Authors:
Girish N. Nair,
Robin J. Evans,
Volume: 1, Page 1005 Paper number 1564
Abstract:
This paper investigates the problem of stabilizing a linear, discrete-time
plant using a digital link with a finite data rate. The plant model
is infinite-dimensional and time-varying, with a real-valued output
which is zero at negative times and distributed according to a probability
density p at time zero. Finite and infinite horizon costs in terms
of the m-th output moment are defined and the equations of the optimal,
finite horizon coder-controller derived. Asymptotic quantization theory
is then used to obtain the solution as the horizon tends to infinity,
without needing to explicitly solve the finite horizon problem. It
is shown that this limiting coder-controller is optimal with respect
to the infinite horizon cost, provided that p satisfies certain technical
conditions. This immediately leads to a necessary and sufficient condition
for the existence of a coder-controller that takes the m-th output
moment to zero asymptotically with time. If the open-loop plant is
finite- dimensional and time-invariant, this condition simplifies to
an inequality involving the data rate and the unstable system pole
with greatest magnitude. Analagous results automatically hold for the
related problem of state estimation with a finite data rate.
Authors:
Henrik Rehbinder,
Martin Sanfridson,
Volume: 1, Page 1011 Paper number 1513
Abstract:
In this paper we outline a method for optimal off-line scheduling of
a limited bandwidth communication channel that is used for control
purposes. We study LQ-control of parallel control processes and describe
how the theory for periodic control can be used for defining a cost
functional that measures the performances of sampled data systems
in relation to desired continuous time performances. This formulation
results in a complex combinatorial optimization problem which is solved
by exhaustive search and the solution can be viewed as an optimal
allocation of the limited communication resources. The resulting optimal
sequences are typically such that the sampling is nonuniform but the
control law is time varying and computed to take this nonuniform sampling
into account. In an example, two inverted pendulums with different
closed loop performances that share a common communication resource
are studied. The resulting optimal sequences are in agreement with
the intuitive idea that the sampling resources should be focused to
where they are needed the most, that is, to the controller with the
fastest closed loop characteristics.
Authors:
Sangwoo Cho,
Joohwan Chun,
Volume: 1, Page 1017 Paper number 9141
Abstract:
We propose a new position location algorithm based on the bootstrap
filtering using the time difference of arrival (TDOA) measurements.
The proposed algorithm imposes nonlinear kinematic constraints on the
state estimates without destabilizing the algorithm. Such constraints
can be most naturally incorporated in the Bayesian bootstrap filtering
framework. The proposed algorithm is verified through simulation, and
the result demonstrates that our algorithm is more robust than the
extended Kalman filter and the bootstrap filter without constraints.
Authors:
Bong Keun Kim,
Wan Kyun Chung,
Il Hong Suh,
Volume: 1, Page 1019 Paper number 2149
Abstract:
In this paper, a robust control method for synchronizing motions of
a twin-servo system is proposed. Using the correspondence between the
mathematical modeling and the circuit representation, a network representation
of twin-servo system is proposed. And a stabilizing control input is
designed based on robust internal-loop compensator for the separate
system in the presence of uncertainty and disturbance. Skew motion
compensating control input is also designed to maintain the synchronizing
motion during high speed motion. The stability of the whole closed-loop
system is proved based on passivity theory. Through experiments using
a semiconductor chip mounting device, the performance of the proposed
method is evaluated.
Authors:
Boris Andrievsky,
Alexander Fradkov,
Volume: 1, Page 1025 Paper number 2053
Abstract:
The signal transmission by means of a pair of synchronized chaotic
systems (transmitter and receiver) is considered. The approach of adaptive
observers is used for design of the receiver. Two kinds of adaptive
algorithms are investigated in the presence of additive noise in the
channel. The results are illustrated by a number of numerical examples
of signal transmission based on the pairs of synchronized Chua, Duffing
and Metzler systems.
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