L = 100;
kp = 1;
k = eps;
d = (kp-k)/L;
s = tf('s');
KUS = k;
L =100;
Tip = 3;
Ti = 0.1;
k = 0.1;
d = (Tip-Ti)/L;
s = tf('s');
KUS = k+(k/Ti*s);
KOS = 1/(s^3+2*s^2+4*s+2);
K1 = zeros(L,1);
Q = zeros(L,1);
for i=1:1:L
    [y,t] = step(KOS*KUS/(1+KOS*KUS));
    e = 1 - y;
    srednia = mean(e(end-10:end));
    eb = t.*((e - srednia).^2);
    Q(i)= sqrt(trapz(eb,t)^2);
    K1(i)=Ti;
    Ti = Ti+d;
    KUS = k+(k/Ti*s);
end
plot(K1,Q);
[min_value,min_index]=min(Q);
disp(K1(min_index));