Re: Problem about stability of fuzzy control systems

chuey (shehu_1@email.msn.com)
Fri, 18 Dec 1998 18:28:13 +0100 (MET)

Yes, that's almost correct. If one subsystem is unstable, you need
not look for a common P. However, is the unstable subsystem is controllable,
then you can use the feedback law, u(t) = -h_i(x) K_i to stabilize it
at the chosen, stable eigenvalue. In that case, the search for the
common P>0 for the overall system must be conducted. But, if that
unstable subsystem is both unstable and uncontrollable, then forget it.
No need to look for a common P.

-Shehu Farinwata

Howard wrote in message <7265j2$qmr$1@gemini.ntu.edu.tw>...
>hello all
>
>in the following paper
>"Stability analysis and design of fuzzy control systems,
> K. Tanaka, M. Sugeno
> Fuzzy Sets and Systems, V45, 1992,P135~P156"
>they give a stability criterion for a TS fuzzy systems
>
>I have a question
>"if one of the subsystem is unstable,
> does it mean that the inferred system is unstable and
>we need not to check the existence of common positive definite matrix ? "
>
>Thank you !
>
>Howard Liang
>
>
>
>
>

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