Authors:
Serkan Gugercin,
Athanasios C. Antoulas,
Volume: 1, Page 2367 Paper number 1345
Abstract:
In this note, we compare seven model reduction algorithms by applying
them to four different dynamical systems. There are four SVD based
methods, and three moment matching based methods. The results illustrate
that overall, balanced reduction and approximate balanced reduction
are the best when we consider whole frequency range. Moment matching
methods always lead to higher error norms than SVD based methods
due to their local nature; but they are numerically more efficient.
Among them, the rational Krylov algorithm gives the best results.
Authors:
Wanquan Liu,
Victor Sreeram,
Volume: 1, Page 2373 Paper number 1185
Abstract:
In this paper, the model reduction problem for singular systems is
investigated. Firstly, the previous model reduction algorithm reported
in [9] is presented and proved to be wrong. Detail examination of
the algorithm [9] will show that the difficulty of model reduction
for singular systems is to retain its impulsive nature. Thus, based
on this observation, we closely investigate the impulsive controllability
and impulsive observability of singular systems and propose a new decomposition
approach for singular systems. Then a new model reduction algorithm
is designed based on a new decomposition via the machinery of Nehari's
approximation algorithm. This new model reduction algorithm will retain
impulsive nature of the original system. Finally, one example is presented
to illustrate the effectiveness of the proposed model reduction algorithm.
Authors:
Andras Varga,
Volume: 1, Page 2379 Paper number 1122
Abstract:
The balanced truncation approach to model reduction is considered for
linear discrete-time periodic systems with time-varying dimensions.
Stability of the reduced model is proved and a guaranteed additive
bound is derived for the approximation error. These results represent
generalizations of the corresponding ones for standard discrete-time
systems. Two numerically reliable methods to compute reduced order
models using the balanced truncation approach are considered. The square-root
method and the potentially more accurate balancing-free square-root
method belong to the family of methods with guaranteed enhanced computational
accuracy. The key numerical computation in both methods is the determination
of the Cholesky factors of the periodic Gramian matrices by solving
nonnegative periodic Lyapunov equations with time-varying dimensions
directly for the Cholesky factors of the solutions.
Authors:
Andras Varga,
Volume: 1, Page 2385 Paper number 1123
Abstract:
We propose a general method based on the balanced stochastic truncation
(BST) approach for the model reduction of stable linear systems. The
new method relies on a recent general inner-outer factorization result
and extends the applicability of the BST method to systems with infinite
zeros. A computational algorithm with enhanced accuracy for the new
BST model reduction approach is presented. The capabilities and advantages
of the new approach are illustrated on an example.
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