Syntax

[G1,G2] = slowfast(G,ns)

Description

slowfastcomputes the slow and fast modes decompositions of a systemG(s) such that

G(s)contains theNslowest modes (modes with the smallest absolute value) ofG.

$$[G_1(s)]:=\left({\hat{A}}_{11},{\hat{B}}_1,{\hat{C}}_1,{\hat{D}}_1\right)$$denotes the slow part ofG(s). The slow poles have low frequency and magnitude values.

$$[G_2(s)]:=\left({\hat{A}}_{22},{\hat{B}}_2,{\hat{C}}_2,{\hat{D}}_2\right)$$denotes the fast part. The fast poles have high frequency and magnitude values.

The variablensdenotes the index where the modes will be split.

Usefreqsepto separate slow and fast modes at a specified cutoff frequency instead of a specified number of modes.

References

M.G. Safonov, E.A. Jonckheere, M. Verma and D.J.N. Limebeer, “Synthesis of Positive Real Multivariable Feedback Systems”,Int. J. Control, vol. 45, no. 3, pp. 817-842, 1987.

Version History

See Also

schur|modreal|freqsep