pi_dem_c.m

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

function du = pi_dem_c(e,x,Ts)

% du = pi_dem_c(e,x,Ts)
%
% PI-type fuzzy-controller.
%
% This controller relates to the SIMULINK model file pi_dem_s.m 
% of the fuzzy-toolbox and the script file pi_demo.m.
% The controller and example is described in 'On methods for Improving 
% Performance of PI-type Fuzzy Logic Controllers', J.Lee, IEEE Trans. on
% Fuzzy Systems, Vol.1, No.4, Nov.1993. pp.298-301.
%
% FSTB - Fuzzy Systems Toolbox for MATLAB
% Copyright (c) 1993-1996 by Olaf Wolkenhauer
% Control Systems Centre at UMIST
% Manchester M60 1QD, UK
%
% 20-April-1994
 
global E ERROR  R RATE MOMENTS AREAS

% Fuzzification: (e(1)=error e(2)=rate of change in error
Ae  =match(E,e(1),ERROR);
Ade =match(R,e(2),RATE);
% Ae is a row vector containing fit-values to which e(1) fits to the sets.

NB=1; NM=2; NS=3; ZE=4; PS=5; PM=6; PB=7;

% e ->    NB NM NS ZE PS PM PB

FAMbank =[NB NB NB NM NS NS ZE ;  % NB   | error rate
          NB NM NM NM NS ZE PS ;  % NM   V
          NB NM NS NS ZE PS PM ;  % NS
          NB NM NS ZE PS PM PB ;  % ZE
          NM NS ZE PS PS PM PB ;  % PS
          NS ZE PS PM PM PM PB ;  % PM
          ZE PS PS PM PB PB PB];  % PB

aggop='t3mi';  % minimim-operator for the conjunction in the premise.
A=aggregat(Ae,Ade,FAMbank,aggop);

% Using the algebraic-product for the inference and a summation of the 
% outputs. Center Of Gravity method:

du = apsumcog(FAMbank,A,MOMENTS,AREAS);