701 research outputs found
Legal Requirements for Admission to Public Schools
Advanced driver assistance systems for heavy duty vehicles, such as lookahead cruise and gearshift controllers, rely on high quality map data. Current digital maps do not offer the required level of road grade information. This contribution presents an algorithm for on-board road grade estimation based on fusion of GPS and vehicle sensor data with measurements from previous runs over the same road segment. An incremental update scheme is utilized to ensure that data storage requirements are independent of the number of measurement runs. Results of the implemented system based on six traversals of a known road with three different vehicles are presented.QC 20120216</p
Model reduction of networked passive systems through clustering
In this paper, a model reduction procedure for a network of interconnected
identical passive subsystems is presented. Here, rather than performing model
reduction on the subsystems, adjacent subsystems are clustered, leading to a
reduced-order networked system that allows for a convenient physical
interpretation. The identification of the subsystems to be clustered is
performed through controllability and observability analysis of an associated
edge system and it is shown that the property of synchronization (i.e., the
convergence of trajectories of the subsystems to each other) is preserved
during reduction. The results are illustrated by means of an example.Comment: 7 pages, 2 figures; minor changes in the final version, as accepted
for publication at the 13th European Control Conference, Strasbourg, Franc
A Study On Distributed Model Predictive Consensus
We investigate convergence properties of a proposed distributed model
predictive control (DMPC) scheme, where agents negotiate to compute an optimal
consensus point using an incremental subgradient method based on primal
decomposition as described in Johansson et al. [2006, 2007]. The objective of
the distributed control strategy is to agree upon and achieve an optimal common
output value for a group of agents in the presence of constraints on the agent
dynamics using local predictive controllers. Stability analysis using a
receding horizon implementation of the distributed optimal consensus scheme is
performed. Conditions are given under which convergence can be obtained even if
the negotiations do not reach full consensus.Comment: 20 pages, 4 figures, longer version of paper presented at 17th IFAC
World Congres
On the Exact Solution to a Smart Grid Cyber-Security Analysis Problem
This paper considers a smart grid cyber-security problem analyzing the
vulnerabilities of electric power networks to false data attacks. The analysis
problem is related to a constrained cardinality minimization problem. The main
result shows that an relaxation technique provides an exact optimal
solution to this cardinality minimization problem. The proposed result is based
on a polyhedral combinatorics argument. It is different from well-known results
based on mutual coherence and restricted isometry property. The results are
illustrated on benchmarks including the IEEE 118-bus and 300-bus systems
Finite-time Convergent Gossiping
Gossip algorithms are widely used in modern distributed systems, with
applications ranging from sensor networks and peer-to-peer networks to mobile
vehicle networks and social networks. A tremendous research effort has been
devoted to analyzing and improving the asymptotic rate of convergence for
gossip algorithms. In this work we study finite-time convergence of
deterministic gossiping. We show that there exists a symmetric gossip algorithm
that converges in finite time if and only if the number of network nodes is a
power of two, while there always exists an asymmetric gossip algorithm with
finite-time convergence, independent of the number of nodes. For nodes,
we prove that a fastest convergence can be reached in node
updates via symmetric gossiping. On the other hand, under asymmetric gossip
among nodes with , it takes at least node
updates for achieving finite-time convergence. It is also shown that the
existence of finite-time convergent gossiping often imposes strong structural
requirements on the underlying interaction graph. Finally, we apply our results
to gossip algorithms in quantum networks, where the goal is to control the
state of a quantum system via pairwise interactions. We show that finite-time
convergence is never possible for such systems.Comment: IEEE/ACM Transactions on Networking, In Pres
Multi-agent Systems with Compasses
This paper investigates agreement protocols over cooperative and
cooperative--antagonistic multi-agent networks with coupled continuous-time
nonlinear dynamics. To guarantee convergence for such systems, it is common in
the literature to assume that the vector field of each agent is pointing inside
the convex hull formed by the states of the agent and its neighbors, given that
the relative states between each agent and its neighbors are available. This
convexity condition is relaxed in this paper, as we show that it is enough that
the vector field belongs to a strict tangent cone based on a local supporting
hyperrectangle. The new condition has the natural physical interpretation of
requiring shared reference directions in addition to the available local
relative states. Such shared reference directions can be further interpreted as
if each agent holds a magnetic compass indicating the orientations of a global
frame. It is proven that the cooperative multi-agent system achieves
exponential state agreement if and only if the time-varying interaction graph
is uniformly jointly quasi-strongly connected. Cooperative--antagonistic
multi-agent systems are also considered. For these systems, the relation has a
negative sign for arcs corresponding to antagonistic interactions. State
agreement may not be achieved, but instead it is shown that all the agents'
states asymptotically converge, and their limits agree componentwise in
absolute values if and in general only if the time-varying interaction graph is
uniformly jointly strongly connected.Comment: SIAM Journal on Control and Optimization, In pres
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