200 research outputs found
On Resilient Control of Nonlinear Systems under Denial-of-Service
We analyze and design a control strategy for nonlinear systems under
Denial-of-Service attacks. Based on an ISS-Lyapunov function analysis, we
provide a characterization of the maximal percentage of time during which
feedback information can be lost without resulting in the instability of the
system. Motivated by the presence of a digital channel we consider event-based
controllers for which a minimal inter-sampling time is explicitly
characterized.Comment: 7 pages, 1 figur
Resilient Control under Denial-of-Service
We investigate resilient control strategies for linear systems under
Denial-of-Service (DoS) attacks. By DoS attacks we mean interruptions of
communication on measurement (sensor-to-controller) and/or control
(controller-to-actuator) channels carried out by an intelligent adversary. We
characterize the duration of these interruptions under which stability of the
closed-loop system is preserved. The resilient nature of the control descends
from its ability to adapt the sampling rate to the occurrence of the DoS.Comment: 10 pages, abridged version submitte
Self-triggered Coordination over a Shared Network under Denial-of-Service
The issue of security has become ever more prevalent in the analysis and
design of cyber-physical systems. In this paper, we analyze a consensus network
in the presence of Denial-of-Service (DoS) attacks, namely attacks that prevent
communication among the network agents. By introducing a notion of
Persistency-of-Communication (PoC), we provide a characterization of DoS
frequency and duration such that consensus is not destroyed. An example is
given to substantiate the analysis
Towards Stabilization of Distributed Systems under Denial-of-Service
In this paper, we consider networked distributed systems in the presence of
Denial-of-Service (DoS) attacks, namely attacks that prevent transmissions over
the communication network. First, we consider a simple and typical scenario
where communication sequence is purely Round-robin and we explicitly calculate
a bound of attack frequency and duration, under which the interconnected
large-scale system is asymptotically stable. Second, trading-off system
resilience and communication load, we design a hybrid transmission strategy
consisting of Zeno-free distributed event-triggered control and Round-robin. We
show that with lower communication loads, the hybrid communication strategy
enables the systems to have the same resilience as in pure Round-robin
Bias estimation in sensor networks
This paper investigates the problem of estimating biases affecting relative
state measurements in a sensor network. Each sensor measures the relative
states of its neighbors and this measurement is corrupted by a constant bias.
We analyse under what conditions on the network topology and the maximum number
of biased sensors the biases can be correctly estimated. We show that for
non-bipartite graphs the biases can always be determined even when all the
sensors are corrupted, while for bipartite graphs more than half of the sensors
should be unbiased to ensure the correctness of the bias estimation. If the
biases are heterogeneous, then the number of unbiased sensors can be reduced to
two. Based on these conditions, we propose some algorithms to estimate the
biases.Comment: 12 pages, 8 figure
On Persistency of Excitation and Formulas for Data-Driven Control
In a paper by Willems and coworkers it was shown that persistently exciting data could be used to represent the input-output trajectory of a linear system. Inspired by this fundamental result, we derive a parametrization of linear feedback systems that paves the way to solve important control problems using data-dependent Linear Matrix Inequalities only. The result is remarkable in that no explicit system's matrices identification is required. The examples of control problems we solve include the state feedback stabilization and the linear quadratic regulation problems. We also extend the stabilization problem to the case of output feedback control design
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