%                    FLCLI.M
%--------------------------------------------------------------
%    File name "flcli.m"
%    An illustrative program for the design of 
%    Fuzzy Logic Controller.
%--------------------------------------------------------------

clear;                        % clear all variables
dt=0.01;tf=2;                 % sampling period, final time
r=1;                          % command input
x0=[0 0];                     % initial conditions
wn=40;                        % natural frequency
damp=0.3;                     % damping ratio
    
A=[0 1;0 -2*damp*wn];         % SYSTEM MATRICES
B=[0;wn.^2]; C=[1 0]; D=0;    

u=[0 0]';                    % initial control input
t=(0:dt:dt)';                
iter=tf/dt;                   % iteration
%-------------------------------------------------------------
for i=1:iter
    [y,x]=lsim(A,B,C,D,u,t,x0);   % LINEAR PLANT
    x0=x(2,:);                    % continue conditions
    Y1(i,1)=y(2,1);               % record output for PLOT
                                  % PERFORM CONTROL LAW
    u(1,1)=r-y(2,1);              %
    u(2,1)=u(1,1);                % GAIN=1
end;
%---------------------------------------------------------------
x0=[0 0];u=[0 0]';           % RESET INITIAL CONDITIONS

for i=1:iter
    [y,x]=lsim(A,B,C,D,u,t,x0);   % LINEAR PLANT
    x0=x(2,:);                    % continue condition
    Y2(i,1)=y(2,1);               % record output for PLOT
    u(1,1)=fuzzy(Y2,r);           % fuzzy logic control
    u(2,1)=u(1,1);                % control input for PLANT
end;
%---------------------------------------------------------------
%          PLOT  RESULTS
%---------------------------------------------------------------
subplot(211);plot(Y1);title('Response of GAIN=1');
ylabel('OUTPUT');grid;
subplot(212);plot(Y2);title('Response of FUZZY CONTROL');
ylabel('OUTPUT');xlabel('TIME (unit=0.01second)');grid