230 research outputs found
Stochastic Analysis of Synchronization in a Supermarket Refrigeration System
Display cases in supermarket systems often exhibit synchronization, in which
the expansion valves in the display cases turn on and off at exactly the same
time. The study of the influence of switching noise on synchronization in
supermarket refrigeration systems is the subject matter of this work. For this
purpose, we model it as a hybrid system, for which synchronization corresponds
to a periodic trajectory. Subsequently, we investigate the influence of
switching noise. We develop a statistical method for computing an intensity
function, which measures how often the refrigeration system stays synchronized.
By analyzing the intensity, we conclude that the increase in measurement
uncertainty yields the decrease at the prevalence of synchronization.Comment: In Proceedings HAS 2014, arXiv:1501.0540
Model Reduction of Linear Switched Systems by Restricting Discrete Dynamics
We present a procedure for reducing the number of continuous states of
discrete-time linear switched systems, such that the reduced system has the
same behavior as the original system for a subset of switching sequences. The
proposed method is expected to be useful for abstraction based control
synthesis methods for hybrid systems
Model Reduction by Moment Matching for Linear Switched Systems
Two moment-matching methods for model reduction of linear switched systems
(LSSs) are presented. The methods are similar to the Krylov subspace methods
used for moment matching for linear systems. The more general one of the two
methods, is based on the so called "nice selection" of some vectors in the
reachability or observability space of the LSS. The underlying theory is
closely related to the (partial) realization theory of LSSs. In this paper, the
connection of the methods to the realization theory of LSSs is provided, and
algorithms are developed for the purpose of model reduction. Conditions for
applicability of the methods for model reduction are stated and finally the
results are illustrated on numerical examples.Comment: Sent for publication in IEEE TAC, on October 201
Moment Matching Based Model Reduction for LPV State-Space Models
We present a novel algorithm for reducing the state dimension, i.e. order, of
linear parameter varying (LPV) discrete-time state-space (SS) models with
affine dependence on the scheduling variable. The input-output behavior of the
reduced order model approximates that of the original model. In fact, for input
and scheduling sequences of a certain length, the input-output behaviors of the
reduced and original model coincide. The proposed method can also be
interpreted as a reachability and observability reduction (minimization)
procedure for LPV-SS representations with affine dependence
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