62,569 research outputs found
Pinning dynamic systems of networks with Markovian switching couplings and controller-node set
In this paper, we study pinning control problem of coupled dynamical systems
with stochastically switching couplings and stochastically selected
controller-node set. Here, the coupling matrices and the controller-node sets
change with time, induced by a continuous-time Markovian chain. By constructing
Lyapunov functions, we establish tractable sufficient conditions for
exponentially stability of the coupled system. Two scenarios are considered
here. First, we prove that if each subsystem in the switching system, i.e. with
the fixed coupling, can be stabilized by the fixed pinning controller-node set,
and in addition, the Markovian switching is sufficiently slow, then the
time-varying dynamical system is stabilized. Second, in particular, for the
problem of spatial pinning control of network with mobile agents, we conclude
that if the system with the average coupling and pinning gains can be
stabilized and the switching is sufficiently fast, the time-varying system is
stabilized. Two numerical examples are provided to demonstrate the validity of
these theoretical results, including a switching dynamical system between
several stable sub-systems, and a dynamical system with mobile nodes and
spatial pinning control towards the nodes when these nodes are being in a
pre-designed region.Comment: 9 pages; 3 figure
Pinning control of spatiotemporal chaos
Linear control theory is used to develop an improved localized control scheme for spatially extended chaotic systems, which is applied to a coupled map lattice as an example. The optimal arrangement of the control sites is shown to depend on the symmetry properties of the system, while their minimal density depends on the strength of noise in the system. The method is shown to work in any region of parameter space and requires a significantly smaller number of controllers compared to the method proposed earlier by Hu and Qu [Phys. Rev. Lett. 72, 68 (1994)]. A nonlinear generalization of the method for a 1D lattice is also presented
On the pinning strategy of complex networks
In pinning control of complex networks, a tacit believing is that the system
dynamics will be better controlled by pinning the large-degree nodes than the
small-degree ones. Here, by changing the number of pinned nodes, we find that,
when a significant fraction of the network nodes are pinned, pinning the
small-degree nodes could generally have a higher performance than pinning the
large-degree nodes. We demonstrate this interesting phenomenon on a variety of
complex networks, and analyze the underlying mechanisms by the model of star
networks. By changing the network properties, we also find that, comparing to
densely connected homogeneous networks, the advantage of the small-degree
pinning strategy is more distinct in sparsely connected heterogenous networks
Controlling chaos in a chaotic neural network
The chaotic neural network constructed with chaotic neuron shows the associative memory function, but its memory searching process cannot be stabilized in a stored state because of the chaotic motion of the network. In this paper, a pinning control method focused on the chaotic neural network is proposed. The computer simulation proves that the chaos in the chaotic neural network can be controlled with this method and the states of the network can converge in one of its stored patterns if the control strength and the pinning density are chosen suitable. It is found that in general the threshold of the control strength of a controlled network is smaller at higher pinned density and the chaos of the chaotic neural network can be controlled more easily if the pinning control is added to the variant neurons between the initial pattern and the target pattern
Synchronization in Networks of Identical Systems via Pinning: Application to Distributed Secondary Control of Microgrids
Motivated by the need for fast synchronized operation of power microgrids, we
analyze the problem of single and multiple pinning in networked systems. We
derive lower and upper bounds on the algebraic connectivity of the network with
respect to the reference signal. These bounds are utilized to devise a
suboptimal algorithm with polynomial complexity to find a suitable set of nodes
to pin the network effectively and efficiently. The results are applied to
secondary voltage pinning control design for a microgrid in islanded operation
mode. Comparisons with existing single and multiple pinning strategies clearly
demonstrates the efficacy of the obtained results.Comment: 11 pages, 9 figures, submitted to Transactions on Control Systems
Technolog
Pinning control of fractional-order weighted complex networks
In this paper, we consider the pinning control problem of fractional-order weighted complex dynamical networks. The well-studied integer-order complex networks are the special cases of the fractional-order ones. The network model considered can represent both directed and undirected weighted networks. First, based on the eigenvalue analysis and fractional-order stability theory, some local stability properties of such pinned fractional-order networks are derived and the valid stability regions are estimated. A surprising finding is that the fractional-order complex networks can stabilize itself by reducing the fractional-order q without pinning any node. Second, numerical algorithms for fractional-order complex networks are introduced in detail. Finally, numerical simulations in scale-free complex networks are provided to show that the smaller fractional-order q, the larger control gain matrix D, the larger tunable weight parameter , the larger overall coupling strength c, the more capacity that the pinning scheme may possess to enhance the control performance of fractional-order complex networks
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