bett93.m

FISMAT accommodates different arithmetic operators, fuzzification and defuzzification algorithm, imp

function uk = bett93(e,x,T)

% uk = bett93(e,x,T)
% 
% Fuzzy-Controller discribed in Bettenhausen,K.D.: Kontinuirlicher R|hrkessel-
% reaktor mit Neben und Folgereaktion. (Continuously working stirred tank 
% reactor with several coupled reactions) In at - Automatisierungstechnik 41
% 1993, 5, page 159-165. R.Oldenbourg Verlag
% For use with the fuzzy11.M S-function-file from the Fuzzy-Toolbox.
% There ist only one input e (error e(k)) from the system. The second 
% controller input (rate e(k-1)) is calculated in this file. The fuzzy-set 
% deset is not used (set it as a dummy operator: [0] - no empty matrix)
% x is the state vector with x(1)=e(k-1) and x(2)=u(k-1).
% T is the sampling period. (here not used by the controller) 
% The Fuzzy-Sets must be defined outside this function.
%
% FSTB - Fuzzy Systems Toolbox for MATLAB
% Copyright (c) 1993-1996 by Olaf Wolkenhauer
% Control Systems Centre at UMIST
% Manchester M60 1QD, UK
%
% 22-April 1994 (Not tested)
 
global ESET OSET

% Fuzzification:
% fuzzsiyi() for the 'vectorform' of fuzzy-sets. fuzzifi() for the more 
% flexible 'matrixform'.
ek =fuzzsiyi(ESET,e);
eko=fuzzsiyi(OSET,x(1));
% First row for e(k-1)=SN, second row for e(k-1)=N, ... , first column for
% e(k)=SN, second column for e(k)=N and so on
SN=1; N=2; O=3; P=3; SP=4;

rt=[ SN N O P P  ;
     SN N O P P  ;
     SN N O P SP ;
      N N O P SP ;
      N N O P SP ];

% Using of Zadeh AND-Minimum operator and the Lukasiewicz OR=bounded sum:
rb=rtinf(rt,ek,eko,'t3mi','s1bs'); 
% Defuzzification:
% (Center of Gravity Method and MAX-MIN Inference)
duk=defucoga(rb,OSET,'min');
uk=duk+x(2);