Future power networks will be characterized by safe and reliable
functionality against physical malfunctions and cyber attacks. This paper
proposes a unified framework and advanced monitoring procedures to detect and
identify network components malfunction or measurements corruption caused by an
omniscient adversary. We model a power system under cyber-physical attack as a
linear time-invariant descriptor system with unknown inputs. Our attack model
generalizes the prototypical stealth, (dynamic) false-data injection and replay
attacks.
This work presents a distributed method for control centers in a power
network to estimate the operating condition of the power plant, and to
ultimately determine the occurrence of threatening situations. State estimation
has been recognized to be a fundamental task for network control centers to
ensure correct and safe functionalities of power grids. We consider (static)
state estimation problems, in which the state vector consists of the voltage
magnitude and angle at all network buses.
Consider a weighted and undirected graph, possibly with self-loops, and its
corresponding Laplacian matrix, possibly augmented with additional diagonal
elements corresponding to the self-loops. The Kron reduction of this graph is
again a graph whose Laplacian matrix is obtained by the Schur complement of the
original Laplacian matrix with respect to a subset of nodes.
The paper studies the visibility maintenance problem (VMP) for a
leader-follower pair of Dubins-like vehicles with input constraints, and
proposes an original solution based on the notion of controlled invariance. The
nonlinear model describing the relative dynamics of the vehicles is interpreted
as linear uncertain system, with the leader robot acting as an external
disturbance. The VMP is then reformulated as a linear constrained regulation
problem with additive disturbances (DLCRP).
We propose distributed algorithms to automatically deploy a group of mobile
robots to partition and provide coverage of a non-convex environment. To handle
arbitrary non-convex environments, we represent them as connected graphs. Our
partitioning and coverage algorithm requires only short-range, unreliable
pairwise "gossip" communication among the agents. The algorithm has two
components: (1) a motion protocol to ensure that each robot communicates with
its neighbors at least sporadically, and (2) a pairwise partitioning rule to
update territory ownership whenever two robots communicate.
This article presents a distributed algorithm for a group of robotic agents
with omnidirectional vision to deploy into nonconvex polygonal environments
with holes. Agents begin deployment from a common point, possess no prior
knowledge of the environment, and operate only under line-of-sight sensing and
communication. The objective of the deployment is for the agents to achieve
full visibility coverage of the environment while maintaining line-of-sight
connectivity with each other.
This work focuses on decentralized decision making in a population of
individuals each implementing the sequential probability ratio test. The
individual decisions are combined into a decentralized decision via an
aggregation rule chosen from a family of aggregation rules, denoted as q out of
N rule. We study how the population size affects the performance of the
decentralized decision making, i.e., the decision accuracy and time. In a group
applying the q out of N, a global decision is reached as soon as q out of the N
decision makers agree on an answer.
Distributed abstract programs are a novel class of distributed optimization
problems where (i) the number of variables is much smaller than the number of
constraints and (ii) each constraint is associated to a network node. Abstract
optimization programs are a generalization of linear programs that captures
numerous geometric optimization problems.
In the current discussion about the future smart power grid one of the major
problems is that of transient stability, which is the power system's ability to
maintain synchronism in the presence of transient disturbances. This paper
proposes a novel network-based approach to this problem resulting in concise
and purely algebraic conditions that relate transient stability of a power
network to the underlying network parameters and state.
We consider the problem of sensor selection for time-optimal detection of a
hypothesis. We consider a group of sensors transmitting their observations to a
fusion center. The fusion center considers the output of only one randomly
chosen sensor at the time, and performs a sequential hypothesis test. We
consider the class of sequential tests which are easy to implement,
asymptotically optimal, and computationally amenable. For three distinct
performance metrics, we show that, for a generic set of sensors and binary
hypothesis, the fusion center needs to consider at most two sensors.
We consider the problem of sensor selection for time-optimal detection of a
hypothesis. We consider a group of sensors transmitting their observations to a
fusion center. The fusion center considers the output of only one randomly
chosen sensor at the time, and performs a sequential hypothesis test. We
consider the class of sequential tests which are easy to implement,
asymptotically optimal, and computationally amenable. For three distinct
performance metrics, we show that, for a generic set of sensors and binary
hypothesis, the fusion center needs to consider at most two sensors.