re:help for controller

Eng.Tamer Samy (tasamy@iti-idsc.gov.eg)
Tue, 13 Oct 1998 22:11:59 +0200 (MET DST)

Dear jose ;
all you said is nice and is known to all of fuzzy pepole ...
but i want to ask for thing .. may be new a bit ..what is the reason for
normalization?? then a way to convert a T.F is more good as it will be a
good issue plus the search i am in???
the ranges i got it from the conventional controller e edot and U
when i apply the fuzzy controller the fuzzy make thew system unstable
then a need for systematic approach is needed ...
waiting for your reply
thanks
tamer
----------
> From: Jos Manuel Andrade <jandrade@telcel.net.ve>
> To: Eng.Tamer Samy <tasamy@iti-idsc.gov.eg>
> Subject: RE: Re:Fuzzy controller
> Date: 08/ /1419 04:25
>
> Hi Tamer:
>
> ----------
> > De: Eng.Tamer Samy <tasamy@iti-idsc.gov.eg>
> > A: Jos Manuel Andrade <jandrade@telcel.net.ve>
> > CC: Jos Manuel Andrade <jandrade@telcel.net.ve>
> > Asunto: Re: Re:Fuzzy controller
> > Fecha: Jueves 15 de Enero de 1998 07:30 PM
> >
> > Dear Jos
> > It nice to have friends and co-operation through the net. about your
> > questions...
> > 1-The science need no language except methodlogy
>
> Sure!
>
> > 2-About the paper there are many but i want to make to you easier
>
> Ok!
>
> > 3- I have the equations associated with the plant, and i can
program
> > in mathlab
> > fuzzy toolbox or C any thing ...but i prefer mathlab ...
>
> Ok!
> Where you find the equations?
>
> > 4-My problem is damping the electric power system . first you have the
> > matrix of state space Xdot=AX+BU you have the eigen values near zero or
> for
> > R.H.S
> > you put the conventional controller G(S)=1/(1+T1s)*(1+T2s)/(1+T3s)
> > *(1+T4s)/(1+T5s)
> > for making the eigen values shift left ...then the oscillations of the
> > system will be damped zeta (damping) will increase
> > I have first the system without control
> > X(dot) = AX
> > Y =CX
> > dont care with U now as X(dot)=AX+BU
> > X-----> 28 element
> > as i have the model for system of 4 generators each one has 7 state
space
> > and i have poles near the right hand side
> > then with T.F controller
> > X(dot) = AX
> > Y =CX
> > after i put the controller for system of 4 generators each one has 7
> state
> > space
> > X-----> 28 element 40 element as each generator has 10 state space
> > (3 for the controller)
> > i can send you the data of A,X
> > before and after one controller for each generator ...
>
> All this information is good for Modern Control, where the designer
works
> in State Space, but in fuzzy control is not necessary. Perhaps is usefull
> to understand plant's dynamics or to compare with fuzzy controller.
> You need to define the following: Inputs and Outputs Variables, Range of
> Variables, this step is very important, because you need define
normalized
> universes, i.e. K.B (Knowledge Base). Next, you need to know the dynamics
> of the plant in linguistic terms, with this information you'll can
> construct the rule base.
> With respect to inference engine you can use max-min, or max-prod, or
you
> can use both and compare it.
> Defuzzification: generally we uses COG ("Center Of Gravity" method.).
> There is not a method to convert a conventional controller into fuzzy
> controller, remember that design of fuzzy controllers is heuristic,
still.
> Let me know your comments, please.
> Thanks!
> Eng. Jos Manuel Andrade.
> > ----------

############################################################################
This message was posted through the fuzzy mailing list.
(1) To subscribe to this mailing list, send a message body of
"SUB FUZZY-MAIL myFirstName mySurname" to listproc@dbai.tuwien.ac.at
(2) To unsubscribe from this mailing list, send a message body of
"UNSUB FUZZY-MAIL" or "UNSUB FUZZY-MAIL yoursubscription@email.address.com"
to listproc@dbai.tuwien.ac.at
(3) To reach the human who maintains the list, send mail to
fuzzy-owner@dbai.tuwien.ac.at
(4) WWW access and other information on Fuzzy Sets and Logic see
http://www.dbai.tuwien.ac.at/ftp/mlowner/fuzzy-mail.info
(5) WWW archive: http://www.dbai.tuwien.ac.at/marchives/fuzzy-mail/index.html