Unstable System Approximation; Related Functions - National Instruments NI MATRIXx Xmath Specification Sheet

Unstable System Approximation

Related Functions

© National Instruments Corporation
It follows by a result of [BoD87] that the impulse response error for t > 0
satisfies:
g t g
–
r
Evidently, Hankel norm approximation ensures some form of
approximation of the impulse response too.
A transfer function G(s) with stable and unstable poles can be reduced by
applying
stable( )
former is reduced and then the unstable part can be added back on. For
additional information about the
Help.
,
stable() redschur()
t 1 2 2i 2 r
– +
to separate G(s) into a stable and unstable part. The
ophank( )
,
balmoore()
2-23
Chapter 2 Additive Error Reduction
ns
∑
G G
+
i j
i r
+
function, refer to the Xmath
Xmath Model Reduction Module