step_response.m

this is model for pendulum with matlab, indentification system theory

clc; 

% Tinh du lieu vao - ra de nhan dang mo hinh tuyen tinh

Teta2_bar=pi/6;
To1_bar = 17.9661
Teta2_nga=Teta2(:,2)-Teta2_bar;
To1_nga=To1(:,2)-To1_bar;

%Nhan dang
alpha=10;
N=length(Teta2_nga);
Teta2n=Teta2_nga;
Teta2n_1=[0; Teta2_nga(1:N-1)];
ghat=(Teta2n-Teta2n_1)/alpha;             % Dap ung xung uoc luong duoc theo cong thuc (6.6) Ljung,1999 

%So sanh voi dap ung xung dung cua he thong;
num=[42.58]
den=[1 5.025 23 56.01 20.04]
G0s=tf(num,den)
G0z=c2d(G0s,0.1)    % Ham truyen dung cua he thong can nhan dang
G0z=c2d(G0s,0.1)
N=length(Teta2);
g0=impulse(G0z,200);

err=(g0(1:N)-ghat)'*(g0(1:N)-ghat)/N       % Sai so nhan dang 
plot(1:N,ghat,'r',1:N,g0(1:N),'b');    % So sanh sai so truc quan dung do thi 
legend('ghat','g0');