations incurred by network reconfiguration, communication failures, and redundant sensors integration. In this paper, to handle the foregoing limitations imposed by centralized design, state observers are designed in a distributed manner facilitated by pinning control precepts. On the one hand, this novel approach adds fault tolerance with respect to communication link failures. On the other hand, the proposed approach brings flexibility of integrating additional sensors into the network. In addition, this approach affords a reduction of computational cost. A sufficient condition to guarantee stability of the closed-loop system is derived. The controllers, though in the end implemented in a distributed way, are designed in a centralized framework, where linear-quadratic-regulator theory is adopted to handle the fact that separation principle fails to hold in the networked observer and controller design. Numerical simulation results of a piezoelectric actuated smart flexible system are presented, and the effectiveness of the proposed design is thereby verified.status: publishe

Cooperative control of multi-agent systems: optimal and adaptive design approaches

Task complexity, communication constraints, flexibility and energy-saving concerns are all factors that may require a group of autonomous agents to work together in a cooperative manner. Applications involving such complications include mobile robots, wireless sensor networks, unmanned aerial vehicles (UAVs), spacecraft, and so on. In such networked multi-agent scenarios, the restrictions imposed by the communication graph topology can pose severe problems in the design of cooperative feedback control systems.  Cooperative control of multi-agent systems is a challenging topic for both control theorists and practitioners and has been the subject of significant recent research. Cooperative Control of Multi-Agent Systems extends optimal control and adaptive control design methods to multi-agent systems on communication graphs.  It develops Riccati design techniques for general linear dynamics for cooperative state feedback design, cooperative observer design, and cooperative dynamic output feedback design.  Both continuous-time and discrete-time dynamical multi-agent systems are treated. Optimal cooperative control is introduced and neural adaptive design techniques for multi-agent nonlinear  systems with unknown dynamics, which are rarely treated in literature are developed. Results spanning systems with first-, second- and on up to general high-order nonlinear dynamics are presented. Each control methodology proposed is developed by rigorous proofs. All algorithms are justified by simulation examples. The text is self-contained and will serve as an excellent comprehensive source of information for researchers and graduate students working with multi-agent systems. The Communications and Control Engineering series reports major technological advances which have potential for great impact in the fields of communication and control. It reflects research in industrial and academic institutions around the world so that the readership can exploit new possibilities as they become available