Hello,
I am working with MIMO systems and have made a comparison between the results obtained using the Matlab function 'feedback()' and computing the closed loop transfer function 'by hand'. There are differences between them I don't understand.
The code below illustrates the issue. I define a forward path array of transfer functions G and close the loop with K in the feedback path.
To compute the feedback manually I calculate CL = G/(I+K*G).
If you run this code fragment you will see that 'cl1' and 'cl2' do not agree. I don't understand why not. Can anyone enlighten me please?
Thanks,
Chris
g11 = tf(1,[1 0]);g12 = tf(2,[1 0]);g21 = tf(3,[1 0]);g22 = tf(4,[1 0]);G = [g11 g12;g21 g22];k = 2;K = [k 0;0 0];cl1 = feedback(G,K,-1)I = eye(2);cl2 = G / (I + K*G)
Best Answer