40,324 research outputs found
New advances in H∞ control and filtering for nonlinear systems
The main objective of this special issue is to
summarise recent advances in H∞ control and filtering
for nonlinear systems, including time-delay, hybrid and
stochastic systems. The published papers provide new
ideas and approaches, clearly indicating the advances
made in problem statements, methodologies or applications
with respect to the existing results. The special
issue also includes papers focusing on advanced and
non-traditional methods and presenting considerable
novelties in theoretical background or experimental
setup. Some papers present applications to newly
emerging fields, such as network-based control and
estimation
Inertial-sensor bias estimation from brightness/depth images and based on SO(3)-invariant integro/partial-differential equations on the unit sphere
Constant biases associated to measured linear and angular velocities of a
moving object can be estimated from measurements of a static scene by embedded
brightness and depth sensors. We propose here a Lyapunov-based observer taking
advantage of the SO(3)-invariance of the partial differential equations
satisfied by the measured brightness and depth fields. The resulting asymptotic
observer is governed by a non-linear integro/partial differential system where
the two independent scalar variables indexing the pixels live on the unit
sphere of the 3D Euclidian space. The observer design and analysis are strongly
simplified by coordinate-free differential calculus on the unit sphere equipped
with its natural Riemannian structure. The observer convergence is investigated
under C^1 regularity assumptions on the object motion and its scene. It relies
on Ascoli-Arzela theorem and pre-compactness of the observer trajectories. It
is proved that the estimated biases converge towards the true ones, if and only
if, the scene admits no cylindrical symmetry. The observer design can be
adapted to realistic sensors where brightness and depth data are only available
on a subset of the unit sphere. Preliminary simulations with synthetic
brightness and depth images (corrupted by noise around 10%) indicate that such
Lyapunov-based observers should be robust and convergent for much weaker
regularity assumptions.Comment: 30 pages, 6 figures, submitte
Generalized Holographic Principle, Gauge Invariance and the Emergence of Gravity a la Wilczek
We show that a generalized version of the holographic principle can be
derived from the Hamiltonian description of information flow within a quantum
system that maintains a separable state. We then show that this generalized
holographic principle entails a general principle of gauge invariance. When
this is realized in an ambient Lorentzian space-time, gauge invariance under
the Poincare group is immediately achieved. We apply this pathway to retrieve
the action of gravity. The latter is cast a la Wilczek through a similar
formulation derived by MacDowell and Mansouri, which involves the
representation theory of the Lie groups SO(3,2) and SO(4,1).Comment: 26 pages, 1 figur
Mathematical control of complex systems
Copyright © 2013 ZidongWang et al.This is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
An energy-based state observer for dynamical subsystems with inaccessible state variables
This work presents an energy-based state estimation formalism for a class of dynamical systems with inaccessible/ unknown outputs, and systems at which sensor utilization is impractical, or when measurements can not be taken. The
power-conserving physical interconnections among most of the dynamical subsystems allow for power exchange through their power ports. Power exchange is conceptually considered as information exchange among the dynamical subsystems and further utilized to develop a natural feedback-like information
from a class of dynamical systems with inaccessible/unknown outputs. This information is used in the design of an energybased state observer. Convergence stability of the estimation error for the proposed state observer is proved for systems with linear dynamics. Furthermore, robustness of the convergence stability is analyzed over a range of parameter deviation and model uncertainties. Experiments are conducted on a dynamical system with a single input and multiple inaccessible outputs (Fig. 1) to demonstrate the validity of the proposed energybased state estimation formalism
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Stability analysis and observer design for neutral delay systems
Copyright [2002] IEEE. This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of Brunel University's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.This paper deals with the observer design problem for a class of linear delay systems of the neutral-type. The problem addressed is that of designing a full-order observer that guarantees the exponential stability of the error dynamic system. An effective algebraic matrix equation approach is developed to solve this problem. In particular, both the observer analysis and design problems are investigated. By using the singular value decomposition technique and the generalized inverse theory, sufficient conditions for a neutral-type delay system to be exponentially stable are first established. Then, an explicit expression of the desired observers is derived in terms of some free parameters. Furthermore, an illustrative example is used to demonstrate the validity of the proposed design procedur
Infinite horizon control and minimax observer design for linear DAEs
In this paper we construct an infinite horizon minimax state observer for a
linear stationary differential-algebraic equation (DAE) with uncertain but
bounded input and noisy output. We do not assume regularity or existence of a
(unique) solution for any initial state of the DAE. Our approach is based on a
generalization of Kalman's duality principle. The latter allows us to transform
minimax state estimation problem into a dual control problem for the adjoint
DAE: the state estimate in the original problem becomes the control input for
the dual problem and the cost function of the latter is, in fact, the
worst-case estimation error. Using geometric control theory, we construct an
optimal control in the feed-back form and represent it as an output of a stable
LTI system. The latter gives the minimax state estimator. In addition, we
obtain a solution of infinite-horizon linear quadratic optimal control problem
for DAEs.Comment: This is an extended version of the paper which is to appear in the
proceedings of the 52nd IEEE Conference on Decision and Control, Florence,
Italy, December 10-13, 201
An Energy-Based State Observer for Dynamical Subsystems with Inaccessible State Variables
This work presents an energy-based state estimation formalism for a class of dynamical systems with inaccessible/ unknown outputs, and systems at which sensor utilization is impractical, or when measurements can not be taken. The power-conserving physical interconnections among most of the dynamical subsystems allow for power exchange through their power ports. Power exchange is conceptually considered as information exchange among the dynamical subsystems and further utilized to develop a natural feedback-like information from a class of dynamical systems with inaccessible/unknown outputs. This information is used in the design of an energybased state observer. Convergence stability of the estimation error for the proposed state observer is proved for systems with linear dynamics. Furthermore, robustness of the convergence stability is analyzed over a range of parameter deviation and model uncertainties. Experiments are conducted on a dynamical system with a single input and multiple inaccessible outputs (Fig. 1) to demonstrate the validity of the proposed energybased state estimation formalism
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